Monday, 15 August 2011 20:27
A 16 year old Florida girl has died after a rare parasite infected her brain during a swim in a river near her home.
Health officials have not determined a cause of death, but they suspect that Nash may have caught the parasite that causes the infection, amoebic encephalitis, during her swim. The dangerous and rare parasite is commonly found in stagnant freshwater during hot weather, as well as poorly tended pools or hot tubs. The parasite enters the victim through the nose and then attacks the brain and spinal cord.
There are typically fewer than five cases a year in the entire country, and only one person has survived the infection since the 1970s.
Barry Inman, an epidemiologist with the Brevard County Health Department said:
"We got a result from the hospital in Orlando and they did a spinal tap on her, and they looked on the cerebral spinal fluid and they saw the amoeba. We have like one or two maybe a year. Sometimes we go a few years without having any cases in the United States."
Doctors think that the girl, Courtney Nash, contracted amoebic meningoencephalitis, a deadly infection caused by an amoeba that lurks in warm river and pond waters.
This disease occurs more often during the warmer months of the year and in warmer climates. Patients with it may have a history of swimming, diving, bathing, or playing in warm, generally stagnant, freshwater during the previous few days to two weeks.
Most often, the symptoms of are indistinguishable from acute bacterial meningitis, and acute onset occurs over hours to 1-2 days.
Symptoms include high fever, headache, photophobia, stiff neck, nausea, and vomiting, while additional symptoms include confusion, somnolence, seizures, and coma.
Amoebas have a single cell that appears to be not much more than cytoplasm held together by a flexible cell wall. Floating in this cytoplasm all kinds of cell bodies can be found. The most obvious is the nucleus. Some species have only one nucleus; others may have hundreds of nuclei.
Apart from the nucleus, the cell may contain water expelling vesicles and all kinds of inclusions (digested food). Many species of amoeba also bear small crystals.
PAM and GAE are both extremely rare but continue to be reported. Primary amebic meningoencephalitis (PAM) is more common in warmer regions and in the warmer months of spring and summer. From 1937-2007, 121 cases (0-8 per year) were reported. Approximately 60 cases of Balamuthia GAE have been reported since 1975. Those caused by Sappinia are even more rare.
More than 440 cases have been reported; although rare, cases of PAM and granulomatous amebic encephalitis (GAE) have been reported worldwide, reflecting the ubiquity of the organisms. More than 125 cases of Balmuthia GAE have been reported since 1975. Most reports come from the United States, Australia, and Europe; this frequency is likely because of identification and reporting bias. In addition, a predominance of cases occurs in warmer climes and during warmer seasons of the year.
These infections are nearly uniformly fatal. Only 5 survivors of PAM have been reported; this represents approximately 3% of reported cases. The high mortality rate is likely because of the difficulty of diagnosis and poor-to-marginal response to therapy. In most individuals with PAM or GAE, diagnosis is made after their deaths.
Written by Sy Kraft