Detection of Human polyomavirus 2 (HPyV2) in oyster samples in northern Brazil.

BACKGROUND: Human polyomavirus 2 (HPyV2 or JCPyV) is persistent in the environment due to its excretion in urine and feces; it is detected in samples of wastewater, surface water and drinking water. A lack of basic sanitation and sewage collection results in the presence of this virus in food, especially in oysters, since they are bioaccumulators and are consumed in their natural form, thus posing a risk to human health. METHODS: This study investigated the frequency of HPyV2 in samples of oysters marketed in northeastern Pará State, Brazil, and optimized a real-time PCR (qPCR) protocol for the detection of an endogenous oyster control. A total of 217 oysters in 22 pools from five municipalities in the state of Pará were analyzed. Samples underwent dissection and total maceration of oyster tissue using a viral concentration technique, followed by DNA extraction with phenol-chloroform and amplification of the VP1 region for molecular detection via qPCR. RESULTS: HPyV2 was detected in 18.2% (4/22) of the pooled samples, with frequencies of 25, 20, 20 and 16% in the municipalities of Salinópolis, Augusto Corrêa, São Caetano de Odivelas and Curuçá, respectively. Notably, the sample pool from the municipality of Bragança did not have detectable HPyV2 and this was the only sampled location with a water treatment station. In this study, Crassostrea genus-specific primers (AFL52 ribosomal RNA gene) of oyster were developed for use as an endogenous control in the qPCR analysis, which will be useful for future studies. CONCLUSIONS: The detection of HPyV2 in oyster samples commercialized in the state of Pará shows the circulation of this virus in the studied municipalities. Thus, it is necessary to implement measures for improving sewage collection and basic sanitation to avoid contamination of water and food with HPyV2.

Human polyomaviruses 10 and 11 in faecal samples from Brazilian children.

The human polyomaviruses (HPyVs) 10 and 11 have been detected in faecal material and are tentatively associated with diarrhoeal disease. However, to date, there are insufficient data to confirm or rule out this association, or even to provide basic information about these viruses, such as how they are distributed in the population, the persistence sites and their pathogenesis. In this study, we analysed stool specimens from Brazilian children with and without acute diarrhoea to investigate the excretion of HPyV10 and HPyV11 as well as their possible associations with diarrhoea. A total of 460 stool specimens were obtained from children with acute diarrhoea of unknown aetiology, and 106 stool specimens were obtained from healthy asymptomatic children under 10 years old. Samples were collected during the periods of 1999-2006, 2010-2012 and 2016-2017, and found previously to be negative for other enteric viruses and bacteria. The specimens were screened for HPyV10 and HPyV11 DNA by the polymerase chain reaction (PCR). Randomly selected positive samples were sequenced to confirm the presence of HPyV10 and HPyV11. The sequenced strains showed a percent of nucleotide identity of 93.4-99.6% and 85.5-98.9% with the reference HPyV10 and HPyV11 strains, respectively, confirming the PCR results. HPyV10 and HPyV11 were detected in 7.2% and 4.7% of the stool specimens from children with and without diarrhoea, respectively. The prevalence of both viruses was the same among children with diarrhoea and healthy children. There was also no difference between boys and girls or the degree of disease (severe, moderate or mild) among groups. Phylogenetic analysis showed that all of the genotypes described so far for HPyV10 and HPyV11 circulate in Rio de Janeiro. Our results do not support an association between HPyV10 and HPyV11 in stool samples and paediatric gastroenteritis. Nevertheless, the excretion of HPyV10 and HPyV11 in faeces indicates that faecal-oral transmission is possible.