title: Population hemoglobin mean and anemia prevalence in Papua New Guinea: new metrics for defining malaria endemicity?
abstract: BACKGROUND
  The hypothesis is that hemoglobin-based metrics are useful tools for estimating malaria endemicity and for monitoring malaria control strategies. The aim of this study is to compare population hemoglobin mean and anemia prevalence to established indicators of malaria endemicity, including parasite rates, rates of enlarged spleens in children, and records of (presumptive) malaria diagnosis among populations living with different levels of malaria transmission.
  
  
  RESULTS
  Convenience sample, multisite cross-sectional household surveys conducted in Papua New Guinea. Correlations (r(2)) between population Hb mean and anemia prevalence and altitude, parasite rate, and spleen rate were investigated in children ages 2 to 10 years, and in the general population; 21,664 individuals from 156 different communities were surveyed. Altitude ranged from 5 to 2120 meters. In young children, correlations between altitude and parasite rate, population Hb mean, anemia prevalence, and spleen rate were high (r(2): -0.77, 0.73, -0.81, and -0.68; p<0.001). In the general population, correlations between altitude and population Hb mean and anemia prevalence were 0.83 and 0.85, respectively. Among young children, parasite rate correlated highly with anemia prevalence, population Hb mean, and spleen rate (r(2): 0.81, -0.81, and 0.86; p<0.001). Population Hb mean (corrected for direct altitude effects) increased with altitude, from 10.5 g/dl at <500 m to 12.8 g/dl at >1500 m (p<0.001).
  
  
  CONCLUSIONS
  In PNG, where Plasmodium vivax accounts for an important part of all malaria infections, population hemoglobin mean and anemia prevalence correlate well with altitude, parasite, and spleen rates. Hb measurement is simple and affordable, and may be a useful new tool, alone or in association with other metrics, for estimating malaria endemicity and monitoring effectiveness of malaria control programs. Further prospective studies in areas with different malaria epidemiology and different factors contributing to the burden of anemia are warranted to investigate the usefulness of Hb metrics in monitoring malaria transmission intensity.
authors.affiliation: Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea. nicolas.senn@gmail.com
authors.forename: Nicolas
authors.initials: N
authors.lastname: Senn
authors.forename: Seri
authors.initials: S
authors.lastname: Maraga
authors.forename: Albert
authors.initials: A
authors.lastname: Sie
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Rogerson
authors.forename: John C
authors.initials: JC
authors.lastname: Reeder
authors.forename: Peter
authors.initials: P
authors.lastname: Siba
authors.forename: Ivo
authors.initials: I
authors.lastname: Mueller
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000740:Anemia / Q000097:blood / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D019353:Endemic Diseases / Q000517:prevention & control*; D005260:Female; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D007223:Infant; D008288:Malaria / Q000097:blood / Q000453:epidemiology* / Q000635:transmission; D016778:Malaria, Falciparum / Q000097:blood / Q000453:epidemiology / Q000635:transmission; D016780:Malaria, Vivax / Q000097:blood / Q000453:epidemiology / Q000635:transmission; D008297:Male; D008875:Middle Aged; D010219:Papua New Guinea / Q000453:epidemiology; D011159:Population Surveillance; D015995:Prevalence; D012044:Regression Analysis; D013163:Splenomegaly / Q000473:pathology; D018709:Statistics, Nonparametric; D055815:Young Adult
chemical_list: D006454:Hemoglobins