LAKE JACKSON, Texas (AP) — Texas officials have warned residents of some communities near Houston to stop using tap water because it may be tainted with a brain-eating microbe.

The Texas Commission on Environmental Quality warned the Brazosport Water Authority late Friday of the potential contamination of its water supply by naegleria fowleri.

The commission issued an advisory warning people not to use tap water for any reason except to flush toilets in Lake Jackson, Freeport, Angleton, Brazoria, Richwood, Oyster Creek, Clute and Rosenberg, as well as for Dow Chemical-Freeport and the Clemens and Wayne Scott state prison units.

It said the advisory will remain in place until the Brazosport authority's water system has been thoroughly flushed and tests on water samples show the system's water is again safe to use. It said in a statement that it was unclear how long it would be before the tap water was again safe.

The Brazosport Water Authority’s water source is the Brazos River.

Naegleria fowleri is a free-living microscopic amoeba, or single-celled living organism commonly found in warm freshwater and soil, according to the U.S Centers for Disease Control and Prevention. It usually infects people when contaminated water enters the body through the nose, from where it travels to the brain and can cause a rare and debilitating disease called primary amebic meningoencephalitis.

The infection is usually fatal and typically occurs when people go swimming or diving in warm freshwater places such as lakes and rivers. In very rare instances, naegleria infections may also occur when contaminated water from other sources (such as inadequately chlorinated swimming pool water or heated and contaminated tap water) enters the nose.

Copyright 2020 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed without permission.