'Explosive diarrhea' outbreak source remains a mystery

Tracking the origin of an outbreak in the US that causes explosive diarrhoea has proved a challenge for public health experts searching for answers about how it started - and how it's spreading. Cyclosporiasis, a parasitic infection that spreads through contaminated water or food, often during the summer, has now reached 34 states and infected nearly 7,000 people, according to the Centers for Disease Control and Prevention (CDC). The main symptom of the rarely fatal illness is frequent, watery diarrhoea. Some experts told the BBC that the parasite is notoriously difficult to trace, a task possibly complicated in part by cuts to federal health agencies. "This isn't like detecting a needle in a haystack. It's like detecting a microscopic portion of a needle in a haystack," said Steven Mandernach, executive director of the Association of Food and Drug Officials. One reason the parasite is so hard to track is that it takes one to two weeks for people to fall ill after infection, said Jodie Guest, senior vice chair of epidemiology at Emory University's Rollins School of Public Health. With most food-related illnesses, people tend to experience symptoms within a couple of hours, making i