ADVANCEMENT OF THE SCIENCE
Khan et al. (2013) used diagnostic tests and reported that 550 out of 2,964 (18.6%) patients were positive for typhoid in Quetta (Balochistan Province). They found that typhoid occurrence was higher in children between the ages of 5 and 10 and in the sum- mer season; disease occurrence was similar among genders. Siddiqui et al. (2015) con- ducted a cross-sectional study in Karachi and found that 19 out of 209 food handlers were positive for S. enterica serovars: 4.3% were pos- itive for typhoidal serotype and the remaining were non-typhoidal serovars. All typhoidal serovars demonstrated antibiotic sensitivity against cefixime, chloramphenicol, nalidixic acid, and ofloxacin (Siddiqui et al., 2015). An outbreak of 101 cases was reported from two subdistricts of Hyderabad between November 2016 and March 2017. The pre- sumptive source of this outbreak was con- tamination of drinking water with sew- age water. Children were more commonly aected, with a median case age of 0–60 months (Yousafzai et al., 2019). Israr et al. (2022) found that 22% of drinking water samples were positive for Salmonella Typhi in Peshawar. The higher occurrence of this disease in Pakistan is due to poor personal hygiene, substandard sanitation, and persis- tent poverty (Arif & Naheed, 2012). Unfortunately, cases of extensively drug- resistant typhoid fever (XDR-TF) are rising in Pakistan. According to the Weekly Field Epi- demiological Report by the Pakistan National Institute of Health, a total of 5,741 confirmed cases of XDR-TF were documented across all districts of the Sindh Province between November 2016 and June 2021 (Butt et al., 2022). Pakistan is the first country in the world to introduce a typhoid conjugate vac- cine into its routine vaccination program (Akram et al., 2020), which can prevent the onset of typhoid disease. E. coli E. coli is a common cause of gastrointestinal infection in human beings. The severity of infection depends on the type of pathogenic E. coli . The bacterium has six known pathogenic types (Donnenberg, 2013): enteroinvasive E. coli (EIEC), enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), enterohemor- rhagic E. coli (EHEC), enteroaggregative E. coli (EAEC), and diusely adherent E. coli (DAEC). E. coli is the salient microorganism
among the coliform group and drinking water quality is evaluated by its load. The bacterium is likely to be associated with many diarrheal outbreaks in Pakistan, but the data from those outbreaks have not been eectively docu- mented and reported. Symptomatically, E. coli infection resembles rotavirus infection. More- over, outbreaks are less likely traced to E. coli because of the standard treatment and man- agement regimens for common diarrheal dis- eases. Researchers have, however, frequently reported the presence and isolation of E. coli from tap water, groundwater, and floodwater. The concentration of E. coli in water sources correlates with socioeconomic sta- tus of communities. A dense population and low economic status lead to compromise on the proper disposal of wastewater and hence contamination of drinking water (Iqbal et al., 2019). Some places engineer a gravity-flow water system. This system of pipes, which brings water from the source closer to peo- ple, comes with a high risk of contamination, though. In Abbottabad, people drink water that is delivered via a gravity-flow water sys- tem. Specifically, surface water from a ravine in the east of Abbottabad is channeled down- stream to supply water after treatment to city residents. The system overcomes the shortage of the availability of drinking water in Abbot- tabad and adjoining areas. Water likely gets contaminated, however, due to the choking of water supply through silt as the water is directed over a large distance. A study that sampled water in dierent locations in Abbottabad determined that 75% of water samples tested positive for E. coli (Jadoon et al., 2021). A similar study from Peshawar reported 52% of water samples were contaminated with E. coli (Israr et al., 2022). Younas et al. (2016) studied a pediatric popu- lation and found the infection incidence of E. coli to be 42.4%, with EPEC at 20.2%. Fatima et al. (2021) conducted a comprehensive lon- gitudinal study from 2018 to 2020 through- out dierent seasons to study the presence of coliforms in the drinking water of Karachi. They deemed a range of 60–69% of the drink- ing water samples unfit for consumption due to coliform presence. Furthermore, studies from Islamabad and Lahore in 2014 found 40% and 73% of water samples tested positive for coliforms, respectively (Hisam et al., 2014; Zareen et al., 2014). Another comprehensive study was
performed in 20 dierent locations within the city of Dera Ghazi Khan in Southern Punjab. Groundwater was reported to contain 25–50 CFU/ml of E. coli (Javaid et al., 2022). Surprisingly, in six villages of Vehari District in Eastern Punjab, another study team found zero E. coli/ 100 ml of water samples (Khan et al., 2022). The transmission of E. coli is fecal–oral in nature: Contamination of sur- face water and groundwater with feces is the main mode of E. coli transmission. Eective treatment of wastewater before it is disposed of in water bodies can decrease the E. coli load to an acceptable level. Control Measures Control of waterborne diseases requires the involvement of both public and private sec- tors along with the active involvement of local communities. There is a dire need in Pakistan for the implementation of legisla- tion regarding the provision of safe water. Controlling and backtracking of outbreaks should be integrated with the Early Flood Warning System so that epidemiologists and microbiologists can eectively play their part in the control of waterborne diseases. The water quality of rivers and canals should be regularly monitored for microbial loads. Furthermore, industries or housing societ- ies should be penalized—necessitating the implementation of a legal framework—for contaminating freshwater sources. Additionally, the chlorination concentra- tion in tap water and water treatment plants should be carefully monitored. The param- eters of coliforms and other bacteria should be strictly in compliance with the Pakistan Environmental Protection Agency. And lastly, the availability of vaccines for rotavirus and typhoid should be ensured for the public. Community awareness programs for good hygienic practices should be initiated and maintained. Mobilization of philanthropists is needed for the development of water filtra- tion plants in remote areas where people rely on lakes or groundwater for drinking water. Waterborne diseases can be prevented by adopting personal hygiene measures, drink- ing boiled or chlorinated water, and washing vegetables and fruits with boiled or chlori- nated water. Care should be taken when using community pools, as well as when swimming in lakes, rivers, and canals. Handwashing is recommended with soap and water for at
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Volume 86 • Number 4
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