Pepper mild mottle virus in wastewater in Egypt: a potential indicator of wastewater pollution and the efficiency of the treatment process.

There is increasing evidence that the fecal indicator bacteria that are routinely used for testing water quality are inadequate for ensuring protection of the public health. Pepper mild mottle virus (PMMoV) has recently been suggested as an alternative indicator of human fecal contamination in water; however, in Egypt there are no data available about its occurrence and concentration in aquatic environment. The concentration of PMMoV in the influent and effluent of three wastewater treatment plants was measured using qRT-PCR over a period of one year and compared to that of human adenovirus (HAdV), which is considered an indicator for human fecal contamination. PMMoV was detected in ~ 94% of the influent samples and 78% of the effluent samples, with concentrations ranging from 3.9 × 104 to 3.3 × 108 genome copies/l (GC/l) in the influent and 3.9 × 104 to 1.2 × 107 GC/l in the effluent. Similarly, HAdV was identified in 88% and 78% of the influent and effluent samples, respectively. The HAdV concentration ranged between 1.5 × 104 and 1.5 × 107 GC/l for the influent and 2.6 × 104 and 4.4 × 106 GC/l for the effluent. No significant difference was found between the removal ratio of PMMoV and HAdV. Viral reduction of 0.2-1.9 log10 and 0.2- 2.3 log10 by the treatment process was observed for PMMoV and HAdV, respectively. Both viruses showed no clear seasonality. Our data support the use of PMMoV as a fecal indicator of wastewater contamination and a process indicator for the performance of the treatment process.