Needle stick: Infectious risk

Advanced, Clinical Subspecialties

Hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) are the three bloodborne infectious organisms which pose the greatest percutaneous exposure risk to the anesthesiologist. Other risk factors which increase their potential infectious transmissibility include hollow-bore needles, the depth of needle penetration, and quantity of infectious particles to which an individual is exposed. Below is a summary of the infectious risk of (1)HBV, (2)HCV, and (3) HIV:

Hepatitis B Virus

Of the three viruses, hepatitis B virus is the most transmissible via percutaneous exposure. HBV can survive outside of the body for up to seven days and can be infectious even on needles without visible blood. In unvaccinated individuals, the risk of seroconversion ranges from 6-30%. If infected, HBV rarely leads to fulminant hepatitis or transforms into chronic disease (5% of immunocompetent adults). All health care workers are encouraged to complete the hepatitis B vaccination (series of three injections). The Occupational Safety and Health Administration (OHSA) requires that healthcare facilities provide the vaccine free of cost. If an individual without immunity is exposed, hepatitis B immunoglobulin (HBIG) can be administered in addition to the hepatitis B vaccine.

Hepatitis C Virus

The hepatitis C virus is not transmitted efficiently via percutaneous exposure, with a risk of seroconversion ranging from 0.5-2%. Unlike HBV, if infected, the majority progresses to chronic disease. Luckily, there is now direct-acting antiviral agents, which completely clear 90% of those treated from infection. If exposed, an individual should be tested within 48 hours of occurrence, with repeat testing 3 weeks or greater from the time of initial exposure.

Human Immunodeficiency Virus

HIV is an RNA retrovirus which is spread through blood or serum-derived fluid. The virus binds to cells like helper T-lymphocytes, with a CD4+ surface antigen, integrating itself into the host DNA and replicating. The percutaneous infectious rate is the lowest of the three pathogens at 0.3% risk of seroconversion. Following an exposure, the source patient should have their HIV status tested. Post-exposure prophylaxis (PEP) should be administered as soon as possible after an exposure if the source is HIV+ or their HIV status is unknown. A full course of PEP generally consists of a 28-day, three-drug regimen of tenofovir, emtricitabine, and raltegravir or dolutegravir. Regardless of PEP therapy, the CDC recommends retesting the exposed at 6 weeks, 12 weeks, and 6 months after the incident.

Bloodborne Pathogens

Risk of seroconversion after Percutaneous Exposure

Progression to Chronic Disease

Hepatitis B

6-30%**

5% of immunocompetent adults

Hepatitis C

0.5-2%

75-85%

HIV

0.3%

100%

**In those without serologic immunity

70%

Answered correctly

2020

Year asked

Author
Eryn Thiele, MD