Cyclospora: largest US outbreak of explosive diarrhoea parasite is over, health officials say

The largest outbreak of an intestinal infection that spread across several US states and affected more than 12,000 people has ended, the Centers for Disease Control and Prevention (CDC) announced on Friday.

Two people have died and 570 were hospitalised in recent months in relation to the outbreak of cyclospora, a microscopic parasite that can cause explosive diarrhoea.

In an advisory notice saying the outbreak was over, the CDC said cases had “significantly declined”, and it was continuing to investigate the cause of the infection.

Officials have linked the outbreak, which affected 21 states, to lettuce imported from Mexico by Taylor Farms, a key supplier for many US food outlets.

Taylor Farms announced a voluntary recall of lettuce sourced from central Mexico, while the US fast-food chain Taco Bell said it has removed lettuce from the supplier from its menu.

Cyclospora causes an intestinal illness called cyclosporiasis. It is spread through contaminated food or water and can cause symptoms including severe diarrhoea.

The CDC says deaths from cyclosporiasis are uncommon, as it is “not usually life-threatening”.

Health officials in Michigan said that the two deaths, which both happened in the state, were of people who had “significant underlying health conditions that may have been impacted by cyclosporiasis and dehydration”.

According to CDC data, there have been nearly 20,000 confirmed cyclosporiasis cases since 1 May, as well as more than 1,000 hospitalisations. Forty-nine states, as well as DC, have reported cases.

The agency notes that the true number of people who have been sick with the parasite is likely to be much higher.

While the majority of these were linked to the contaminated lettuce, thousands were not.

UK health officials too have warned about the outbreak following recent cases contracted by returning travellers.

Before the latest outbreak the worst year for infections was 2019, when there were about 4,700 across the country.