Impact Of Child Malnutrition On The Igg Antibody Response To Plasmodium Falciparum Infections At Ishiara Hospital Embu County, Kenya

ABSTRACT

Pre-school children represent the population most vulnerable to malaria and malnutrition in Sub-Saharan Africa. The available data is conflicting as to whether malnutrition is associated with an increased or decreased risk of malaria. This study sought to determine the impact of child malnutrition on anti-P. falciparum IgG response in a comparative cross-sectional approach. Anthropometric measurements of height and weight plus standard deviation in Z-scores were determined in 380 children aged between 2 and 60 months visiting Ishiara District Hospital, Embu County. Children with less than -2 Z scores of height-for-age were classified as stunted and those with less than -2 Z scores of weight-for-height were classified as wasted. In total 70% of the children were malnourished and of these 30% were stunted, 37% were wasted while 3% had both stunting and wasting. Children aged 10-19 months had the highest prevalence of stunting and wasting (30%) while those aged 50-60 months had the least number (1%). The density of P. falciparum in the peripheral blood of the participating children was determined microscopically using Giemsa stained thin and thick smears, while the IgG antibody responses to the parasite was assessed using the enzyme-linked immunoabsorbent assay. Children that were well-nourished had a lower mean parasite density (530 per microlitre) compared to those that were severely wasted (590). Statistical analysis showed that there was a non-significant positive correlation between the parasite density and the varying levels of wasting (r = 0.4; P > 0.05). A similar pattern was also observed between well-nourished and stunted participants. However, for the severely malnourished participants the positive correlation between the well nourished (880) and those that were wasted and stunted (530) was highly significant (r = 0.7 ; P < 0.01). For the IgG response it was observed that children with normal nutritional status had the highest mean IgG antibody level of 1.90 compared to the severely wasted who had a mean IgG antibody level of 1.20. This implies that there was a negative correlation between wasting and IgG response that was statistically significant (r = -0.7; P < 0.05). The same pattern of correlation was observed between the well nourished participants and those that were stunted (r = -0.6; P < 0.05) and also between those that were well-nourished and those with both wasting and stunting (r = -0.8 ; P < 0.05). In conclusion, this study showed that child malnutrition modulates IgG antibody response to P. falciparum malaria in terms of IgG levels in children below five years of age, thus predisposing them to P. falciparum infection. Therefore malaria prevention and control programmes should consider nutrition interventions in the management of malaria in children less than five years of age.