When the Mumbai Aids Control Society was faced with a series of complaints by people who said that they had acquired the Human Immunodeficiency Virus, or HIV, through blood transfusions from blood banks, it decided to take a closer look.

When a person is diagnosed with HIV, counsellors at government-run Integrated Counselling and Testing Centres take down a detailed patient history to ascertain how the infection was transmitted.

As part of its investigation, which started in August, officials at the Mumbai Aids Control Society studied the history of 85 HIV-positive individuals who claimed that they had contracted the life-threatening infection through blood transfusions. Of these, the team tracked down 48 patients of which only 21 reconfirmed that they had got the infection as a result of a blood transfusion. Upon investigation, the team was able to identify the blood banks as the cause of infection only in the case of four patients.

The Mumbai Aids Control Society, however, does not plan to intervene in the working of these blood banks as there is no evidence that the four patients contracted HIV from the blood supplied by these banks.

Why the investigation?

Under the Drugs and Cosmetics Act, it is mandatory for blood banks to test donated blood for transfusion transmissible infections, including HIV.

“Only after the banks are assured that the blood is free of the transfusion transmissible infection, it is given for transfusion,” said Dr S Acharya, additional project director, Mumbai District Aids Control Society.

The most common mode of HIV transmission is unsafe sex, followed by the use of infected needles.

In India, at least 2,234 people were reported to have been infected with HIV due to blood transfusions between October 2014 and March 2016. The National Aids Control Organisation released these figures in June in response to a Right to Information plea filed by activist Chetan Kothari.

Acharya said that she and her team at the Mumbai’s Aids Control Society decided to carry out an inquiry into the matter as it wanted to debunk the idea that people were contracting HIV through blood transfusions.

“There were repeated queries about the safety of blood transfusions,” said Acharya. “We just thought we will reconfirm from patients who reported getting HIV as a result of a blood transfusion.”

In the course of its investigation, Acharya said that the society found a patient who said that he had undergone an operation for which he had received a blood transfusion but he did not remember where the blood was brought from.

She added: “One patient said that he underwent the blood transfusion in Bihar.”

People reported to have contracted HIV through blood transfusion in Mumbai.

A slim chance

Acharya conceded that “no laboratory test in the world can tell you that the blood is infection free… [as] there is always a window period where the blood though infected may not be positive when tested”.

For instance, several infections, such as Hepatitis A, B, C and HIV, have a window period during which the virus does not show up in a blood test. So, if a person contracts the HIV today and decides to donate blood the next day, the laboratory that tests the blood will not detect the virus in it. The window period for HIV is usually between three weeks and three months, depending on the technology used at the laboratory.

But Acharya added that less than 1% of HIV infections in India can be attributed to unsafe blood transfusions.

‘Honesty works best'

Before donating blood, a donor is expected to answer a set of questions, which include enquiries about recent illness and unsafe sexual activity. These questions help blood banks screen donors.

Acharya said that people who have contracted HIV rarely confess to unsafe behavioural practices that could have led to the infection, and give a “false history” instead.

“We have to understand that patients are giving a subjective history and we have to accept what they say,” said Acharya. “There is no evidence to back their claim.”

Said Dr Zarin Soli Bharucha, chair of the Federation of Bombay Blood Banks, Mumbai: “If people start answering these questions honestly, we can have zero transfusion transmissible infections…It will be wrong if the blood banks are punished as they are only doing their job. No test can pick an infection which is in its window period.”

Bharucha pointed out that the fact that the Mumbai Aids Control Society could only find four patients who could recall the name of the blood banks from where they believed that they had contracted the infection was proof that most patients were casually blaming blood transfusions for their HIV status.

“If they admit to high-risk behaviour they will face stigma,” said Bharucha. “But if they blame blood, people will sympathise with them instead.”