Helminths of the guinea pig, Cavia porcellus (Linnaeus), in Brazil

Update of Cestodes Parasitizing Neotropical Hystricomorphic Rodent

This review aims at identifying cestodes that are present in hunted rodent species in the neo-tropical region. The rodent species that was investigated were the capybara (Hydrochoerus hydrochaeris, Linnaeus, 1766), lappe (Cuniculus paca, Linnaeus, 1766), agouti (Dasyprocta leporina, Linnaeus, 1758), chinchilla (Chinchilla chinchilla, Lichtenstein, 1829), Trinidad spiny rat (Proehimys trinitatus, Allen and Chapman, 1893), nutria (Myocastor coypus, Molina, 1782), and vizcacha (Lagostomus maximus, Desmarest, 1817). These rodent species are utilized for their meats in many rural communities in the Caribbean and South America. These rodents belong to the hystricomorphic group. Raillietina demerariensis Daniels, 1895 was commonly found in the gastrointestinal tract of D. leporina, C. paca and P. trinitatus. Similarly, in the liver, muscle and subcutaneous tissue the metacestodes on Echinococcus vogeli Daniels, 1895 and Echinococcus oligarthrus was found in the lappe and agouti. The capybara was found to have the most species of cestodes in its gastrointestinal tract when compared to the agouti and lappe. However, metacestodes were not recorded in the tissues of the capybara. This surprising feature shows the effect of the difference in feeding habits between the capybara and the agouti and lappe. The literature reviewed in this study includes scientific publications on cestodes and metacestodes of Hystricomorphic rodents. An exhaustive search was performed using the digital repositories in Google Scholar, Scielo, Redalyc, Scopus and Pubmed. Literature searched spanned the years 1970-2021. Cestodes of zoonotic significance were E. vogeli and E. oligarthrus, with humans becoming infected when consuming eggs of contaminated food and water. The agouti and lappe act as intermediate host in the life cycle of E. vogeli and E. oligarthrus, the definitive host (canids and felids) become infected by consuming of tissue infected with metacestodes. Humans become infected through the ingestion of eggs from the definitive host where cystic lesions develop in the liver, lungs and other abdominal organs.

Trichuris spp. in Animals, with Specific Reference to Neo-Tropical Rodents

Trichuriasis is the clinical disease of animals infected with the parasite of the genus Trichuris. This review attempts to present information on Trichuris spp. infestation in neo-tropical rodents that are utilized for meat consumption by humans. Neo-tropical rodents utilized for meat production can be divided into two categories: those that have been domesticated, which include the guinea pig (Cavia porcellus), and those that are on the verge of domestication, such as the capybara (Hydrochoerus hydrochaeris), lappe (Cuniculus paca/Agouti paca), and agouti (Dasyprocta leporina). This document reviews the literature on the species of Trichuris that affects the rodents mentioned above, as well as the clinical signs observed. The literature obtained spans over sixty years, from 1951 to 2020. Trichuris spp. was found in these neo-tropical rodents mentioned. However, there is a dearth of information on the species of Trichuris that parasitize these animals. The capybara was the only rodent where some molecular techniques were used to identify a new species named T. cutillasae. In most cases, Trichuris spp. was found in combination with other endoparasites, and was found at a low prevalence in the lappe and guinea pig. The presence of Trichuris spp. ranged from 4.62-53.85% in the agouti, 4.21-10.00% in the lappe, 50% in the capybaras, and 1-31% in guinea pigs. Further work must be done towards molecular identification of various Trichuris spp. present in these rodents, as well as the clinical effect of infection on the performance of agouti, lappe, capybara, and guinea pigs.

Endoparasites of Domesticated Animals That Originated in the Neo-Tropics (New World Tropics)

This review serves to summarize parasites found in Domesticated animals which were found in the Neo-Tropics. Indigenous domesticated Neo-tropical animals include South American camelids, (Lama gunacoa, Lama glama, Lama pacos, Vicuna vicuna), guinea pigs (Cavia porcellus), chinchillas (Chinchilla lanigera), turkeys (Meleagris gallopavo) and ducks (Cairina moschata, Anas platyrhynchos, Dendrocyga autumnalis). These animals were chosen due to their origin of existence (Neo-tropics) and over time these animals became domesticated and were distributed throughout the world. Over eighty (80) references were collected for this review and the papers spanned over eighty (80) years from 1934 to 2018. The gastrointestinal parasites reported for each animal were tabulated and their effects in the animal noted. Parasites reported in domesticated Neo-tropical animals had little to no effect on wild and free ranging animals with a few cases of illness and decreased productivity. The majority of articles viewed these animals as reservoir host which can infect humans and other domesticated livestock. It must also be noted that research done in the past did not focus on the effect these parasites had on these animals but only observed their potential as reservoirs for parasitic diseases.

Parasitic fauna of domestic cavies in the western highlands of Cameroon (Central Africa)

BACKGROUND

Domestic cavies (Cavia porcellus) are increasingly reared in rural areas of Cameroon for meat and income generation. Unfortunately, health constraints due to various pathogens including parasites stand as one of the major obstacles to the development of cavy industry in the country. The main objective of this study was to investigate the species of gastrointestinal parasites in cavy husbandry in the western highlands of Cameroon and to detect external parasites in those animals affected with dermatological disorders.

METHODS

Pooled fecal samples were collected from 62 privately-own farms, as well as individual fecal samples from 21 animals at the Teaching and Research Farm of the University of Dschang, and examined for parasite eggs and oocysts/cysts. Ectoparasites were also collected from cavies and identified.

RESULTS

The overall infection rate with both helminthes and arthropods was 40.3 %. Ectoparasites were found in 19 out of 62 farms (30.6 %) while 12.9 % of farms were infected with helminthes. Eggs of Graphidium strigosum (8.1 %), Trichostrongylus sp. (3.2 %) and Paraspidodera uncinata (3.2 %) were found at farm level. Oocysts of Eimeria caviae and eggs of Paraspidodera uncinata were found in 14.3 and 9.5 % of examined animals respectively. Concerning ectoparasites, Cordylobia anthropophaga and Pulex sp. were observed in 25.8 % and 6.6 % of farms respectively.

CONCLUSION

The parasites are apparently composed of host-specific species in the original habitat (South America) and species acquired later from other mammals. These parasites are either deleterious to cavy health or zoonotic. Preventive measures should be put in practice to avoid their presence on farms due to their harmful effect on cavy rearing.

New record of anoplocephalid eggs (Cestoda: Anoplocephalidae) collected from rodent coprolites from archaeological and paleontological sites of Patagonia, Argentina

Results of paleoparasitological examination of rodent coprolites collected from archaeological and paleontological sites from Patagonia, Argentina, are present. Each coprolite was processed, rehydrated, homogenized, spontaneously sedimented and examined using light microscope. Coprolites and eggs were described, measured and photographed, and were compared with current faeces of Lagidium viscacia. Eggs with morphological features, attributed to an anoplocephalid cestode were found in samples collected from Cueva Huenul 1 (36°56'45″S, 69°47'32″W, Neuquén Province, Holocene) and Los Altares Profile (43º53'35″S, 68º23'21″W, Chubut Province, Late Holocene). These are the first findings of this anoplocephalid from faecal material from patagonic rodents.

Variation in the helminth community structure ofThrichomys pachyurus(Rodentia: Echimyidae) in two sub-regions of the Brazilian Pantanal: the effects of land use and seasonality

The Pantanal is a large ecosystem located in South America. This preserved area is seasonally flooded due to abundant rainfall during the summer and the subsequent overflow of the Paraguai River. In this paper, we examine the helminth community structure in the wild rodentThrichomys pachyurusduring the wet and dry seasons in two locations of the preserved and cattle ranching areas in the Southern Pantanal. We identified 12 species of helminth, and, although we did not find any differences in species richness between locations within the Pantanal, we found that richness was higher during the wet season. Helminth species were largely aggregated in both farm locations and during seasons. The most common helminth species were more abundant during the dry season than during the wet season, which may have been due to the increased habitat availability and rodent population increase. The intensity of the infection also followed the same pattern for most helminths. The trichostrongylids (Heligmostrongylus crucifer,H. almeidaiandPudica cercomysi) were dominant at both farm locations. The land use of each area was not correlated with helminth diversity. However, species composition of the helminth community ofT. pachyurusdiffered between locations and may be correlated with environmental differences between the habitats. The seasonality of the Pantanal was highly correlated with helminth parasitism inT. pachyurus.

Helminths of rabbits (Lagomorpha, Leporidae) deposited in the Helminthological Collection of the Oswaldo Cruz Institute

Helminth samples (n = 35) recovered from Oryctolagus cuniculus (Linnaeus, 1758) Lilljeborg, 1873 (3) and from another rabbit species, Sylvilagus brasiliensis (Linnaeus, 1758) Thomas, 1901 (32), from August 1909 to February 1948 and that are deposited in the Helminthological Collection of the Oswaldo Cruz Institute were analyzed. The studied samples were represented by the cysticercus of the cestode Taenia pisiformis (Bloch, 1780) and by the nematodes Passalurus ambiguus (Rudolphi, 1819), Vianella fariasi (Travassos, 1915), Longistriata perfida Travassos, 1943, Trichostrongylus retortaeformis (Zeder, 1800). The scope of the present investigation is to survey the parasites infecting these hosts, commonly used as laboratory animal models in scientific research and supply figurative data on the helminths in order to provide their easy identification, since the presence of autochthonous parasite burdens, if undetected or misinterpreted, can alter the final results of experimental assays, mainly those related to immunological approaches, when cross-reactions can occur.