High levels of enterococci, a bacteria commonly found when fecal pathogens are present, have been found at Public Bath Beach in Waikiki and Haena Beach on Kauai, the Hawaii Department of Health’s Clean Water Branch said Wednesday.

Levels of 384 enterococci per 100 milliliters of water were detected at Public Beach and 164 enterococci per 100 milliliters at Haena Beach during routine beach monitoring. These levels exceeded the threshold of 130 bacteria per 100 milliliters, triggering public advisories not to swim at affected beaches until the advisories are lifted.

“The advisory for this beach is posted because testing for enterococci indicate that potentially harmful microorganisms such as bacteria, viruses, protozoa, or parasites may be present in the water,” DOH announced. “Swimming at beaches with pollution in the water may make you ill.”

The most common illness associated with exposure to fecal pathogens in beach water is gastroenteritis, the advisory said. Symptoms include nausea, vomiting, stomachache, diarrhea, headache or fever. Swimmers in polluted water also are at risk of ear, eye, nose and throat infections.

The department warned that children, the elderly and people with weakened immune systems are most at risk.

Public Bath Beach, whose offshore break is popular with surfers, is situated between the Waikiki Natatorium and Queen’s Beach, which stretches to the Kapahulu Groin.

Both beaches have been posted with warning signs, DOH said, and the advisories will remain in effect and the water tested daily until results no longer exceed the threshold.

For more information, and to sign up to receive email alerts about bacterial and brown water advisories and sewage spills, go to bit.ly/2Gjbf2q.