One of them was found to have carried the deadly Nipah virus (NiV) as specimens of the virus were found in his body, said an IEDCR press release on Sunday.
Although direct evidence of Nipah could not be found in them, it is assumed that the other four victims came in touch him and extracted the virus, leading to their death.
The virus specimens were not found among survivors and those who came in touch with the deceased either. Nevertheless the medical team enlisted their names and kept them under observation.
Outbreak investigations in Bangladesh have identified two routes of transmission of Nipah virus
from its natural reservoir, fruit bats of the genus Pteropus to human: drinking of raw date palm sap (khejurer rosh) contaminated with NiV and close physical contact with Nipah infected patients.
The team was unable in this case however, to establish that the person in whom Nipah was found had consumed khejurer rosh.
Earlier on February 27, a five-member medical team of IEDCR visited the house in Bhandardah village in Baliadanga upazila over the deaths of five members of a family mysteriously in the space of 15 days.
The team comprised Doctor Gazi Shah Alam, Doctor Tanzina Nowrin, Doctor Debashish Kumar Shah, Doctor Shahnaz Parvin and Doctor Ismail Khan. They were later joined by another 4-member team.
The team talked to surviving family members, locals, local representatives and collected samples from the house, said Doctor Shah Newaz, civil surgeon (acting) of Thakurgaon.