title: Malaria vaccine study site in Irian Jaya, Indonesia: Plasmodium falciparum incidence measurements and epidemiologic considerations in sample size estimation.
abstract: Malaria epidemiologic and entomologic studies were performed during both the high transmission and low transmission seasons to characterize the Plasmodium falciparum malaria transmission at a proposed malaria vaccine trial site in Irian Jaya, Indonesia. The study population consisted of two subsets: native Irianese men with lifelong exposure to malaria and transmigrants who arrived from a nonmalarious area 2.5 years before the start of the study. All subjects received a radical cure for malaria and were then monitored weekly by blood film. Both P. falciparum malaria attack rates and incidence densities were calculated; transmigrants had a significantly higher rate (P = 0.003) than the Irianese during the low transmission season study (20-weeks long) but not during the high transmission season study (12-weeks long). Lack of exposure-induced immunity left the transmigrants at a minimum 17-25% greater relative risk of becoming parasitemic compared with the Irianese during the low transmission season study. During the high transmission season study, 50% of the transmigrants were P. falciparum positive by week 6 and 50% of the Irianese by week 9. During the low transmission season, 50% of the transmigrants were positive by week 10 and 43% of the Irianese were positive by week 17. Entomologic studies showed that Anopheles koliensis was the predominant vector (> 98% of anopheline catch). Entomologic inoculation rates for P. falciparum were 0.018 and 0.39 infective bites/person/night for the low and high transmission seasons, respectively. New P. vivax cases represented between 16% and 42% of all initial malaria cases.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Malaria Program, Naval Medical Research Institute, Bethesda, Maryland.
authors.forename: T R
authors.initials: TR
authors.lastname: Jones
authors.forename: J K
authors.initials: JK
authors.lastname: Baird
authors.forename: M J
authors.initials: MJ
authors.lastname: Bangs
authors.forename: B A
authors.initials: BA
authors.lastname: Annis
authors.lastname: Purnomo
authors.forename: H
authors.initials: H
authors.lastname: Basri
authors.forename: S
authors.initials: S
authors.lastname: Gunawan
authors.forename: S
authors.initials: S
authors.lastname: Harjosuwarno
authors.forename: P D
authors.initials: PD
authors.lastname: McElroy
authors.forename: S L
authors.initials: SL
authors.lastname: Hoffman
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D000852:Anopheles / Q000469:parasitology; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007214:Indonesia / Q000453:epidemiology; D007303:Insect Vectors / Q000469:parasitology; D016778:Malaria, Falciparum / Q000188:drug therapy / Q000453:epidemiology* / Q000208:ethnology / Q000517:prevention & control; D016780:Malaria, Vivax / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010963:Plasmodium falciparum / Q000276:immunology / Q000302:isolation & purification*; D010966:Plasmodium vivax / Q000302:isolation & purification; D016052:Protozoan Vaccines; D012621:Seasons; D014171:Transients and Migrants
chemical_list: D016052:Protozoan Vaccines