A detailed study on the health of Jarawas revealed this dangerous trend. "Jarawas would need to be regularly innoculated if we have to prevent the disease from spreading," says A&N Tribal Health Deputy Director Dr R Thulasi Dasan. He says the source of the disease has not been traced.

Dr Dasan thinks preventing the spread of this disease may not be difficult now, as the Jarawas have begun understanding the concept of medical attention. "Now, they accept the instructions. Earlier, they would only consume sweet syrups and they invariably refused tablets and injections. But they now are more amenable to allopathic treatment," he says.

He attributes this confidence among the Jarawas to their handling of the last four epidemics which broke out since 1998. "There has not been even a single casualty due to timely and proper medical attention," he says.

The actual population of Jarawas is not available. During the study conducted on court orders, the Island's health department covered 251 of them. The local anthropologists put their tally at 264 while Director Tribal Welfare says the Jarawas population will be around 300.

Ninety four per cent of the population is below 44 years. More than half of the population constitutes of children below 14 years. Local anthropologists say, "Jarawas are in the category of Classical Hunters and worldwide their average age is 50 to 55 years."

The sex ratio among the Jarawas is very healthy - 98 females for every 100 males. The study, conducted last year found maximum number of Jarawas to be in the reproductive phase. "Almost 35 per cent of Jarawas were below 14 years then. They all are now ready to reproduce. This will help in maintaining the population of the tribe," explains Dr Dasan.

The study also found 42 per cent of the Jarawas to be suffering from one or the other skin disease. Nine per cent had some respiratory tract infection.

But none of the Jarawas were found with symptoms of diabetes or blood pressure. The Jarawas do not eat salt at all. "After studying the Jarawas, I am certain that both diabetes and blood pressure are lifestyle and diet related diseases," the doctor says.

Despite heavy fat consumption (the tribals' staple diet is pig meat), the study found no traces of cholesterol. "Their body temperature is lower and pulse rate slower compared to the general people. The Jarawas have only two blood groups - O (70 %) and A (30 %) and all RH positive," says Dr Dasan.

The study also tracked reasons of deaths in the aboriginals. Dr Dasan says the scholars faced many problems in establishing reasons for death among the Jarawas. "The Jarawas have a memory lasting three days. And, they can count only up to five.

"We could find evidence of 327 deaths over the past 50 years. Nearly 63 per cent of these occurred due to respiratory tract infections. Another 21 per cent of the deaths were because of gastroenteritis or malaria," he adds.

The study has made certain recommendations to tackle the health of the Jarawas. Among other things, "they need to be immunised as they have no acquired immunity to new infections. Besides, regular treatment for skin diseases - but skin problem will not end until the Jarawas improve their personal hygiene."