title: Epidemiology of malaria in the Papua New Guinean highlands.
abstract: OBJECTIVE
  To conduct an in-depth investigation of the epidemiology of malaria in the Papua New Guinea (PNG) highlands and provide a basis for evidence-based planning and monitoring of intensified malaria control activities.
  
  
  METHODS
  Between December 2000 and July 2005, 153 household-based, rapid malaria population surveys were conducted in 112 villages throughout the central PNG highlands. The presence of malaria infections was determined by light microscopy and risk factors assessed using a structured questionnaire.The combined dataset from all individually published surveys was reanalysed.
  
  
  RESULTS
  The prevalence of malaria infections in the different surveys ranged from 0.0% to 41.8%(median 4.3%) in non-epidemic surveys and 6.6% to 63.2% (median 21.2%, P < 0.001) during epidemics. Plasmodium falciparum was the predominant infection below 1400 m and during epidemics, Plasmodium vivax at altitudes >1600 m. Outside epidemics, prevalence decreased significantly with altitude, was reduced in people using bed nets [odds ratio (OR) = 0.8, P < 0.001] but increased in those sleeping in garden houses (OR = 1.34, P < 0.001) and travelling to highly endemic lowlands (OR = 1.80, P < 0.001). Below 1400 m, malaria was a significant source of febrile illness. At higher altitudes, malaria was only a significant source of febrile illness during epidemic outbreaks, but asymptomatic malaria infections were common in non-epidemic times.
  
  
  CONCLUSIONS
  Malaria is once again endemic throughout the PNG highlands in areas below 1400–1500 m of altitude with a significant risk of seasonal malaria outbreaks in most area between 1400–1650 m. Ongoing control efforts are likely to result in a substantial reduction in malaria transmission and may even result in local elimination of malaria in higher lying areas.
authors.forename: Inoni
authors.initials: I
authors.lastname: Betuela
authors.forename: Seri
authors.initials: S
authors.lastname: Maraga
authors.forename: Manuel W
authors.initials: MW
authors.lastname: Hetzel
authors.forename: Tony
authors.initials: T
authors.lastname: Tandrapah
authors.forename: Albert
authors.initials: A
authors.lastname: Sie
authors.forename: Simon
authors.initials: S
authors.lastname: Yala
authors.forename: Julius
authors.initials: J
authors.lastname: Kundi
authors.forename: Peter
authors.initials: P
authors.lastname: Siba
authors.forename: John C
authors.initials: JC
authors.lastname: Reeder
authors.forename: Ivo
authors.initials: I
authors.lastname: Mueller
mesh_terms: D004196:Disease Outbreaks; D019353:Endemic Diseases; D006306:Health Surveys; D006801:Humans; D008288:Malaria / Q000453:epidemiology* / Q000382:microbiology; D016778:Malaria, Falciparum / Q000453:epidemiology; D016017:Odds Ratio; D010219:Papua New Guinea / Q000453:epidemiology; D015995:Prevalence; D011795:Surveys and Questionnaires