title: Lymphatic filariasis in Papua New Guinea: distribution at district level and impact of mass drug administration, 1980 to 2011.
abstract: BACKGROUND
  Lymphatic filariasis (LF) caused by Wuchereria bancrofti is present at high prevalence in some parts of Papua New Guinea. However, there has been no rigorous data-based representative assessment of nationwide prevalence of LF. The LF programme has been daunted by the scope of the problem, and progress on mass drug administration (MDA) has been slow and lacking in resources.
  
  
  METHODS
  A systematic literature review identified LF surveys in Papua New Guinea between 1980 and 2011. Results were extracted by location, time period and test used (blood slide, immunochromatographic test (ICT) or Og4C3 ELISA) and combined by district. Three criteria schemes based on the Global Programme to Eliminate Lymphatic Filariasis guidelines, with modifications, were developed to classify and prioritize districts by prevalence level. Results of repeated surveys in the same sites were used to investigate the impact of MDA on LF prevalence over the time period.
  
  
  RESULTS
  There were 312 distinct survey sites identified in 80 of the 89 districts over the 31-year period. The overall LF prevalence in the sites tested was estimated at 18.5 to 27.5% by blood slide for microfilariae (Mf), 10.1% to 12.9% by ICT and 45.4% to 48.8% by Og4C3. Biases in site selection towards areas with LF, and change in type of assay used, affected the prevalence estimates, but overall decline in prevalence over the time period was observed. Depending on the criteria used, 34 to 36 districts (population 2.7 to 2.9 million) were classed as high endemic (≥5% prevalence), 15 to 25 districts (1.7 to 1.9 million) as low endemic (<5%) and 20 to 31 (1.3 to 2.2 million) as non-endemic. Nine districts (0.7 million) had no information. The strong impact of MDA, especially on microfilaria (Mf) prevalence, was noted in sites with repeat surveys.
  
  
  CONCLUSIONS
  This analytical review of past surveys of LF in Papua New Guinea enables better estimation of the national burden, identifies gaps in knowledge, quantifies and locates the population at risk, and can be used to predict the likely impact of MDA and/or vector control. Better targeting of districts by level of prevalence will strengthen the control programme, facilitate monitoring of the disease trend and increase the likelihood of reaching the target of LF elimination by 2020.
authors: Department of Public Health, Tropical Medicine and Rehabilitation Sciences, James Cook University, Cairns and Townsville, Queensland, Australia. patricia.graves@jcu.edu.au
authors: Patricia M
authors: PM
authors: Graves
authors: Leo
authors: L
authors: Makita
authors: Melinda
authors: M
authors: Susapu
authors: Molly A
authors: MA
authors: Brady
authors: Wayne
authors: W
authors: Melrose
authors: Corinne
authors: C
authors: Capuano
authors: Zaixing
authors: Z
authors: Zhang
authors: Luo
authors: L
authors: Dapeng
authors: Masayo
authors: M
authors: Ozaki
authors: David
authors: D
authors: Reeve
authors: Kazuyo
authors: K
authors: Ichimori
authors: Walter M
authors: WM
authors: Kazadi
authors: Frederick
authors: F
authors: Michna
authors: Moses J
authors: MJ
authors: Bockarie
authors: Louise A
authors: LA
authors: Kelly-Hope
mesh_terms: D000818:Animals; D003140:Communicable Disease Control / Q000639:trends; D003625:Data Collection; D004605:Elephantiasis, Filarial / Q000175:diagnosis / Q000453:epidemiology / Q000517:prevention & control*; D019353:Endemic Diseases / Q000517:prevention & control; D005369:Filaricides / Q000008:administration & dosage*; D006801:Humans; D010219:Papua New Guinea / Q000453:epidemiology; D015995:Prevalence; D016896:Treatment Outcome; D014958:Wuchereria bancrofti / Q000187:drug effects* / Q000276:immunology / Q000302:isolation & purification
chemical_list: D005369:Filaricides