Abstract

Glucose-6-phosphate dehydrogenase enzyme deficiency (G6PD) is one of the malaria hypotheses, in addition to haemoglobinopathy, ovalocytosis, and thalassaemia, among others, that confer resistance to the severity of malaria infection to their carriers. High prevalent rates of these red blood cell abnormalities are known to correlate with malaria endemicity of an area as a natural selection. This study, which was part of a broader study, tried to investigate the level of G6PD enzyme activity as a protective polymorphism contributing to low morbidity and mortality rate in people living in stable malaria transmission areas. Well, stained-Giemsa thick blood smears were viewed under a light microscope x100 objective by a well-trained microscopist and quantitation of asexual stages of the parasite was done by counting the number of asexual form against leucocytes, assuming 8000 leucocytes /uL. The G6PD status of the study subjects was determined by the methaemoglobin reduction method, using Sigma Kit 203-A (Sigma-Adrich, Inc., St Louis, MO, USA) on freshly withdrawn venous blood devoid of haemolysis. The result showed that 3 different types of G6PD polymorphism were identified in 72 cases: Heterozygous 11(15.28%), homozygous 21 (29.17%) and hemizygous 40 (55.56%).  Seventy-two per cent prevalence seen in this study is far above what was reported for Africa by previous studies. Higher parasite density was found in study subjects with normal G6PD activity (6000/uL). The high prevalence rate of this red blood cell enzyme polymorphism is suspected to be responsible for protection against the severity of Plasmodium falciparum malaria infection found in the study, despite the high malaria endemicity of the area. The seventy-two percent G6PD enzyme deficiency prevalence rate seen in this study shows that the frequency of this enzyme deficiency depends on a particular area of study rather than geographical contraption.

Key words: Frequency, glucose-6 phosphate dehydrogenase, holoendemic.