Drinking water used by Kathmandu and Lalitpur metropolitan city residents for drinking has been found contaminated with deadly microbes.

According to officials at the Lalitpur Metropolitan City, 180 of 540 water samples collected from wards 7, 8, 9, 15, and 17 of the metropolis were found contaminated with faecal coliform.

Similarly, of 506 samples of drinking water collected from wards 11, 12, and 13 of Kathmandu Metropolitan City, 98 were contaminated with faecal coliform.

The presence of faecal coliform, a microscopic organism that thrives in the intestines of warm-blooded animals or their faeces, indicates sewage contamination in the drinking water, according to doctors.

Officials at the Health Office Lalitpur have reported the presence of deadly microbes in all water samples, including those from the water utility and well water of the areas that saw cholera outbreaks this year.

“Faecal coliform has been detected in all water samples from the cholera-hit areas,” said Shree Bhadra Sharma, a lab technician at the Health Office Lalitpur. In July, officials had confirmed a cholera outbreak in Thaiba area in Godawari Municipality of Lalitpur.

“Water samples collected from other areas too have been found problematic,” Sharma said.

Of 81 people who tested positive for cholera in various districts nationwide in the ongoing monsoon season, 53 were from Lalitpur districts. Health authorities say they had launched an awareness campaign and chlorinated the drinking water to tackle the contamination.

Kathmandu reported 12 cases of cholera infection during the period.

Cholera is a highly infectious disease that causes severe diarrhoea and vomiting, which in turn results in dehydration and can lead to death within a few hours if left untreated. The World Health Organisation says cholera is a global threat to public health and an indicator of inequality and a lack of social development.

Health officials said that the Vibrio cholera 01 Ogawa serotype has been confirmed in the stool sample of an infected patient. They say even jar water, widely considered safer than water from other sources, has been contaminated with faecal coliform.

Doctors say this is not the first time that the water used by people in the Valley was found contaminated with potentially deadly microbes. What concerns them more is that water quality has not improved significantly.

“Consumption of water contaminated with human faeces causes diarrheal infections,” said Dr Arjun Sapkota, chief of the Health Office, Kathmandu. “We have launched an awareness drive in the areas where cholera cases were detected, and water samples were found to be contaminated with deadly microbes.”

Doctors say consumption of contaminated water not only causes diarrheal infections and cholera but also increases the chances of contracting dysentery, typhoid, and hepatitis A and E.

Initiating awareness drives and ensuring safe drinking water are the only ways to save people from water-borne diseases, according to them.

A combination of careful surveys, provision of safe drinking water, good sanitation and hygiene standards, social mobilisation and treatment are required to contain the spread of infection, they say.