Prevalence of several infectious diseases in the District Dera Ismail Khan, Khyber Pakhtunkhwa, Pakistan

Aims: Infectious disease is a health disorder and is the leading cause of morbidity and mortality in humans globally. The present study determined the prevalence of several highly infectious diseases in the District Dera Ismail Khan. Subject and Methods: The retrospective study include the indoor data from December 2019 through November 2021 (two years) were collected from the admin oce of District Head Quarter Teaching Hospital, Dera Ismail Khan. Results: Overall diarrhea/dysentery showed the highest (59.1%) while pulmonary tuberculosis demonstrated the lowest prevalence (1.8%) and May contributed the largest share (16%), while February lowest (3.9%). Diarrhea/dysentery has relative the highest prevalence for most of the months. Overall diarrhea/dysentery, enteric/typhoid, and pneumonia contribute to 91.4% share of the studied diseases. The overall prevalence of the diseases increased steadily from March through May. Diarrhea/dysentery and malaria resulted in the highest prevalence of 19.6% and 17.1%, respectively in May, while enteric/typhoid revealed the highest prevalence of 24.4% in August. Pneumonia (23.5%) in June, Pulmonary tuberculosis (26.2%) in November, Extra Pulmonary tuberculosis in March (65.4%). Conclusion: Monthly and seasonal variations occurred in the prevalence of the diseases which is associated with an increase in vector population and an increase in temperature.


Introduction
An infection is the attack of body tissues by pathogenic organisms, their reproduction, and the response of the host tissues to the infectious agents and their toxin. The transmission of pathogens from person to person occurs through the spread of direct contact, water, or foodborne transmission, through inhalation in airborne droplets, body uids, and vectors such as mosquitoes and ticks.
Diarrhea is worldwide, one of the most common illnesses among children (Cohn 1991;Khan et al. 2004). Diarrhea is symptomized by loose or watery stool with dehydration and loss of body minerals and is caused by bacteria Salmonella, Shigella, Escherichia coli, parasites, and toxins. Acute diarrhea is short-lived and only lasts for 1-3 days. It is a viral infection or spread by consuming unhygienic food and water contained pathogens. While, chronic diarrhea is more severe, long-lived, and continues for many weeks. It may be caused due to any existing disease or food intolerances. Diarrhea contributes 16% of all child mortality in Pakistan (Quadri et al. 2013). Dysentery is characterized by in ammation of the intestine and bloody diarrhea, led to dehydration, and is caused by bacteria Shigella and Entamoeba histolytica. Typhoid is a bacterial infection, caused by Salmonella typhi that can lead to high fever diarrhea, and vomiting. All these aforementioned diseases are water and food-borne.
Both Pneumonia and pulmonary tuberculosis (PTB) are lower respiratory tract infections (LRTIs). Pneumonia is an in ammation of the lung, affecting alveoli, caused by Streptococcus pneumoniae, and is characterized by dry cough, chest pain, fever, and di culty in breathing. Pneumonia is the single largest cause of mortality in children globally (Tribune 2020) and is the second-highest contributor to childhood morbidity and mortality in Pakistan (Hussain et al. 1997), accounting for 25% of overall mortality in children in the country (Tribune 2020). Pneumonia is the most killer disease of children aged <5 years in Pakistan (Anonymous 2008). More than 500,000 children of <5 years and 96,000 adults succumb to pneumonia every year in Pakistan (Tribune, 2020).
While, PTB is caused by Mycobacterium tuberculosis, and is one of the deadliest diseases of lung globally (Khan 2020). PTB is transmitted through inhaling air containing droplets released by sneezing and coughing of an infected individual (WHO 2010; Ricks et al. 2011;Khaliq et al. 2015). Respiratory infections account for 20-30% of the total mortality of children in Pakistan (Naz et al. 2018). Extrapulmonary tuberculosis (EPTB) is also caused by Mycobacterium tuberculosis and is tuberculosis (TB) within a location in the body except for lungs including most commonly are the lymph nodes, kidney, bladder, bones, joints, genital tract, intestine, brain meninges, skin, adrenals, and eyes ). TB is one of the top 10 causes of death globally (WHO 2020;Li et al 2021). Pakistan ranked fth among 30 high-TB burden countries (Khaliq et al. 2015, Khan 2017WHO 2018;Tahseen et al. 2020) which covered 87% of the TB cases globally [Khan 2020;Qadeer et al. 2016;Khan 2017). This is the rst study that deals with the seasonal and monthly prevalence of several major infectious diseases in the District Dera Ismail Khan including diarrhea/dysentery, typhoid/enteric, malaria, pneumonia, PTB, and EPTB. Further studies are required to know about the sex and age-wise prevalence of the studied diseases to more effectively control the said diseases in the study area. The nding of the present research help in adopting timely strategies including mass awareness about the prevalence of the said diseases, improving hygienic conditions, and adopting preventive measures including vaccination of the people and spray to kill vectors of the diseases to reduce the rate of diseases in the study area.

Diagnosis of the infectious diseases
A variety of laboratory tests/techniques are used to diagnose infectious diseases including samples of blood, urine, stool, mucus, or other body uids are examined mostly under a microscope or occasionally culturing the pathogens to nd out the causes of the diseases.  Khan. The data was sorted and the average monthly consolidated report of the diseases for December, and January through June of the study, periods were prepared.
The distribution of the frequencies of the diseases over the months was analyzed with the Pearson chi-square test (X-squared = 17131, df = 55, p-value < 2.2e-16) for the association between diseases and months, and found to be signi cant (p < 0.0001), followed by post hoc pairwise comparisons. Benjamini & Hochberg's (1995) method, at a level = 0.01, for adjusting the p-values for multiple comparisons was used. All months were pairwise statistically different from each other (p < 0.0001).

Seasonal prevalence of the diseases
Diarrhea/dysentery has highly prevailed during late spring/early summer (Table 1). Enteric/Typhoid was highest in the late summer. Malaria was highest in early summer, followed by relatively higher in late summer through late autumn but was lowest in mid-summer. Pneumonia was highest in early summer, followed by in late winter as well as in spring. PTB was highest in late early winter, while EPTB was highest during spring.
A steady increase in the overall prevalence of the diseases (mainly contributed by diarrhea/dysentery) from February and reach to pick in May in the present study (Table 1) is because of rising temperature and the increasing population of ies/mosquitoes, as both play an important role in the transmission of such diseases. Diarrhea/dysentery contributed the largest to the overall prevalence of studied infectious diseases in D.I.Khan, emphasize the fact that ies play a major role in the transmission of the disease in the study area. This is because the 1) favorable conditions for breeding prevailed which promote an increased population of ies in the area, and 2) the unhygienic conditions including unhygienic feeding to the babies. All the diseases except for both types of tuberculosis showed early summer as the peak season of transmission in the study area. February revealed the lowest prevalence of the diseases mainly because of low temperature hence the low population of vectors. Previous research is not su ciently available on the monthly/seasonal prevalence of diarrhea and typhoid in Pakistan. Nevertheless, the highest prevalence of diarrhea in late spring and early summer (April-May) and the highest peak of typhoid in May (Table 1) was supported by Khan et al (2021) who investigated gastroenteritis in children aged ≤15 years in Bannu and found April followed by May represented the highest prevalence of gastroenteritis. Mirza et al (2012) investigated stool samples in combined military hospital D.I.Khan to determine different intestinal parasites responsible for gastrointestinal disorder/diarrhea in the general population of D.I.Khan, and found Taenia saginata was the most frequently observed parasite (15.76%). Giardia lamblia (both vegetative and cyst forms) accounted for a 3.09% prevalence. Hymenolepis nana contributed 1.34% prevalence, Ancylostoma duodenale (29%), Entamoeba histolytica (vegetative form only: 0.17%), and Ascaris lumbricoides was the least frequently observed (0.11%). Literature is not available on the seasonal/monthly prevalence of pneumonia and extrapulmonary tuberculosis in Pakistan.
Comprehensive studies of monthly/seasonal prevalence of malaria in D.I.Khan was conducted previously. Malaria was at its peak in May, followed by October, and lowest in June (Table 1), and was supported by Ahmad et al. (2015) who found the highest prevalence of malaria in October, while the lowest was recorded in June in Dir Lower. The transmission of malaria occurred throughout the year but more cases were reported from July through November after the rains (Macdonald 1957;Detinova, 1962). Malaria steadily increased during April-May, following a sudden decrease in June (Table 1) Khan (2014) concluded that P. vivax was common during August-October with a peak in October, whereas P. falciparum infection was most common during October-December with a peak in October in the district Bannu. Ullah et al. (2020) found 366 (91.5%) showed high prevalence in early summer and during late summer through autumn. Pneumonia demonstrated the highest prevalence in early summer. While, pulmonary tuberculosis and extrapulmonary tuberculosis revealed the highest prevalence in late autumn and spring, respectively (Table 1).
The developing countries should adopt several preventive strategies for reducing the burden of infectious diseases including 1) mother feeding instead of bottle feeding, 2) proper ies and mosquito control, 3) use of mosquito net during sleeping, 4) proper disposal of patients stool and phlegm, 5) adopting a hygienic way of life such as hand washing and covered and boiled food and drinking, and 6) proper early vaccination.

Limitations
The present research work deals with the prevalence of several infectious diseases in the District Dera Ismail Khan. The study includes only the general prevalence of the diseases and doesn't include sex and age-wise distribution of the diseases and the etiology of the disease in the study area. Figure 1 Percentage monthly relative prevalence of several infectious diseases (indoor patient's data) in Dera Ismail Khan from December 2019 through November 2021 (Two years): each month showed combined data for the said period.