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Family members of a 12-year-old Florida boy who was infected by a rare and deadly amoeba say the organism that was attacking his brain is gone.

According to a Facebook page the family set up to support Zachary Reyna, doctors told family members Wednesday morning that antibiotics defeated the infection, and tests showed negative activity from the amoeba.

“Thank you Jesus for giving us another day with Zac and another day of hope,” a Wednesday Facebook post said.

“This is a small victory but we know the battle is not over. Extensive damage was done to his brain and we need to pray for any form of activity to come from his brain.”

The southwest Florida boy was infected with Naegleria fowleri (nuh-GLEER-ee-uh FOWL-er-eye), a microscopic single-celled living amoeba that is commonly found in freshwater lakes, ponds and rivers.

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It can cause a rare brain infection called primary amebic meningoencephalitis (PAM) that destroys brain tissue and is usually fatal, the Florida Department of Health said in a news release last week. State officials confirmed Reyna was battling PAM.

Infections from the amoeba are rare. Florida officials cited federal statistics showing that 28 infections were reported in the U.S. from 2003 to 2012, mostly from exposure to contaminated recreational water. A person cannot be infected with the amoeba by drinking contaminated water, state officials said, and the amoeba is not found in salt water.

Victims typically are exposed to the bug while swimming or doing water sports in warm ponds, lakes, rivers and canals during the hot summer months, mostly in the South.

Family members said the boy was infected while knee boarding with friends in a ditch near his family’s LaBelle home on Aug. 3. He is being treated in the intensive care unit at Miami Children’s Hospital. Hospital officials weren’t commenting on Reyna’s condition Wednesday.

Experts say the amoeba gets up the nose and travels to the brain where it causes PAM, which destroys brain tissue. It’s a medical mystery why some people who swim in amoeba-containing water get the fatal nervous system condition while many others don’t.

Initial symptoms usually start within 1 to 7 days and may include headache, fever, nausea and vomiting. The disease progresses rapidly, and other symptoms can include stiff neck, confusion, loss of balance, seizures and hallucinations.

State officials said people can reduce the risks of becoming infected by limiting the amount of water going up the nose, avoiding water-related activities in warm freshwater when temperatures are high and water levels are low, and avoid digging in or stirring up sediment while in shallow, warm freshwater areas.