Siliguri, May 8: Shortage of blood in north Bengal, especially in the Siliguri region, has been compounded this year with the low frequency of voluntary donation camps and turnouts at them.

Added to this is an unwelcome tag that HIV transmission through blood and blood products has been quite high, as much as 1.8 per cent compared to the state average of 0.5 per cent and national average of 0.8 per cent. The figure was arrived at on the basis of information provided by patients at the Voluntary Counselling and Testing Centre (VCTC) of North Bengal Medical College and Hospital (NBMCH).

A Supreme Court ruling in 1996 made it mandatory for all blood banks to test each collected unit for HIV and other blood-borne diseases. But it is only after 2003 that the banks started carrying out the order stringently, a senior official of a government blood bank said.

“In such a situation, it is a matter of concern that 1.8 per cent of HIV infections as detected at the VCTC have been through blood and its products (like plasma and Factor 8),” said a senior official of the West Bengal State AIDS Prevention and Control Society.

A cumulative total of 1,624 persons have been detected HIV positive between August 2002 (when the centre started) and March 2008, the counsellor in charge of the VCTC said. NBMCH being the referral hospital for six north Bengal districts as well as the region’s only anti-retroviral therapy centre, the number of people taking the test at the medical college could be taken as a representation of the AIDS situation in this part of the state.

The director of the Regional Blood Transfusion Centre at NBMCH, Mridumoy Das, while confirming that stringent procedures were being followed at all government blood banks, said the likelihood of the virus not being detected during testing because of the “window period” was also very low.

The window period is that time (usually 21 to 28 days) that the virus does not show up in a blood sample because a person was infected with HIV just before he or she donated blood. By thus escaping the test, the blood unit goes to the bank and is transfused to a patient.

“But the possibility of this happening and the virus spreading in such a way is one in one lakh units,” said Das, saying that he would make inquiries with the VCTC as to how this high figure came about. The counsellor has, however, said no such detections have occurred over the past year. “Those interviewed said their infections may have taken place about five or six years back, which is quite likely as the manifestation of AIDS symptoms takes so many years to show up.”

Das, however, said: “HIV detected after collection from donation camps is between 0.4 and 0.9 per cent, which is at par with other places in the country”.

The director added that the stocks at the NBMCH blood bank “were not very good”. Camps were not being held frequently as they used to be. “The DYFI, which used to contribute around 20-22 per cent of the annual collection, held its last camp on January 29 this year. But last year, the organisation had held at least one camp every two months.”

“Only 23 per cent of the total blood required in Siliguri is donated by its residents, unlike in Malda where 90 per cent of the need is met through voluntary camps,” Das said.