Deadly brain-eating disease worries local medics
Published:Sunday | August 21, 2011 | 12:00 AM
The free-living amoebae (FLA) belongs to Acanthamoeba and Sappinia genera as well as Balamuthia mandrillaris and Naegleria fowleri species, occurring worldwide and can potentially cause infections in humans and other animals.
All four amoebae cause infections of the central nervous system (CNS) that are normally lethal. The lethal amoebae enters the body through the nose, where it feeds on the brain until the person dies.
Professor John Lindo, a parasitologist at the University Hospital of the West Indies, points out that since the discovery of the disease in Australia in the 1960s, it has been reported in 15 other countries in Africa, Asia, Europe and North and South America and the number of cases worldwide has been increasing.
For the last eight years, the University of the West Indies (UWI) has been leading studies, in conjunction with the University of LaLaguna (ULL) in Spain on the Acanthamoeba genus. Acanthamoeba Granulomatous Encephalitis is a chronic, pro-gressive infection of the CNS that may also involve the lungs.
The scientists leading the research are Dr Jacob Lorenzo Morlaes (Institute of Tropical Medicine, ULL) and Professor Lindo. During this period, Acanthamoeba strains with pathogenic potential to humans and other animals have been isolated from water sources from all over Jamaica.
In a study published in the Annals of Tropical Medicine and Parasitology, the research group reported that from the collected samples, strains with pathogenic potential were shown as 60 per cent in tap water, 68.4 per cent in river water, and 40.4 per cent of the sea-water samples.
Australia was the only country where Naegleria fowleri had been associated with public water supplies.
Last week, there were three reported deaths associated with the brain-eating amoebae disease in the southern United States by the Centers for Disease Control. Some 124 cases have been reported in the US since 1978.
According to Professor Lindo, the disease infects persons during swimming in warm, contaminated freshwater, mostly ponds, falls, rivers, lakes and swimming pools. Most victims have been children or young adults.
For the so-called 'brain-eating amoeba', Naegleria fowleri, symptoms begin one to 14 days after exposure to the disease. "There may be changes in taste and smell, headache, fever, nausea, vomiting, and stiff neck as seen in other types of meningitis. After this, the person becomes confused, hallucinates and may have seizures. The disease progresses rapidly over three to seven days, with death occurring from seven to 14 days after exposure," Professor Lindo explained.
The organisms occur in several sources in many countries and scientists are now working to understand their real threat to public health.
According to Professor Lindo, in Jamaica, this situation is no different as scientists work to understand where the organisms are present and what potential they have to cause severe disease.
"This potential is based upon the genetic make-up of the organisms and the potential for it to become invasive. Current research is focused on these two issues and we will be in a better position to estimate the impact on public health once this research is completed."
prevention methods
He said classical prevention methods include strict adherence to contact lens hygiene and avoidance of contaminated lakes and ponds. Research, he said, was needed in Jamaica to estimate the risk from different environmental sources.
He admitted that research was lagging in the Caribbean; however, cases have been reported from Guadeloupe.
These are some of the burning issues that will be discussed at the UWI-organised, XIV International Meeting on the Biology and Pathogenicity of Free Living Amoebae at the Iberostar in Montego Bay from October 10-14.
At this meeting, world-leading scientists and clinicians will gather to discuss recent advances in diagnosis, treatment, pathogenicity and basic biology of free living amoebae. To date, delegates from the following countries have registered to attend, including Argentina, Austria, Chile, Czech Republic, Denmark, Germany, Iran, Ireland, Italy, Korean Republic, Mexico, Peru, Spain, Sweden, Taiwan, Thailand, United Kingdom and the United States.
The major objective is the sharing of advances in free-living amoebae research in the various areas.