ABSTRACT
From 2009 to 2013 the diversity of noroviruses (NoVs) in children (⩽5 years) hospitalized with gastroenteritis in South Africa was investigated. NoVs were genotyped based on nucleotide sequence analyses of partial RNA-dependent RNA polymerase (RdRp) and capsid genes. Seventeen RdRp genotypes (GI.P2, GI.P3, GI.P6, GI.P7, GI.P not assigned (NA), GI.Pb, GI.Pf, GII.P2, GII.P4, GII.P7, GII.P13, GII.P16, GII.P21, GII.Pc, GII.Pe, GII.Pg, GII.PNA) and 20 capsid genotypes (GI.1, GI.2, GI.3, GI.5, GI.6, GI.7, GI.NA, GII.1, GII.2, GII.3, GII.4, GII.6, GII.7, GII.10, GII.12, GII.13, GII.14, GII.16, GII.17, GII.21) were identified. The combined RdRp/capsid genotype was determined for 275 GII strains. Fifteen confirmed recombinant NoV strains circulated during the study period. NoV GII.P4/GII.4 (47%) and GII.Pe/GII.4 (18%) predominated, followed by GII.PNA/GII.3 (10%) and GII.P21/GII.3 (7%). Other prevalent strains included GII.Pg/GII.12 (6%) and GII.Pg/GII.1 (3%). Two novel recombinants, GII.Pg/GII.2 and GII.Pg/GII.10 were identified. In 2013 the replacement of GII.4 New Orleans 2009 and GII.P21/GII.3, which predominated during the early part of the study, with GII.4 Sydney 2012 and GII.PNA/GII.3 was observed. This study presents the most comprehensive recent data on NoV diversity in Africa.
Subject(s)
Caliciviridae Infections/virology , Capsid Proteins/genetics , Gastroenteritis/virology , Norovirus/genetics , RNA-Dependent RNA Polymerase/genetics , Caliciviridae Infections/epidemiology , Capsid Proteins/metabolism , Child, Preschool , Female , Gastroenteritis/epidemiology , Humans , Infant , Infant, Newborn , Male , Molecular Sequence Data , Phylogeny , Prevalence , RNA-Dependent RNA Polymerase/metabolism , Sequence Analysis, DNA , South Africa/epidemiologyABSTRACT
Over a 2-year period, from January 2009 to December 2010, water samples were collected from three rivers (Klip, Rietspruit and Suikerbosrand) in the Vaal River System, South Africa. Enteric viruses were recovered by a glass wool adsorption-elution method and concentrated using polyethylene glycol/sodium chloride precipitation. Sapoviruses (SaVs) were detected using published sapovirus (SaV)-specific primers and Taqman probes in a two-step real-time reverse transcription-polymerase chain reaction assay. Based on sequence analysis of the 5'-end of the capsid gene, SaVs were genotyped. In 2009, SaVs were detected in 39% (15/38) of samples from the Klip river, 83% (5/6) from the Rietspruit and 14% (1/7) of samples from the Suikerbosrand river. In 2010, SaVs were detected in 54% (14/26) of Klip river samples, 92% (11/12) from the Rietspruit and 20% (2/10) of samples from the Suikerbosrand river. SaV strains identified in the water samples were characterised into several GI and GII genotypes. The presence of SaVs in these rivers indicates human faecal contamination which may pose a potential health risk to persons exposed to these water sources during domestic or recreational activities.
Subject(s)
Rivers/microbiology , Sapovirus/classification , Sapovirus/isolation & purification , Animals , Cloning, Molecular , Environmental Monitoring , Phylogeny , Sapovirus/genetics , South Africa , Water MicrobiologyABSTRACT
AIM: To investigate the diversity of human caliciviruses (HuCVs) in wastewater from small- to medium-sized communities in five provinces of South Africa (SA). METHODS AND RESULTS: Wastewater samples (51) were screened for norovirus (NoV) GI, GII, GIV and sapovirus (SaV) using real-time reverse transcription (RT)-PCR. Partial capsid nucleotide sequences were analysed for genotyping. At least one HuCV was detected in 42 samples (82%) with NoV GI being detected in 15 (29%), NoV GII in 32 (63%) and SaV in 37 (73%) samples. NoV GIV was not detected. Five NoV GI genotypes (GI.1, GI.3, GI.4, GI.8 and GI.unassigned), eight NoV GII genotypes (GII.2, GII.3, GII.4, GII.6, GII.7, GII.12, GII.13 and GII.17) and six SaV genotypes (GI.2, GI.3, GI.6, GI.7, GII.1 and GII.2) were characterized. CONCLUSIONS: Many NoV and SaV genotypes were detected in wastewater, demonstrating a high genetic diversity of HuCVs in the surrounding communities. Caliciviruses were characterized from several provinces in SA, indicating widespread occurrence in the country. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides valuable new data on CVs circulating in SA, including the first data on SaV strains from wastewater in Africa. Environmental surveillance is especially important in countries like SA where outbreak reporting systems or routine HuCV surveillance is lacking.
