Bloodborne Pathogens, Exposures, Risks, and Prophylaxis as related to HIV and hepatitis
The following information is provided as a brief guide to define an exposure and to list body fluids regarded as potentially infectious. Risks of transmission and prophylaxis for hepatitis B and C are included.
An 8 page booklet "Exposure to Blood: What Healthcare Personnel Need to Know" (July 2003) is available at the CDC site.
The following information has been condensed from the:
MMWR June 2001 Updated U.S. Public Health Service Guidelines for the Management of Occupational Exposure for HBV, HCV and HIV and Recommendations for Postexposure Prophylaxis and the September MMWR September 2005 Updated U.S. Public Health Service Guidelines for Management of Occupational Exposure to HIV and Recommendations for Post Exposure Prophylaxis.
Bloodborne Pathogen: an organism that causes HIV, Hepatitis B and/or C.
An exposure occurs when a health-care personnel (including student) has a percutaneus injury (needlestick or cut with a sharp object) or contact of mucous membrane or nonintact (chapped or open wound) skin with another personís blood, tissue or other body fluids that are potentially infectious.
Potentially infectious blood and body fluids include
fluids containing visible blood
synovial fluid, pleural fluid
and amniotic fluid
Exposure to saliva occurs during a dental procedure is considered an exposure.
Unless visible blood is present, the following body fluids are NOT considered to be potentially infectious:
The risk for transmitting hepatitis B/C or HIV from these fluids and materials is extremely low.
The occupational transmission risk of Hepatitis B has become extremely low since the 3-series Hepatitis B vaccine was developed. Its high rate of use decreased occupationally acquired cases of Hepatitis B by 95%. The risk of developing clinical hepatitis from a needle contaminated with Hepatitis B surface antigen + blood in a non-vaccinated individual is approximately 1-6%. The HBV can live in dried blood at room temperature on environmental surfaces for up to one week. Proper disinfection of surfaces is very important!
Hepatitis C has become a higher risk than Hepatitis B or HIV. The average incidence of HCV conversion after a percutanuous exposure is 1.8%. Transmission rarely occurs from mucous membrane exposures and no transmission from skin exposure (intact or non-intact skin) is known. Between 15-25% of patients with acute HCV infection resolve the infection without treatment. Coinfection of the source patient with HIV may increase the risk of transmitting HCV.
A percutaneous exposure from an HIV infected person carries a risk of 0.3% (3 in 1000). The risk of transmitting HIV from a mucocutaneous exposure is even less (.09%). The degree of risk depends upon type of needle/instrument (hollow bore vs solid); depth of injury; needle placement within vein or artery; amount of blood or body fluid; and terminal illness of the source patient. Terminally ill HIV+ patients have higher transmission rates, but viral load needs to be considered. Low viral load does not eliminate the risk but reduces it.
IUnvaccinated persons can decrease risk of developing Hepatits B by 70-75% with a dose of hepatitis B immune globulin (HBIG) after an exposure. The hepatitis series should be started as soon as possible post exposure. Keep yourself safe and help reduce the incidence of Hepatitis B by being vaccinated.
A titre should be drawn 1-2 months after completion of the vaccine series to determine if immunity has been achieved.
There is no prophylaxis or vaccine for Hepatitis C. Antiviral medications do not affect transmission of HCV. Ribaviron/interferon is useful in eradicating chronic HCV infections, but is not indicated for prophylaxis.
Antivirals to decrease the risk of transmission are useful, depending upon the degree of risk. It is best to begin antiviral therapy within 2 hours of the exposure, but is still effective if started within 24 hours. Rapid HIV tests quickly determine HIV status of the source patient.
Truvada and Isentress may be initiated for exposures; known HIV + source patients or one that refuses testing or is not available for testing. The type of injury is considered when making a decision to prescribe antivirals. Zovudine has shown an 81% decrease in transmission rates of HIV, efficacy has not been established for most antiviral drugs but is assumed to be comparable.
If antivirals are prescribed, additional lab tests (urine pregnancy test, CBC and CMP) are ordered to monitor for side effects (elevated liver function tests, anemia, neutropenia, hyperglycemia, pancreatitis etc.). Labs will be drawn at baseline and periodically throughout treatment.
Needlesticks and other exposure can be frightening. Low transmission rates, Hepatitis B vaccination, and appropriate use of antivirals greatly decrease risks. If you are concerned about infection and transmitting virus to a sexual partner or a breast-fed infant, please take precautions.