Human adenovirus-associated health risk in the recreational waters of the Yal-ku lagoon in the Mexican Caribbean

Abstract

The study objective was to evaluate human faecal contamination impacts in the Yal-ku lagoon in the Mexican Caribbean and to estimate adenovirus infection and illness risks associated with recreational exposure during water activities. A total of 20 water samples (10 from each site × two sites) (50 L) were collected monthly over a period of 12 months from two selected sampling sites in the swimming area of the Yal-ku lagoon. The occurrence of faecal-associated viruses was explored, and human adenovirus (HAdV) and pepper mild mottle virus (PMMoV) concentrations were quantified. A quantitative microbial risk assessment (QMRA) model was used to estimate exposure and subsequent adenovirus infection and illness risk for 1 h of swimming or snorkelling. Somatic and F + -specific coliphages occurred in 100% of the samples. Both HAdV and PMMoV were detected at a 60% frequency thereby indicating persistent faecal inputs. PMMoV concentrations (44–370 GC/L) were relatively lower than the concentrations of HAdV (64–1,000 GC/L). Estimated mean adenovirus risks were greater for snorkelling than for swimming by roughly one to two orders of magnitude and estimated mean illness risks for snorkelling were >32/1,000. Human faecal contamination is frequent in the Yal-ku lagoon, which is associated with human gastrointestinal illness. HIGHLIGHTS Human faecal contamination detected in a Mexican Caribbean lagoon.; The rainfall seasons posed the greatest risk.; Estimated risks were greater for snorkelling than for swimming by one to two orders of magnitude.; Estimated mean illness risks for snorkelling were >32/1,000.;

Keywords

• adenovirus
• coastal lagoon
• exposure
• recreational waters
• risk
• virus faecal markers