Genetic diversity and population genetics of Schistosoma haematobium isolated from children in Lusaka and Siavonga districts, Zambia.

ABSTRACT

Urogenital schistosomiasis remains a pervasive health challenge in rural Zambian communities. This study explores the molecular epidemiology and genetic diversity of Schistosoma haematobium using mitochondrial genes (cox1 and nadh1). Urine samples from 421 children in Siavonga and Lusaka districts, Zambia, were collected between December 2020 and February 2022. Microscopy and DNA extraction facilitated the identification of S. haematobium, followed by amplification, sequencing, and phylogenetic analysis of cox1 and nadh1 genes. Phylogenetic analysis revealed clustering with samples from mainland African countries, emphasizing shared haplotypes. Both mitochondrial genes exhibited substantial diversity, with 5 haplotypes from 37 cox1 sequences and 12 haplotypes from 23 nadh1 sequences. High haplotype diversity (0.621-0.808) and low nucleotide diversity (0.00181-0.03288) were observed. Siavonga and Lusaka districts shared the majority of S. haematobium haplotypes. Molecular variance and genetic differentiation analysis indicated variations within populations rather than between populations (cox1 -0.025, nadh1 0.01646). These findings suggest a limited differentiation between S. haematobium populations in Siavonga and Lusaka, potentially indicating gene flow. Tajima's test revealed negative values, indicating a departure from neutrality, introduction of rare alleles, and recent population expansion. This study contributes essential insights into S. haematobium population genetics, crucial for effective urogenital schistosomiasis control in Zambia.