R. rattus y R. norvegicus, como reservorio de endoparásitos zoonóticos en Ecuador

Objetivo. Recolectar información sobre la presencia de parasitosis intestinales en roedores, con énfasis en parásitos de importancia médica en humanos. Materiales y métodos. Se realizó un estudio parasitológico para detectar la presencia de helmintos en roedores en zonas urbanas y rurales de cinco provincias del Ecuador entre el 2014 y 2017. Los roedores fueron capturados y transportados al Centro Referencia Nacional de Parasitología del Instituto Nacional de Investigación en Salud Pública – Guayaquil, para su posterior análisis. Resultados. Se encontraron 125/211 (59.2%) ratas con endoparásitos, 13/20 (65%) R. rattus y 112/191 (58.6%) R. norvegicus. El nemátodo más prevalente fue Nippostrongylus brasiliensis (para ambas especies de roedores), y Heterakis spumosa, seguido por los cestodos: Hymenolepis diminuta, H. nana, Moniliformis moniliformis y Cysticercus fasciolaris. Conclusiones. La presencia de cuatro especies de cestodos zoonóticos en los roedores muestreados que viven cerca comunidades humanas, representan un riesgo potencial de infecciónpara los habitantes, especialmente en el caso de R. norvegicus (presento mayor diversidad de especies parasitarias).Por lo tanto, el control de la población de roedores en las áreas residenciales y las recomendaciones a la población local sobre el riesgo de transmisión de enfermedades a través de roedores parece ser totalmente necesario.

Parasites and Parasitic Diseases of Laboratory Animals in Plateau State Nigeria: The Zoonotic Implications

Parasitic infections in laboratory animals, are detrimental to the success of researches and can also infect personnel and researchers. This study is aimed at investigating the parasitic infections of laboratory animals maintained in animal houses of The National Veterinary Research Institute, Vom, Nigeria, as well determining the zoonotic implications of the parasites. Two hundred and six laboratory animals (55 guinea pigs, 72 rabbits, 29 rats and 50 mice) were sampled. Faecal samples and skin scrapings were collected and subjected to parasitological analyses. Pathological examinations were conducted on laboratory animals that had skin lesions. Sixteen different species comprising of 7 nematodes, 5 cestodes, 3 protozoans, and 1 mite were detected. Eimeria species (40/206; 19.42%; 95% CI = 14.44 – 25.25) was the most prevalent parasite, followed by Syphacia muris (26/206; 12.62%; 95% CI = 8.59 – 17.69). Entamoeba caviae, Tritrichomonas caviae, Rodentolepis microstoma, Rodentolepis nana, Heterakis spumosa, Capillaria hepatica and Cysticercus fasciolaris were the least prevalent with a 0.49% prevalence each. Three, four, five and six different species of parasites were detected in mice, guinea pigs, rats and rabbits respectively. The Chi square analysis revealed that the infection rate of parasites was significantly higher (p = <0.01) in mice compared to guinea pigs, rabbits and rats. Of the Sixteen species of parasites detected, Eimeria species, Syphacia muris, Rodentolepis diminuta, Rodentolepis microstoma, Rodentolepis nana, and Capillaria hepatica are zoonotic. This study showed that 40.29% of the studied laboratory animals were infected with one parasite species or the other. The outcome of this study stresses the zoonotic implications of the parasites detected. We thereby advise researchers and handlers to take caution and apply utmost sanitary measures in the handling of laboratory animals so as to prevent themselves from been infected with these zoonotic parasites.

Helminth Parasites among Rodents in the Middle East Countries: A Systematic Review and Meta-Analysis

Rodents can be a source of zoonotic helminths in the Middle East and also in other parts of the world. The current systematic review aimed to provide baseline data on rodent helminths to recognize the threats of helminth parasites on public health in the Middle East region. Following a systematic search on PubMed, Scopus, and Web of Science, a total of 65 research studies on rodent cestodes, nematodes, and trematodes, which were conducted in the countries of the Middle East, were analyzed. The study identified 44 rodent species from which Mus musculus, Rattus norvegicus, and Rattus rattus were most common (63%) and recognized as the primary rodent hosts for helminth infestation in this region. Cestodes were the most frequently reported (n = 50), followed by nematodes (49), and trematodes (14). The random effect meta-analysis showed that the pooled prevalence of cestode (57.66%, 95%CI: 34.63–80.70, l2% = 85.6, p < 0.001) was higher in Saudi Arabia, followed by nematode (56.24%, 95%CI: 11.40–101.1, l2% = 96.7, p < 0.001) in Turkey, and trematode (15.83%, 95%CI: 6.25–25.1, l2% = 98.5, p < 0.001) in Egypt. According to the overall prevalence estimates of individual studies, nematodes were higher (32.71%, 95%CI: 24.89–40.54, l2% = 98.6, p < 0.001) followed by cestodes (24.88%, 95%CI: 19.99–29.77, l2% = 94.9, p < 0.001) and trematodes (10.17%, 95%CI: 6.7–13.65, l2% = 98.3, p < 0.001) in the rodents of the Middle East countries. The review detected 22 species of helminths, which have zoonotic importance. The most frequent helminths were Capillaria hepatica, Hymenolepis diminuta, Hymenolepis nana, and Cysticercus fasciolaris. There was no report of rodent-helminths from Bahrain, Jordan, Lebanon, Oman, United Arab Emirates, and Yemen. Furthermore, there is an information gap on rodent helminths at the humans-animal interface level in Middle East countries. Through the One Health approach and countrywide detailed studies on rodent-related helminths along with their impact on public health, the rodent control program should be conducted in this region.

Natural Cysticercus fasciolaris infection in rodents from a rural area in Yucatan, Mexico

Cysticercus fasciolaris is the larval stage of Taenia taeniaeformis, a parasite that predominantly affects felines. It, however, has zoonotic significance since humans can be accidental hosts. Rodents and lagomorphs act as Intermediate hosts in this parasite’s life cycle. The aim of this study was to determine the natural occurrence of infection with Cysticercus fasciolaris in rodents from a rural area in Yucatan, Mexico. Rodents were captured in 40 dwellings and two neighboring areas of low deciduous forest. A total of 153 individuals of seven different species were captured: 65 Rattus rattus (42.5%), 44 Mus musculus (28.8%), 22 Heteromys gaumeri (14.4%), 11 Ototylomys phyllotis (7.2%), 9 Peromyscus yucatanicus (5.9%), 1 Peromyscus leucopus (0.6%), and 1 Sigmodon hispidus (0.6%). All animals were examined for evidence of parasitic liver infection. Rattus rattus was the only species to present positive Cysticercus fasciolaris infection (18.5%, 12/65). We thus concluded that there was no evidence of a transmission cycle with wild rodent species.

INTERACTIONS BETWEEN CYSTICERCUS FASCIOLARIS AND COMMON RATS

The objective of this study was to determine the relationship of C. fasciolaris with common rats. Cysticercus fasciolaris is the larval stage of Taenia taeniaeformis . Development of metacestodes ( Cysticercus fasciolaris) occur in the liver of rodents. An urban and a sylvatic cycle occurs. A total of 40 liver specimens of rats were examined. Histopathological examination revealed the presence of multiple hepatic cysts, and the C. fasciolaris larva was surrounded by granulation tissue. Large and separated ûbroblasts in different orientations with some neoplastic changes were seen in advanced hepatic cysticercosis. The bladder involved the larva and large chamber containing the small chamber and opalescent fluid. The scolex of the mature larva is distinctly large, bearing four lateral distinct suckers, a rostellum armed with double, and alternating rows of hooks.

Histological morphology and pathological changes in liver of rats naturally infected with larval stage Cysticercus fasciolaris of Taeniae taeniaeformis

The aim of this study is to describe the morphology of Cysticercus fasciolaris by using light microscopy, and the pathological changes in the liver of rats naturally infected. A total of 50 liver specimens of local rats (Wister rats) were collected for examination. The gross lesions showed the presence of single or multiple cysts. Microscopic findings revealed the presence of larvae within the cysts which represent the larvae Cysticercus fasciolaris of the adult parasite Taeniae taeniaeformis which inhabited the small intestine of the domestic cats surrounded by fibrous connective tissue infiltrated with inflammatory cells (mononuclear cells and plasma cells). These lesions cause pressure atrophy to the adjacent hepatic parenchyma. In advanced hepatic infection there is a tendency to undergo neoplastic changes (fibroma). Other pathological lesions seen in the liver parenchyma were necrosis, apoptosis with infiltration of chronic inflammatory cells in the portal area, in addition; to formation of early granulomas with congestion of blood vessels which contain neutrophiles in their lumina with extensive area of hemorrhages in liver parenchyma. In conclusion the C. fasciolaris infction induce hepatic neoplasia in rat livers (fibroma) in advance cases of heavy infection, which could be developed to fibrosarcoma in future.

Cysticercus fasciolaris in Brown Rats (Rattus norvegicus) in Grenada, West Indies

Cat is the definitive host of Taenia taeniaeformis (T. taeniaeformis). Cysticercus fasciolaris (C. fasciolaris), the larval stage of T. taeniaeformis, develops in small rodents which act as intermediate host. The aim of this study was to estimate the prevalence of C. fasciolaris in brown rats (Rattus norvegicus) in the densely human populated parishes, St. George’s and St. David’s of Grenada, West Indies. One hundred and seventy rats were trapped near the residential areas from May to July, 2017 and examined for C. fasciolaris in their liver. Of the 170 rats 115 (67.6%, CI 95% from 60.1 to 74.6) were positive for the larval stage of T. taeniaeformis. One to three cysts were observed in each liver, containing a single larva in each cyst. The prevalence was 77.9% in St. George and 59.1% in St. David which is a significant difference (p<0.05) between the two parishes under study. Based on gender, prevalence in males was 60.9% and females 74.7%. Significant difference was observed between young and adult rats (p=0.03). Prevalence in young rats was 45.0% compared to adults (70.7%). Further study of risk assessment in the cat population in areas of the present research is strongly suggested.