Human enteric viruses in sewage and their discharge into the ocean

Abstract

Twenty-four hourly as well as 12 two-hour composite samples of Honolulu's untreated sewage which is discharged into the ocean were assayed for human enteric viruses. Both sampling methods yielded similar results with peaks of virus discharge occurring between 11 to 14 h and again between 20 to 23 h. Over a 24 h period, 8.5 × 10¹⁰ PFU of virus based on the 24 hourly samples and 7.5 x 10¹⁰ PFU based on the 12 two-hour composite samples were determined to be discharged into the ocean via the sewage ocean outfall. Four-hour composite samples of sewage from two selected communities were also analyzed for human enteric viruses. Higher concentrations of viruses were consistently recovered from the sewage draining Kuhio Park Terrace community than from Nuuanu community and support the hypothesis that a community (Kuhio Park Terrace) characterized by a relatively high percentage of children, high density and low socio-economic conditions will excrete higher amounts of enteric viruses than a community (Nuuanu) with contrasting characteristics.