B'lore researchers discovered HIV in 1958

Deadly incursion

The deadly virus was first spotted in India in 1986 among sex workers in Chennai. It was identified as HIV-1 subtype C, the commonest strain found in India, so far accounting for more than 96 per cent of the infections.

But studies undertaken by scientists from Jawaharlal Nehru Centre for Advanced Scientific Research and St John’s Medical College with researchers of Karolinska Institute, Stockholm, reveal that the same strain may be present in India as early as in 1958.

The researchers provided a range—1947 to 1970—as the virus’s likely introduction period. This means HIV may have come to India any time in those 23 years. However, the mean value was 1958, making it the most likely time when the virus was introduced.

“This is the first experimental attempt to define the date of origin of HIV in India,”JNCASR professor Udaykumar Ranga, part of the study team, told Deccan Herald. The gene-based molecular clock analysis of HIV-1 is being used to trace the virus back in time. The technology is new, being in use since 2006, with Brazil and South Africa as its success stories. It is being tried in India for the first time.

“The source of 1958 HIV could be several African countries, including Botswana, Malawi, South Africa, Tanzania, Zambia and Zimbabwe,” said Ujjwal Neogi, a scientist at St John’s Medical College, Bangalore, who presented the findings at the National Institute of Immunology here.

Neogi said more research was required to better understand exactly how the virus was imported from Africa as well as why acquired immune deficiency syndrome (Aids) did not manifest till late 1980s though it entered India in 1958.

The long hiding period, however, is not surprising to scienists given the HIV’s uncanny ability to remain inside the host for years without symptoms. “The first HIV-1 discovery was in 1983. But a recent study showed the presence of the virus in 1960 in Congo,” he said.

It is also possible that the virus did not cause any major outbreak in the absence of a critical mass of infected persons. “A flood of potential danger does not happen on the first day after rain. You wait until the water level crosses a minimum level. This doesn’t mean that the first few rain drops did not contribute to the danger,” Ranga explained.

More research was required to properly place the missing pieces of the jigsaw puzzle. “This is one block in the elephant. Many more missing blocks should be put in place,” Ranga said. The technology was not foolproof. The discovery, however, might not be of clinical significance because medical intervention strategies depended on what was in circulation today and not on what was in the past, he added.