A three-member team of the Institute of Epidemiology, Disease Control and Research (IEDCR) today started investigating the deaths of two children who died of an unidentified disease in Rajshahi recently.

The team visited Rajshahi Medical College Hospital (RMCH), talked to doctors and the parents of the children. They also visited residences of the affected persons and collected samples, said Brigadier General FM Shamim Ahmed, the director of the hospital.

The team consists of two doctors -- Dr Kyaw Thowai Prue Prince, a medical officer, Dr Md Mainul Hasan, a FETP-B fellow, and Mohammad Ali Zinnah, senior medical technologist.

"They're following detailed medical procedures to detect the cause behind the deaths and also find out if the infections are causing any outbreak," he said.

Muntaha Marisha, a two-year-old girl died of unidentified disease on February 14. She suffered symptoms of high fever, vomiting, and black rashes on her skin.

Four days later her five-year-old sister Muftahul Mashia also died with similar symptoms.

After the second death on February 17, their parents Manjur Hossain, 35, and Poly Khatun, 30 were quarantined at the RMCH.

The father is a mathematics teacher at Rajshahi Cadet College in Sardah of Charghat upazila. The family lives in the teachers' quarter of the college.

The parents were released from the hospital this afternoon, said the RMCH director.

"they have been advised to stay isolated at their house for next 14 days," the director says.

"First, we suspected viral encephalitis in which a viral infection causes inflammation of the brain," said the RMCH director.

But tests at IEDCR showed the children were neither infected with Nipah virus, nor they had tuberculosis encephalitis, nor Japanese encephalitis.

"The IEDCR team came here for further investigation," the director says.

The two children had jujubes (a kind of date) before falling sick, said Roich Uddin, one of the relatives of the family.

The team also inspected the jujube tree and collected samples from left-overs of fruits, the hospital staffers said.