Assessment of Genetic Diversity in Plasmodium falciparum and Antibody Responses to Erythrocyte Surface Antigens among Minna’s Children, Nigeria.

 Abstract:

Malaria poses a significant global public health challenge, especially in regions with frequent transmission. Among the affected population, children under the age of five are particularly vulnerable, accounting for a higher proportion of malaria-related mortalities. This cross-sectional study aimed to investigate the genetic diversity of Plasmodium falciparum and the antibody responses to erythrocyte surface antigens among children in Minna, Nigeria. Blood samples were collected from both asymptomatic cases (children residing in residential communities in Minna with no fever symptoms) and symptomatic cases (children with fever symptoms attending selected healthcare facilities) during the study period. The parasite density and infective stage were determined by preparing thick and thin films of blood samples using the Giemsa staining technique. Additionally, a complete blood count was performed to assess the hematological indices of the blood samples. Enzyme-linked immunosorbent assay (ELISA) was utilized to measure the IgG antibody levels against P. falciparum in the blood samples. The samples were further analyzed using polymerase chain reaction (PCR) to characterize the genetic diversity and gene types. The study included a total population of 316 children, aged between 6 months and 17 years, sampled from February to July 2018, with 181 (57%) males and 135 (43%) females. Of the 316 blood samples screened for P. falciparum infection, 238 (75.37%) were found to be infected, with 39 (16.39%) from asymptomatic children and 199 (83.61%) from symptomatic children. There was no significant difference between sex and P. falciparum infection. Anaemia was more prevalent in P. falciparum-infected cases compared to non-infected cases, but the regression model indicated that P. falciparum was not a significant predictor of anaemia. The ELISA results demonstrated that P. falciparum-infected cases showed higher specific IgG antibody responses (64, 68.81%) than negative P. falciparum samples, although the difference was not significant. Gene diversity analysis revealed MAD20 and FC27 as the predominant alleles for MSP1 and MSP2, respectively. Asymptomatic cases showed a predominance of K1 and FC27 alleles, while symptomatic cases showed a predominance of FC27 and MAD20 alleles. A high malaria transmission intensity due to mixed infection was observed in Minna, with an overall multiplicity of infection (MOI) of 2.22. The MOI for symptomatic cases (2.21) was slightly lower than that for asymptomatic cases (2.41). The study revealed a high level of gene diversity within the antigenic markers of MSP1 and MSP2 (0.714 and 0.830, respectively). These findings highlight the potential of malarial antibodies and gene diversity as essential markers for assessing differences in malaria parasite transmission intensity. Continuous genetic surveillance of P. falciparum will serve as a crucial tool in monitoring changes in gene types and the effectiveness of intervention programs.

Assessment of Genetic Diversity in Plasmodium falciparum and Antibody Responses to Erythrocyte Surface Antigens among Minna’s Children, Nigeria.