At least 51 cases of cholera have been reported in Kathmandu and Lalitpur in the last one month, according to the National Public Health Laboratory (NPHL).

“Of the total 63 samples, 51 tested positive for cholera,” said Dr Geeta Shakya, director of the NPHL. Three cholera cases have been found in Kathmandu and 48 in Lalitpur.

The Epidemiology and Disease Control Division (EDCD) said the first case was reported in a patient who lived in a slum in Teku.

Dr Guna Nidhi Sharma of EDCD, however, ruled out an epidemic outbreak of the disease, saying there are sporadic cases so far.

“It becomes a major cause for concern when people in large numbers from the same community are affected,” said Dr Sharma. “But nonetheless, precautionary measures must be taken to prevent the disease from spreading.”

The threat of cholera spread increases during rainy season as Vibrio cholera, the bacteria that causes cholera, naturally occurs in aquatic sources such as wetlands, lakes, water puddles, paddy fields and stagnant water.

“Most of the cases have been reported in Lalitpur but they are from different areas of the city,” said Dr Sharma.

According the EDCD, people between 15 and 25 years of age have been affected the most and majority of them belong to low socio-economic background.

Most of the patients are children and those involved in menial labour.

Experts at the EDCD said contaminated water is the main reason behind increased cases of cholera.

Experts have urged all to drink boiled water or use water purifiers for cholera prevention and avoid contaminated food.