©2018 Mahoning Valley Water Inc.  Naegleria fowleri A New Hazard to Recreational Swimmers      Naegleria fowleri is perhaps one of the most daunting waterborne pathogens known in the United States.  Although infections are still rare—with a 1 in 100 million chance of contracting the disease—the fatality rate is nearly 100 percent, with few treatment options available.  The parasitic protozoa is actually a free-living amoeba commonly present in soils and surface waters above 80 degrees Fahrenheit, in such diverse places as Europe, Australia, New Zealand, Thailand, Africa, India, Korea, Japan, Peru, Venezuela, Panama and the United States.      The amoeba infects by entering the nasal passages of swimmers, traveling up the cells of the nervous system to the brain, where it effectively destroys brain tissue, causing severe illness and usually death within about a week. Origin      Naegleria fowleri was first  recognized as a human pathogen in 1965, and since then more than 179 cases have been recorded, with 81 reported in the U.S. alone.  Infections usually occur in healthy, young people.  Because death is so rapid and almost certain, confirmation of the disease is usually established post-mortem, after an examination of brain tissue or cerebrospinal fluid.      The pathogen has been isolated from warm, fresh or brackish water including swimming pools, ponds, lakes, streams, hot springs, thermally polluted waters, dust, soil, and sewage.  N. fowleri can enter nasal passages when water is forced into the nose via diving or jumping but may also become motile into nasal cavities if the swimmer is submerged underwater.  Cases have also occurred in persons with no recent contact with water, suggesting an airborne route where dust particles may have been a carrier of the stable cyst form of the organism. Occurrence      Evidence of Naegleria presence has mounted over the years.  The organism has been isolated from hot water systems of hospitals, where 22 percent of the samples collected from six hospitals were positive.  A year round survey of aquatic environments in Tulsa, Okla., showed that N. fowleri could be isolated from 18 percent of the 2,016 processed water samples collected.  A study of 30 hot spring spas in Kanagawa, Japan, revealed that Naegleria could be isolated from 46.7 percent of samples taken.  Finally, in Egypt, Naegleria species were detected in 12 out of 16 swimming pool samples and 6 out of 10 surface water and canal samples.      During the period of 1995-1996 the Centers for Disease Control (CDC) and the U.S. Environmental Protection Agency (USEPA) reported 37 outbreaks from 17 states that were attributed to recreational water exposure.  Of these, 22 were outbreaks of gastroenteritis, nine were of dermatitis and six were of Primary Amoebic Meningitis (PAM), caused by N. fowleri, all six of which were fatal. Morbidity and Mortality      Infections with N. fowleri usually result in PAM, a deadly disease of the brain with symptoms usually occurring between 3 to 7 days after infection and include: Swelling and fluid buildup in the brain Nose bleeds Swollen lymph nodes Rapid, shallow breathing Light sensitivity, drooping eyelids Severe headache and nausea Loss of appetite, smell and taste Vomiting Sore throat, stiff neck and back, cramping, weakness Confusion, seizures, coma, and death      If detected early enough, treatment with antibiotics and anti-fungal medications may prevent the spread of the disease; however, many of the symptoms listed are the result of damage that has already occurred in the brain.  At least four persons have been treated successfully following infection.      According to the CDC, there is an average of 1 to 3 infections in the U.S. each year.  In 1995, the six fatal cases of PAM attributed to N. fowleri were all acquired during July and August involving children ranging in ages from 4 to 11 years.  Infection was from a shallow lake, pond, canal or river.  Five of the six cases occurred in Texas and one in Florida.      Many countries have low autopsy rates and thus some researchers believe that the incidence of N. fowleri and other pathogenic amoeba may be under-diagnosed worldwide.  In one U.S. instance, an 11 year old boy died of what was diagnosed as bacterial meningitis.  Following donations of several of his organs, it was later discovered the actual cause of death was PAM caused by N. fowleri. Avoidance       N. fowleri is found worldwide and is commonly present in soils and surface waters.  These free living amoebae are the main predators of bacterial populations and play a major role in the ecological balance of many environmental systems.  Humans are frequently exposed to the amoebic organism but few infections occur.  In most cases it seems a specific set of criteria must be present before infections occur.  Primarily, the organism must not only be present, but it must be present in very high numbers.  In addition, the organism must be introduced to the nasal passages.      Some of the recommendations to avoid infection are:  do not swim in stagnant waters; do not submerge totally underwater at hot spring recreational sites; use nose plugs or hold your nose closed when jumping into potentially contaminated water sources; and remove the water from nasal passages after swimming by blowing your nose.  It is imperative to maintain proper disinfectant residual levels in public and private pools and spas. Swimming pools should maintain a chlorine residual of at least 1 to 2 parts per million. MAHONING VALLEY WATER