‘‘When the prevalence rate increases, the number of deaths also increases. People dying this time must have got infected 10 years ago,’’ said Broun.

Broun says the 4-lakh figure, however, like the 5.7 million HIV/AIDS cases, is a mathematical derivation and not a headcount. Scientists have used factors like India’s average age of survival after the infection, data on the average age of people with HIV and the number of people on Anti-Retoviral Treatment.

‘‘It is a method we have used to estimate the figures for all the countries,’’ said Broun.

The Indian government, too, is preparing a report on the number of deaths in the country. Likely to be out this month, it’s being prepared by the National Institute of Medical Statistics. The model for estimation is based on assessing the mortality of the population without HIV and comparing it with the mortality rates.

Another survey funded by the Gates Foundation and the Canadian government is basing its results on actual interviews and counts. Though the official figure of the number of people living with HIV is 5.2 million, the UNAIDS report put the figure at 5.7 million, the highest in the world. While the government gave the estimates for adult population (15 to 49 years of age), UNAIDS went ahead and estimated that an additional 1 lakh children and 4 lakh people above 50 years needed to be added. ‘‘Ours is a cradle-to-grave figure,’’ said Broun. The only silver lining: the percentage of affected population is below one per cent, in South Africa it’s 20 per cent, said L.M. Nath, former AIIMS director and an AIDS epidemiologist.

... contd.