Prevalence of noroviruses (NoV) in healthy children and HIV infected adults in Cameroon

Abstract

Background: Enteric viruses, notably noroviruses are a common cause of diarrhoea worldwide and may be detected in both symptomatic and assymptomatic persons This study carried out on fecal samples in Cameroon describes the shedding of NoVs in healthy children and adults infected with HIV but without symptoms of diarrhoea. Methods & Materials: The study was conducted in Limbe, between October and December 2009, South West region of Cameroon. Study participants included 54 healthy children, aged 5-15 and 93 HIV infected adults,aged 16-75 without any symptoms of diarrhoea. Fecal samples were collected in sterile leak-proof plastic labelled containers.10% fecal suspensions were made in phosphate buffered saline–pH 7.2 and centrifuged at 8000 x g for 5 minutes.Nucleic acid(NA) was extracted after initial storage at -80 °c by MagNA pure Lc total NA isolation kit, Roche Diagnosis, GmbH, Manheim, Germany. Reactions were performed in an ABI 7300 real time PCR system, Applied Biosystems, Foster city, CA, USA). Each sample was amplified in 4 parallel reaction wells for identification of 8 HEV, namely NoV GI, NoV GII, sapovirus (saV), rotavirus (RoV), astrovirus(AstV), adenovirus(AdV), hepatitis A virus(HAV) and enterovirus(EV). Results: Human Enteric viruses were common with a prevalence of 53.7% in children and 35.5% in adult participants. Mixed infections (2-5 agents) were detected in fecal samples from 65% of the children and co-infection with NoV was demonstrated in almost all cases of mixed infections. Conclusion: This study demonstrating a high prevalence of NoV and other Diarrhoea-related HEV in healthy children in Cameroon is likely an indication of an ongoing trend of of global circulation of these HEVs. Furthermore, the high prevalence of NoV genotypes, usually associated with non-bacterial diarrhoea outbreaks in developing Countries and detected in feacl samples of healthy children in Cameroon suggest that healthy children may be an important reservoir for the the virus.