The Incidence of Malaria in Human Population of Shergarh District Mardan Pakistan

Malaria being one of the most infectious diseases is caused by unicellular parasites belong to Plasmodium genus. There are five malaria causing species of this genus including Plasmodium vivax, plasmodium falciparum, plasmodium ovale, plasmodium malariae and plasmodium knowelsi [1,2]. These species show variation in their morphology and drug resistance pattern, geographic distribution and their mode of pathologic process [2]. In 2016, an estimated number of 216 million cases of malarial infection have occurred worldwide leading to an estimated 445,000 deaths [3]. P. falciparum is taken into account the foremost fatal among all species, and accounts for most of the deaths due to malaria infection worldwide [4]. This infection is transmitted by a bite of infected Anopheles, female mosquito specie that introduces the plasmodium in its secretion into human blood system and leading to a number of symptoms including headache and fever, and in severe cases leading to death [5]. The infection is often diagnosed by the microscopic examination of blood using blood films or with antigen-based fast diagnostic tests. Molecular techniques are employed to diagnose the infection; however, these molecular strategies are not widely used because of their quality and cost [6]. Malaria infection is widely occurred in 109 countries mostly located in the tropics and sub-tropics [7].


ARTICLE INFO abstract
This study aimed at investigating the occurrence of malaria infection in human population of Shergarh district Mardan during August 2015 to July 2016. Sum of 2830 blood samples were collected from male (n=1560) and female (n=1270) febrile patients visiting Rural Health Center (RHC) Shergarh. All samples were subjected to microscopic analysis to determine the prevalence of plasmodium genotypes in the study area. Among 2830 studied samples 228 samples (8.056%) were found to be positive for malaria including 122 (53.50%) male and 106 (46.49%) female positive subjects. All of the positive samples were detected with only plasmodium vivax infection. Age wise distribution of positive cases revealed the higher rate of infection as 122/228 (53.07%) in group C (31-45 years) followed by group B (16-30 years) as 70/228 (30.70%) and A group (4-15 years) as 37/ 228 (16.22%). The highest rate of infection was recorded in September as 49/228 (21.49%) followed by August, October and May as 32/228 (14.03%), 31/228 (13.59%) and 31/228 (13.59%), respectively. While the lowest number of cases was found in January and February each as 1/228 (0.43%) followed by March and July as 4/228 (1.75%) and 5/228 (2.19%), respectively. It was concluded that malaria is still a major problem in rural population of District Mardan especially in Shergarh region might be due to poor sewage system and improper irrigation system in the area. Effective and prompt measures should be taken to curb the malarial infection at local and nationwide level in Pakistan by the government and non-government organizations.
of malaria infection occurred in Seventies. Within the last 20 years, rise in malarial cases has been attributed to prolonged monsoon season and floods that affected twenty million individuals in over sixty districts [13]. P. vivax contributed 65% of cases while the remaining 35% cases were caused due to P. falciparum infection, in Pakistan. In spite of malaria control and vector management programs in Pakistan, 5 million new cases of malaria and a substantial number of deaths are reported. Approximately 37% of cases have been reported in the areas of Pakistan located near Afghanistan border and other neighbor countries [14]. This study was designed to report the incidence of malaria infection along with the distribution of prevalent plasmodium species in Shergarh; a rural area of district Mardan Pakistan.

Study Area
This study was carried out at Rural Health Center (

Sample Collection
Some necessary information was collected from subjects regarding sex, age, residence, parent's occupation, general health condition, past history of malarial infection, surrounding conditions of their home, and presence or absence of domestic animals. Blood samples were collected from subjects and labeled properly.

Preparation of Thick and Thin Blood Smears
Thick and thin smear were prepared on the same slide from the finger pricked blood samples of all subjects under study. Fixation of the thin smear was done with methyl alcohol. Blood films were stained with 10% Giemsa stain. The screening was done under microscope 100X objective with oil immersion. All slides were cross checked by senior microscopist in RHC (Shergarh) Mardan.

Results
During current study blood samples of 2830 subjects with fibril fever were investigated for malaria infection. Out of 2830 samples, 228 samples were found positive for malaria showing 8.05% incidence of malaria infection in the area. In positive samples, 122 (53.50%) were found as males while106 (46.5%) were females. The highest ratio of positive cases was observed in male subjects in age group C as 65(28.50 %) followed by age group B as 42 (18.42%) and lowest in age group A as 15(6.57%) ( Figure 1). In female the highest ratio was reported in age group C that is 56 (24.56%) followed by age group B as 28 (12.28%) and lowest in age group A as 22(9.64%) cases. Among the infection causing species, P. vivax species was found to be responsible for all the infections in the area reported in this study while no other species including P. falciparum has been founded (Table 1)( Figure   2). Month wise prevalence of plasmodium parasite was found the highest in September as 49 (21.49%) while the lowest rate was found in months of January and February as only 1 (0.43%) followed by month of March and July as 4 (1.75%), and 5(2.19%) respectively ( Figure 3). Among the studied samples of 1270 female subjects, 106 were found positive. The mean prevalence of malaria was high in non-pregnant women as compared to pregnant women. In pregnant women the prevalence was very low that is 8 (7.54%) while in non-pregnant it was recorded as 98 (92.45%) infected subjects ( Figure 4).

Discussion
Malaria is considered to be one amongst the leading causes of morbidity and mortality worldwide, particularly in tropical and sub tropical areas of the world. Another study conducted in Lal Qila, Lower Dir, revealed 29% malaria incidence [17] while 27% in Bannu [18] and about 33% in Barkhan and Kohlu districts of Balochistan have also been reported [19]. A study conducted in Abbottabad reported 7% malaria cases [20], while Buner district had 7% prevalence [21]. A study conducted on clinical isolates from Sindh province reported about 3% malaria endemic [21]. Within population variation in prevalence and distribution of plasmodium species might exist, unfortunately, there are no simple methodological explanations for this variability. Variation in malaria prevalence reflects the different dynamic of malaria transmission among different areas of Pakistan [22]. Similarly, a report from Dera Ismail Khan, revealed 95% of malaria cases were of P. vivax, [23] another study reported 96% P. vivax cases from Manshera [24], 82% P. vivax cases in Quetta [25] and 72% cases in Jacobabad [26]. A comprehensive higher population survey on malarial isolates from all over Pakistan reported P.
The doable reason of high infection is that relapses overtimes occurred in P. vivax not in P. falciparum. The second reason is that P. vivax is usually gift in tropical and climatic zone areas [28]. This study shows that there was a considerable connection between malaria infection and gender in the study area as a higher infection rate was observed in males than females. It has been suggested for the disproportionate cases of malaria in male patients might be due to increased contact because males are more expected to work outside furthermore males not be as well covered as females which might be the possible reason for infected Anopheles bites. The malarial infections may also be associated with some degree of complicated sign and symptoms included prostration, any impairment of consciousness, convulsions or any manifestation of shock, decreased urinary output, respiratory distress or abnormal bleeding should be treated with parenteral rather than oral drugs [29].

Conclusion
This study showed that the prevalence rate of malaria infection is comparatively more in male population with age