Occurrence of zoonotic gastrointestinal parasites of rodents and the risk of human infection in different biomes of Brazil.

Rodents are synanthropic mammals adapted to several ecosystems, where they can contribute to the transmission of zoonotic pathogens, including gastrointestinal parasites. The aim of this study was to study the occurrence of gastrointestinal parasites from rodents and discuss the risk of transmission to humans. Fecal samples (n = 110) from different rodent species, namely, Cerradomys subflavus (n = 4), Mus musculus (n = 14), Rattus norvegicus (n = 80), Rattus rattus (n = 8) and Thrichomys apereoides (n = 4), were analyzed using the FLOTAC technique. Of the samples examined, 73.6% (81/110) tested positive for at least one gastrointestinal parasite. The most commonly identified parasites were Aspiculuris sp., Hymenolepis nana, Moniliformis sp., Syphacia sp., Strongyloides spp., Taenia spp., and Trichuris spp. eggs, Angiostrongylus cantonensis larvae and Entamoeba spp. cysts. The findings of this study demonstrate that rodents living in different Brazilian biomes are parasitized by a wide range of parasites, including some of public health concern. Therefore, the proximity of rodents to human settlements may represent a tangible risk of infection for people living in these areas.

Roedores são mamíferos sinantrópicos adaptados a vários ecossistemas, onde podem contribuir para a transmissão de patógenos zoonóticos, incluindo parasitas gastrointestinais. O objetivo deste estudo foi descrever a ocorrência de parasitos gastrointestinais de roedores e discutir o risco de transmissão ao ser humano. Amostras fecais (n = 110) de diferentes espécies de roedores, a saber, Cerradomys subflavus (n = 4), Mus musculus (n = 14), Rattus norvegicus (n = 80), Rattus rattus (n = 8) e Thrichomys apereoides (n = 4), foram analisados pela técnica FLOTAC. Das amostras examinadas, 73,6% (81/110) apresentaram resultado positivo para pelo menos um parasito gastrointestinal. Os parasitos mais comumente identificados foram ovos de Aspiculuris sp., Hymenolepis nana, Moniliformis sp., Syphacia sp., Strongyloides spp., Taenia spp., Trichuris spp., larvas de Angiostrongylus cantonensis e cistos de Entamoeba spp. Os resultados deste estudo demonstraram que os roedores que vivem em diferentes biomas brasileiros são parasitados por uma ampla variedade de parasitos, incluindo alguns problemas de saúde pública. Portanto, a proximidade de roedores com assentamentos humanos pode representar um risco de infecção nessas áreas.

Applicability of FLOTAC® technique in recovering equine strongyle larvae in the pasture: A comparison study.

The FLOTAC® technique represents a highly sensitive method for the isolation of oocysts, eggs, and larvae of parasites in faeces. This assay could be used for detecting free-living stages of nematodes in the pasture but no attempt has been assessed so far. Therefore, the performance of FLOTAC® technique for isolating infective larvae of nematodes in the environment was investigated and compared with the spontaneous sedimentation (SST) and centrifugal sedimentation (CST) techniques. The study was conducted in a horse farm located in northeastern Brazil, where the occurrence of strongyle larvae had been previously reported. Pasture samplings were collected monthly from January to May 2016 in a 376 m2 crop area harvested with the Guinea grass Panicum cultivar Massai. The recovery of third-stage larvae (L3) was performed using the FLOTAC®, SST and CST techniques. Values of Cohen's kappa coefficient, sensitivity, specificity, positive and negative predictive values, and accuracy of each technique were assessed. Although strongyle larvae were evenly detected, with the FLOTAC® technique yielded the highest number of positive samples (i.e., 41%, 41/100, p < .0001). The main parasites isolated belonged to the Cyathostominae and Strongylinae subfamilies. Based on these results, the FLOTAC® technique should be considered as practical and safe method for the isolation of nematode larvae in the pasture, thus opening a new potential use for this tool in the field.