'Explosive diarrhoea' outbreak remains a mystery as officials struggle to find sources

'Explosive diarrhoea' outbreak remains a mystery as officials struggle to find sourcesImage source, PAUL J. RICHARDS/AFP via Getty ImagesByMadeline Halpert and Kayla EpsteinPublished9 minutes agoTracking 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 31 states and infected over 3,000 people, according to state health departments. 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 Manderach, 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 it easier to find the food that caused them, Guest said.Testing food for the cyclospora parasite is also far more complex than with other pathogens, said Manderach said , executive director of the Association of Food and Drug Officials.The process requires washing large amounts of the potentially tainted food to remove the cyclospora organisms, reducing the runoff, and then testing it to see if the parasite was present."You'd have to have truckloads of lettuce to get to that point," said Manderach, who previously dealt with cyclosporiasis outbreaks as a food-safety official in Io...