Around 50 children and many adults of an isolated tribe in the Andaman and Nicobar islands have contracted measles in the past month, says a bbc report. That works out to around 20 per cent of the total population of the tribe.

Doctors warn the illness could seriously affect the Jarawa tribe, which once numbered 5,000 but is now down to only about 270 people. No deaths have been reported, however. Initially officials claimed it was just a "heat rash'. But doctors at the Pant Government Hospital in the islands capital Port Blair later confirmed it was measles.

In 1999 too, 108 Jarawas had contracted measles but officials had denied it initially like in the present case. Environmentalists have criticised authorities for not protecting the tribes and preserving their habitat.