UNB, Dhaka :Diarrhoea has been spreading in the capital due to the drinking of unsafe water in absence of adequate supply of safe water to the city dwellers this summer.The number of diarrhoea patients has gone up sharply at the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b) over the last few days.About 492 patients were admitted to the icddr,b in the capital till 4 pm on Friday, while the number was 467 till 4 pm on Thursday.icddr,b sources said, a total of 786 patients were admitted to the iccddr,b Dhaka hospital in 24 hours on Wednesday who fell sick by the water-bone disease while 736 patients admitted on Thursday. According to the icddr,b data, nearly 14,000 patients were admitted to the icddr,b Dhaka hospital this month up to April 22, while Mirpur Treatment Centre has treated 2,311 patients during the period.Doctors at the icddr,b Dhaka hospital said the cases of diarrhoea are increasing in the city amid sweltering heat and due to drinking of contaminated water. The number of diarrhoea patients usually goes up before and after the rainy season, they said. The hospital authorities had to engage more doctors and staff to cope with the influx of diarrhoea patients, Nasmeen Ahmed, icddr,b senior communications manager, told UNB.