ADVANCEMENT OF THE SCIENCE
Demographics and Water Quality in Pakistan
lyzed the drinking water from the four prov- inces of Pakistan and found coliforms present in 64% (Punjab), 67% (Khyber Pakhtunkhwa), 83% (Sindh), and 78% (Baluchistan) of the water samples (Soomro et al., 2011). These data suggest that due to the presence of micro- bial pathogens, the country’s drinking water is not safe for human consumption. Water in Pakistan is heavily contaminated with coliforms and fecal coliforms, which was confirmed by a study that evaluated >7,000 drinking water samples and found total coliforms and fecal coliforms in an aver- age of 58–71% of samples across the country (Nabeela et al., 2014). Lahore is Pakistan’s second-largest city, with a population of approximately 10 million people. The bac- teriological quality of bottled drinking water available in Lahore was evaluated and 2 out of 20 (10%) of the bottled water samples tested positive for fecal coliform contamination— suggesting that even some of the bottled water is unsafe for human consumption in Pakistan (Yousaf & Chaudhry, 2013). Waterborne Hepatitis Waterborne hepatitis is a highly contagious infection in humans that is caused by the hepatitis A virus (HAV) and hepatitis E virus (HEV). The disease is primarily transmitted via the fecal–oral route. In the early stages, the disease is asymptomatic, but viremia is pres- ent. In the clinical stage of infection, there is an acute inflammation of the liver. HAV has a high prevalence (up to 90%) in children who live in developing countries (Franco et al., 2012). Many cases of waterborne hepati- tis appear in dierent cities of Pakistan in the form of outbreaks and sporadic cases. In Karachi, contamination of drinking water with sewage water led to 79 cases of waterborne hepatitis at a boys’ vocational training center. The aected boys were using the contaminated tap water for drinking purposes and for wash- ing raw vegetables (Subuktageen et al., 2019). Rizwan et al. (2023) reported on another out- break of viral hepatitis in Karachi that aected 109 people and reported HAV at 85%, HEV at 12%, and HAV/HEV at 2.1%. Vegetables that were being washed with contaminated water from rusted pipes were the possible source. Another study examined an outbreak of HEV in Swat (Khyber Pakhtunkhwa Prov- ince) that aected 299 people. The source of the virus was found to be tap water in rusted
drinking water pipes. When drinking water pipes are rusted, suction due to the nega- tive pressure develops, leading to mixing of drinking and sewage water (Din et al., 2018). Water contaminated with feces is the major source of virus transmission. Water from overflowing gutters seeps into supply lines of drinking water reservoirs, result- ing in its contamination. A study conducted on the presence of HEV in Islamabad and Rawalpindi revealed that approximately 41% and 45% of the samples were positive for the virus, respectively (Ahmad et al., 2010). Similarly, Ahmad et al. (2018) determined the presence of HAV in drinking water in Lahore and Rawalpindi, with a prevalence of 12.5% and 21.1%, respectively (Table 1). Moreover, water-associated HAV can remain infectious in water for up to 3 months (Bar- rett et al., 2019). These findings indicate that the lack of appropriate sewage water treatment is the leading cause of HAV in Pakistan. Cur- rently, there is no special program in Pakistan to curtail the spread of HAV and HEV. Rotavirus Neonatal Diarrhea Rotavirus occurs most commonly in infants and causes a gastroenteric infection that leads to severe watery diarrhea, vomiting, fever, abdominal pain, and dehydration (Stanifer & Boulant, 2020). The virus can survive in the environment and can with- stand low humidity. The morbidity of the virus is high and one third of infected chil- dren with severe diarrhea die. In 2015–2016, Sadiq, Bokhari, et al. (2019) performed a study in Rawalpindi and Islam- abad to evaluate the incidence of rotavirus. The study found that 26.5% of diarrheic samples from hospitalized children were positive for rotavirus (Sadiq, Bokhari, et al., 2019). After the vaccine was available in the same cities, the same research group found that the positivity rate was decreased to 21–22%, suggesting that rotavirus vaccination can help prevent rotavi- rus disease (Sadiq, Bostan, et al., 2019). Rashid et al. (2021) tested the drinking water supplied by municipal authorities in Karachi and found that 23% of the samples were positive for rotavirus. Similarly, Umair et al. (2018) conducted a study at tertiary care hospitals in Lahore and Rawalpindi and found the overall rotavirus positivity rate to be 23.2%. Additionally, reports from Peshawar and Karachi suggest the associa-
Based on results from the Pakistan Social and Living Standards Measurement Survey (Paki- stan Bureau of Statistics, 2013), the major sources of drinking water for people in Paki- stan are tap water (32%), hand pumps (28%), motor pumps (27%), and dug wells (4%). Underground water is the most important water supply source in many areas of Paki- stan. In Pakistan, groundwater availability has reduced from 5,000 m 3 /year to 1,000 m 3 / year since 1950 (Nabi et al., 2019). In many cities in Pakistan, sewage water is illegally disposed of in rivers after only screen- ing and straining—but without microbial decontamination. This untreated sewage water contaminates the sources of fresh water (e.g., lakes, rivers). Monsoon season, rainfall, and floods, along with the lack of adequate infra- structure and resources, lead to an increase in the odds of drinking water contamina- tion. Ineective sewage systems, extreme cli- matic conditions, and floods become sources of introducing microbial pathogens into the clean drinking system (Daud et al., 2017). The mixing of microbial pathogens with industrial waste, domestic waste, pesticides, and fertilizers are basic determinants of water pollution (Praveen et al., 2016). According to guidelines of the World Health Organization (WHO) and Pakistan Environmental Protec- tion Agency (2008), acceptable standards for microbial quality dictate that there should be zero E. coli or thermotolerant coliforms per 100 ml of drinking water. The regular sur- veillance by the Pakistan Council of Research in Water Resources suggests that the quality of drinking water in Pakistan has remained below standards (Soomro et al., 2011). Diseases related to microbial contamina- tion of water aect people across Pakistan. The water resources of major cities across all prov- inces, as well as in Islamabad, are worse than the permissible microbial standards that WHO sets for water. In addition to Islamabad, cities with drinking water below WHO permissible microbial standards include Lahore, Faisala- bad, Rawalpindi, Sialkot, Gujranwala, Multan, and Bahawalpur in Punjab Province; Karachi and Hyderabad from Sindh Province; Peshawar, Abbottabad, Mingora, and Mardan in Khyber Pakhtunkhwa Province; and Quetta, Ziarat, Khuzdar, and Loralai in Balochistan Province (Nabeela et al., 2014). A national study ana-
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Volume 86 • Number 4
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