title: Prospects for malaria eradication in sub-Saharan Africa.
abstract: BACKGROUND
  A characteristic of Plasmodium falciparum infections is the gradual acquisition of clinical immunity resulting from repeated exposures to the parasite. While the molecular basis of protection against clinical malaria remains unresolved, its effects on epidemiological patterns are well recognized. Accumulating epidemiological data constitute a valuable resource that must be intensively explored and interpreted as to effectively inform control planning.
  
  
  RESULTS
  Here we apply a mathematical model to clinical data from eight endemic regions in sub-Saharan Africa. The model provides a quantitative framework within which differences in age distribution of clinical disease are assessed in terms of the parameters underlying transmission. The shorter infectious periods estimated for clinical infections induce a regime of bistability of endemic and malaria-free states in regions of mesoendemic transmission. The two epidemiological states are separated by a threshold that provides a convenient measure for intervention design. Scenarios of eradication and resurgence are simulated.
  
  
  CONCLUSIONS
  In regions that support mesoendemic transmission, intervention success depends critically on reducing prevalence below a threshold which separates endemic and malaria-free regimes.
authors.affiliation: Instituto Gulbenkian de Ciência, Oeiras, Portugal.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Aguas
authors.forename: Lisa J
authors.initials: LJ
authors.lastname: White
authors.forename: Robert W
authors.initials: RW
authors.lastname: Snow
authors.forename: M Gabriela M
authors.initials: MG
authors.lastname: Gomes
mesh_terms: D017954:Africa South of the Sahara / Q000453:epidemiology; D000818:Animals; D009033:Culicidae; D006801:Humans; D007303:Insect Vectors; D016778:Malaria, Falciparum / Q000453:epidemiology / Q000517:prevention & control* / Q000635:transmission