We don't mean to spoil your summer but a parasite that causes diarrhea illness could be lurking in the pool you're swimming in.

The CDC released a report on Friday warning that Cryptosporidium has risen by almost 13% per year from 2009 to 2017.

Cryptosporidium is the leading cause of outbreaks of diarrhea linked to water and the third leading cause of diarrhea associated with animal contact in the United States.

Between the 8-year-span there have been 444 outbreaks from 40 states [and Puerto Rico] which resulted in almost 7,500 sick individuals. During this time almost 300 people were hospitalized and one case resulted in death. The majority of the problem (35%) is because of swimming pools & water playgrounds. A person gets the parasite if they swallow the contaminated water. If infected, people experience a "profuse, watery diarrhea that can last up to 3 weeks..."

The parasite has a high tolerance for chlorine and can live in a pool for up to a week.

Centers for Disease Control and Prevention

Outbreaks of Cryptosporidiosis rise the most in July and August.

To prevent cryptosporidiosis, the CDC recommends not swimming or going to daycare when experiencing diarrhea.

Get more info here.