Be careful when you go for a swim in the neighbourhood pool this summer. The parasitic infection Cryptosporidium - known as Crypto - is on the rise in the US, according to the Centres for Disease Control and Prevention (CDC).
The parasite is the most common cause of diarrhoea linked to swimming pools and water parks, and it spreads when people swallow something that has come into contact with the faeces of a sick person (such as pool water).
The CDC says the infection can make "healthy people sick for up to three weeks with watery diarrhoea, stomach cramps, nausea, or vomiting, and can lead to dehydration".
In 2016, there were at least 32 outbreaks in the country, double the number from 2014. In 2016, Ohio identified 1,940 people with Crypto after observing only 571 cases annually between 2012 and 2015.
The Crypto parasite is hard to kill, since it can survive the standard levels of chlorine and other pool disinfectants that kill most other germs within a few minutes.
To get rid of Crypto, the CDC recommends closing pools after contamination for an hours-long period of 'hyperchlorination'.
Keeping Crypto out of a pool also means relying on people to be responsible about showering before getting in a pool and staying away from the water if they have recently suffered from diarrhoea.
But that doesn't always happen - a recent survey by the Water Quality and Health Council found that 25 percent of adults said they'd swim within an hour of having diarrhoea and just over half never shower before getting in the pool.
After realising that the parasite was on rise, the CDC launched a DNA-fingerprinting tracking system for identifying Crypto outbreaks in 2010.
To avoid getting sick, the CDC recommends not swallowing any water while you swim, which is easier said than done, of course. It just takes a mouthful of water that's been contaminated to make you sick.
Experts also urge people to rinse off before diving in, and to take kids on frequent bathroom breaks. They also suggest changing diapers for young ones in a separate area away from the pool.
And if you've been sick with Crypto? Stay out of the water, please.
This article was originally published by Business Insider.
More from Business Insider: