Nepal on Thursday received 550,000 doses of anti-cholera vaccine from the Unicef and the World Health Organisation.

Of the 1,018,100 doses the organisations committed to supply for the containment of the cholera, which has been spread since the first week of August in Birgunj Metropolitan City, and adjoining local units of Parsa and Bara districts, the remaining doses will arrive on Friday.

“We received 550,000 doses of cholera vaccine today [Thursday],” said Dr Abhiyan Gautam, chief of the Immunisation Section at the Family Welfare Division under the Department of Health Services. “The remaining doses of the vaccine will arrive on Friday.”

Cholera is a highly infectious disease that causes severe diarrhoea and vomiting, which can lead to dehydration and death within a few hours if left untreated. The National Public Health Laboratory, which carried out tests on stool samples of the infected people, confirmed that Vibrio cholerae o1 Ogawa serotype is responsible for the outbreak.

At least four people have died and over 1,500 others have been hospitalised in the two districts since last month. New cases are resurging in the local units of Parsa district including Birgunj Metropolitan City. Health officials said the number of new infections has quadrupled in the past week.

Amid rising cases, the hospital administration has asked the provincial government to manage additional health workers. Officials say medics deputed earlier to assist the hospital have already returned.

Health officials say that with increased rainfall and a halt to the door-to-door campaign due to unrest caused by Gen Z protests, cholera cases have begun rising again.

Officials say all people above one year of age from all municipalities of Parsa district and six adjoining municipalities in Bara district, the areas hardest hit by the outbreak, will be administered with oral cholera vaccine immediately after the Dashain holidays.

“Vaccination will be launched after Dashain only,” said Gautam.

Public health experts say the Birgunj outbreak is the largest since the Jajarkot epidemic in 2009. Sixteen years ago, the far-western district of Jajarkot saw a major cholera outbreak that killed several and infected hundreds. They say the Birgunj outbreak exposes critical gaps in the government’s preparedness and response system, and water and sanitation conditions.

Experts are particularly alarmed by both the severity of the outbreak and the deaths it has caused.

Nepal often witnesses outbreaks of water- and food-borne diseases, including cholera, during the monsoon season as floodwaters contaminate most of the drinking water sources.

Last year, at least 95 cholera cases were confirmed in Kathmandu, Lalitpur, Jajarkot, Pyuthan, Makawanpur, Rolpa, Sindhupalchok, Achham, and Rautahat districts. The health ministry administered cholera vaccine to people from the affected areas of Kapilvastu, Rautahat, and Kathmandu a few years ago to halt the spread of the disease.

Poor sanitation and hygiene make the country highly vulnerable to waterborne diseases, including diarrhoea, dysentery, typhoid, hepatitis, and cholera, especially in the monsoon season, according to doctors.

They say the risk of waterborne diseases will not decrease until the water and sanitation conditions improve, and people get safe drinking water. Several other factors, including storage conditions, supply pipes, and pollution of water sources, also determine the quality of water supplied to households.

The World Health Organisation says cholera is a global threat to public health, and a multifaceted approach is the key to controlling the disease and reducing deaths.