Methods to Prevent and Treat AIDS: Blood Transfusion, Transplants

by Food and Drug Administration (FDA)

(Page 2 of 3)

Medical and Dental Equipment

To protect patients and health-care providers against exposure to potentially contaminated blood and other body liquids, FDA established quality standards for latex and synthetic rubber gloves used during surgery and patient examination. U.S. manufacturers of these products are requested to test samples from each lot to make sure they show no sign of leakage when filled for two minutes with 1,000 milliliters of water, and that they meet the standards of the American Society for Testing and Materials for stress resistance, tensile strength, materials, and dimensions. FDA also tests samples of domestic and imported surgical and patient examination gloves, using the same criteria.

FDA has joined CDC and the American Dental Association in urging dentists to autoclave — sterilize by steam under pressure — dental hand pieces and accessories between patients to remove possible contaminants. In addition, FDA requires that all such equipment must be designed to withstand autoclaving, and the labeling must include instructions for the sterilization process.

While most dentists are believed to comply with the recommendations for autoclaving, it's a good idea to ask what preventive measures the dentist follows before making an appointment.

Blood Transfusion

Each year, about 3.6 million Americans receive transfusions of blood products. FDA inspects the more than 3,000 donor centers where blood and blood components are collected and processed, and continuously updates requirements and standards designed to prevent disease transmission through transfusion.

Blood collection centers and manufacturers and distributors of blood products are responsible for maintaining five layers of overlapping safeguards.

First, potential donors must answer questions about their health and risk factors. Those whose blood may pose a health hazard are encouraged to exclude themselves. A trained and competent health professional then interviews potential donors about their medical histories.

Donors can be temporarily excluded from donating blood for such reasons as having a temperature, cold, cough, or sore throat on the day of the donation. Potential donors are permanently excluded from donating blood for reasons including evidence of HIV infection, male homosexual activity since 1977, and a history of intravenous drug abuse or viral hepatitis.

Second, blood establishments must keep current a list of deferred donors and check donor names against that list.

Third, after donation, the blood is tested for such blood-borne agents as HIV, hepatitis and syphilis.

The fourth layer of protection prevents general use of any blood products that have not been thoroughly tested.

The fifth layer of protection is FDA's requirement that blood establishments must investigate any breaches of safeguards and correct deficiencies. An error or accident can result from improper testing, incorrectly labeled components, improper interpretation of test results, improper use of equipment or failure to follow the manufacturers' directions for its use, or accepting units from donors who should have been deferred.

The system has helped reduce the risk of transfused HIV infection from 1 in 2,500 units of blood in 1985 to 1 in 440,000 to 640,000 units by the end of 1995. Since then, the Coulter test has shortened the typical window period when the HIV virus cannot be detected to less than three months. Health experts expect the use of this test to reduce the risk of transfused HIV infection even further.

Human Tissue Transplants

In December 1993, FDA issued an interim requirement that potential donors of all human tissues for transplantation — including tendons, bone, skin, and corneas — be tested for HIV-1, HIV-2, and hepatitis B and C viruses, and screened for symptoms of AIDS, hepatitis, and high-risk behaviors such as sex between males and intravenous drug abuse. Imported tissues must be accompanied by records showing that the tissues were similarly screened and tested. If such records are not available, the tissues must be shipped under quarantine.

The agency is preparing a final rule and a guideline to ensure uniformity in tissue testing and screening.

About the Author

www.fda.gov
FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.