Bangalore based Hemogenomics in association with Chiron, the diagnostic major, part of Novartis, is now gearing up to increase the use of Nucleic Acid Testing Technology (NAT) to screen human immunodeficiency virus - 1 (HIV-1), Hepatitis B (HBV) and Hepatitis C (HCV) virus in donated blood.

The test is the first simultaneous and single tube NAT solution for HIV-1, HCV and HBV. It detects the viral nucleic acid (RNA/DNA) and reduces the window period of detection for all the three viruses from the current available serological (ELISA) tests.

NAT combines the advantages of direct detection of the organism with sensitivity several orders of magnitude higher than that of traditional methods. The screening of blood for infectious markers (anti HIV 1 & 2, anti HCV and HBsAg) is done using government approved test kits (Elisa or Rapid Kits). Despite these efforts, residual risk of transfusion-transmitted infections remains because of donors in the pre-sero conversion (window period), viral variants, non-seroconverting (immunosilent) or delayed seroconverting carriers (atypical seroconversion), stated Sumit Bagaria, President, Hemogenomics Pvt Ltd.

"The NAT technology along with serological testing can reduce the residual risk to a great extent because it involves highly specific detection of an infectious agent with much higher sensitivity," he added.

The company has been instrumental in bringing in state-of-the-art technologies for disease prevention, diagnosis and monitoring.

"Opting for NAT at blood donation camps in South East Asia has been benefited the population. In Singapore, among the 466,779 samples tested by NAT since October 2007 labs, camps could identify 9 HCV and 10 HBV NAT yield samples (1 in 24,567). Similarly, in Thailand, Hong Kong and in Korea, the NAT yield rate is 1 in 11, 676 samples, 1 in 202,500 samples and 1 in 1, 46,628 samples respectively. Despite these countries having a stringent donor counselling and screening process, a high rate of regular repeat voluntary donation and use of the most sensitive serological tests, have helped to identify a significant number of samples which were NAT reactive but sero-negative.

In India, Indraprastha Apollo Hospitals, Delhi has taken the initiative for NAT implementation for the first time in the country. In the first nine months of implementing NAT, they were able to pick five (3 HBV and 2 HCV) NAT yield samples among 13,331 samples tested (1 in 2,666). In Bangalore, Rotary TTK Blood Bank has set up a dedicated centre to offer NAT.

The application of NAT screening for HIV and HCV is already prevalent. Many countries have also added HBV NAT and others are planning to add it. USA also added West Nile Virus (WNV) NAT to its blood safety programme.

Some of the countries already utilizing the benefits of NAT are the Asia Pacific Region of Australia, India, Indonesia, Hong Kong, Korea, Malaysia, New Zealand, Singapore, Thailand and Japan, Europe, Middle East and Africa which covers Belgium, Denmark, France, Germany, Greece, Ireland, Israel, Italy, Lithuania, Poland, Portugal, Slovenia, Slovakia, South Africa, Egypt, Spain, Switzerland, UK and Scotland. In the Americas, the countries include US, Brazil, Caribbean and Canada.