Helminthic Infections in a Tsunami-Affected Area: Soil Contamination and Infection Rates in the Population

Abstract

Abstract

In February 2005, soil samples from non-tsunami and tsunami-affected areas in Phang-nga Province were examined for helminth objects. The result showed a higher detection r ate in the affected area (15.5%) than the non-affected area (6.7%). In Ban Nam Khem, a mangrove swamp near the s helter of some fishermen who refused to move to the Rescue Centers after the tsunami disaster was highly contaminated with human feces. The detection rate of Ascaris lumbricoides and Trichuris trichiura eggs in s oil was 41.2%. When we repeated the examinations in January and May 2006, the rates had increased to 100 and 60.0%, respectively. The s tools of schoolchildren and inhabitants in the highrisk area were examined by Katz’s modified thick smear technique. The prevalence of soil-transmitted helminths in the population was 34.9%. This was lower than the previous study in Marc h 2004, before the tsunami, when the prevalence was 42.2%; however, there was no statistically significant difference between the two observations. Since it is difficult to change the habit of defecating outside latrines, all infected persons, including inhabitants with a habit of indiscriminate fecal disposal, and all schoolchildren, were treated to eradicate the source of helminthic infection. Health education was given to the community.

The study showed that the tsunami had a minimal effect on the helminthic infection rate in the population. It had a great effect on the environment, since it cleaned up soil polluted with human excreta. However, infected persons passed feces into the environment, and the accumulation of helminth eggs began again.

Keywords : Tsunami disaster, helminth eggs, soil contamination, infection rate, Thailand