Past and Present Status of Soil-transmitted Helminthiases in Thailand

Abstract

Abstract

Control measures for soil-transmitted helminthiases (STH) in Thailand commenced in 1917. With the assistance of the Rockefeller Foundation, hookworm infection control began in Chiang Mai Province, where 80.1% (25,540/31,893) of the population had hookworm eggs in their feces. In 1957, Vajrasthira and Harinasuta reported the prevalence of intestinal helminthic infections in Thailand to be 62.9%. In 1980-81, Pruksaraj et al found nationwide STH prevalence to be 87.0%, and in 1990 Dulyapiree found a similar rate of 87.4% in seven provinces in far southern Thailand. Jongsuksuntigul et al, in 1991, reported the STH prevalence in Thailand for hookworm, Ascaris, Trichuris, and Strongyloides as 27.7, 1.5, 4.3, and 0.2%, respectively. In 1998-2000, Muennoo et al found the STH infection rates in southern Thailand were higher in villages with clustered housing than with dispersed housing, and that the rates were highest in fishermen, followed by farmers, gardeners, and townspeople, respectively. Jongsuksuntigul et al assessed the effectiveness of helminthiasis control in 2001, the final year of the 8th Health Development Plan (1997-2001), and reported an overall hookworm prevalence of 11.4% for Thailand; areas with higher prevalence were regions 3, 4, 7, 8, 9, 11, and 12, with averages of 12.9, 11.0, 11.6, 10.3, 11.6, 19.7, and 21.1%, respectively, with mostly low-moderate infection intensities. Muennoo and Rojekittikhun, in 2003, noted overall STH prevalence and intensity in primary schoolchildren and villagers in Nakhon Si Thammarat Province, 1991-2001, and found prevalence rates of 87.0% (1991), 81.4% (1993), 81.0% (1994), 55.4% (1995), 76.1 and 91.6% (1998), 46.8% (1999), 58.3% (2000), and 48.3% (2001). These included A. lumbricoides (3.7-18.5%), T. trichura (28.5-66.9%), hookworm (18.0-80.0%), E. vermicularis (0.7%), and S. stercoralis (0.3-1.8%). In 2004, Muennoo et al reported the prevalence of intestinal helminth infections in Prachuap Khiri Khan, Chumphon, and Khon Kaen provinces to be 8.0, 9.9, and 10.5%, respectively; and Maipanich et al reported those in Nan, Kanchanaburi, and Sakaeo provinces to be 55.8, 49.4, and 49.5%, respectively.

Keywords: soil-transmitted helminthiases; control; prevalence; Thailand