Incidence of Human Plasmodiasis in Northern and Southern Districts of Khyber Pakhtunkhwa, Pakistan

After informed consent of the subjects a total of 3968 blood smears, both thick and thin, were prepared for the detection of malarial parasites. The current study was carried out in southern districts (Bannu, Lakki, Karak, Kohat, D.I. Khan) and northern districts (Peshawar, Mardan, Charsaddah, Sawabi, Nowshehra) of Khyber Pakhtunkhwa during June 2010 to June 2012. Blood smears were fixed in methyl alcohol and then stained in Giemsa stain for 20-30 min. The slides were screened under microscope for the detection of malarial parasites.

Table I shows overall incidence of Plasmodium prevalence in Southern and Northern districts of Khyber Pakhtunkhwa. Out of total 52.47% prevalence in southern districts 91.07% identified as P. vivax, 6.23% as P. falciparum and 2.69% as mixed infections. In the northern districts the overall incidence of Plasmodium was 43.62% of which P. vivax contributed 91.2%, P. falciparum 6.09% and mixed infections 2.68%.

Similar type of study in India showed 7.2% population in Gujrat infected with Plamodium, of which 72.47.% were identified as P. vivax, 24.1% cases were P. falciparum and 3.44% cases were mixed infections (Trivedi et al., 2010). Similarly, Zarchi et al. (2006) observed infection of Plasmodium in Iranian parts of south-east of Caspian Sea and detected that P. vivax was 61%, P. falciparum was 20.7% and mixed infection was 18.3%, respectively. Yasinzai and Kakar (2012) showed high incidence of P. vivax (81%) and P. falciparum (18.9%) in Jaffarabad district.

Idris et al. (2007) reported 7.2% positive cases in Abbottabad of which P. vivax contributed 72.47%, P. falciparum 24.1% and mixed infection was observed 3.44% cases. Akbar et al. (2006) observed high prevalence of malarial parasites (96.2%) in children of Mansehra, in which P. vivax was 92.2%, and P. falciparum was 7.7%. Jan and Kiani (2001) also observed high incidence of P. vivax (6.33%) compared to P. falciparum (0.67%) in Kashmiri refugees of Muzaffarabad.

Table II shows age wise incidence of Plasmodium. The overall highest incidence was in the age group of 41-45 years (81.63%) followed by age groups 11-20 (61.68%) and 21-30 (47.18%). Age group <1-10 was least affected (22.78%). In all of them P. vivax was the most dominant infection.

Table III shows incidence of plasmodiasis during different season of the year. Highest slides positivity rate (SPR) was observed in August (72.56%) and September (68.52%) and lowest in December (7.93%) and in February (12.62%). From among southern districts high SPR of P. vivax was 92.4% observed in Bannu district followed by 89.7% in Kohat and 89.7% in D.I. Khan, P. falciparum on the other hand showed 8.1% incidence in D.I. Khan and 3.4% in Bannu. Likewise in northern districts P. vivax showed 92.93% SPR in Peshawar followed by 80.76% in Nowshehra district, P. falciparum showed 19.23% incidence in Nowshehra and 2.8% in Charsadda.

Similar type of study was done by Toma et al. (2001), in Laos, in which the prevalence rate of malarial parasites in less than 10 years was 40.7%, 11 to 20 years 52.4%, 21 to 30 years 28.6%, 31 to 40 years 25.0%, 41 to 50 years 7.1% and >50 years 26.3%. Yasinzai and Kakar (2012) reported 32.8% in 1-10 years, 50.6% 11-20 years and 51.5% in the age group of 21 years and above. Likewise Idris et al., (2007) reported 48.27% infection in <15 years age group, 8.96% in 15-30 years, 5.51% in 30-45 years, 16.55% in 45-60 years, 13.79% in 60-80 years and 6.89% in 80 years age group.

In the study percentages of infections is more in 11-20 and 41-50> years age groups, because at that stage children are more exposed to environment, and percentage of infections was high in old age persons are due to low immune response. Similar result has been found by Ali et al. (2013) at district Charsada, adolescence 11-20 years were more infected (22.8%) than younger (1-10 years) and old aged above thirty years were highly (39%) infected.

Seasonal variations were also observed in Khyber Pakhtunkhwa, Pakistan. In the present study high percentage of infection was observed in August (72.56%) and September (68.52%) and lowest in December (7.93%) and February (12.62%). While, Yasinzai and Kakar (2012) observed high percentage of infection was in May (56.8%) and lowest in June (35.2%) in Jafffarabad. High percentage of infections (57.90%) in September and lowest (25.33%) in January detected by Mohammad and Hussain (2003) in Buner district. The differences in the above mentioned studies are due to number of samples, hygienic conditions of the areas, immune response and temperature of the areas etc.

It was concluded that there were significant risk factors for malaria prevalence. The poor hygienic condition, no use of antimalarials sprays, use of irrigated land, sharing the house with livestock, improper diagnosis, high temperature of the area and load shading also play a key role for the spread of malaria in both Southern and Northern belt of Khyber Pakhtunkhwa, Pakistan.

The authors are highly obliged for the cooperation of all Laboratories Incharge and Laboratories Assistant of all the Hospitals of Northern and Southern Districts.

Author has declared that no competing interests exist.