Lake or river waters can provide an enjoyable way to cool down under the hot Texas sun. But those same waters may contain many health hazards, including concentrations of a common ameba that can cause an extremely rare’but deadly’form of meningitis. Some easy-to-remember safety precautions, however, can help prevent potential health problems for people in lakes, rivers, streams or stock ponds. As temperatures rise and water levels drop, higher concentrations of the ameba that causes primary amebic meningoencephalitis’also known as PAM’develop, said Neil Pascoe, a Texas Department of Health (TDH) epidemiologist. “The infection is extremely rare. Only one to three cases are detected in Texas each year,” Pascoe said. For those infected, however, death usually occurs within a week. One case of PAM was reported in Texas last year, three in 2001.” The organisms that cause PAM exist in almost all untreated surface water and thrive in water that is stagnant or slow moving and when water temperature is above 80 degrees. Swimming pools that are properly cleaned, maintained and treated with chlorine are safe, as is salt water. The PAM infection occurs when water containing the organisms is forcefully inhaled into nasal passages’usually from diving, jumping or water skiing. The amoebae then make their way into the brain and spinal cord. Symptoms of PAM include severe headache, high fever, stiff neck, nausea, vomiting and coma. The infection is not spread from person to person. TDH offers these recommendations to reduce the likelihood of PAM or other water-borne infections: ‘ Never swim in stagnant or polluted water. Take “No Swimming” signs seriously. ‘ Hold your nose or use nose plugs when jumping or diving into water. ‘ Avoid swallowing water from rivers, lakes, streams or stock ponds. ‘ Use earplugs, swim goggles or masks if you tend to get ear or eye infections. ‘ Swim in properly maintained pools when possible. ‘ Keep wading pools clean and change the water daily. ‘ Wash open skin cuts and scrapes with clean water and soap. To help keep potential sources of infection out of recreational water, shower before swimming and take young children to the restroom frequently. Children who are not toilet trained should wear a swimsuit or rubber pants over diapers designed to prevent leaks. Check diapers frequently. More common dangers associated with activities around lakes and rivers include injuries from diving into water that hides rocks and debris, diving into shallow water, not using safety equipment and leaving children unattended.