Relative Abundance of Human Bocaviruses in Urban Sewage in Greater Cairo, Egypt

Human bocavirus (HBoV) is predominantly found in the respiratory tract infections and in the stool of patients with gastroenteritis symptoms. However, data on the prevalence of HBoV genotypes in environmental samples are limited. Here we addressed the prevalence of HBoV in sewage collected from three different wastewater treatment plants in Egypt. HBoV-1, HBoV-2, and HBoV-3 were detected, whereas none of the samples were positive for HBoV-4. The median concentration of HBoV in influent samples was 8.5 x 10(3) GC/l for HBoV-1, 3.0 x 10(4) GC/l for HBoV-2, and 2.5 x 10(4) GC/l for HBoV-3. The concentration was reduced but not completely removed in the effluent samples. The median concentration in the outlet samples was 2.9 x 10(3) GC/l for HBoV-1, 4.1 x 10(3) GC/l for HBoV-2, and 2.1 x 10(3) GC/l for HBoV-3. Moreover, no seasonality pattern of HBoVs was found. The high incidence of HBoV in sewage samples provided an evidence of its circulation in the local population. Although the role of HBoV in respiratory or gastro-intestinal infections still remains to be fully elucidated, the risk of infection via contaminated water should be taken into consideration.