Amid monsoon rains causing widespread death and destruction, the risk of infection of water- and vector-borne diseases intensifies.

Officials at the Ministry of Health and Population are bracing for tough days ahead, as the escalating monsoon not only pollutes sources of drinking water but also provides breeding grounds for various disease-spreading vectors.

“Over 2,000 people from 73 districts have already tested positive for the dengue virus and several districts have witnessed outbreaks of waterborne diseases, including cholera,” said Dr Yadu Chandra Ghimire, director at the Epidemiology and Disease Control Division. “We are aware of the possible risks and have alerted the relevant agencies.”

The division said that 23 cholera cases have already been confirmed in Lalitpur, Kailali and Kathmandu districts. Likewise, as many as 2,061 people from 73 districts have tested positive for dengue. Health facilities across the country have been grappling with a surge in water- and vector-borne diseases.

“Infection of the dengue virus has not risen this time compared to the previous years,” said Ghimire. “Ongoing rain has contaminated drinking water sources which increases the risk of potential outbreaks of waterborne diseases in the coming days.”

According to data provided by the division, among the 73 districts that reported dengue outbreaks, Kathmandu has the highest number of cases at 249, followed by Jhapa 130, Chitwan 105, Tanahun 87, Makawanpur 78, Kaski 74, Bhojpur 62, Kavrepalanchok 60, and Okhaldhunga with 59 cases.

Dengue is a mosquito-borne disease transmitted by female Aedes aegypti and Aedes albopictus mosquitoes. The same vector also transmits chikungunya, yellow fever, and Zika, according to the World Health Organisation.

Public health experts say reported cases could be just the tip of the iceberg, as around 80 percent of those infected are asymptomatic.

Likewise, 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 samples of the infected patients. They concede that the outbreaks of the deadly disease are being reported only from the districts having active case surveillance programmes. Active cholera surveillance is being carried out from 27 health facilities in Kathmandu Valley and 10 in Kailali district.

The monsoon season in Nepal is a time of epidemics during which thousands of people across the country become infected with waterborne and vector-borne diseases. Officials warned that health facilities could witness an uptick in the number of viral fever cases, and waterborne diseases—diarrhoea, dysentery, food poisoning, and snakebites—in the coming days.

The Ministry of Health and Population last month urged provincial and local health authorities not to grant leave to health workers during the monsoon season and step up vigilance about the potential risks.

Officials say that they have been raising awareness through all available means to inform people of the risks and directed agencies concerned to stockpile essential medicines.

Doctors say the only ways to prevent deaths from waterborne diseases, including diarrhoea, are to raise awareness and ensure safe drinking water.

They say a combination of careful surveys, ensuring safe drinking water, maintaining sanitation and hygiene, social mobilisation and treatment are required to contain the spread of the diarrhoeal infection.