Effects of permethrin-treated bed nets on immunity to malaria in western Kenya II. Antibody responses in young children in an area of intense malaria transmission

• Published in: The American journal of tropical medicine and hygiene Vol. 68; no. 4 Suppl; p. 108
• Main Authors: Kariuki, Simon K, Lal, Altaf A, Terlouw, Dianne J, ter Kuile, Feiko O, Ong'echa, John M O, Phillips-Howard, Penelope A, Orago, Alloys S S, Kolczak, Margarette S, Hawley, William A, Nahlen, Bernard L, Shi, Ya Ping
• Format: Journal Article
• Language: English
• Published: United States 01-04-2003
• Subjects: Antibodies, Protozoan - blood; Antibody Formation; Bedding and Linens; Child, Preschool; Cross-Sectional Studies; Enzyme-Linked Immunosorbent Assay - methods; Humans; Immunoglobulin G - blood; Infant; Insecticides - pharmacology; Kenya - epidemiology; Malaria - epidemiology; Malaria - immunology; Malaria - prevention & control; Malaria - transmission; Permethrin - pharmacology; Prevalence; Kenya
• ISSN: 0002-9637
• DOI: 10.4269/ajtmh.2003.68.108

As part of a large community-based trial on the impact of insecticide (permethrin)-treated bed nets (ITNs) on childhood morbidity and mortality in an area of intense perennial malaria transmission in western Kenya, we assessed the effects of ITNs on malaria-specific humoral responses in young children. The IgG responses to Plasmodium falciparum pre-erythrocytic antigens circumsporozoite protein (CSP) and liver stage antigen-1 (LSA-1) and the blood stage antigen merozoite surface protein-1 (MSP-1(19) kD) in children less than three years old were investigated during a series of cross-sectional surveys. At 14 and 22 months after the introduction of ITNs, the frequencies and levels of IgG to CSP and LSA-1 were significantly lower in children from ITN villages than in children from control villages (P < 0.001). In contrast, the prevalence of IgG to MSP-1 was significantly higher in children from ITN villages at 14 months (P = 0.0069), but not at 22 months. Our results show that decreased exposure by ITNs reduces IgG responses to pre-erythrocytic antigens, but there was no evidence that two years of ITN use compromises IgG responses to blood stage antigens in these young children in this malaria holoendemic area.