Published: 19-06-2013 00:00 | Updated: 23-02-2014 14:17

Molecular analyses describe HIV epidemic in India

A new doctoral thesis from Karolinska Institutet describes important properties of the HIV-1 subtype C (HIV-1C) epidemic in India. HIV-1C is the fastest spreading viral subtype and the one that has infected most people around the world.

In his doctoral thesis, Ujjwal Neogi, doctoral student at Karolinska Institute's Department of Medicine, Huddinge, has provided confirmation that India's national AIDS programme has been a success.

"The molecular analyses presented in the thesis show that the epidemic has remained stable in India since 1990," says Ujjwal Neogi. "The antiretroviral treatment worked for over 97 per cent of patients during a follow-up period of almost four years provided that they had a good initial response and stuck to the prescribed regimen."

Ujjwal Neogi also studied the roots of HIV-1C in India. The subtype was discovered in Ethiopia in the mid-1980s by a team of researchers led by Professor Anders Sönnerborg, who was Ujjwal Neogi's principal supervisor. The DNA sequence of the virus has now been analysed in patient samples collected between 2007 and 2011, and using the genetic differences between different samples and the known rate of change of individual genes, Ujjwal Neogi has calculated backwards and concluded that today's HIV-1C virus in India developed from one or a few genetically related viral strains that arrived from South Africa in the early 1970s. Knowledge of the evolution of the virus, its origin and spread is essential to the future development of a strategy for dealing with HIV-1 in India and other countries.

The thesis also discusses several issues that can help to guide the control of HIV in India and other areas of limited resources, such as the possibility of using DNA instead of RNA during analyses for monitoring drug resistance and thus avoiding having to keep the samples in cold storage. It also described mutations linked to drug resistance in children, young people and adults, the significance of individual properties of the host for the development of drug resistance, and the expression of viral co-receptors in infants infected through the mother.

"One surprise was that over half of the young people with an HIV-1C infection have high levels not only of the virus but also of CD4+ T cells," says Ujjwal Neogi. "They are well and show no symptoms of AIDS despite high levels of the virus in the blood."

The study is the result of a collaboration between Karolinska Institutet (Stockholm), St John's Medical College Hospital (Bangalore), the National Institute of Immunology (New Delhi) and the University of California (San Francisco), and was financed through the EU's Seventh Framework Programme, the AIDS International Training and Research Program from the USA's National Institutes of Health, the Physicians Against AIDS Research Fund, the Sven Gard Research Fund and Erasmus Mundus. Dr Neogi's principal supervisor was Professor Anders Sönnerborg, Karolinska Institutet. The thesis defence took place on 11 June 2013.

Doctoral thesis

Translational genomics of HIV-1 subtype C in India: molecular phylogeny and drug resistance
Ujjwal Neogi
Karolinska Institutet 2013, ISBN: 978-91-7549-172-1