Screening algorithms and HIV risk to blood transfusion recipients

Overview

Blood banks screen for viral infections to reduce risk of transmission through transfusion. More sensitive screening algorithms are typically more expensive. This group will simulate scenarios to estimate the “residual risk” (i.e. the probability of infectious blood being transfused, despite screening) and the cost per transfusion-associated infection averted using epidemiological data from a population based model of HIV in South Africa.

Things to consider

• This group is recommended for:
  • Participants interested in applying model-based estimates to real world problems
  • Participants with good programming skills
  • Participants with interest in simulation of processes
  • Participants interested in learning more about diagnostics and blood safety issues

Background

Blood banks have to keep the risk that infectious agents will be transmitted through blood transfusions as low as possible. Hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV) are examples of pathogens that spread through infectious blood transfusions before blood banks were able to screen donated units effectively. However, all tests (whether they detect the pathogen itself, such as Nucleic Acid Testing (NAT) assays) or antibodies against the pathogen (usually termed “serological assays”) have imperfect sensitivity (i.e. not every case will be successfully detected) and “window periods” (i.e. a delay, varying in individual patients, but often with a well-known average duration) between the time an individual is infected and when the assay or multi-assay algorithm is able to detect the infection.

Data

• Sensitivities, window periods and costs of a range of HIV screening assays
• HIV prevalence and incidence estimates obtained from the THEMBISA model
• Publicly available blood donation data

Resources

References

• Fiebig, EW, DJ Wright, BD Rawal, PE Garrett, RT Schumacher, L Peddada, …, & MP Busch. (2003). Dynamics of HIV viremia and antibody seroconversion in plasma donors: implications for diagnosis and staging of primary HIV infection. AIDS 17(13): 1871-1879.
• Zou, S, SL Stramer, & RY Dodd. (2012). Donor testing and risk: current prevalence, incidence, and residual risk of transfusion-transmissible agents in US allogeneic donations. Transfusion Medicine Reviews 26(2): 119-128.
• Dodd, RY, EP Notari, D Nelson, GA Foster, DE Krysztof, Z Kaidarova, …, & B Custer. (2016). Development of a multisystem surveillance database for transfusion‐transmitted infections among blood donors in the United States. Transfusion 56(11): 2781-2789.
• Cable, R, N Lelie, & A Bird. (2013). Reduction of the risk of transfusion‐transmitted viral infection by nucleic acid amplification testing in the Western Cape of South Africa: a 5‐year review. Vox sanguinis 104(2): 93-99.
• Chavez, P., Wesolowski, L., Patel, P., Delaney, K., & Owen, S. M. (2011). Evaluation of the performance of the Abbott ARCHITECT HIV Ag/Ab combo assay. Journal of Clinical Virology, 52, S51-S55.
• Roche. (2007). Roche1 COBAS1 AmpliPrep/COBAS1 TaqMan HIV-1 Qual Test. Branchburg, NJ. Roche.