India's Tamil Nadu, Andhra Pradesh, Telangana and Karnataka states make up for 50 per cent of the country's 770,000 HIV patients as of May 2014, said a report published on The Times of India.

Andhra Pradesh (including Telangana) tops the list with 170,000 HIV-affected people, followed by Maharashtra with 143,000 people. Karnataka has just over one hundred people with HIV, the news website quoted the Union ministry of health and family as saying.

Experts, however, attribute the rising number of reported cases in the southern states to efficient screening of the virus during the past few years.

States such as Uttar Pradesh, Rajasthan and Madhya Pradesh, which are larger both in area and population, have not recorded many cases.

It is pertinent to mention that despite the large number of HIV cases in the South, the number of fresh cases emerging every year in the country, including Andhra Pradesh, Maharashtra, Tamil Nadu and Karnataka, has dropped significantly since 2010.

According to the health ministry, the total number of new cases has halved across the country during the past three years — from 310,000 fresh cases in 2010-11 to 150,000 cases in 2013-14.