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Donated blood being transfused into you may not be entirely safe, even after it has undergone the present day gold standard Elisa test.
After studying 5,818 donated blood samples that tested safe through Elisa, AIIMS' department of transfusion medicine ran the samples through the Nucleic Acid Testing (NAT) and found five samples to contain Hepatitis B and Hep C virus. This saved the lives of 15 people who could have got transfused with the infected blood.
Faculty in charge of AIIMS' blood bank Dr Kabita Chatterjee, who conducted the "Novartis Diagnostic NAT study", told TOI, "Elisa is not fullproof against transfusion transmitted infections like HIV and Hepatitis. That's why we have introduced NAT in AIIMS. With Elisa known to give false negatives, it is better to use NAT as an additional layer of safety."
According to Dr Debasish Gupta, national programme officer of blood safety at NACO, several private hospitals now use NAT which is sensitive enough to identify samples that contained viral genetic material during the window period -- the length of time after infection that it takes to detect antigens of the virus or for a person to develop enough specific antibodies to be detected by current testing.
Dr Gupta said, "Though Elisa test is very good in detecting HIV, NAT helps in detecting infected samples during the window period which escapes an Elisa. HIV transmission through blood transfusion is 1.1% of all reported HIV cases. Around 10 million units of blood are used for transfusion every year now."
India's annual blood donation rate is growing by 4%. The current donations are collected and screened in over 2,000 blood centres across the country.
The National Blood Policy formed in 1990s says donated blood has to be tested for five tests -- HIV, HBV, HCV, syphilis and malaria. It is mandatory for all blood banks and hospitals to make available blood for transfusions only after it is declared infection free. However, very often, the window period can infect patients being transfused with donated blood.
After studying 5,818 donated blood samples that tested safe through Elisa, AIIMS' department of transfusion medicine ran the samples through the Nucleic Acid Testing (NAT) and found five samples to contain Hepatitis B and Hep C virus. This saved the lives of 15 people who could have got transfused with the infected blood.
Faculty in charge of AIIMS' blood bank Dr Kabita Chatterjee, who conducted the "Novartis Diagnostic NAT study", told TOI, "Elisa is not fullproof against transfusion transmitted infections like HIV and Hepatitis. That's why we have introduced NAT in AIIMS. With Elisa known to give false negatives, it is better to use NAT as an additional layer of safety."
According to Dr Debasish Gupta, national programme officer of blood safety at NACO, several private hospitals now use NAT which is sensitive enough to identify samples that contained viral genetic material during the window period -- the length of time after infection that it takes to detect antigens of the virus or for a person to develop enough specific antibodies to be detected by current testing.
Dr Gupta said, "Though Elisa test is very good in detecting HIV, NAT helps in detecting infected samples during the window period which escapes an Elisa. HIV transmission through blood transfusion is 1.1% of all reported HIV cases. Around 10 million units of blood are used for transfusion every year now."
India's annual blood donation rate is growing by 4%. The current donations are collected and screened in over 2,000 blood centres across the country.
The National Blood Policy formed in 1990s says donated blood has to be tested for five tests -- HIV, HBV, HCV, syphilis and malaria. It is mandatory for all blood banks and hospitals to make available blood for transfusions only after it is declared infection free. However, very often, the window period can infect patients being transfused with donated blood.