Visual Detection of Multiple Viral Amplicons by Dipstick Assay: Its Application in Screening of Blood Donors a Welcome Tool for the Limited Resource Settings

Abstract

Hepatitis B virus (HBV) is a significant cause of transfusion-transmitted infections. To achieve entirely HBV-safe transfusion still appears to be an unreachable objective, at least in the high-prevalence regions of the developing world. Transfusion-related HBV safety depends on the screening technique adopted by the blood banks and its prevalence in the community, and the more sensitive the screening technique adopted the less the chance of transmitting HBV infection through the transfusion (1). All endeavors towards lowering the risk of transfusion transmitted HBV and/or HCV infection play an important role in prevention of this preventable human suffering. This is particularly significant in the developing countries with limited resources and overstretched health budgets. A recently published report by Dineva et al. is a remarkable achievement in this direction (2). The authors have introduced a simple, sensitive, instrument-independent technique for visual detection of multiple nucleic acid hybridization on the dipstick membrane. The report shows high sensitivity and reproducibility of the test for detection of HBV DNA, HCV RNA, and human immunodeficiency virus RNA among blood donors by minipools. Unfortunately, the genomic screening technology is still expensive and not affordable for the developing regions of the world where these viruses are highly endemic, which not only increases the risk of transfusion-transmitted HBV and/or HCV infection but is perhaps an important mode of spread of this infection. Most of the developing countries are screening the collected units of blood for HBsAg, anti-HBc, anti-HBs, and anti-HCV by enzyme immunoassay. The blood units which are anti-HBc positive or anti-HCV positive are rejected, thus leading to high rejection rates of collected units of blood. At this center, 3.2% of units are rejected because of isolated anti-HBc positivity (4). The rejection of these invaluable collected blood units and exclusion of the munificent volunteer blood donors because of isolated anti-HBc or anti-HCV positivity lead to chronic shortage of blood. The blood units which are isolated as being anti-HBc positive may not necessarily contain HBV DNA when tested by the nucleic acid amplification testing (NAT) technology, or anti-HCV-positive units may not be positive for HCV RNA if tested by PCR. Hence, they can perhaps be utilized if the low-cost genomic screening resources are made available to the developing countries; on the other hand, the anti-HBc- and/or anti-HBs-positive donors might be positive for HBV DNA if tested by the sensitive NAT assay system (3, 5). The visual detection dipstick method for detection of HBV and HCV nucleic acid appears an attractive alternative to the intricate instrument-dependent methods for the countries with limited resources. This simple instrument-independent method is less expensive than the conventional instrument-dependent method and can be adopted by the blood banks of the developing countries where these viruses are highly endemic to possibly ensure the achievement of zero risk of transfusion-transmitted HBV and HCV infection. This will not only ensure the safe blood transfusion at lesser testing cost but will also reduce the preventable human suffering of transfusion-transmitted HBV and HCV infection.