Pesticide water may spread norovirus

Contaminated water used to dilute pesticides could be responsible for viruses such as norovirus entering the food chain, Dutch scientists warn. Katharina Verhaelen, Martijn Bouwknegt, Saskia A. Rutjes and Ana Maria de Roda Husman of the Center for Infectious Disease Control in the Netherlands said human norovirus, also known as the stomach flu, is one of the most common viruses in the world. The virus is highly contagious, causing vomiting and diarrhea and some 800 die of it each year in the United States. Currently there is no cure. The consumption of fresh produce is frequently associated with outbreaks of human norovirus but it remains difficult to identify where in the supply chain the virus first enters production, the researchers said. The researchers said farmers use various water sources in growing fruit and vegetables, including well water and different types of surface water such as river water or lake water that can harbor human norovirus. Eight different pesticides were analyzed in the study; each was diluted with human norovirus contaminated water. The researchers tested whether traces of the virus were present in the samples after the water was mixed with the pesticides. The study, published in the International Journal of Food Microbiology, found pesticides did not counteract the effects of the contaminated water. The study authors concluded the application of pesticides on fresh produce might not only be a chemical hazard, but may in fact also be a microbiological risk factor; both having consequences on public health. A recent U.S. study found half of norovirus was traced to the surface of produce.