Dondero, T JParsons, R EO'Holohan, D R2009-05-272009-05-271975-12-01Dondero TJ, Parsons RE, O'Holohan DR. Increased frequency of chloroquine resistant P. falciparum on a rubber estate in Peninsular Malaysia during two years of systematic chloroquine treatment. The Southeast Asian Journal of Tropical Medicine and Public Health. 1975 Dec; 6(4): 488-94http://imsear.searo.who.int/handle/123456789/34831The Southeast Asian Journal of Tropical Medicine and Public Health.Chloroquine pressure was applied over a 22 month period on a somewhat isolated, malarious rubber estate by examination of residents at 4-week intervals and treatment of parasitaemias with chloroquine. During this time the monthly attack rate for P. falciparum rose four-fold to an average of nearly 18% per month, while that of P. vivax remained relatively constant at about 8%. Eight in vivo chloroquine resistance studies, which allowed both detection of late recrudescing R-I resistance and estimation of the risk of reinfection, showed an apparent rise in the drug resistance rate, from 12% to 20% prior to the study to the range of 40-50%. Virtually all resistance encountered was R-I in nature. There was no convincing evidence of chloroquine resistance among 148 tested P. vivax infections.engBlood --parasitologyChloroquine --pharmacologyDrug Resistance, MicrobialHumansLongitudinal StudiesMalaria --drug therapyMalaysiaPlasmodium falciparum --drug effectsR FactorsRecurrenceJournal Article