Quantitative Detection and Characterization of Human Adenoviruses in the Buffalo River in the Eastern Cape Province of South Africa

Buffalo River is an important water resource in the Eastern Cape Province of South Africa. Over a 1-year period (August 2010-July 2011), we assessed the prevalence of human adenoviruses (HAdVs) at a total of 6 sites on the river and three dams along its course. HAdVs were detected by real-time quantitative PCR in about 35 % of the samples with concentrations ranging from 1.2 x 10(1) genome copies (GC)/l to 4.71 x 10(3) GC/l. HAdVs were detected at 5 of the 6 sampling sites with the detection rate ranging from 8.3 % at Rooikrantz Dam to 92 % at Parkside. The HAdV concentrations across the sampling sites were as follows: Parkside (3.25 x 10(2)-4.71 x 10(3) GC/); King William's Town (1.02 x 10(2)-4.56 x 10(3) GC/l); and Eluxolzweni (1.17 x 10(2)-3.97 x 10(2) GC/l). Significantly (P < 0.05) higher concentrations were detected at the non-dam sites compared to the dam sites. A very low mean concentration of 1.86 x 10(1) HAdV GC/l was observed at Bridle Drift Dam. While HAdVs were detected only once at Rooikrantz Dam (1.74 x 10(1) GC/l), no HAdV was detected at Maden Dam. Epidemiologically important serotypes, Ad40/41, constituted 83.3 %, while Ad21 made up 16.7 % of the all HAdVs detected and were characterized by qualitative PCR. The Buffalo River presents a public health risk heightened by the presence of Ad 40/41 and Ad21. Our results make imperative the need for assessing water sources for viral contamination in the interest of public health. This work is a significant contribution to the molecular epidemiology of adenoviruses and to the best of our knowledge this is the first report on detection of enteric virus from surface waters in the Eastern Cape.