Here is how to avoid contracting this rimming-related infection.

There is an outbreak of shigella among gay and bisexual men in San Diego County, which has issued a health advisory in response.

County health officials reported 334 cases in 2017 — the highest count in 20 years — and 97 cases of the highly contagious this year, reports NBC News. Of this group, 25 percent were men who have sex with men. Homeless people, at 7 percent, were also highly impacted.

Shigella is an intestinal disease, similar to E.coli, that is spread through stool. An individual can contract shigella by changing a diaper, consuming contaminated foods or water, or through sexual contact, according to the Centers for Disease Control and Prevention.

Gay and bi men who engage in sexual activities like rimming or fingering, which would transfer stool to mouth, are particularly at risk.

Symptoms, which include diarrhea, fever, and stomach pain, can persist up to a week; in serious cases, symptoms last a month. An individual can remain contagious for up to two weeks after symptoms disappear.

Individuals experiencing these symptoms should contact a health care professional for treatment, although the CDC reports that antibiotic-resistant strains have emerged.

Those diagnosed with shigella should wait up to two weeks before having sex. Health experts also recommend using condoms for oral sex, applying dental dams for rimming, and washing hands after sexual contact.