Blood transfusions, a life-saving medical intervention, carry the potential risk of transfusion-transmitted infections (TTIs). These infections result from the introduction of pathogens into the recipient’s bloodstream. A wide variety of organisms, including bacteria, viruses, prions, and parasites can be transmitted through blood transfusions. To ensure the utmost safety in blood banking, comprehensive testing protocols are paramount.

Transfusion-Transmitted Infections (TTIs)

National standards for blood centers and transfusion services advocate the performance of mandatory tests on blood samples collected in pilot tubes at the time of collection. Any whole blood or components from units testing positive/reactive/initially reactive are promptly discarded.

Syphilis Testing

Each donation of whole blood shall be subjected to a serological test for syphilis, employing methods such as VDRL/RPR, TPHA, ELISA, CLIA, or any other validated sensitive method.

Viral Hepatitis Screening

Test for hepatitis B (HBsAg) and hepatitis C (antiHCV) by Enzyme-Linked Immunosorbent Assay (ELISA)/ Chemiluminescence Immunoassay (CLIA)/ or an alternative approved method with similar or higher sensitivity, which is a validated method should be done on each unit of blood. To enhance blood safety, consider supplementing with technologies like nucleic acid tests (NAT) known for their comparable or superior sensitivity. In cases where smaller centers lack ELISA/CLIA capabilities, they may release blood after rapid tests. However, it is strongly advised to transition to ELISA/CLIA, as rapid testing is not the recommended standard for optimal blood safety.

HIV Testing

All collected blood units should be screened for HIV 1 & 2 antibodies, utilizing Enzyme-Linked Immunosorbent Assay (ELISA), Chemiluminescence Immunoassay (CLIA), or an alternative approved validated method. Universal NAT testing in Blood Centers is recommended and may be implemented in a phased manner.

Malaria Testing

Malaria testing involves screening all blood units for malarial parasites using a validated, approved, and sensitive antigen test. The use of pLDH based assays specific to PAN malarial species is recommended.

Despite these rigorous measures, a residual risk of TTI transmission exists. Causes of this residual risk include the early stage of infection, low-level chronic carrier states, non-seroconversion, and various laboratory or technical errors.

Addressing Residual Risks

1. Diagnostic Window Period: In the early stages of infection, there is a window period during which the infection may not be detectable.
2. Chronic Carrier State: Asymptomatic donors may carry a low-level chronic infection, potentially testing negative in screening.
3. Non-Seroconverts: Some individuals may not produce detectable antibodies even after infection.
4. Errors: Laboratory, human, mechanical, or technical errors can contribute to the residual risk.

Transasia’s offerings for accurate and timely detection of TTIs

Transasia Bio-Medicals Ltd. offers total diagnostic solutions for screening of transfusion transmissible infections (TTIs) and confers early and accurate detection of TTIs. Our product portfolio encompasses ELISA screening kits – ErbaLisa HIV Gen 4, ErbaLisa SEN and PICO HBsAg, ErbaLisa HCV Gen4 Ag + Ab, ErbaLisa Syphilis, ErbaLisa Malaria PAN (pLDH), etc. Our ErbaLisa range includes HCV Gen 4 Ag + Ab kits for core antigen and antibody detection, HCV Gen 3 V2 kits for qualitative antibody detection, and HIV Gen 4 kits for simultaneous p24 Antigen and Antibodies to HIV 1 and HIV 2 detection. The ErbaLisa PICO and SEN HBsAg kits employ sandwich ELISA for qualitative hepatitis B virus detection with heightened analytical sensitivity. Additionally, our ErbaLisa Syphilis screening kits allow qualitative determination of total antibodies (IgM, IgA, and IgG) for Treponema pallidum. Designed for blood banks and clinical laboratories, these ELISA kits ensure best-in-class sensitivity, specificity, and accurate results in screening and diagnosis. The ErbaLisa PAN (pLDH) helps detection of various malarial parasitic infections.

Despite these challenges, ongoing advancements in diagnostic technologies and stringent testing protocols aim to minimize these risks, ensuring the safety of blood and its components. Blood centers continue to evolve, leveraging science to safeguard public health in the face of transfusion-transmitted infection risks.

References:

1. National standards for blood centres & Blood transfusion services, 2^nd edition, Chapter 8.