Angiostrongylus costaricensis is a zoonotic parasitic nematode described for the first time in 1971 by Pedro Morera and Rodolfo Céspedes in Costa Rica. This parasite causes an infection known as abdominal angiostrongyliasis, affecting mainly school-aged children and young adults. Infection with A. costaricensis has been associated with a myriad of rodent and mollusk species in the Americas and the Caribbean, as its natural hosts and reservoirs. In this commemorative review, we highlight the extensive research collected through a 50-year journey, which includes ecological, pathological, and molecular studies on A. costaricensis and its implicated disease. We also identify major knowledge gaps in its evolutionary history, the ecological role of imported and invasive mollusk species, and immune response. We propose that the advent of -omics analyses will allow us to gather novel information regarding A. costaricensis biology and infection dynamics, as well as to promote the design of much-needed sensitive and specific diagnostic tools.

Vector-borne pathogens in amphibians and reptiles represent an emerging concern in wildlife, with implications for ecosystem dynamics and potential zoonotic risks. In this study, we screened 108 animals from Costa Rica, including 46 captive snakes, 24 free-ranging reptiles, and 38 free-ranging amphibians, for the presence of Trypanosomatidae, Anaplasmataceae, Borrelia, Rickettsia, and Hepatozoon spp. Blood smear analysis revealed protozoa gametocytes in 3.7 % of the animals sampled, and 11.1 % of amphibians and reptiles were molecular positive for at least one pathogen. Specifically, 7.4 % of the samples tested positive for Leishmania spp., 1.85 % for Trypanosoma spp., 0.9 % for Anaplasma spp., and 1.85 % for Hepatozoon spp. Notably, this study reports the first molecular detection of Leishmania in an amphibian species (Rhinella horribilis) and confirms the presence of mammalian pathogenic Leishmania infantum in captive snakes in Central America. The presence of potential zoonotic agents in both captive and free-ranging herpetofauna underscores the importance of screening wildlife species, including understudied host groups such as amphibians, to better understand their role in disease ecology.

Many new marine parasite species are added every year. Still, in some places, mainly tropical regions, marine parasites have been little studied. An exhaustive review of the indexed publications where species of parasites are reported in the marine environments of Costa Rica was carried out. The history of research on marine parasites in this region is also reviewed. A total of 146 species of marine parasites have been reported in Costa Rica as parasites of 61 different species of hosts. Most of these parasites correspond to trematodes and cestodes, found mainly in the digestive tract of their vertebrate hosts. In Costa Rica, marine parasites have been studied mainly in sea turtles, elasmobranchs, fish, and dolphins. Most marine parasites have been reported based on morphological identifications of adult stages, and most of the work done so far consists of taxonomic identifications (species reports), with little contribution to the pathology and other aspects of the parasites–hosts interactions. The technical difficulties for research in marine parasitology, the lack of sampling in certain groups of hosts, and the lack of a consolidated research group in marine wildlife parasitology in Costa Rica are factors that have prevented a greater and faster advance in the knowledge of the biodiversity of marine parasites in this country.

Cylicospirura is a genus of spirocercid nematodes infecting felids around the globe. Eleven species have been characterised, with C. felineus and C. subaequalis being reported in jaguarundis, Herpailurus yagouaroundi , from Brazil. Herein, we described spirocercid reddish worms collected from three jaguarundis from Costa Rica by using hierarchical clustering and dendrogram plots of morphological characters reported from our specimens and compared to other Cylicospirura spp., histopathological observations of associated lesions, and phylogenetic analyses of both mitochondrial and ribosomal loci. Nematodes were found within stomach nodules located in the submucosa causing a pyogranulomatous, multifocal, nodular, and sclerosing gastritis. In addition, the collected worms differed from their congeners by having a longer body and smaller muscular and glandular oesophagus, subsequently showing lower total oesophagus to body length percentage and ratio of glandular to muscular oesophagus. Cytochrome oxidase subunit 1 and internal transcribed spacer 1 analyses revealed that worms were 8.33 to 8.66% different from C. felineus, C. subaequalis , or C. petrowi and 15.2 to 15.4% different from C. petrowi , respectively. Moreover, sequences derived from collected worms clustered separately from other Cylicospirura spp. available in GenBank® in the phylogenetic trees. By using an integrative taxonomy approach, the nematodes collected from stomach nodules of jaguarundis were described as a new taxon, for which the name Cylicospirura wishkai sp. nov. is proposed.