Siliguri, April 23: The HIV infection has assumed an “epidemic-like” proportion in north Bengal, with Siliguri and Islampur having the highest concentration of positive persons, the latest sentinel surveillance carried out by the West Bengal State AIDS Prevention & Control Society says.

At a time when infection rates in the rest of the country are plateaued out, the number of new cases in north Bengal is on the rise. “We had to change our approach to the interventions being carried out in the region because of the almost epidemic-like situation here,” said Mahesh Nathan, the team leader of the society’s Project Support Unit, over the phone from Calcutta today.

The areas of concern that have emerged are the injecting drug users in Darjeeling district (see chart), with a high concentration in Siliguri, and the female sex workers of Islampur and Panjipara in North Dinajpur. Sex workers in Khalpara, in Siliguri, also appear to be susceptible. A new and growing category where infections are occurring is men who have sex with men (MSM).

The surveillance — an annual exercise carried out at ante-natal centres, clinics for sexually transmitted diseases, and targeted intervention sites for female sex workers and injecting drug users — reveals the recent trends and epidemiology of the spread of the virus in the state. The latest, 11th round, was held between October 2007 and January 2008.

Unlinked anonymous testing is done on blood samples drawn at the surveillance sites by the participating organisations and the findings sent to the society’s office in Calcutta. “Subsequent intervention strategies are drawn up on the basis of these findings,” Nathan said.

A visit to the Anti-Retroviral Therapy (ART) centre at North Bengal Medical College and Hospital, the only one in the state outside Calcutta, corroborated the surveillance findings. Doctors at the centre examine all HIV positive persons and, after a CD4 test, decide whether ART should commence. This therapy, though not a cure, improves the quality of life of an AIDS patient and staves off death in most cases.

“Of the 1,300 enrolled on ART at the centre now, a significant and growing number is from Islampur/Panjipara,” said a counsellor attached to the centre. Another indication that the infection is on the rise is the number of enrolments. “We are now having to start the therapy on about 70 new cases every month, up from 30 four months back,” the counsellor, requesting anonymity, said.

Similarly, the number of injecting drug users starting the therapy is also increasing, especially from the three hill sub-divisions and Siliguri. Needle exchange programmes, at one time considered controversial, and oral substitution therapy have had to be started in a major way, Nathan said.

“North Bengal has several factors that are encouraging the spread of the virus, from a significant number of brothels and flying sex workers and men in uniform who frequent them, to trafficking in both drugs and humans. Truckers using the Siliguri corridor are also prone to getting infected,” he added.

On the brighter side, the fact that more people are coming forward to get their blood tested at the several integrated counselling and testing centres (each district hospital has one now) is an indication that the fear of discrimination has come down considerably.