Kozhikode: The health condition of a nine-year-old boy, the son of the 42-year-old man who died of suspected Nipah infection, remains critical, officials here said.

The condition of the other infected person, the 30-year-old brother-in-law, remains stable, they added.

An official of the health department said doctors are keeping a close watch on the infected persons. "While the youth's condition is satisfactory, the minor has not shown improvement. But, the medical team is trying its best to save both," the official said.

After the death of Kallad native, health authorities put four of his immediate relatives under medical observation. They include the wife of the deceased, their children aged four and nine, his brother-in-law and a 10-month-old infant.

Initially, they all had shown symptoms of Nipah except the man's wife, health officials said.

The samples of the nine-year-old boy and a 30-year-old man turned positive, and others turned negative when the results came.