title: Population screening for glucose-6-phosphate dehydrogenase deficiencies in Isabel Province, Solomon Islands, using a modified enzyme assay on filter paper dried bloodspots.
abstract: BACKGROUND
  Glucose-6-phosphate dehydrogenase deficiency poses a significant impediment to primaquine use for the elimination of liver stage infection with Plasmodium vivax and for gametocyte clearance, because of the risk of life-threatening haemolytic anaemia that can occur in G6PD deficient patients. Although a range of methods for screening G6PD deficiency have been described, almost all require skilled personnel, expensive laboratory equipment, freshly collected blood, and are time consuming; factors that render them unsuitable for mass-screening purposes.
  
  
  METHODS
  A published WST8/1-methoxy PMS method was adapted to assay G6PD activity in a 96-well format using dried blood spots, and used it to undertake population screening within a malaria survey undertaken in Isabel Province, Solomon Islands. The assay results were compared to a biochemical test and a recently marketed rapid diagnostic test.
  
  
  RESULTS
  Comparative testing with biochemical and rapid diagnostic test indicated that results obtained by filter paper assay were accurate providing that blood spots were assayed within 5 days when stored at ambient temperature and 10 days when stored at 4 degrees. Screening of 8541 people from 41 villages in Isabel Province, Solomon Islands revealed the prevalence of G6PD deficiency as defined by enzyme activity < 30% of normal control was 20.3% and a prevalence of severe deficiency that would predispose to primaquine-induced hemolysis (WHO Class I-II) of 6.9%.
  
  
  CONCLUSIONS
  The assay enabled simple and quick semi-quantitative population screening in a malaria-endemic region. The study indicated a high prevalence of G6PD deficiency in Isabel Province and highlights the critical need to consider G6PD deficiency in the context of P. vivax malaria elimination strategies in Solomon Islands, particularly in light of the potential role of primaquine mass drug administration.
authors.affiliation: Queensland Institute of Medical Research, Herston, QLD 4006, Australia.
authors.forename: Melissa
authors.initials: M
authors.lastname: Kuwahata
authors.forename: Rushika
authors.initials: R
authors.lastname: Wijesinghe
authors.forename: Mei-Fong
authors.initials: MF
authors.lastname: Ho
authors.forename: Anita
authors.initials: A
authors.lastname: Pelecanos
authors.forename: Albino
authors.initials: A
authors.lastname: Bobogare
authors.forename: Losi
authors.initials: L
authors.lastname: Landry
authors.forename: Hugo
authors.initials: H
authors.lastname: Bugora
authors.forename: Andrew
authors.initials: A
authors.lastname: Vallely
authors.forename: James
authors.initials: J
authors.lastname: McCarthy
mesh_terms: D001793:Blood Preservation; D001800:Blood Specimen Collection; D057075:Enzyme Assays / Q000379:methods*; D005260:Female; D005952:Glucose-6-Phosphatase / Q000235:genetics; D005955:Glucosephosphate Dehydrogenase Deficiency / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology*; D006801:Humans; D008288:Malaria / Q000097:blood / Q000201:enzymology; D008297:Male; D008403:Mass Screening; D008542:Melanesia / Q000453:epidemiology; D015995:Prevalence; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results; D017678:Sex Distribution; D013696:Temperature
chemical_list: D011933:Reagent Kits, Diagnostic; D005952:Glucose-6-Phosphatase