With the arrival of summer, the number of diarrhoea patients in and around the capital has gone up steeply this month compared to last month.

A total of 14,203 patients received treatment at the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b) in the first 18 days of this month, meaning as many as 789 patients were treated daily on average, up from the last month’s daily average of 504.

Experts mainly attributed this rise in diarrhoea cases to consumption of unsafe water and food by the people.

Foodborne illness peaks in the summer because foodborne bacteria grow fastest at temperatures between 32 to 43 degrees Celsius. During the summer months, the warmer temperatures and higher humidity are ideal for bacterial growth, according to Food Safety and Inspection Service of the USA.

The Dhaka Met office said the capital yesterday recorded the highest temperature of the month -- 35.4 °C.

Last year, the highest temperature in April was 36.5 °C.

Dr Azharul Islam Khan, chief physician and head of hospitals at the icddr,b, said the number of diarrhoea patients increased this year compared to last year.

Patients were mainly coming from the city’s Jatrabari, Dakkhin Khan, Mirpur, Mohammadpur, Tejgaon, Badda, Khilgaon and Lalbagh areas, he told The Daily Star.

Azharul said a tent was set up on the hospital premises around two weeks ago to accommodate additional patients, which increased their capacity to 923 patients from 675.

He said they would further enhance the capacity if needed.

The physician suspected that poor quality of supply water in some city areas might have led to the rise in diarrhoea cases.

He advised people with diarrhoea symptoms to have oral saline and visit the nearest hospital at the earliest if the condition deteriorates.

He also suggested that breastfeeding mothers should feed their babies properly and take fresh food and water to avoid getting diarrhoea.

Taqsem A Khan, managing director of Dhaka Water Supply and Sewerage Authority, said there were no coliform or fecal coliform bacteria in Wasa water.

Claiming Wasa water to be 100 percent safe for drinking, he said these bacteria, which are responsible for diarrhoea, can grow in water reservoirs of buildings if those are not cleaned for long.

Visiting the icddr,b yesterday, this correspondent found that patients, mostly adults from lower and middle income groups, were receiving treatment.

Shajahan, a pick-up van driver from Kuril area, said his wife had been undergoing treatment for the last three days. His 10-year-old elder daughter was looking after the younger one at home.

“But five-year-old Sia Moni also fell sick and was admitted to the hospital today [yesterday],” said the father of the two.

Rahima Begum, a 30-year-old patient from Gabtali, came to the icddr,b yesterday morning.

Her mother Renu Begum said they had to bring drinking water from a nearby mosque for the last three months due to bad odour in the Wasa water.

Abul Hossain, owner of a medical store on Satis Sarkar Road in the city’s Gandaria, said sale of oral saline has increased by about 30 percent at his store in the last couple of weeks.