title: High prevalence of mefloquine-resistant falciparum malaria in eastern Thailand.
abstract: In order to assess the risk and predictors of mefloquine resistance we monitored a cohort of 113 patients in eastern Thailand who had been treated for uncomplicated falciparum malaria with a single dose of 15 mg/kg of the drug and followed up for 42 days. The overall treatment failure rate at day 42 was 59.1% (95% confidence interval (CI) = 50%, 68%) with only 2.7% of the patients being lost to follow-up. There were 6.4% RIII, 20.9% RII, 31.8% RI, and 40.9% sensitive responses, based on a modified WHO classification. A low haemoglobin level on the day of treatment and diarrhoea during the first two days after treatment were independent predictors of treatment failure. These findings remained statistically significant in a Cox proportional hazards model, after controlling for other baseline characteristics and adverse effects. Although a history of digestive disorders prior to treatment was associated with diarrhoea on day 2 (P = 0.024), it was in itself not a predictor of treatment failure (adjusted hazard ratio = 1.16; 95% CI = 0.35, 2.14). A total of 60 patients with an R response were hospitalized for 7 days to receive supervised treatment with quinine-tetracycline. Only three had a positive thick smear for asexual forms of Plasmodium falciparum 14 days later, and quinine-tetracycline therefore remains a good alternative treatment for mefloquine-resistant falciparum malaria.
authors.affiliation: Epidemiology Department, Harvard School of Public Health, Boston, MA 02115.
authors.forename: A L
authors.initials: AL
authors.lastname: Fontanet
authors.forename: D B
authors.initials: DB
authors.lastname: Johnston
authors.forename: A M
authors.initials: AM
authors.lastname: Walker
authors.forename: W
authors.initials: W
authors.lastname: Rooney
authors.forename: K
authors.initials: K
authors.lastname: Thimasarn
authors.forename: D
authors.initials: D
authors.lastname: Sturchler
authors.forename: M
authors.initials: M
authors.lastname: Macdonald
authors.forename: M
authors.initials: M
authors.lastname: Hours
authors.forename: D F
authors.initials: DF
authors.lastname: Wirth
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D016001:Confidence Intervals; D004351:Drug Resistance; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D016778:Malaria, Falciparum / Q000188:drug therapy / Q000453:epidemiology*; D008297:Male; D015767:Mefloquine / Q000494:pharmacology*; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000378:metabolism; D015995:Prevalence; D016016:Proportional Hazards Models; D013785:Thailand / Q000453:epidemiology; D017211:Treatment Failure
chemical_list: D015767:Mefloquine