Comparison of mefloquine, chloroquine plus pyrimethamine-sulfadoxine (Fansidar), and chloroquine as malarial prophylaxis in eastern Thailand.

From July 1983 to March 1984 a randomized double blind prophylactic trial in Thai gem miners working across the border in Cambodia was conducted to determine the prophylactic efficacy of 3 drug regimens against P. falciparum and P. vivax malaria along the Thai-Cambodian border. Gem miners have a high incidence of malaria. Maximum duration of individual participation was 14 weeks. Of 334 participants in this study who were seen every 2 weeks, 145 received mefloquine 500 mg fortnightly, 112 received chloroquine 300 mg base weekly plus Fansidar (1000 mg sulfadoxine and 50 mg pyrimethamine) fortnightly and 77 received chloroquine as 300 mg base weekly. The significant reduction of vivax malaria in study subjects (compared to background incidence) implied good compliance with self administration of chloroquine in the intervening weeks between scheduled appointments. The attack rate in each prophylactic regimen was 2188 cases/1000/year with mefloquine, 8338 cases/1000/year with chloroquine-Fansidar and 10,207 cases/1000/year receiving chloroquine alone. There was a 79% prophylactic efficacy for mefloquine and 18% efficacy for the chloroquine plus Fansidar regimen compared to chloroquine. Using life table analysis, 56% of the mefloquine group, 6% of the chloroquine-Fansidar group and 4% of the chloroquine group were malaria free at the end of the 14 weeks study. The chloroquine plus sulfadoxine-pyrimethamine regimen prescribed for prophylaxis is no longer effective for multidrug resistant strains of P. falciparum in the study area. This study also seriously questions the efficacy of mefloquine prophylaxis.

Incidence of daily drug use as reported by a population of Thai partners working near United States military installations: a preliminary study.

A survey of 497 women, all of whom solicited partners from among American soldiers, indicated that 15% of this Thai population uses drugs and/or alcohol daily. Since behavioral observation made during this interview, as well as inconsistencies in responses on the survey, strongly suggested a reluctance to report drug use, it is judged that reported drug use represents an underestimate of true daily usage rate. The influence of transactions between these Thai women and their American associates upon drug use in each group was assessed from the perspective of the Thai informants. There appears to neither a great deal of drug use by Americans induced by interpersonal relationships with these Thai women, nor a great deal of Thai drug use which can be directly attributed to the influence of American soldiers. Alternate methods of data collection are suggested to substantiate this finding. An in-depth study of the relations established between these respondents and their American partners is planned to better interpret these results.