Fact-checked by Grok 2 weeks ago

Angiostrongylus cantonensis

Angiostrongylus cantonensis, commonly known as the rat lungworm, is a metastrongylid nematode parasite in the family Angiostrongylidae that primarily infects rats as definitive hosts but causes eosinophilic meningitis in humans and other incidental hosts.^[1] This zoonotic pathogen measures 16–26 mm in length for adult females and 13–20 mm for males, with larvae developing through multiple stages in intermediate hosts.^[2] Native to Southeast Asia, it has spread globally, posing significant public health risks in tropical and subtropical regions.^[3] The life cycle of A. cantonensis begins when adult worms reside in the pulmonary arteries and right ventricle of rats, where females produce eggs that hatch into first-stage larvae (L1) in the lungs; these are then coughed up, swallowed, and excreted in feces.^[1] Gastropod mollusks, such as snails and slugs, ingest the L1 larvae from contaminated rat feces, in which the larvae molt to infectious third-stage larvae (L3) over 2–3 weeks.^[1] Rats complete the cycle by consuming infected mollusks, allowing L3 larvae to migrate to the brain and spinal cord before maturing in the lungs; paratenic hosts like freshwater prawns, crabs, or amphibians can also harbor L3 larvae.^[1] Humans acquire the infection accidentally by ingesting raw or undercooked intermediate hosts or contaminated produce, leading to larval migration to the central nervous system without completing the reproductive cycle.^[1] Epidemiologically, A. cantonensis is endemic in Southeast Asia (e.g., Thailand, Vietnam), the Pacific Islands (e.g., Hawaii), and parts of the Americas and Caribbean, with more than 7,000 human cases reported globally as of 2025 and increasing outbreaks due to globalization and invasive snail species.^[4] In humans, infection manifests as neuroangiostrongyliasis, with symptoms appearing 1–3 weeks post-exposure, including severe headache, neck stiffness, paresthesias, nausea, vomiting, and low-grade fever; severe cases involve cranial nerve palsies, encephalitis, or rarely death from increased intracranial pressure.^[5] Diagnosis relies on clinical history, cerebrospinal fluid analysis showing eosinophilia (>10% eosinophils), and supportive serology or PCR, as larvae are rarely visualized.^[5] Treatment is primarily supportive, involving analgesics for pain, corticosteroids (e.g., prednisone) to reduce inflammation, and sometimes repeated lumbar punctures to alleviate pressure; anthelmintics like albendazole are avoided or used cautiously due to potential worsening of symptoms from dying larvae.^[6] Prevention focuses on avoiding raw mollusks and washing produce thoroughly, alongside rat control and public education in endemic areas.^[7] Ongoing surveillance is crucial as the parasite expands into new regions like Europe (e.g., first continental records in 2023) and mainland United States (e.g., Georgia in 2025).^[4]^[8]

History and Discovery

Initial Identification

The nematode parasite now known as Angiostrongylus cantonensis was first discovered in 1935 by H. T. Chen, who identified it in the pulmonary arteries and hearts of domestic rats (Rattus norvegicus and Rattus rattus) collected in Guangzhou (formerly Canton), China.^[9] Chen described the species as Pulmonema cantonensis, establishing it as a new genus and species within the family Metastrongylidae based on its morphological features and location in the host.^[9] In the following years, additional reports emerged from Japanese researchers investigating similar parasites in rats. During the 1940s, Nomura and colleagues documented A. cantonensis (then under its original nomenclature) in rat lungs across regions of Japan and occupied territories, contributing early insights into its distribution in East Asia and referring to it as the "rat lungworm."^[10] These findings built on Chen's description but did not yet connect the parasite to human health risks. The genus Pulmonema was later synonymized with Angiostrongylus by Dougherty in 1946, reclassifying the species as Angiostrongylus cantonensis to reflect its phylogenetic affinities within the Strongylida order.^[9] The first potential human infection was recognized in 1945 in Taiwan, where Nomura and Lin identified nematode larvae in the cerebrospinal fluid of a patient exhibiting eosinophilic meningitis, suspecting a link to rat lungworms but without definitive confirmation at the time.^[11] This case marked an early suspicion of zoonotic potential, though the etiological role of A. cantonensis in human disease was not fully established until 1961, when experimental and epidemiological evidence solidified the connection.^[12]

Key Research Milestones and Outbreaks

In 1961, researchers led by Lyle Rosen confirmed the role of Angiostrongylus cantonensis as the causative agent of eosinophilic meningitis in humans through the recovery of the parasite from the brain of a deceased patient in Hawaii and subsequent experimental infections in animal models, establishing a direct link between the rat lungworm and the disease.^[13] This breakthrough built on earlier suspicions from outbreaks in the Pacific and provided the first definitive evidence in the Americas, prompting intensified global surveillance for the parasite. During the 1960s and 1970s, significant outbreaks of eosinophilic meningitis linked to A. cantonensis occurred across Pacific Islands and Southeast Asia, highlighting the parasite's zoonotic potential. In Tahiti, French Polynesia, a major epidemic from 1958 to 1961 affected hundreds of individuals, primarily through consumption of raw snails, marking one of the earliest documented mass occurrences. Similar incidents in Thailand during this period involved hundreds of cases, often associated with eating raw or undercooked freshwater snails like Pila ampullacea, leading to widespread recognition of dietary risks in endemic areas.^[14] Research in the 1980s and 1990s expanded understanding of the parasite's geographical spread beyond Asia and the Pacific, with studies documenting its presence in Australia and the Caribbean. In Australia, A. cantonensis was first detected in rat populations along the eastern coast in the 1950s, followed by the first human case in 1971 near Brisbane that underscored the role of invasive snails in transmission.^[15] Caribbean studies during this era identified the parasite in wildlife and mollusks, setting the stage for later human infections and emphasizing vector dispersal via international trade. Key diagnostic advancements in the 1970s included the development of serological tests, such as enzyme-linked immunosorbent assays (ELISA), which enabled reliable detection of anti-A. cantonensis antibodies in cerebrospinal fluid and serum, improving case confirmation and epidemiological tracking.^[14] By the 2000s, the World Health Organization recognized A. cantonensis as an emerging zoonosis, integrating it into global reports on neglected tropical diseases and advocating for enhanced control measures. Notable outbreaks in 2004–2005 further illustrated the parasite's expanding threat: in China, outbreaks such as the one in Wenzhou in 2004 affected dozens due to contaminated snails. Concurrently, in Brazil, the first confirmed autochthonous human cases were reported in 2007 in the southeastern region, signaling the parasite's establishment in South America.^[16] In the 2010s and 2020s, the parasite continued to emerge in new regions, with the first human case reported in Europe (Spain) in 2019 and detections in the mainland United States (e.g., Florida) by 2021, highlighting ongoing global spread facilitated by trade and climate factors.^[17]

Taxonomy and Morphology

Classification

Angiostrongylus cantonensis is classified within the kingdom Animalia, phylum Nematoda, class Chromadorea, order Rhabditida, superfamily Metastrongyloidea, family Angiostrongylidae, genus Angiostrongylus, and species A. cantonensis.^[9] This placement positions it among the metastrongyloid nematodes, a group characterized by their parasitic lifestyle in the lungs and vasculature of mammalian hosts. The family Angiostrongylidae encompasses several species that infect the cardiovascular and respiratory systems of vertebrates, with A. cantonensis distinguished by its specific adaptation to rodent definitive hosts.^[15] The species was first described in 1935 as Pulmonema cantonensis by Chen from rats in Canton (now Guangzhou), China, and independently as Hemostrongylus ratti by Yokogawa in 1937 from rats in Japan. These names were later synonymized, and the current designation Angiostrongylus cantonensis was established in the 1940s following taxonomic revisions that recognized the genus Angiostrongylus. An additional synonym, Parastrongylus cantonensis, has been used but is now generally accepted under the genus Angiostrongylus.^[1] A. cantonensis is differentiated from congeners like A. costaricensis, which causes abdominal angiostrongyliasis by migrating to the mesenteric arteries of rodents in the Americas, and A. vasorum, the canine heartworm that primarily inhabits the pulmonary arteries and right ventricle of dogs and wild canids in Europe and North America.^[15] These distinctions are based on host specificity, anatomical location in the host, and geographical distribution, with A. cantonensis uniquely associated with eosinophilic meningitis in accidental human hosts. Since the 1990s, the internal transcribed spacer 2 (ITS-2) region of ribosomal DNA has served as a key genetic marker for species differentiation, enabling precise identification through sequence analysis and restriction fragment length polymorphism (RFLP) patterns that distinguish A. cantonensis from A. costaricensis and other close relatives.^[18]

Physical Description

Angiostrongylus cantonensis is a slender, thread-like nematode characterized by its cylindrical body covered in a tough cuticle exhibiting transverse striations. Adult females typically measure 18–33 mm in length and 0.28–0.5 mm in width, while adult males are smaller, ranging from 15.5–23 mm in length and 0.2–0.35 mm in width; both sexes have a transparent body with a smoothly rounded anterior end.^[19]^[20] The mouth is simple, lacking a buccal capsule or lips, and features two or three small teeth arranged in a transverse row.^[19] Males possess a well-developed bursa supported by rays and long spicules for copulation, contributing to their distinctive morphology.^[1] The eggs of A. cantonensis are thin-shelled, oval-shaped structures measuring approximately 60–80 µm in length, containing developing embryos that hatch into first-stage larvae within the host's lungs.^[9] First-stage larvae (L1) are 250–300 µm long and about 15 µm wide, with a bent tail and small dorsal tooth.^[21] Third-stage larvae (L3), the infective form to definitive hosts, are larger at 425–550 µm in length, featuring a notched tail with a pointed terminal projection and often encased in sheathed exuviae from previous molts.^[1]^[9]

Life Cycle

Developmental Stages

Adult female Angiostrongylus cantonensis deposit eggs in the small branches of the pulmonary arteries within the lungs of the definitive host, where they hatch into first-stage larvae (L1). These L1 larvae break into the alveolar spaces, ascend the bronchi and trachea to the pharynx, are swallowed into the digestive tract, and subsequently excreted in the feces.^[1]^[22] Upon ingestion by intermediate hosts such as mollusks, the L1 larvae penetrate the intestinal wall and migrate into the tissues, where they undergo two molts to develop into second-stage larvae (L2) and then third-stage larvae (L3), the infective stage. This progression from L1 to L3 typically requires 2-3 weeks.^[1] In the definitive host, ingested L3 larvae excyst in the intestine, penetrate the gut wall, and migrate via the bloodstream to the central nervous system (brain and spinal cord), where they develop into young adults over about 4-6 weeks. The young adults then migrate through the venous system to the pulmonary arteries and right ventricle, where they fully mature into dioecious adults and reproduce.^[9]^[23] The prepatent period, from ingestion of L3 larvae to the appearance of L1 larvae in the feces, ranges from 37 to 45 days in experimentally infected rats, while the patent period during which L1 larvae are shed typically lasts 18-50 days.^[24]^[25] Larval development occurs with full progression to L3 between 20°C and 31°C; development ceases below approximately 15°C.^[26]^[27]^[28]

Transmission Dynamics

The transmission of Angiostrongylus cantonensis follows a fecal-oral route, wherein first-stage larvae (L1) are excreted in the feces of infected rats, leading to environmental contamination that exposes intermediate hosts to infection.^[29] These L1 larvae are ingested by mollusks, the primary intermediate hosts, where they molt and develop into the infective third-stage larvae (L3) over approximately 2–3 weeks, depending on temperature and host species.^[9] Humans acquire the infection accidentally through ingestion of L3 larvae, most commonly via consumption of raw or undercooked mollusks such as snails and slugs, or through contaminated fresh produce like unwashed salads and vegetables that have contacted infected mollusks or their mucus.^[29] For instance, slime trails from infected gastropods can deposit L3 larvae on leafy greens, posing a risk during food preparation in endemic areas.^[4] Paratenic hosts play a key role in amplifying transmission by harboring non-developing L3 larvae, which remain viable and infective; examples include freshwater prawns, crabs, frogs, and certain vegetation that inadvertently transport the larvae into the food chain without supporting further parasite maturation.^[30] This mechanism extends the parasite's reach beyond direct mollusk consumption, increasing exposure opportunities in aquatic and terrestrial ecosystems.^[9] Direct human-to-human transmission does not occur, as humans function as dead-end hosts where the larvae cannot reproduce or produce eggs capable of perpetuating the cycle.^[1] L1 larvae exhibit limited environmental persistence, surviving up to 1–2 weeks in moist conditions such as water or damp soil, which is critical for their availability to intermediate hosts but declines rapidly under dry or high-temperature exposures.^[12]

Hosts and Ecology

Definitive Hosts

The definitive hosts of Angiostrongylus cantonensis are primarily species within the genus Rattus, including the Norway rat (Rattus norvegicus) and the black rat (Rattus rattus), with the Polynesian rat (Rattus exulans) also serving as a competent host in certain regions.^[31]^[32] In these rats, adult worms reside in the pulmonary arteries and right ventricle of the heart, where they mate and produce eggs that hatch into first-stage larvae (L1); these larvae migrate to the lungs, are coughed up, swallowed, and subsequently excreted in the feces to continue the life cycle.^[33]^[34] Prevalence of infection in endemic rat populations can be notably high, reaching up to 93.9% in wild Rattus spp. on eastern Hawai'i Island as detected by PCR, with 72.7% harboring adult worms.^[35] In Southeast Asia and Pacific regions, such as in Hawaii, overall prevalence in rats is around 63.8%, with higher rates in R. exulans (77.4%) compared to R. rattus (47.6%).^[32] Infection intensity typically ranges from a few to dozens of adult worms per infected rat, with examples including an average of 26.6 nematodes (range 1–100) in urban Rattus spp. and up to 62 worms in individual cases from the United States.^[17]^[36] In definitive hosts, A. cantonensis infection generally causes minimal pathology, allowing rats to remain asymptomatic or exhibit only mild respiratory or behavioral changes despite heavy burdens, which contributes to efficient parasite transmission.^[34]^[37] The parasite shows geographic adaptation, with higher prevalence and intensity observed in tropical and subtropical urban rat populations, where environmental conditions favor the life cycle.^[35]^[32]

Intermediate and Paratenic Hosts

The intermediate hosts of Angiostrongylus cantonensis are exclusively gastropod mollusks, including terrestrial snails and slugs as well as some aquatic species, which support the development of first-stage larvae (L1) into infective third-stage larvae (L3).^[1] Prominent examples include the giant African snail (Achatina fulica) and the golden apple snail (Pomacea canaliculata), both of which are invasive species facilitating the parasite's spread in non-native regions.^[38] In endemic areas, infection rates in these hosts can reach up to 45% for A. fulica and lower but significant levels for P. canaliculata (around 2%), highlighting their role in maintaining high larval burdens within snail populations. Within intermediate hosts, ingested L1 larvae undergo two molts to reach the infective L3 stage, a process that typically takes 13 to 21 days under optimal conditions, with L3 larvae remaining viable in the snail for up to a year.^[39] A single infected snail can produce thousands of L3 larvae, with reports documenting up to 20,000 per individual in some cases, enabling substantial parasite amplification during this developmental phase.^[40] Paratenic hosts, which do not support further larval development but serve as transport vectors, include a range of freshwater and terrestrial invertebrates and vertebrates such as prawns, crabs, planarians, and frogs.^[29] In these hosts, L3 larvae encyst in tissues like muscles or organs without molting, remaining infective until the host is consumed by a definitive host.^[41] These paratenic hosts contribute to transmission amplification by accumulating larvae through predation on multiple infected intermediate hosts, thereby increasing the infective dose available to rats in food chains and enhancing overall parasite dissemination.^[38]

Epidemiology

Global Distribution and Emergence

Angiostrongylus cantonensis, the causative agent of rat lungworm disease, originated in Southeast Asia and southern China, where it was first identified in rats in Guangzhou in 1935.^[4] The parasite's global dissemination has been facilitated primarily by the movement of infected definitive hosts, such as Rattus rats, via international shipping routes. By the mid-20th century, it had spread to the Pacific region, with establishment in Hawaii documented in 1961 through infections in rats and subsequent human cases.^[42] Similarly, the first reports in the Americas emerged in the 1960s, including in Brazil around 1966, marking the beginning of its expansion into tropical and subtropical areas of South America.^[43] In the Caribbean, introductions were noted by the late 1980s, likely through similar anthropogenic pathways involving trade and travel.^[44] Today, A. cantonensis is endemic in more than 30 countries, spanning Southeast Asia, the Pacific Islands, parts of North and South America, and increasingly in Africa and Europe. Recent records include the first detection in Argentina in 2024 and 29% prevalence in urban rats in Sydney, Australia, in 2024.^[45]^[46] Recent emergences highlight its ongoing expansion: in Madagascar, 2024 surveys detected the parasite in both definitive rat hosts and intermediate snail hosts, confirming a new African focus.^[33] In the United States, a 2024 investigation in Houston, Texas, revealed a 20% prevalence of A. cantonensis in black rats (Rattus rattus) from a zoo facility, suggesting local transmission cycles in urban environments.^[17] Europe, previously considered free of the parasite, has seen initial detections, including fatal infections in non-human primates at a Spanish zoo from 2020 to 2022 and in rats and gastropods in southern Italy in 2024.^[47]^[4] Climate change is driving further emergence by altering the distribution of intermediate gastropod hosts, as warmer temperatures and shifting precipitation patterns expand suitable habitats for moisture-dependent snails.^[48] Modeling studies indicate that these environmental changes could facilitate a northward shift in the parasite's range by the 2050s, particularly in regions experiencing increased rainfall and milder winters, potentially introducing risks to temperate zones.^[49]

Risk Factors and Incidence Trends

The primary risk factor for human infection with Angiostrongylus cantonensis is the ingestion of raw or undercooked intermediate hosts, particularly snails and slugs containing third-stage larvae.^[50] Infections can also result from consuming undercooked paratenic hosts such as prawns, crabs, frogs, or freshwater shrimp, or from larvae-contaminated vegetables and greens washed in unclean water.^[50]^[11] In Thailand, where raw snail consumption is a cultural practice in some regions, this accounts for a substantial portion of cases, with approximately 180 infections reported annually, predominantly in the northeast.^[51]^[52] Certain populations face elevated risks due to behavioral or environmental exposures. Children are particularly vulnerable owing to habits like pica, which increases accidental ingestion of larvae-laden mollusks, while travelers to endemic areas, such as the Pacific Islands or Southeast Asia, represent a growing group through inadvertent consumption during tourism.^[53]^[54] Immunocompromised individuals may experience more severe outcomes from even low-level exposures.^[53] Case incidence often peaks during rainy seasons, when increased moisture boosts mollusk populations and facilitates larval shedding onto produce.^[55]^[56] Globally, over 7,000 human cases of angiostrongyliasis have been documented, though underreporting is widespread due to diagnostic challenges and non-notifiable status in many regions, suggesting true annual incidence may range from thousands to tens of thousands.^[4] In Asia, trends show sustained endemicity; for instance, 125 cases (92 confirmed, 33 suspected) were reported in China's Dali Prefecture from 2007 to 2021, with peaks linked to seasonal snail festivals.^[57] Taiwan, where the first human case was identified in 1945, has recorded hundreds of infections historically, though recent comprehensive counts remain limited.^[58] Incidence is rising in the Americas, driven by the parasite's spread via invasive rats and mollusks. In the United States, detections have expanded to southern states like Georgia in 2024, with climate factors such as warmer temperatures and heavier rainfall promoting intermediate host proliferation.^[59] Animal infections, including in zoo-held primates like lemurs, have also surged in the 2020s, with multiple fatal cases reported in U.S. and European facilities, highlighting zoonotic spillover risks and a 20% prevalence in rats near a Texas zoo in 2024.^[60]^[17]

Human Angiostrongyliasis

Pathogenesis

Following ingestion of third-stage larvae (L3) of Angiostrongylus cantonensis, typically through contaminated food or intermediate hosts, the larvae are released in the human small intestine and rapidly penetrate the intestinal mucosa to enter the bloodstream. From there, they migrate via the circulatory system to the central nervous system (CNS), including the brain and spinal cord, typically arriving within several days to a week.^[5]^[19]^[61]^[62] Within the CNS, the L3 larvae molt and develop into fourth-stage larvae and then immature adults, causing direct mechanical damage through their movement and burrowing into neural parenchyma. This triggers a robust eosinophilic inflammatory response, characterized by the recruitment of eosinophils and formation of granulomatous lesions around the parasites. The immature adults typically survive for 2 to 8 weeks before dying, unable to reproduce or produce eggs in humans, as the host environment does not support full maturation or oviposition.^[5]^[62]^[1] Unlike in definitive rat hosts, where larvae migrate from the CNS to the lungs for maturation in pulmonary arteries, humans lack this compatible vascular site, resulting in the parasites becoming trapped and degenerating within the brain tissue.^[61]^[34] The host immune response exacerbates CNS damage, with a predominant type 2 (Th2) cytokine profile driving eosinophil activation and infiltration. Key mediators include interleukin-5 (IL-5), which promotes eosinophil survival, recruitment, and degranulation, leading to heightened inflammation and tissue injury. Eosinophil-derived proteins, such as major basic protein, further contribute to neuronal damage and blood-brain barrier disruption. Disease severity is dose-dependent, with infections involving more than 10 larvae associated with more intense eosinophilic responses and worse outcomes, though human cerebrospinal fluid (CSF) typically lacks eggs or first-stage larvae due to the absence of reproduction.^[63]^[64]^[65]

Clinical Manifestations

Human infection with Angiostrongylus cantonensis typically manifests as eosinophilic meningitis, with an incubation period of 1 to 3 weeks following ingestion of infective larvae.^[66] During the acute phase, severe headache is the most common symptom, affecting 94% to 97% of patients, often accompanied by neck stiffness in approximately 50% of cases and paresthesia in 50% to 70% of individuals.^[66]^[67]^[68] These sensory disturbances arise as larvae migrate through neural tissues, irritating the meninges and causing radicular pain.^[69] In severe cases, patients may experience vomiting (affecting about 60%), low-grade fever, and cranial nerve palsies, such as facial weakness or oculomotor dysfunction, occurring in up to 30% of cases.^[67]^[70] Rare complications include encephalitis with altered mental status or seizures, particularly in heavy infections.^[71] Ocular angiostrongyliasis represents a distinct variant, where larvae invade the eye, leading to uveitis, blurred vision, and potential permanent vision loss due to retinal damage from larval tracks.^[72] Most cases resolve spontaneously within 2 to 8 weeks, with symptoms gradually improving as the immune response clears the non-reproductive larvae.^[54] However, chronic sequelae occur in approximately 10% of patients, manifesting as persistent hyperesthesia, headache, or neuropathy lasting months.^[73] The fatality rate is low, less than 1%, though it is higher in young children and the elderly due to increased risk of severe meningoencephalitis.^[74]^[71]

Diagnosis, Treatment, and Prevention

Diagnostic Techniques

Diagnosis of Angiostrongylus cantonensis infection, also known as angiostrongyliasis, relies on a combination of clinical evaluation, laboratory tests, and imaging, as no single pathognomonic test exists.^[75] The hallmark clinical finding is cerebrospinal fluid (CSF) eosinophilia, defined as more than 10% eosinophils or an absolute count exceeding 10 eosinophils per microliter, which occurs in over 95% of cases and strongly suggests the infection when accompanied by symptoms mimicking bacterial meningitis.^[76]^[77] This eosinophilic pleocytosis in CSF is a key diagnostic indicator, often exceeding 20-70% in confirmed cases, and supports presumptive diagnosis in endemic areas with relevant exposure history.^[78] Imaging techniques, particularly magnetic resonance imaging (MRI), aid in visualizing central nervous system involvement. MRI commonly reveals leptomeningeal enhancement, hyperintense signals in the subcortical white matter, and occasionally linear tracks suggestive of larval migration in the brain parenchyma.^[79]^[80] These findings, observed in a majority of patients with eosinophilic meningitis due to A. cantonensis, help differentiate from other causes but are not specific.^[81] Serological assays detect antibodies against A. cantonensis antigens, with enzyme-linked immunosorbent assay (ELISA) and Western blot targeting IgG being widely used. The 31-kDa antigen-based IgG ELISA demonstrates high sensitivity, often reported at 100% in experimental and clinical validations, while Western blot confirms specificity by identifying immunoreactive bands.^[82] These tests on serum or CSF achieve sensitivities of 80-100%, though cross-reactivity with other helminths can occur.^[83] Molecular methods, such as real-time polymerase chain reaction (RT-PCR) targeting A. cantonensis DNA, provide confirmatory evidence with detection in CSF samples, showing positivity in up to 67% of eosinophilic meningitis cases attributable to this parasite.^[84] PCR on blood is less sensitive but feasible for early detection in some hosts.^[85] Recent advances include environmental diagnostics via larval recovery from snail hosts. A 2024 technique involves extracting and examining the buccal cavity of intermediate snail species, such as Pomacea canaliculata, to recover A. cantonensis larvae, enabling rapid field identification of infection foci.^[86] Challenges in diagnosis stem from the absence of a definitive test, requiring integration of epidemiological exposure (e.g., consumption of raw mollusks), clinical features, and laboratory results. Differential diagnosis often includes gnathostomiasis, which presents with migratory subcutaneous swellings and radiculomyelitis rather than predominant meningitis, though both cause eosinophilia.^[76] This overlap necessitates serological or molecular confirmation to avoid misattribution.^[87]

Treatment Options

Treatment of human angiostrongyliasis primarily involves supportive care to manage symptoms such as headache and neck stiffness associated with eosinophilic meningitis, as there is no specific cure for this dead-end infection in humans.^[6] Analgesics, including nonsteroidal anti-inflammatory drugs or opioids as needed, are used to alleviate pain, while adequate hydration helps prevent complications from dehydration.^[6] Corticosteroids form the cornerstone of therapy to reduce inflammation caused by larval migration in the central nervous system; a typical regimen is prednisone at 1 mg/kg daily for 2 weeks, followed by a slow taper over an additional 2 weeks.^[88] Antiparasitic agents like albendazole (15 mg/kg/day divided into two doses for 14 days, not exceeding 800 mg/day) or ivermectin are sometimes administered to target the larvae, but their use is controversial and must be cautious due to the risk of paradoxical worsening of inflammation from dying parasites releasing antigens.^[89]^[90] These drugs are typically combined with corticosteroids to mitigate this risk, with studies showing improved outcomes in moderate to severe cases when co-administered.^[91] Ivermectin, while effective in paralyzing larvae in vitro, is less commonly used in humans for this indication compared to albendazole.^[92] Most patients recover fully with supportive care and corticosteroids alone, as the larvae eventually die without completing their life cycle in humans.^[93] In mild cases, antiparasitics are often contraindicated to avoid unnecessary inflammation, with treatment limited to symptom relief.^[6] Recent clinical analyses, including a 2022 review, confirm that albendazole-corticosteroid combinations are effective in over 97% of treated human cases, reducing symptom duration and sequelae without significant adverse events.^[89]^[94]

Preventive Measures

Preventing infection with Angiostrongylus cantonensis, the causative agent of angiostrongyliasis, primarily involves interrupting the parasite's life cycle through targeted hygiene practices, pest management, and community-level interventions.^[95] Food hygiene measures are essential to avoid accidental ingestion of infective third-stage larvae (L3), which reside in intermediate hosts such as snails and slugs or contaminate produce via their slime. Individuals in endemic areas should avoid eating raw or undercooked snails, slugs, freshwater prawns, land crabs, frogs, or other potential hosts, as these can harbor viable larvae.^[95] Thoroughly washing fruits and vegetables under running water removes adhering mollusks or contaminated mucus, while cooking potentially infected items like snails or slugs to an internal temperature of at least 74°C (165°F) kills the larvae.^[96] Hands and utensils should be washed after handling raw mollusks to prevent cross-contamination.^[95] Controlling rat populations, the definitive hosts where adult worms reside in the lungs, is critical to reducing environmental contamination with L1 larvae shed in feces. Urban deratting programs, including trapping and rodenticides, combined with proper waste management to eliminate food sources and harborage sites, effectively break the transmission cycle in residential and agricultural settings.^[97] In Hawaii, integrated rodent control has been emphasized as part of broader efforts to limit parasite reservoirs near human habitats.^[98] Public education campaigns in endemic regions promote awareness and behavioral changes to minimize exposure. In Hawaii, a $1 million state initiative launched in 2017 included media broadcasts, school garden programs, and professional development for educators to teach avoidance of raw mollusks and promotion of garden hygiene, resulting in increased community vigilance.^[99] Similar efforts focus on messaging like thorough produce washing and prompt removal of snails from gardens.^[100] Surveillance systems aid early detection and response by monitoring intermediate host populations and human cases. Regular sampling of snails for L3 larvae prevalence, coupled with mandatory reporting of suspected eosinophilic meningitis, enables targeted interventions in outbreak hotspots.^[57] Sentinel surveillance in wildlife, such as hedgehogs or rodents, has proven effective for tracking emergence in new areas.^[101] Vector management in high-risk agricultural zones employs molluscicides to suppress snail populations that amplify transmission. Niclosamide and metaldehyde-based products, applied judiciously in farms and gardens, reduce intermediate host density without excessive environmental impact when integrated with cultural practices like habitat modification.^[102] In Hawaii, such measures are recommended for commercial produce operations to prevent larval contamination.^[103] As climate change expands suitable habitats for snails and rats into temperate regions, adaptive prevention includes heightened surveillance in vulnerable areas and tailored guidelines for emerging hotspots, emphasizing proactive mollusk control amid shifting seasonal patterns.^[34]

Zoonotic and Veterinary Impact

Infections in Animals

Angiostrongylus cantonensis infections in wildlife primarily affect rats as definitive hosts, where the parasite completes its life cycle with minimal clinical signs, often remaining asymptomatic even at high worm burdens.^[104] In contrast, dogs serve as incidental hosts and experience severe neural angiostrongyliasis, manifesting as pneumonia, central nervous system involvement with signs like ataxia, paresis, and hyperesthesia, frequently resulting in fatal outcomes due to larval migration-induced inflammation.^[20]^[105] Captive animals, especially non-human primates in zoological settings, face significant risks from A. cantonensis. Between December 2020 and March 2022, three fatal cases of eosinophilic meningoencephalitis occurred in two red-fronted brown lemurs (Eulemur rufus) and one ring-tailed lemur (Lemur catta) at Bioparc Fuengirola in Spain, representing the first documented instances in European non-human primates.^[106] Similar outbreaks have been reported in zoos across the southeastern United States, involving species such as red ruffed lemurs (Varecia rubra) in Louisiana and black-and-white ruffed lemurs (Varecia variegata) in Georgia, with affected animals exhibiting lethargy, neurological deficits, and high mortality rates.^[107]^[108] In other species, infections lead to notable neurological impairments. Horses develop motor weakness, ataxia, lameness, and lumbar paralysis from larval invasion of the central nervous system.^[109] Opossums, such as the white-eared opossum (Didelphis albiventris), present with circling, depression, and other nervous signs culminating in eosinophilic meningoencephalitis.^[110] Amphibians like frogs act as paratenic dead-end hosts, harboring infective larvae without supporting further development or reproduction of the parasite.^[33] The pathology in non-human animals involves infective third-stage larvae penetrating the intestinal wall, migrating hematogenously to the central nervous system, and eliciting severe eosinophilic inflammation, hemorrhage, and malacia along their tracks.^[105] In dogs, larval development arrests in the brain and spinal cord without completing the reproductive cycle, leading to persistent neurological damage.^[111] Recent trends indicate rising infections in non-endemic zoo environments, driven by global trade in animals and horticultural products that facilitate the introduction of infected rats and intermediate hosts.^[112] For instance, a 20% prevalence of A. cantonensis was detected in black rats at a Houston zoo, underscoring the zoonotic and veterinary risks in such facilities.^[17]

Public Health and Conservation Concerns

Angiostrongylus cantonensis poses a significant zoonotic threat as an emerging pathogen in non-tropical regions, with detections reported in the United States and Europe in 2025. In August 2025, a 20% prevalence of the parasite was identified in black rats at a zoo facility in Houston, Texas, USA, highlighting risks to both wildlife and humans in subtropical urban environments. Similarly, in southern Italy's Campania region, the parasite was detected in rats and gastropods during the same period, marking its expansion into Mediterranean Europe. In Spain, infections were confirmed in rodents from the protected wetland of s'Albufera on Mallorca in early 2025, and fatal cases occurred in non-human primates at a zoo. Underreporting remains a critical barrier to control efforts, as the parasite is classified as a neglected pathogen due to low public awareness and diagnostic challenges, leading to incomplete surveillance in affected areas.^[17]^[4]^[47]^[113] Conservation concerns arise from the parasite's role in exacerbating the impacts of invasive species on island ecosystems. Invasive rats, primary definitive hosts, facilitate the parasite's spread to remote islands, where it infects native and endemic wildlife, potentially disrupting food webs and contributing to biodiversity loss. Intermediate hosts, such as invasive snails (e.g., the giant African land snail), serve as vectors that amplify transmission while competing with native gastropods, further threatening fragile island biota. In protected areas like Mallorca's wetlands, high prevalence in rodents underscores risks to endangered species, including captive animals in zoos, where infections have caused mortality in non-human primates. Ecosystem-level effects, including altered parasite-host dynamics, highlight the need for integrated management of invasive vectors to preserve biodiversity.^[17]^[22]^[114] Economic burdens in Pacific regions, particularly Hawaii, stem from outbreaks affecting public health and tourism. Since becoming reportable in 2007, Hawaii has confirmed over 80 cases of human angiostrongyliasis through 2017, with ongoing incidents in 2025, including three statewide, one on Kauai, incurring substantial healthcare and surveillance costs. State initiatives, such as a $1 million public awareness campaign launched in 2017, illustrate the financial strain on resources for education, testing, and vector control, while infections linked to contaminated produce impact agriculture and deter tourism in endemic areas.^[115]^[116]^[99] Future risks are amplified by climate change, with models projecting substantial range expansion for A. cantonensis by 2100. In Hawaii, simulations under increased temperature and precipitation scenarios forecast heightened habitat suitability at higher elevations, potentially extending the parasite's reach into previously unsuitable temperate zones globally. This expansion, driven by warmer conditions favoring snail vectors and rat populations, necessitates One Health approaches that integrate human, animal, and environmental surveillance. Sentinel monitoring of wildlife, such as hedgehogs in Europe, combined with systematic rodent and gastropod sampling, enables early detection and coordinated interventions across sectors.^[49]^[117]^[101]

References

[1]
DPDx - Angiostrongyliasis cantonensis - CDC
Jun 20, 2019 · Angiostrongylus (=Parastrongylus) cantonensis, also called the rat lungworm, is a common cause of human eosinophilic meningitis (neural angiostrongyliasis) and ...
[2]
Angiostrongyliasis - StatPearls - NCBI Bookshelf
Oct 28, 2024 · Angiostrongylus cantonensis, commonly known as the "rat lungworm," is a parasitic nematode that causes eosinophilic meningitis in humans.
[3]
An Overview of Angiostrongylus cantonensis (Nematoda - MDPI
Our study aims at the growing incidence of angiostrongylosis in humans, alongside its clinical course and possible causes.5. Angiostrongylus... · 5.1. Angiostrongylus... · 6. Angiostrongylus...<|control11|><|separator|>
[4]
Clinical Treatment of Rat Lungworm - CDC
May 9, 2024 · Angiostrongylus cantonensis Treatment is usually supportive with the use of analgesics for pain and corticosteroids to limit the inflammatory ...
[5]
About Rat Lungworm Disease - CDC
Jun 24, 2024 · The life cycle is completed when rats eat infected snails or slugs and the larvae further mature to become adult worms. Species. Angiostrongylus ...
[6]
Zoonotic Rat Lungworm Angiostrongylus cantonensis in ... - CDC
Aug 19, 2025 · This nematode has an indirect life cycle, requiring a rodent definitive host and a gastropod intermediate host (2). The cycle begins when a ...
[7]
Biology, Systematics, Life Cycle, and Distribution of Angiostrongylus ...
Angiostrongylus cantonensis was first described from rats in China by Chen in 1935 and placed in the genus Pulmonema, as Pulmonema cantonensis. The same species ...
[8]
Paratenic hosts of Angiostrongylus cantonensis and their relation to ...
During the 1940s, cases of EM occurred on several Pacific islands ... Memorandum on the first report of Angiostrongylus in man, by Nomura and Lin, 1945.
[9]
Human Parasitic Meningitis Caused by Angiostrongylus cantonensis ...
Since the first human infection was reported in Taiwan in 1945, many cases have been reported, mainly in children and most of them in the 1970s and 1980s.
[10]
[PDF] A Review of Rat Lungworm Infection and Recent Data on Its ...
1962, Alicata 1991). This was the first time, globally, a direct link was made between this nematode species and human disease.<|control11|><|separator|>
[11]
Eosinophilic Meningoencephalitis Caused by a Metastrongylid Lung ...
1. Rosen, L.; Laigret, J.; and Bories, S.: Observations on Outbreak of Eosinophilic Meningitis on Tahiti, French Polynesia , Amer J Hyg 74:26-42 ( (July) ) 1961 ...
[12]
Human Angiostrongylus cantonensis: an update - PubMed
Angiostrongylus cantonensis was first discovered in 1935 and has become an important emerging pathogen causing human angiostrongyliasis. Major outbreaks of ...
[13]
Angiostrongylus cantonensis: a review of its distribution, molecular ...
May 26, 2016 · Angiostrongylus cantonensis is a metastrongyloid nematode found widely in the Asia-Pacific region, and the aetiological agent of angiostrongyliasis.
[14]
Genetic Characterization and Detection of Angiostrongylus ...
In this study, we reviewed the current methods, concepts, and applications of molecular approaches to better understand the genetic characterization.Genotyping Of A. Cantonensis · Internal Transcribed Spacer... · Cytochrome C Oxidase Subunit...<|control11|><|separator|>
[15]
Rat Lungworm Angiostrongylus cantonensis (Chen, 1935 ...
Rat lungworm (Angiostrongylus cantonensis) has been slowly spreading around the world. First described by Chen (1935) from rats in China.
[16]
Angiostrongylus cantonensis - Companion Animal Parasite Council
Jul 2, 2025 · Angiostrongylus cantonensis is a zoonotic parasite causing eosinophilic meningitis in humans. Species. Canine (incidental host). Angiostrongylus ...
[17]
Angiostrongylus - an overview | ScienceDirect Topics
The length of L1 larvae is 300–400 μm, while the width is about 15 μm. Other typical features of the larva are the bent tail and the adjacent small, dorsal ...
[18]
Insights into the biology of the rat lungworm, Angiostrongylus ...
Apr 30, 2025 · Angiostrongylus cantonensis is a parasitic nematode with a complex life cycle involving rats as definitive hosts and gastropods as intermediate hosts.
[19]
An Overview of Angiostrongylus cantonensis (Nematoda
Jun 20, 2023 · Our aim of this review is to provide a thorough analysis of the available literature on human angiostrongylosis in the Indian subcontinent and ...
[20]
Insights into the biology of the rat lungworm, Angiostrongylus ...
Apr 30, 2025 · Angiostrongylus cantonensis (family Angiostrongylidae), the rat lungworm, is a parasitic nematode first described in southern China in 1935 [1].
[21]
The life history of the rat lung-worm, Angiostrongylus cantonensis ...
The prepatent period in the rat usually lies between 42 and 45 days, and young adults emerge on the surface of the brain from the 12th to 14th day, ...Missing: patent | Show results with:patent
[22]
An examination of the prepatent period and the absence ... - PubMed
Based on developmental data in the literature, it is suggested that 37 days represents the minimum prepatent period for A. cantonensis in this host.Missing: patent | Show results with:patent
[23]
(PDF) An examination of the prepatent period and the absence of a ...
Aug 6, 2025 · Based on developmental data in the literature, it is suggested that 37 days represents the minimum prepatent period for A. cantonensis in this ...Missing: patent | Show results with:patent
[24]
Effects of temperature on the larval development ofAngiostrongylus ...
WhenB. glabrata were maintained at different, constant temperatures, the first-stage larvae developed to third-stage larvae between 20° and 31° C.
[25]
Effects of temperature on the larval development of Angiostrongylus ...
Abstract. The effects of temperature on the larval development of Angiostrongylus cantonensis in Biomphalaria glabrata were studied under controlled conditions.
[26]
The effect of temperature on the development of Angiostrongylus ...
We studied the effects of different temperatures on the larval development of Angiostrongylus cantonensis in the freshwater snail Pomacea canaliculata.
[27]
Rat Lungworm: Causes and How It Spreads - CDC
May 8, 2024 · The parasite is not able to complete its life cycle in humans and eventually dies in the abdomen.
[28]
Detection of Rat Lungworm (Angiostrongylus cantonensis) in ... - CDC
Aug 19, 2025 · This rat lungworm has an indirect life cycle involving rats (mainly Rattus spp.)
[29]
Angiostrongylus cantonensis Infection in Brown Rats (Rattus ... - CDC
Sep 20, 2023 · This vectorborne nematode has an indirect life cycle in which several rodent species, including Rattus spp., serve as definitive hosts (1).<|separator|>
[30]
High prevalence of Angiostrongylus cantonensis (rat lungworm) on ...
Dec 18, 2017 · High prevalence of Angiostrongylus cantonensis (rat lungworm) on eastern Hawai'i Island: A closer look at life cycle traits and patterns of infection in wild ...
[31]
Variation in Angiostrongylus cantonensis infection in definitive ... - NIH
An overall infection prevalence of 86.2% was observed in P. martensi and 63.8% in rats, with R. exulans (77.4%) greater than R. rattus (47.6%). We found ...
[32]
Angiostrongylus cantonensis Lungworms in Definitive and ... - CDC
Aug 26, 2025 · The life cycle of this parasitic nematode involves rats as definitive host and snails and slugs as intermediate hosts; humans act as incidental ...
[33]
A closer look at life cycle traits and patterns of infection in wild rats ...
The life cycle of A. cantonensis includes five larval stages (L1-L5) before becoming a sexually mature adult with larvae increasing in size throughout each ...<|control11|><|separator|>
[34]
THE FINDING OF ANGIOSTRONGYLUS CANTONENSIS IN RATS ...
between April 1986 and February 1987 were infected with Angiostrongylus cantonensis. (3-62 worms per rat). This is the first report of the parasite from ...
[35]
Isolate-specific rat brain transcriptional responses to rat lungworm ...
The rat lungworm (Angiostrongylus cantonensis) is an invasive parasite of rats that in accidental hosts, such as dogs and humans, causes eosinophilic meningitis ...
[36]
Pathways for Transmission of Angiostrongyliasis and the Risk of ...
The first clinically diagnosed case in Hawai'i was in 1961 when a man ... Human Angiostrongylus cantonensis, Jamaica. Emerg Infect Dis. 2005;11(12): ...
[37]
[PDF] The Rat Lungworm Lifecycle
Angiostrongylus cantonensis Lifecycle. Rat: definitive host. Rat lungworm eggs are laid in lungs of rat. Eggs hatch and first stage larvae exit the rat in rat.
[38]
Neuroangiostrongyliasis Infection Risk Near Preschool Centres in ...
Jun 2, 2025 · Angiostrongylus cantonensis L3 found in the AcanR3990 qPCR positive slugs after digestion. ... 20,000 × L3 larvae, respectively. This slug ...
[39]
Angiostrongylus cantonensis - an overview | ScienceDirect Topics
Third-stage larvae are transmitted to paratenic hosts (freshwater shrimps, land crabs, frogs, toads, monitor lizards, and planarians) through their ingestion of ...
[40]
Global Spread of an Emerging Tropical Disease in
Nov 7, 2022 · Infection with A. cantonensis is one of the leading causes of eosinophilic meningitis worldwide. After humans become infected, the most dramatic ...<|separator|>
[41]
Angiostrongylus cantonensis and Rat Lungworm Disease in Brazil
This parasite, widespread in Southeast Asia and some Pacific islands, has now dispersed to other regions, including Latin America. The spread of this emerging ...
[42]
The recent introduction of Angiostrongylus cantonensis and its ...
Aug 10, 2023 · Angiostrongylus cantonensis (rat lungworm) is the main pathogen responsible for eosinophilic meningitis in humans. One of its intermediate snail ...
[43]
The Global Spread Pattern of Rat Lungworm Based on ... - MDPI
May 31, 2023 · Human cases and outbreaks have occurred in the new endemic areas, including South America and Spain. The growing genetic data of A. cantonensis ...
[44]
Mortality associated with Angiostrongylus cantonensis in non ...
Angiostrongylus cantonensis caused the death of three lemurs in a zoo in Spain. This is the first known record of the species affecting European non-human ...
[45]
and Temperature-Driven Emergence of Neural Angiostrongyliasis in ...
Nevertheless, temperature does largely influence larval development ... Studies on growth and distribution of Angiostrongylus cantonensis larvae in Ampullarium ...
[46]
Modelling the distribution in Hawaii of Angiostrongylus cantonensis ...
Projections under climate change (to 2100) indicated increased suitability in regions with estimated increased precipitation and temperatures, suitable ...
[47]
Human angiostrongyliasis - The Lancet Infectious Diseases
Human angiostrongyliasis caused by Angiostrongylus cantonensis, a rat lungworm, has been reported globally. Human infections are acquired by ingestion of ...
[48]
Case Report: Angiostrongylus cantonesis Myelitis in Thailand - PMC
In Thailand, approximately 100 A. cantonensis infections are reported annually, and the prevalence is particularly high in the northeast region. A. cantonensis ...Missing: percentage | Show results with:percentage
[49]
Severe angiostrongyliasis with neuropsychiatric symptoms in ...
Humans can get infected by ingesting undercooked snails, rats, freshwater hosts like fish, shrimp, etc that harbor the third-stage AC larvae, or by consuming ...
[50]
An Outbreak of Eosinophilic Meningitis Caused by Angiostrongylus ...
We describe a large outbreak of A. cantonensis–associated eosinophilic meningitis among a group of US travelers returning from Jamaica.
[51]
Rainfall- and Temperature-Driven Emergence of Neural ...
Angiostrongylus cantonensis, commonly known as the “rat lungworm,” is a ... This seasonality aligns with periods of optimal temperature and moisture conditions ...
[52]
https://ojrd.biomedcentral.com/articles/10.1186/s13023-022-02532-1
[53]
Monitoring the trends of Angiostrongylus cantonensis infection in ...
The current distribution of A. cantonensis and the number of angiostrongyliasis cases reported are concentrated in tropical regions of South-east Asia (China, ...Missing: 2020-2025 | Show results with:2020-2025
[54]
Review of Cases of Angiostrongyliasis in Hawaii, 2007–2017 in
Jul 8, 2019 · Traditionally, since the first human Angiostrongylus infection was identified in 1945 in Taiwan, infections have been most commonly ...
[55]
Detection of Rat Lungworms in Invasive Mollusks, Georgia, USA, 2024
Aug 11, 2025 · We collected A. cantonensis larvae from 2 host species, invasive apple and mystery snails, from bodies of water in Georgia, USA.
[56]
Climate a factor driving increased cases of rat lungworm disease in ...
Jun 17, 2025 · Rat lungworm disease is caused by the parasite Angiostrongylus cantonensis, which is naturally found in rats. However, humans and dogs are ...
[57]
Angiostrongylus cantonensis in a Red Ruffed Lemur at a Zoo ... - NIH
A red ruffed lemur (Varecia rubra) from a zoo in Louisiana, USA, was euthanized for worsening paresis. Brain and spinal cord histology identified eosinophilic ...Missing: increase | Show results with:increase
[58]
The Brief Case: Angiostrongylus cantonensis Eosinophilic ...
Sep 25, 2017 · Following ingestion by rodents, the L3 larvae migrate to the brain, where they develop into young adults before migrating to the subarachnoid ...
[59]
Central nervous system manifestations of Angiostrongylus ...
2. Angiostrongylus cantonensis morphology. Angiostrongylids are small nematodes with thin cylindrical bodies and a reduced bursa in males, which are associated ...Missing: mouth | Show results with:mouth<|control11|><|separator|>
[60]
Preliminary expression profile of cytokines in brain tissue of BALB/c ...
Jun 14, 2015 · Angiostrongylus cantonensis (A. cantonensis) infection can result in ... IL-5, IL-10, and IL-13 showed Th2 cell predominance in ...<|separator|>
[61]
IL-17A neutralizing antibody attenuates eosinophilic meningitis ...
Nov 1, 2019 · In this study, we report that A. cantonensis infection causes eosinophil accumulation and elevation of IL-5 and -13 levels. This was accompanied ...
[62]
Successful Management of Angiostrongylus Cantonensis-Induced ...
... Angiostrongylus cantonensis as the causative pathogen through next-generation ... IL-5 plays an essential role in orchestrating eosinophilic inflammation ...
[63]
Eosinophilic Meningitis Attributable to Angiostrongylus cantonensis ...
The most common infectious cause of eosinophilic meningitis is Angiostrongylus cantonensis, which is transmitted largely by consumption of snails/slugs.
[64]
Angiostrongylus cantonensis Is an Important Cause of Eosinophilic ...
We utilized polymerase chain reaction (PCR) to demonstrate that Angiostrongylus cantonensis was responsible for 67.3% of 55 cases of eosinophilic meningitis.
[65]
Eosinophilic meningitis due to Angiostrongylus cantonensis in Europe
At least 22 cases of Angiostrongylus cantonensis infection have been reported in Europe to date. · Cases have mainly come from French Polynesia, Southeast Asia, ...Review · Epidemiology · Discussion
[66]
Clinical manifestations of eosinophilic meningitis due to ... - Neurology
Patients typically presented with severe headache; neck stiffness and fever were usually mild or absent. Paresthesias were noted by most adults. The ...
[67]
Clinical Manifestations of Eosinophilic Meningitis Due to Infection ...
The median incubation period was 22 (1-30) days. Six patients (31.6%) had papilledema or cranial nerve palsies. Abnormal cerebellar signs were found in 2 ...Missing: percentages | Show results with:percentages
[68]
Eosinophilic Meningitis Caused by Angiostrongylus cantonensis
Jul 13, 2017 · A. cantonensis is one of the major causes of human eosinophilic meningitis. The larvae invade the blood and lymph vessels in the digestive tract ...Abstract · Keywords · Figure 2
[69]
Comprehensive Review of Ocular Angiostrongyliasis with Special ...
Some patients with optic neuritis developed obvious hypopsia or even vision loss, which would seriously influence the quality of life of patients. Prompt ...
[70]
Clinical Characteristics of Long-Term Complications of Severe Rat ...
A report from Thailand found that this form occurred in less than 10% of RLWD cases but had a mortality rate of at least an 80%. Several confirmed reported ...
[71]
Eosinophilic meningitis in Thailand. Clinical studies of 484 typical ...
The latter entity was generally benign and self-limited with a case mortality ratio of less than 0.5%. Acute severe headache was the most significant symptom.Missing: fatality rate
[72]
Clinical Testing and Diagnosis for Rat Lungworm - CDC
May 9, 2024 · A diagnosis of A. cantonensis is strongly suggested when symptoms suggest bacterial meningitis, but testing reveals eosinophilia.Missing: methods | Show results with:methods
[73]
Differential Diagnosis of CNS Angiostrongyliasis: A Short Review - NIH
The diagnostic criterion for eosinophilic meningitis (EOM) is the identification of an absolute count of 10 eosinophils per ml or more than 10% of the total ...
[74]
Eosinophilic meningitis - UpToDate
INTRODUCTION. Eosinophilic meningitis is defined as the presence of more than 10 eosinophils/mm3 in the cerebrospinal fluid (CSF) and/or eosinophils ...
[75]
Eosinophilic Meningitis Due to Angiostrongylus cantonensis in a ...
The first case of human infection in North America was reported in 1995 in a ... Memorandum on the first report of Angiostrongylus in man, by Nomura and Lin, 1945.
[76]
MR Findings of Eosinophilic Meningoencephalitis Attributed to ...
Jun 1, 2000 · We report the clinical features and the findings revealed by MR imaging and MR spectroscopy in six patients with eosinophilic meningoencephalitis.
[77]
Unusual Larva in the CSF and Unique MRI Findings in a Case of ...
We describe a rare case of eosinophilic meningitis caused due to Angiostrongylus cantonensis (rat lungworm) following ingestion of raw monitor lizard meat.<|separator|>
[78]
Brain Magnetic Resonance Imaging Abnormalities in Eosinophilic ...
In this retrospective study, we investigated the brain MR features of eosinophilic meningitis caused by human infection with A. cantonensis.
[79]
Comparison of Antibody Isotype Response to Angiostrongylus ...
Apr 21, 2023 · The IgG isotype showed 100% sensitivity in detecting A. cantonensis infection, which validates the use of IgG indirect ELISA with 31 kDa antigen ...
[80]
Immunodiagnostic Detection of Angiostrongylus cantonensis ...
The current status of laboratory diagnosis of Angiostrongylus cantonensis infections in humans using serologic and molecular methods. Hawaii J Med Public ...
[81]
Guidelines for the diagnosis and treatment of neuroangiostrongyliasis
Infection may cause a spectrum of disease ranging from mild, self-limited headache to severe, neurologic debilitation, coma and rarely death.
[82]
Detection of Angiostrongylus cantonensis in the Blood and ...
Apr 24, 2015 · This study was conducted to determine if genomic DNA from A. cantonensis is detectable by qPCR in the blood or tissues of experimentally infected rats.
[83]
A new diagnostic technique for identifying Angiostrongylus spp ...
Jul 9, 2024 · In this study, a new method for diagnosing A. cantonensis infection in gastropods was developed by recovering larvae from the buccal cavity of three snail ...
[84]
[PDF] ies STATE OF HAWAIʻI July 21, 2025 Dear Healthcare Provider
Jul 21, 2025 · This RT-PCR test detects Angiostrongylus cantonensis DNA in cerebrospinal fluid (CSF) and is anticipated to enable earlier diagnosis of and ...
[85]
Monoclonal Antibodies Against Excretory/Secretory Antigens of ...
Nov 4, 2010 · In the present study, four murine monoclonal antibodies (MAbs) were generated against the excretory/secretory (ES) products of Angiostrongylus cantonensis ...Preparation Of Mabs Against... · Elisa Assays · Results And Discussion
[86]
Angiostrongylus | Johns Hopkins ABX Guide
Mar 5, 2023 · Dx: no diagnostic test unless the parasite or eggs are found in surgically removed tissue. Therefore, a clinical diagnosis is usually a ...
[87]
[PDF] Preliminary Guidelines for the Diagnosis and Treatment of Human ...
Aug 29, 2018 · High prevalence of Angiostrongylus cantonensis (rat lungworm) on eastern Hawaii Island: A closer look at life cycle traits and patterns of ...
[88]
Clinical Efficacy and Safety of Albendazole and Other ...
In those where albendazole-corticosteroid co-therapy was used, 97.87% reported it to be effective (323 patients, 130 animals). albendazole, anthelmintics, ...Abstract · METHODS · Human Data · Discussion
[89]
Angiostrongyliasis - Infectious Diseases - Merck Manuals
A. cantonensis causes eosinophilic meningitis, with neurologic symptoms, neck stiffness, and sometimes fever or other systemic symptoms. Diagnosis is by lumbar ...
[90]
Treatment of angiostrongyliasis using a combination of albendazole ...
A 1-week treatment with a combination of albendazole and dexamethasone appears both safe and beneficial in the treatment of angiostrongyliasis.
[91]
In vitro efficacy of anthelmintics on Angiostrongylus cantonensis L3 ...
The paralysis induced by ivermectin/moxidectin may slow the progression of infection, while simultaneously increasing the period of exposure to the nematicidal ...
[92]
Rat Lungworm: Causes, Symptoms & Treatment - Cleveland Clinic
Most people get mild or no symptoms, but the parasite can infect your brain and cause headaches, neck stiffness, vomiting and neurological (brain and nerve) ...
[93]
Angiostrongyliasis | Treatment & Management | Point of Care
Oct 28, 2024 · Treatment of A cantonensis infection focuses on managing symptoms, reducing inflammation, and lowering intracranial pressure. Most cases resolve ...
[94]
Preventing Rat Lungworm - CDC
May 8, 2024 · To prevent rat lungworm, do not eat raw or undercooked snails or slugs in areas where the parasite is found.Missing: guidelines 2025
[95]
Control Measures for Slug and Snail Hosts of Angiostrongylus ... - NIH
(A) eggs and neonates. Eggs are about 2.5 mm in diameter. (B) Adult with yellowish-brown flattened fingernail-shaped shell visible on the dorsum. The ...Missing: dimensions | Show results with:dimensions
[96]
Neuroangiostrongyliasis (Rat Lungworm) | Disease Outbreak ...
Neuroangiostrongyliasis, also known as rat lungworm, is a disease that affects the brain and spinal cord. It is caused by a parasitic nematode (roundworm ...
[97]
[PDF] Avoid Contracting Angiostrongyliasis (Rat Lungworm Infection)
Prevention of the infection is mainly through sanitary food handling practices. On farms and in gardens, ef- forts should be made to eliminate rodents, snails, ...
[98]
Rat Lungworm: Hawaii Kicks Off $1 Million Campaign To ... - Civil Beat
Aug 2, 2017 · Gov. David Ige announced Wednesday that his administration is embarking on a two-year campaign aimed at curbing the spread of rat lungworm ...Missing: angiostrongyliasis | Show results with:angiostrongyliasis
[99]
A Hawaii public education programme for rat lungworm disease ...
Education is essential for lowering cases of Angiostrongyliasis in Hawaii. A professional development course on rat lungworm disease (RLWD) prevention was ...Missing: campaigns | Show results with:campaigns
[100]
Angiostrongylus cantonensis Nematode Invasion Pathway, Mallorca ...
Jun 6, 2022 · The life cycle of A. cantonensis worms includes rats as definitive and gastropods as intermediate hosts; crustaceans, planarians, amphibians, ...
[101]
Molluscicidal activity and mechanism of toxicity of a novel ...
Aug 10, 2017 · However, there is only one molluscicide, niclosamide, recommended by the World Health Organization. Niclosamide has been used for several ...
[102]
[PDF] Reducing Risks Associated with Rat Lungworm Infection and ...
use may not be authorized for use on commercial farms. Pesticides lethal to slugs and snails, called mollusci- cides, should be part of an overall control ...
[103]
https://www.ctahr.hawaii.edu/oc/freepubs/pdf/fst-39.pdf
[104]
Twenty two cases of canine neural angiostrongylosis in eastern ...
A. cantonensis shows obligate neurotropism, i.e. larvae must migrate through the central nervous system (CNS) before taking up residence in the pulmonary ...
[105]
Mortality associated with Angiostrongylus cantonensis in non ...
Apr 5, 2025 · Between December 2020 and March 2022, three cases of fatal meningoencephalitis were documented in two red-fronted brown lemurs (Eulemur rufus) ...
[106]
(PDF) Angiostrongylus cantonensis in a Red Ruffed Lemur at a Zoo ...
Aug 9, 2025 · Between December 2020 and March 2022, three cases of fatal meningoencephalitis were documented in two red-fronted brown lemurs (Eulemur rufus) ...
[107]
Angiostrongylus cantonensis infection in a captive non-human ...
Sep 3, 2025 · Angiostrongylus cantonensis infection in a captive non-human primate (Varecia variegata) from the southeastern United States · Authors.Missing: outbreaks | Show results with:outbreaks
[108]
Nematodes Causing CNS Disease in Animals - Nervous System
Paratenic hosts are freshwater prawns, land crabs, coconut crabs, and planarians. Larvae invade the cerebrum and develop in the neural parenchyma for ~2 weeks, ...Missing: timeline | Show results with:timeline
[109]
Eosinophilic meningoencephalitis caused by rat lungworm ...
Feb 22, 2022 · Angiostrongylus cantonensis is a worldwide zoonotic parasite that causes eosinophilic meningoencephalitis in many species of animals ...
[110]
Canine Neural Angiostrongyliasis - WSAVA2007 - VIN
Canine Neural Angiostrongyliasis (CNA) is caused by the obligatory neural migration of Angiostrongylus cantonensis larvae in dogs.
[111]
Trade and Deforestation Predict Rat Lungworm Disease, an ...
Sep 9, 2021 · Our study provides a preliminary view of the associations between species introductions, deforestation, and risk of A. cantonensis exposure in people.
[112]
Living in the city: Angiostrongylus cantonensis is a novel threat to an ...
Feb 26, 2025 · Angiostrongylus cantonensis, the rat lungworm, is a metastrongyloid parasite that uses rodents as definitive hosts, mollusks as intermediate ...Missing: mouth teeth striations
[113]
Invasive Snails and an Emerging Infectious Disease: Results from ...
Eosinophilic meningitis is caused by the rat lungworm (Angiostrongylus cantonensis). This parasite is endemic in Southeast Asia, Australia, the Caribbean, and ...
[114]
Review of Cases of Angiostrongyliasis in Hawaii, 2007–2017 - PMC
We confirmed 82 reported cases between 2007 and 2017. There was a median of seven cases per year, and the majority (57%) of cases occurred between January and ...
[115]
[PDF] ies STATE OF HAWAIʻI October 13, 2025 Dear Healthcare Provider
Oct 13, 2025 · This is the first case of neuroangiostrongyliasis reported on Kaua'i since 2019. In 2025 thus far, we have had 3 confirmed cases of rat lungworm ...
[116]
Distribution of rat lungworm, now and into future - ScienceDaily
Aug 1, 2018 · Under these future climate conditions, rat lungworm was predicted to expand its range to higher elevations in Hawai'i. The findings imply that ...