Abdominal angiostrongyliasis (AA) is an emerging infection caused by the nematode Angiostrongylus costaricensis. Human infection occurs through ingestion of food contaminated with infective third-stage larvae (L3). Although endemic in Central and South America, AA remains underdiagnosed and underrecognized in clinical practice. We report the case of a female patient with a history of bariatric surgery, residing in southern Brazil, who presented with right lower quadrant abdominal pain and mild eosinophilia. Initial diagnostic hypotheses included infectious colitis, neoplasia and ischemic processes. Following surgical intervention and histopathological examination, AA was confirmed by identification of the parasite within a mesenteric artery. This case highlights an atypical presentation and definitive diagnosis established by histopathology despite negative polymerase chain reaction (PCR) results. This report underscores the importance of including AA in the differential diagnosis of abdominal conditions particularly in endemic regions. It also emphasizes the need for enhanced specificity of serological and molecular diagnostic methods.

Angiostrongyliasis is a parasitic disease caused by Angiostrongylus costaricensis (Latin America) and A. cantonensis (Asia/Pacific). Abdominal angiostrongyliasis often mimics appendicitis, challenging clinical diagnosis and requiring histopathological confirmation. We report a severely malnourished infant in Honduras presenting with 10 days of severe abdominal pain and vomiting, complicated by respiratory insufficiency and seizures. Brain CT revealed cortical atrophy, suggesting a chronic underlying neurologic condition. Laboratory tests showed leukocytosis, lymphocytosis, and massive eosinophilia. Exploratory laparotomy for suspected appendicitis identified an ileal perforation, requiring intestinal resection. Histopathology confirmed non-caseating granulomas containing A. costaricensis larvae within the mesenteric arteriovenous plexus, alongside scattered eggs. This is the first confirmed human case of abdominal angiostrongyliasis with suspected, unconfirmed extraintestinal involvement in the Olancho Department of Honduras. These findings emphasize the critical need for increased clinical awareness and public health measures against this overlooked parasitic infection.

The nematode Angiostrongylus cantonensis is a rat lungworm, a zoonotic pathogen that causes an emerging infectious disease known as neuroangiostrongyliasis or rat lungworm disease. This study evaluates the efficacy of a vaccine developed for a related species, Angiostrongylus costaricensis, to A. cantonensis in the definitive rat host. Wild-caught rats (Rattus rattus) (n = 28) were mated in captivity to produce uninfected F1 progeny. A total of 43 F1 rats were involved in this trial; 20 non-vaccinated, 21 vaccinated, and two unvaccinated, uninfected. F1 offspring in the vaccinated group were intranasally vaccinated with two doses of PP2 A vaccine, a serine/threonine phosphatase 2 A at a dose of 4 μg vaccine and 4 μg adjuvant/25 g body weight at >3 mos. of age. Unvaccinated rats similarly received 4 μg adjuvant/25 g body weight. Rats were gavaged with 50 L3 stage larvae at ~four weeks post-treatment. Necropsies were conducted at 47-50 days post-live challenge and spleen weight, spleen length, lung and heart weights, and the numbers of worms in heart and lungs were recorded. An average of 23.17 adult worms were found among all F1 rats. We found no significant differences between vaccinated and unvaccinated rats in rat body weight (p = 0.883), spleen weight (p = 0.963), spleen length (p = 0.830), lung weight (p = 0.830), heart weight (p = 0.849), and number of worms in heart and lungs (p = 0.621). A TaqMan™ Custom Array (Applied Biosystems) cytokine assay was used to evaluate gene expression of 12 different cytokines in spleen tissue from 23 rats and no significant differences in cytokine (CT) levels were observed between vaccinated and unvaccinated rats (p values range 0.154-0.988). Thus, the A. costaricensis PP2A vaccine, under these conditions, did not provide adequate protective immunity to guard against infection by A. cantonensis in wild rats.

Angiostrongyliasis, an infection caused by nematodes of the genus Angiostrongylus spp., includes nine species in the Americas. Angiostrongylus costaricensis induces eosinophilic enteritis in humans and has been documented in Guatemala. Humans are considered accidental or final hosts of A. costaricensis, as they do not release eggs or larvae in their faeces. Most reported cases present with abdominal angiostrongyliasis (AA). Parasitic structures are difficult to identify in inflammatory lesions and larvae can occasionally migrate to extraintestinal organs. The gold standard for diagnosing A. costaricensis is histopathological analysis, confirmed by the identification of eggs, larvae in tissues, and/or adult worms in the vascular lumen. In our department, two cases of A. costaricensis affecting pulmonary vessels were diagnosed histopathologically. Given the rarity of pulmonary involvement, the cases were consulted with Dr. Carlos Graeff-Teixeira.

Angiostrongylus cantonensis is a metastrongyloid nematode that is one of the most common pathogens to cause eosinophilic meningitis. Commonly referred to as the “rat lungworm,” it is transmitted by both rats (definite hosts), snails, and slugs (intermediate hosts) among some other transport hosts (see below). The parasite is most prevalent in the Asia-Pacific regions; however, outbreaks and sporadic cases have been reported outside of the endemic areas. To date, nine species have been identified, but A. cantonensis and A. costaricensis remain the most important human pathogens.

Terrestrial mollusks, including the invasive giant African snail (Lissachatina fulica), pose significant public health risks due to their role as carriers of various pathogens, such as Angiostrongylus cantonensis and Angiostrongylus costaricensis. This scoping review aims to provide a comprehensive evaluation of diseases associated with Lissachatina fulica and other terrestrial mollusks, with a particular focus on the prevention, diagnosis, and treatment of these conditions. Following the Joanna Briggs Institute guidelines and the PRISMA-ScR framework, we conducted a systematic search and filtered results, identifying 27 relevant case reports and series for analysis. Our findings reveal that ingesting raw or undercooked snails is the most hazardous exposure route, with a 75% mortality rate in affected adults, particularly in regions where snail consumption is culturally significant, such as France. A. cantonensis is the primary cause of eosinophilic meningitis, while A. costaricensis leads to abdominal angiostrongyliasis. The review also highlights the widespread impact of L. fulica in countries like France, the United States, Brazil, and Colombia, emphasizing the global nature of the threat. Children show consistent vulnerability across all exposure types, underscoring the need for targeted preventive strategies. This review underscores the urgent need for public health interventions, particularly educational campaigns to inform communities about the dangers of L. fulica. Additionally, it highlights the importance of enhancing diagnostic methods and expanding surveillance to better manage the risks associated with these invasive snails. The findings provide valuable insights for the scientific community and recommend a multidisciplinary approach to effectively mitigate the public health risks posed by L. fulica across diverse regions.

Metastrongyloid nematodes typically reside as adults in the cardiopulmonary systems of their mammalian definitive hosts, potentially causing severe diseases. Of particular concern are Angiostrongylus cantonensis and A. costaricensis, which can cause eosinophilic meningitis and abdominal angiostrongyliasis, respectively, in their accidental human hosts. Several metastrongyloid species of medical and veterinary importance have been documented in the Canary Islands. However, the gastropod species acting as intermediate hosts for some of these nematodes in the archipelago remained unknown. This study aimed to investigate the occurrence of metastrongyloid nematodes in terrestrial and aquatic gastropods, including both endemic and non-native species, on Tenerife. Foot samples from terrestrial and aquatic gastropods were analyzed using a multiplex PCR targeting the Internal Transcribed Spacer 1 (ITS1), allowing the specific detection of A. cantonensis, A. vasorum, Aelurostrongylus abstrusus, Crenosoma striatum, Troglostrongylus brevior, and Crenosoma vulpis. Five metastrongyloid species, namely C. striatum, A. cantonensis, Ae. abstrusus, A. vasorum, and an unidentified metastrongyloid, were identified within both non-native and endemic terrestrial gastropods. In the aquatic snail Physella acuta, only A. cantonensis and C. striatum were detected. This study confirms the introduction of various metastrongyloids associated with non-native mammalian fauna and provides new data on the occurrence of these nematodes in non-native and endemic gastropod species, including their presence in aquatic environments on the Canary Islands.

Abdominal angiostrongyliasis (AA) is a zoonotic and severe parasitic infection caused by Angiostrongylus costaricensis. AA is currently diagnosed by the observation of A. costaricensis-compatible structures in biopsies or the detection of antibodies in serological tests. However, molecular methods targeting homologous sequences of A. costaricensis have not been designed before, and therefore, an HRM-coupled qPCR was developed to detect the internal transcribed spacer 1 (ITS1) of the parasite. The present assay successfully amplified DNA of A. costaricensis obtained from different hosts and identified slight sequence differences through the HRM analysis. The detection limit of the HRM-qPCR was 0.00036 ng/µL, 1.0 ng/µL, and 0.1 ng/µL when A. costaricensis DNA was diluted in nuclease-free water, whole blood, and sera, respectively, which highlights its potential use for cell-free DNA detection. Moreover, the reaction did not cross-amplify DNA of Angiostrongylus cantonensis, Strongyloides stercoralis, and other nematodes, thus emphasizing its specificity. Additionally, the assay tested positive in formalin-fixed paraffin embedded biopsies with visible A. costaricensis adults or eggs, but not in samples without evident parasites or a low number of larvae, which suggests that the reaction is useful for confirming the presence of the nematode in clinical samples. Finally, DNA of sera from patients with AA was evaluated with the HRM-qPCR but none tested positive, possibly due to long storage periods of the samples which could have led to cfDNA degradation. These results indicate that this assay may be useful in the confirmation of AA and its prospection for cell-free DNA detection protocols.

Angiostrongylus cantonensis and Angiostrongylus costaricensis are known human pathogens responsible for eosinophilic angiostrongyliasis and abdominal angiostrongyliasis, respectively. Humans are accidental hosts, where infection occurs through the consumption of the infective larva stage 3 in intermediate or paratenic hosts. The proven method for abdominal angiostrongyliasis diagnosis is the histological examination through tissue biopsy, while the diagnosis of eosinophilic angiostrongyliasis is the detection of larva in the cerebrospinal fluid. As there is molecular evidence of cryptic species within A. cantonensis and A. costaricensis lineages, along with morphological similarities within both lineages, accurate species identification and disease diagnosis may be challenging. Moreover, species within the lineages share similar intermediate and definitive hosts and geographic distribution. For example, both A. cantonensis and Angiostrongylus malaysiensis (a closely related species in A. cantonensis lineage) overlap in their geographic distribution in Southeast Asia. Additionally, variations in the molecular makeup of A. costaricensis and A. cantonensis lineages may impact the pathogenicity, infectivity, and disease severity of angiostrongyliasis. Understanding of the genetic diversity of both lineages is a cornerstone for improved diagnosis and disease intervention, especially in a changing global environment. To shed light and provide insights into the genetic diversity of the Angiostrongylus lineages causing human angiostrongyliasis, we aim to present an up-to-date review of the studies conducted and genetic markers used for A. costaricensis and A. cantonensis lineages. The implications for accurate molecular identification and diagnosis of human angiostrongyliasis are also discussed.

Although rare, Angiostrongylus costaricensis infection may be a more prevalent etiology of inflammatory bowel disease than ulcerative colitis and Chron's disease in endemic areas in Central and South America. The present study reviewed the occurrence of A. costaricensis in Brazil, its clinical presentation and pathology; and proposed diagnostic criteria and case definitions for abdominal angiostrongyliasis (AA). Southern and southeastern Brazilian regions are the main endemic areas, and AA affects both genders and all age groups. A review of all 23 published reports of 51 Brazilian patients highlighted the following features that were subsequently classified as minor diagnostic criteria: abdominal pain, palpable mass in the right lower abdominal quadrant, history of exposure, ileocecal tumor, and intestinal perforation with wall thickening. Proposed major criteria include right lower quadrant abdominal pain, blood eosinophilia, positive serology (antibody detection), intense eosinophilic infiltration that involves all strata of the intestinal wall, eosinophilic granulomatous reaction, and eosinophilic vasculitis. In addition to the definitions of suspected and possible cases according to increasing strength of evidence of this infection, demonstration of worms/eggs/larvae in tissues or Angiostrongylus DNA in tissues or serum are required for a confirmed diagnosis. The application of the proposed criteria and definitions may improve patient management, epidemiologic surveillance, and identification of new endemic areas.

Angiostrongylus costaricensis is a metastrongyloid nematode that primarily infects the mesenteric arteries of wild rodents. This parasite is endemic in several regions of the American continent, and in humans, causes a disease known as abdominal angiostrongyliasis. Despite the important health implications of this nematode, there are limited studies investigating the involvement of wild animals in its life cycle. In this study, we present the clinical manifestations, pathologic findings, and molecular diagnosis, to the best of our current knowledge, of the first documented onset of cerebral angiostrongyliasis because of A. costaricensis infection in a juvenile free-ranging opossum (Didelphis marsupialis). Histopathological findings stress the presence of eosinophilic meningoencephalitis with nematodes present within the lesions, and PCR was positive for cox1 and ITS1 reactions. The obtained sequences for a 279 bp fragment of ITS1 were 100% identical to A. costaricensis from Costa Rica. This case highlights the substantial difficulties in diagnosing neuroangiostrongyliasis, yet underscores the importance of considering A. costaricensis as a potential culprit behind neurological conditions in wild marsupials. It acts as an urgent call to action to improve surveillance programs tracking infectious and parasitic diseases causing mortality in wildlife populations.

Angiostrongyliasis is a parasitic disease caused by larvae of the genus Angiostrongylus, with Angiostrongylus cantonensis and Angiostrongylus costaricensis being the two main species causing diseases in humans [...].

We investigated parasitic zoonoses caused by protozoans and helminths in urban and peri-urban rat populations (Rattus norvegicus and R. rattus) in Spanish cities. Rats were trapped and then dissected to remove adult helminths, and the contents of the large intestine were retrieved for the study of parasitic forms. The Midi Parasep® solvent free (SF) technique was used to concentrate the parasites in the intestinal contents. Some of the rats studied (n = 8) were infected by the rat lungworm, Angiostongylus cantonensis, whose first stage larvae (L1) are shed in rat faeces. After the concentration technique, L1 larvae were found in the sediment of 6 of the 8 positive rats. The two negative sediment samples were due to the presence of either only adult females or, in addition to males, only young females in the lungs of the rats. In view of our results, Midi Parasep® SF turned out to be a simple, rapid, inexpensive, and sensitive method to detect nematode larvae, such as the L1 larvae of A. cantonensis (or A. costaricensis), in natural and experimentally infected rats.