Responses to albendazole treatment for hookworm infection in ethnic Thai and immigrant in west-central Thailand

Abstract

Ethnic Thai and immigrant schoolchildren and villagers of Bo-ong, a village in Pilok sub-district, Thong Pha Phum District, Kanchanaburi Province, western Thailand, were investigated for helminth infections in September 2003 and July 2004. Among the 143 schoolchildren, total cumulative hookworm prevalence in both surveys was 58.7%, with 47.6% for Thais and 63.4% for immigrants, while among the 183 villagers, it was 69.4% (Thais: 60.6%; immigrants: 75.0%). The efficacy of 400mg single-dose albendazole among different hookworm-infected racial/ethnic groups was analyzed 21 days' post-treatment. Kato-Katz and polyethylene tube cultivation methods were used for stool examination. Among the 211 hookworm-positive cases in both surveys, only 82 cases from the last survey were followed up. By Kato-Katz technique, for the schoolchildren and villagers combined, the cure rate tended to be higher among the immigrants (65.0%) than the Thais (54.6%) (p = 0.445). By Sasa's modified Harada-Mori culture technique, the cure rates also differed by racial grouping, and were higher (46.3%) among the immigrants and lower (27.8%) among the Thais (p = 0.269). However, similar egg reduction rates were found for the two racial groups, at 96.0 and 92.6%, respectively. In addition, a higher intensity of hookworm infection tolerated albendazole therapy, lower cure rates were obtained in moderate-to-heavy infections (56.3%) and higher rates for light infections (63.6%) among the total population. There were no significant differences in drug efficacy among the 2 ethnic groups of Thai and immigrants (p > 0.05) in Kanchanaburi Province, Thailand.