title: Malaria morbidity in high and seasonal malaria transmission area of Burkina Faso.
abstract: BACKGROUND
  Malariometric parameters are often primary endpoints of efficacy trials of malaria vaccine candidates. This study aims to describe the epidemiology of malaria prior to the conduct of a series of drug and vaccine trials in a rural area of Burkina Faso.
  
  
  METHODS
  Malaria incidence was prospectively evaluated over one year follow-up among two cohorts of children aged 0-5 years living in the Saponé health district. The parents of 1089 children comprising a passive case detection cohort were encouraged to seek care from the local health clinic at any time their child felt sick. Among this cohort, 555 children were randomly selected for inclusion in an active surveillance sub-cohort evaluated for clinical malaria during twice weekly home visits. Malaria prevalence was evaluated by cross-sectional survey during the low and high transmission seasons.
  
  
  RESULTS
  Number of episodes per child ranged from 0 to 6 per year. Cumulative incidence was 67.4% in the passive and 86.2% in the active cohort and was highest among children 0-1 years. Clinical malaria prevalence was 9.8% in the low and 13.0% in the high season (p>0.05). Median days to first malaria episode ranged from 187 (95% CI 180-193) among children 0-1 years to 228 (95% CI 212, 242) among children 4-5 years. The alternative parasite thresholds for the malaria case definition that achieved optimal sensitivity and specificity (70-80%) were 3150 parasites/µl in the high and 1350 parasites/µl in the low season.
  
  
  CONCLUSIONS
  Clinical malaria burden was highest among the youngest age group children, who may represent the most appropriate target population for malaria vaccine candidate development. The pyrogenic threshold of parasitaemia varied markedly by season, suggesting a value for alternative parasitaemia levels in the malaria case defintion. Regional epidemiology of malaria described, Sapone area field centers are positioned for future conduct of malaria vaccine trials.
authors: Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso.
authors: Alphonse
authors: A
authors: Ouédraogo
authors: Alfred B
authors: AB
authors: Tiono
authors: Amidou
authors: A
authors: Diarra
authors: Souleymane
authors: S
authors: Sanon
authors: Jean Baptiste
authors: JB
authors: Yaro
authors: Esperance
authors: E
authors: Ouedraogo
authors: Edith C
authors: EC
authors: Bougouma
authors: Issiaka
authors: I
authors: Soulama
authors: Adama
authors: A
authors: Gansané
authors: Amathe
authors: A
authors: Ouedraogo
authors: Amadou T
authors: AT
authors: Konate
authors: Issa
authors: I
authors: Nebie
authors: Nora L
authors: NL
authors: Watson
authors: Megan
authors: M
authors: Sanza
authors: Tina J T
authors: TJ
authors: Dube
authors: Sodiomon Bienvenu
authors: SB
authors: Sirima
mesh_terms: D002050:Burkina Faso / Q000453:epidemiology; D002675:Child, Preschool; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D019353:Endemic Diseases; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008288:Malaria / Q000453:epidemiology* / Q000469:parasitology / Q000635:transmission; D016778:Malaria, Falciparum / Q000453:epidemiology; D008297:Male; D009017:Morbidity; D059208:Parasite Load; D018512:Parasitemia / Q000453:epidemiology / Q000469:parasitology; D015995:Prevalence; D011446:Prospective Studies; D012621:Seasons