title: Prevalence of malaria across Papua New Guinea after initial roll-out of insecticide-treated mosquito nets.
abstract: OBJECTIVE
  To assess the population prevalence of malaria in villages across Papua New Guinea (PNG) following the first roll-out of free long-lasting insecticidal nets (LLIN).
  
  
  METHODS
  Between October 2008 and August 2009, a household survey was conducted in 49 random villages in districts covered by the LLIN distribution campaign. The survey extended to 19 villages in sentinel sites that had not yet been covered by the campaign. In each village, 30 households were randomly sampled, household heads were interviewed and capillary blood samples were collected from all consenting household members for microscopic diagnosis of malaria.
  
  
  RESULTS
  Malaria prevalence ranged from 0% to 49.7% with a weighted average of 12.1% (95% CI 9.5, 15.3) in the national sample. More people were infected with Plasmodium falciparum (7.0%; 95% CI 5.4, 9.1) than with P. vivax (3.8%; 95% CI 2.4, 5.7) or P. malariae (0.3%; 95% CI 0.1, 0.6). Parasitaemia was strongly age-dependent with a P. falciparum peak at age 5-9 years and a P. vivax peak at age 1-4 years, yet with differences between geographical regions. Individual LLIN use and high community coverage were associated with reduced odds of infection (OR = 0.64 and 0.07, respectively; both P < 0.001). Splenomegaly in children and anaemia were common morbidities attributable to malaria.
  
  
  CONCLUSIONS
  Malaria prevalence across PNG is again at levels comparable to the 1970s. The strong association of LLIN use with reduced parasitaemia supports efforts to achieve and maintain high country-wide coverage. P. vivax infections will require special targeted approaches across PNG.
authors.affiliation: Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea.|Swiss Tropical and Public Health Institute, Basel, Switzerland.|University of Basel, Basel, Switzerland.
authors.forename: Manuel W
authors.initials: MW
authors.lastname: Hetzel
authors.affiliation: Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea.
authors.forename: Hector
authors.initials: H
authors.lastname: Morris
authors.affiliation: Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea.
authors.forename: Nandao
authors.initials: N
authors.lastname: Tarongka
authors.affiliation: Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea.|Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.|Department of Medical Biology, University of Melbourne, Parkville, Vic., Australia.
authors.forename: Céline
authors.initials: C
authors.lastname: Barnadas
authors.affiliation: Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea.|School of Public Health, The University of Queensland, Herston, Qld, Australia.
authors.forename: Justin
authors.initials: J
authors.lastname: Pulford
authors.affiliation: National Department of Health, Waigani, Papua New Guinea.
authors.forename: Leo
authors.initials: L
authors.lastname: Makita
authors.affiliation: Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Siba
authors.affiliation: Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.|Department of Medical Biology, University of Melbourne, Parkville, Vic., Australia.|Barcelona Centre for International Health Research, Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.
authors.forename: Ivo
authors.initials: I
authors.lastname: Mueller
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003695:Delivery of Health Care / Q000379:methods; D005191:Family Characteristics; D005260:Female; D006801:Humans; D007223:Infant; D057148:Insecticide-Treated Bednets / Q000706:statistics & numerical data; D007306:Insecticides; D008288:Malaria / Q000453:epidemiology / Q000469:parasitology / Q000517:prevention & control*; D008297:Male; D009032:Mosquito Control / Q000379:methods*; D010219:Papua New Guinea / Q000453:epidemiology; D018512:Parasitemia / Q000453:epidemiology / Q000469:parasitology / Q000517:prevention & control*; D010961:Plasmodium; D011247:Pregnancy; D015995:Prevalence; D011322:Primary Prevention / Q000379:methods*; D012111:Residence Characteristics; D055815:Young Adult
chemical_list: D007306:Insecticides
keywords: Insecticide-treated Bednets; Papua New Guinea; Surveys; falciparum malaria; vivax malaria