LINTHICUM, MD, April 29 - A study by Yale and CDC researchers suggests that a sophisticated holding policy recently implemented by the blood plasma industry is a cost-effective part of the overall strategy for preventing the spread of HIV and other infections from blood plasma donors to recipients. The paper is being presented at a convention of the Institute for Operations Research and the Management Sciences (INFORMS®) in the Cincinnati Convention Center on Monday, May 3 at 1 PM.
The paper is entitled, "Hold Everything! Holding policies for Protecting Plasma Supplies." The authors are Edward H. Kaplan, Yale School of Management, and Glen A. Satten, United States Centers for Disease Control and Prevention.
Picking the Better of Two HIV Tests
The authors used operations research and statistical modeling to assess holding periods to reduce the chance of a potentially infectious unit being passed on for further processing. If done correctly, subsequent plasma processing eliminates the risk of HIV transmission through heat treatment. The researchers evaluated two additional measures that would guard against the rare possibility that processing could be done incorrectly.
Considering the sometimes competing pressures of cost vs. safety, they compared two possible strategies for screening plasma donations for HIV before processing: (1) holding all of a donor's blood plasma donations for a specific time and (2) testing the same plasma using a new, expensive screening test called PCR (polymerase chain reaction).
Holding all of a person's blood plasma units for 21 days reduces the probability that an infectious donation escapes detection by 50% at a cost of 29 cents. In contrast, they found, using PCR has the same rate of effectiveness but costs $8, more than 25 times as much.
Achieving the Safest Possible Blood Plasma Supply
A multifaceted approach currently ensures the safety of blood plasma. Advances in testing technology, coupled with heat treatment which inactivates infections such as HIV, HBV, and HCV, has virtually eliminated the risk of infection with these diseases through blood plasma. Occasionally, plasma is collected that is potentially infectious, but not detected because the donor has not yet developed levels of HIV antibody (or p24 antigen) that can be identified by screening tests, the authors explain. This occurs when plasma is collected in donors who were recently infected with HIV. To eliminate the risk of transmission from these donations, blood plasma products are heat treated. There have been no cases of HIV transmission through blood plasma since heat treatment began.
To guard against the possibility of errors in plasma processing, the blood plasma industry has embarked on a comprehensive program to screen out the few potentially infectious units before processing. This program includes accepting only donations from repeat, qualified donors and implementation of the hold period. Under the type of holding policy described in the paper, all donated units are stored before being released for fractionation and the production of plasma products. If a donor tests positive for the infection in question at a subsequent donation, then all of that donor's units currently in storage are discarded. Otherwise, donated units are released for processing at the end of the holding period.
The study will be published in a forthcoming issue of the journal Mathematical Biosciences.
Operations Research
INFORMS® is holding its semi-annual convention in Cincinnati from Sunday, May 2 to Wednesday, May 5. The theme is "Delivering to the Global Consumer." It takes place at the Cincinnati Convention Center and the Omni Netherland Plaza.
The convention includes sessions on topics applied to numerous fields, including commuter transit, e-commerce, health care, information technology, energy, transportation, marketing, telecommunications, and sports. More than 1,300 papers are scheduled to be delivered.
The General Chair is Professor David Rogers of the University of Cincinnati. The convention is underwritten, in part, by a generous grant of $125,000 from Procter & Gamble. For additional information on the conference, including a full list of workshops, visit http://www.informs.org/Conf/Cincinnati99/ The Institute for Operations Research and the Management Sciences (INFORMS®) is an international scientific society with 12,000 members, including Nobel Prize laureates, dedicated to applying scientific methods to help improve decision-making, management, and operations. Members of INFORMS work in business, government, and academia. They are represented in fields as diverse as airlines, health care, law enforcement, the military, the stock market, and telecommunications.