Genetic diversity of Plasmodium vivax and Plasmodium falciparum in Kohat District, Pakistan

Abstract

Malaria is one of the serious diseases threatening human health in Pakistan and contributes to a large proportion of the total malaria deaths in South Asia. However, little is known about the nature and extent of genetic diversity of the malarial parasites circulating in Pakistan. This study was designed to assess the infection status of Plasmodium and the genetic diversity of Plasmodium vivax and Plasmodium falciparum by analyzing msp-3α, msp-3β and msp-1, msp-2 genes respectively using allele specific nested PCR and RFLP assays. For this purpose, 130 field isolates were collected from the individuals who exhibited clinical symptoms associated with malaria in the Kohat region of Khyber Pakhtoonkhwa (KPK), Pakistan. Among 130 blood samples collected, P. vivax was detected in 105/130 (80.8%) and P. falciparum in 21/130 (16.2%). Mixed infections with both parasites were detected in 4/130 (3%) of the isolates. A large number of distinguishable alleles were found for msp genetic markers: 10 alleles for msp-3α and seven for msp-3β with one mixed infection in case of msp-3β. The genotyping of P. falciparum showed that K1+MAD20 mixed genotype was dominant in msp-1 and FC27 in msp-2. The results collectively suggest that P. vivax and P. falciparum populations in this region are highly polymorphic and mixed infections are prevalent.

Genetic diversity in human malarial parasites of Khyber Agency Pakistan

“…Msp-3α was found to have two alleles A and B of which B was more prevalent and polymorphic contradicting previous studies from Iran (Zakeri et al 2006a, b), India and Pakistan (Khatoon et al 2010) where three alleles were observed with type A being the most prevalent. The pvmsp-3β gene resulted in amplification of two major alleles of which 15% of type B remains uncut which mirrors previous findings from Pakistan [Khayber Pakhtoonkhaw] (Khatoon et al 2010 and2012) but contradicting observations from China and Thailand (Yang et al 2006). P. falciparum msp-1 and msp-2 candidates for malaria vaccine development (Moorthy and Hill 2002) have been found to have 11 genotypes for former and 16 for later, which is comparable to 10 and 17 alleles of Thailand (Snounou et al 1999) respectively but somewhat less diverse than 25 alleles of msp-1 and 19 alleles of msp-2 of West Uganda as described by Aubuoy (Aubouy et al (2003).…”

“…From Bannu, Pakistan, all three known genotypes of Pfmsp-1 and two of Pfmsp-2 were observed, with MAD20 occurring in 67% and 3D7/IC in 65% of the isolates, respectively while, 24% of the isolates exhibited mixed-strain infections (Khatoon et al 2010). From Kohat, Pakistan P. falciparum showed that K1+MAD20 mixed genotype was dominant in msp-1 and FC27 in msp-2 (Khatoon et al 2012).…”

“…Conversely, amplification of the P. vivax msp-3β locus produced two allele groups: A (1.7-2.2 kb, 62%) and B (1.4-1.5 kb, 33%), with 5% mixed-strain infections (Khatoon et al 2010). Out of 130 studied isolates from Kohat region of Khyber Pakhtoonkhwa (KPK) 37 Type A, 4 Type B, *Corresponding author: lukh@sund.ku.dk Diversity in human malaria parasites of Pakistan 565 9 Type C, 2 Type D (0.75 kb) and 2 mixed genotypes were investigated using PCR amplification (Khatoon et al 2012).…”

Genetic Diversity of Polymorphic Marker Merozoite Surface Protein 1 (Msp-1) and 2 (Msp-2) Genes of Plasmodium falciparum Isolates From Malaria Endemic Region of Pakistan

“…Most importantly, the use of highly potent antiplasmodial drugs that kill the asexual blood stage parasites and gametocytes are more likely to decrease parasite transmission and clonal diversity (Targett et al, 2001;Greenwood et al, 2008). However, in the adjacent districts (Bannu and Kohat) of Khyber Pakhtunkhwa, polyclonal infections were reported previously (Khatoon et al, 2010;Khatoon et al, 2012). It is worth mentioning that these two districts (Bannu and Kohat) accommodated one million internally displaced persons (IDPs) from tribal areas of North Waziristan Agency (NWA) sharing its border with Afghanistan, which may have introduced new genetically distinct variants of P. falciparum.…”

Table2.DOCX

“…This result is in comparison with a similar study from the south of Pakistan (Ghanchi et al, 2010), Iran, South Africa, Myanmar, Sudan, Senegal, andThailand (Heidari et al, 2007;Soe et al, 2017;Somé et al, 2018;Ndiaye et al, 2019;Eltayeb et al, 2020). However, in two southern districts Bannu and Kohat of Khyber Pakhtunkhwa, less allelic variants of P. falciparum were reported (Khatoon et al, 2010;Khatoon et al, 2012). Similarly, a study from the hypo-endemic area of Colombia reported only one allele of msp-1 and three alleles of msp-2 (Montoya et al, 2003).…”