Two-year monitoring of enterovirus and rotavirus A in recreational freshwater from an island region, Pará State, northern Brazil

Enteric viruses are major causes of waterborne diseases and are present in large quantities in the stools of infected individuals. Its viability in the environment lasts for months, favoring the contamination of water used for consumption and recreation. The study aimed to monitor monthly the circulation of enterovirus (EV) and group A rotavirus (RVA) in recreational freshwater from an island region used as a bathhouse in northern Brazil, from January 2012 to December 2013. The viral RNA was obtained using guanidine isothiocyanate/silica after viral concentration by adsorption-elution method. The molecular detection was carried out by semi (EV) and nested-PCR (RVA) and the amplicons were sequenced on automated sequencer. At least one of these viruses was detected on 40.4% (42/104) of the samples. RVA was the most frequent (n = 32; 30.8%) when compared to EV (n = 20; 19.2%). Co-circulation between both was identified in 9.6% (n = 10). The highest viral positivity was found in SP02 (46.1%). The highest viral positivity was observed during high tides (57.7%; 60/104). Most EV samples were characterized as coxsackievirus (CV) A5 (85.7%, 12/14) and others as Sabin 1 poliovirus (14.2%, 2/14). The RVA positive samples were genotyped as G2, G3, G9, G12, P[8], P[4], and P[6]. These viruses were detected in 35.6% (37/104) of the samples with an acceptable concentration of fecal coliform bacteria. These results demonstrate the contamination of surface water intended for recreation by enteric viruses of Public Health concern even when bacterial indicators are within the tolerated limit, a factor that confirms the need for public policies aimed the sewage treatment before its release into water bodies.