Nowhere in the world is transfused blood considered 100% safe. This, despite the fact that each unit of blood is mandatorily tested for infection, among other things, before transfusion.
This happens because several infections, such as Hepatitis A, B, C and Human Immunodeficiency Virus, have a window period during which the virus doesn’t 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.
Even the best-available technology in the market right now – the Nucleic Acid Amplification Test – only reduces the window period to seven days. It does not entirely eliminate the risk.
But India fares poorly
Despite this limitation, many countries have not reported a case of HIV transmission through blood transfusion for years now. Canada has had no transfusion-transmitted HIV cases since 1985. In the US, the last known case of HIV transmission was in 2008 and the risk of disease spreading through transfusion is one in two million donations. In the UK, the last known case of a viral infection, including HIV, transmitted through blood transfusion was in 2005.
In India, on the other hand, at least 2,234 people are reported to have been infected with HIV while getting blood transfusions in the last 17 months. The National Aids Control Organisation had on Wednesday revealed this in response to a Right to Information plea filed by activist Chetan Kothari.
The organisation, however, has maintained that it has not been scientifically corroborated that the infection was indeed transmitted through transfusion. “The data shows the number of self-reported cases of HIV through blood transfusion during post-test counselling of positive clients,” said Dr Shobini Rajan, Assistant Director-General, National Aids Control Organisation. “This is a socially acceptable way of contracting the disease, as opposed to, say, sexual transmission. These are not proven cases of the virus being transmitted through blood transfusion.”
In India, approximately 0.2% of the donated blood units are detected with HIV. These are then removed from the supply. So, any infected blood that remains was ostensibly within the window period at the time of testing and could go on and infect healthy people.
The National Consumer Disputes Redressal Commission recently ordered a hospital in the outskirts of Mumbai to pay Rs 12,000 to a patient who had contracted HIV 20 years ago after blood transfusion. The court held that the blood was transfused without the woman’s “informed consent”, enlisting the risks of blood transfusion.
Blame it on the technology?
At present, most blood banks in the country use the enzyme-linked immunosorbent assay or ELISA to test for HIV and Hepatitis B and C, among other infections. This is the technology mandated by the Central Drug Standards Control Organisation.
How up-to-date the kits are impacts the window period of the infection. “The new kits that are third- or fourth-generation ELISA kits reduce the window period to about three weeks. But not everyone has this technology,” said Vinay Shetty from Think Foundation, which promotes and organises blood donation camps all over Maharashtra. The organisation works with Thalassaemia patients who need to undergo blood transfusions at least once a month.
The Nucleic Acid Amplification Test, in comparison, reduces the window period to about seven days, but it also increases the cost of the blood unit to Rs 2000 to Rs 2500 per unit, Shetty said.
The current policy of the National Aids Control Organisation caps the price at Rs 1,050 per unit of whole blood in a government institution and Rs 1,450 in a private institution.
“Can patients really afford this technology?” asked Shetty. “We need to do a cost-effect analysis and see if it works out for our patients. Blood is not free in our country.” Government hospitals only provide blood free of cost to Thalassaemia, Haemophilia and sickle-cell disease patients who require repeated transfusions.
Still, states such as Karnataka have implemented the Nucleic Acid Amplification Test technology for all their government hospitals. Some others, including Maharashtra, want to follow suit.
June 3, 2016
Source:
https://in.news.yahoo.com/hiv-transmission-why-blood-transfusion-050000712.html
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