1Department of Anthropology, University of Florida, 2Genetics Institute, University of Florida, 3Emerging Pathogens Institute, University of Florida, 4Department of Environmental and Global Health, University of Florida, 5Hospital Saint Croix, Leogane, Haiti
Thursday Evening, Park Concourse
Sickle cell disease and trait are common erythrocyte disorders that are caused by a mutation in the hemoglobin beta gene. Sickle cell trait (i.e. heterozygous for the sickle cell allele) is selectively advantageous against severe malaria. Haiti is a malaria-endemic country, yet little is known about the prevalence of sickle cell disease and trait in this country. The purpose of our study was to detect the presence of sickle cell disease and trait in Haiti, as part of a larger epidemiological study on malaria in Haiti. Sixty individuals at Hospital St. Croix were first screened for sickle hemoglobin using a solubility-based rapid diagnostic test (RDT), SickleHeme (Michlone Associates, INC). RDT solution turbidity, as an indicator of sickle hemoglobin, was assessed visually and with spectrophotometry. Samples were also genotyped for sickle cell mutations. Of the 62 individuals screened for hemoglobin S using the RDT kit, 11 (17.6%) were positive. Of the 11 RDT positive samples, only six actually carried the sickle cell mutation, and as a heterozygote only. All other samples carried the wildtype genotype. Additionally, we observed “clumping” behavior in some RDT assays after sitting for 8 hours, but only in sickle hemoglobin samples that were confirmed by genotyping. We conclude that that genotyping is the most accurate method to estimate sickle hemoglobin. However, genotyping is expensive and requires specialized equipment. Thus, the “clumping” observation in the RDT assays may be the best option for detecting sickle hemoglobin in Haiti and similar resource-limited regions.
This material is based upon work supported by the Department of Defense Global Emerging Infections Surveillance & Response System (DoD-GEIS) Grant No. C0607_12_UN awarded to BAO and the National Science Foundation Graduate Research Fellowship under Grant No. DGE-0802270 awarded to TEC.