Molecular Epidemiology, Seasonal variation and Phylogenetic analysis of human Plasmodium infection in Khyber Pakhtunkhwa, Pakistan, 2022-2023

Abstract

Abstract Background Malaria remains a serious health problem in Pakistan and 60% of the Pakistani population lives in malaria-endemic regions. This study was undertaken in 10 major districts hospitals of Khyber Pakhtunkhwa, Pakistan to study the malarial infection pattern. The baseline information about the recent epidemiology, age, seasonal variation, gender-wise species distribution using negative binomial regression analysis and phylogenetic analysis of Plasmodium circulating in the study area was included in the objective. Methods Using microscopy total 13363 malaria suspected cases were enrolled. Among the participants, 1004 individuals tested positive via microscopy. The positive cases were subjected to nested PCR to amplify the gene of the 18S rRNA of Plasmodium species. Following successful amplification, the gene sequences were obtained and submitted to the Gene Bank. The phylogenetic tree was constructed using MEGA7. Results A total of 539 cases were recruited from Southern KP with the highest occurrence in Bannu (26.15%) and the lowest in Lakki Marwat (13.72%). From Northern KP 465 cases were enlisted, Peshawar (30.96%) shows the maximum occurrence and lowest from Buner (7.52%). The annual blood examination rate, annual parasite incidence, and slide positivity rate were 0.08%, 0.04% per 1000 population, and 7.52% respectively. The Plasmodium vivax (78.38%), P. falciparum (17.23%), and mixed infection (4.38%) were diagnosed from both zones of KP through microscopy. The PCR analysis confirmed a consistent trend in species identification, with Plasmodium vivax showing a higher percentage than P. falciparum, followed by mixed infections. However, the incidence of malaria was observed to be higher in Southern KP (6.74%), compared to 5.84% in Northern KP. The overall percentage of malaria occurrence in all recruited districts of KP was 6.29%. The males among genders and age group of 1–15 were more affected by malaria. Seasonal analysis revealed that malaria reached its peak during the summer. Conclusion Malaria incidence exhibited a higher prevalence in Southern KP particularly during the summer season. The males and age group of 1–15 were more affected by malaria. In both zones of KP, Plasmodium infections are largely attributed to P. vivax.