Nucleic acid testing: Is it the only answer for safe Blood in India?

BACKGROUND: With the implementation of NAT in countries around the world, there is a growing pressure on the transfusion services in India to adopt NAT testing. India has about 2545 licensed Blood Centres. The Transfusion Services in India are fragmented, poorly regulated and the quality standards are poorly implemented. Blood Centres are still dependent on replacement/family donors and in most places laboratory testing for Transfusion transmitted infections is not quality assured, laboratory equipment are not calibrated and maintained, and validation of results is not carried out. Against the current scenario introducing NAT for screening of blood donors in India would pose a challenge. AIM: To study the prudence of universal NAT testing in India. MATERIALS AND METHODS: A retrospective study of 5 years from 2008-2012 was undertaken to study the true reactivity of donors using WHO strategy II and III and therefore the true seroprevalence of TTI infections in the donor populations. RESULTS: The true reactivity of the donors was much less as compared to the initially reactive donors due to the use of a well designed testing algorithm. In addition having a total voluntary blood collection along with good pre-donation counseling program also reduces the transmission of infections. CONCLUSIONS: What India essentially needs to do is religiously implement the strategies outlined in the WHO Aide-memoire. The blood should be collected only from voluntary non remunerative and repeat donors, there should be stringent donor selection with pre-donation counseling instituted. Strict implementation of quality management system, development of well defined testing startegies and strong haemovigilance system could take us a step in the right direction.

Tracking based baseline restoration for acquisition of impedance cardiogram and other biosignals.

Most of the biosignals have a baseline which may drift over a large range compared to the excursion of the signal of interest. To make effective use of the input dynamic range of the signal acquisition setup, this offset drift needs to be cancelled. The circuit reported here uses amplitude tracking technique for estimation and removal of the baseline drift. This circuit is independent of the processor to which the signal acquisition unit is interfaced.