Two men, aged 64 and 72, suffered fever, muscle pain and fluid build-up in their chests after receiving blood donated by a 52-year-old man, scientists led by Dr Paul Tambyah at the National University of Singapore said in the report. A third man, 74, was infected without suffering any symptoms.

All three were discharged from hospital in good health, the report said.

Dengue, the world's most common mosquito-borne disease, is endemic in Singapore, where it has infected more than 4,600 people this year.

The flu-like illness strikes about 50 million people annually worldwide and leads to about 500,000 hospitalisations, mostly children, according to the World Health Organisation. At least 2.5 per cent of patients die.

'Although screening is expensive, confidence in the blood supply could outweigh cost-effectiveness considerations,' Dr Tambyah and colleagues wrote in a letter to the journal's editor.

Singapore doesn't screen blood donors for dengue because available tests would take four weeks, rendering blood platelets that must be used within five days useless, Mr Tan Hwee Huang, deputy division director of blood supply at the Health Sciences Authority, told Bloomberg in a telephone interview on Tuesday.

Dengue Symptoms Dengue symptoms include high fever, headaches, joint and muscle pain, vomiting and a rash. Usually people with dengue recover within two weeks, according to the US National Institutes of Health.

The infection can be fatal when it turns into dengue haemorrhagic fever, which causes bleeding from the nose, gums or under the skin, or dengue shock syndrome, which causes massive bleeding and shock, according to NIH. There's no vaccine.

The Health Sciences Authority rejects blood donors showing symptoms of dengue, and asks those who may have been exposed to defer giving blood, according to the authority. It also removes blood donations from people subsequently diagnosed with an infection or who show symptoms.

The infected blood came from a repeat donor who gave blood in July last year, the report said. He later told the blood bank he had a fever the day after the donation, prompting an investigation, said the Bloomberg report.

The three men who were subsequently infected were being treated for diseases including diabetes, hypertension, heart disease, kidney failure and cancer.