Plasma levels of DDT/DDE and liver function in malaria control personnel prior to DDT in-door residual spray in Northern Uganda, 2008

Abstract

Where 20 million Ugandans are debilitated by malaria in a year, there is continued need of dichlorodiphenyltrichloroethane (DDT) for vector control while further research is implemented to clarify the health impact of the use of DDT in in-door residual spray (IRS). The aim of the study was to determine plasma levels of DDT/DDE and liver function as base line values in malaria control personnel prior to IRS of DDT in Northern Uganda. The study design was a cross sectional prospective laboratory-centred. The sites were districts of Apac, Kitgum, Oyam and Pader in Northern Uganda. The volunteer participants were clinically examined and blood samples were taken in heparinised tubes for pre-spray screening for DDT/DDE and plasma ALT, AST, and GGTenzyme activity levels as measures of liver function. DDT/DDE was extracted with methanol from plasma and assayed using ELISA kits from Abraxis,USA while plasma enzyme activity levels were analyzed using routine clinical chemistry automated methods of KonelabTM. All the 109 plasma samples collected before IRS contained DDT/DDE in a range of 39-108 and a mean (SD) of 63 (19) ppb. All the 95 plasma samples analysed for enzyme activity concentrations of ALT, AST, and GGT showed no abnormal function of the liver: ALT mean (SD) was 10.22 (4.89) u/L, within reference range of up to 40 u/L; AST mean(SD) was 19.91 (8.93) u/L within reference range of up to 40 u/L; GGT mean(SD) was 65.58 (12.05) within substrate-inducible range of the enzyme. In conclusion none of the study participants was DDT-naïve before the chemical was used for IRS in Northern Uganda. The plasma DDT/DDE levels encountered had no deleterious effect on ALT, AST, or GGT enzyme activities as screening measures of liver function.