RESUMO
Naegleria fowleri is found in most geothermal baths of Guadeloupe and has been responsible for the death of a 9-year-old boy who swam in one of these baths in 2008. We wanted to determine the origin for the presence of this amoeba in the water. Water samples were taken at the origin of the geothermal sources and at the arrival in the baths. After filtration, cultures were made and the number of Naegleria present was determined using the most probable number method. Soil samples collected in the proximity of the baths were also tested for the presence of thermophilic amoebae. The species identification was obtained by PCR. During three consecutive months, no Naegleria could be found at the origin of any geothermal source tested. In contrast, N. fowleri was isolated at least once in all baths at the arrival of the water, except one. Thermophilic amoebae could be found in each soil sample, especially near the baths located at a lower altitude, but N. fowleri was only isolated near two baths, which were also the baths most often contaminated with this species. So it appears that the contamination of the water with N. fowleri occurs after emerging from the geothermal source when the water runs over the soil. Therefore, it should be possible to reduce the concentration of N. fowleri in the geothermal baths of Guadeloupe to for example less than 1 N. fowleri/10 L by installing a pipeline between the geothermal sources and the baths and by preventing flooding water from entering the baths after rainfall. By taking these measures, we were able to eliminate N. fowleri from a pool located inside a reeducation clinic.
Assuntos
Fontes Termais/parasitologia , Naegleria fowleri/isolamento & purificação , Recreação , Solo/parasitologia , Água/parasitologia , Altitude , Filtração , Guadalupe , Reação em Cadeia da Polimerase , Chuva , PiscinasRESUMO
In 2008 a fatal case of primary amoebic meningoencephalitis, due to the amoeboflagellate Naegleria fowleri, occurred in Guadeloupe, French West Indies, after a child swam in a bath fed with geothermal water. In order to improve the knowledge on free-living amoebae in this tropical part of France, we investigated on a monthly basis, the presence of Naegleria spp. in the recreational baths, and stream waters which feed them. A total of 73 water samples, 48 sediments and 54 swabs samples were collected from 6 sampling points between June 2011 and July 2012. The water samples were filtered and the filters transferred to non-nutrient agar plates seeded with a heat-killed suspension of Escherichia coli while sediment and swab samples were placed directly on these plates. The plates were incubated at 44°C for the selective isolation of thermophilic Naegleria. To identify the Naegleria isolates the internal transcribed spacers, including the 5.8S rDNA, were amplified by polymerase chain reaction and the sequence of the PCR products was determined. Thermophilic amoebae were present at nearly all collection sites. The pathogenic N. fowleri was the most frequently encountered thermophilic species followed by N. lovaniensis. The concentration of N. fowleri was rather low in most water samples, ranging from 0 to 22 per liter. Sequencing revealed that all N. fowleri isolates belonged to a common Euro-American genotype, the same as detected in the human case in Guadeloupe. These investigations need to be continued in order to counsel the health authorities about prevention measures, because these recreational thermal baths are used daily by local people and tourists.