The Hawaii Department of Health today issued a high bacteria count advisory for Pokai Bay on Oahu.

DOH’s Clean Water Branch detected enterococci levels of 222 per 100 milliliters at Pokai Bay during routine beach monitoring, the department said.

“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,” said the branch. “Swimming at beaches with pollution in the water may make you ill.”

Children, the elderly, and people with weakened immune systems are most likely to develop illnesses or infections after coming into contact with polluted water, usually while swimming, the advisory said.

But while swimming-related illnesses can be unpleasant, they are usually not very serious and require little or no treatment or get better quickly upon treatment, and have no long-term health effects.

The advisory will remain in effect until water sample results no longer exceed the threshold level of 130 enterococci per 100 milliliters.

Brown water advisories are also in effect for Yokohama Bay and Kailua Beach Park on Oahu, and for Maui’s North Shore from Waihee to Hookipa Beach Park.