eMedicine Specialties > Emergency Medicine > Infectious Diseases

Body Fluid Exposures

Author: Darrell G Looney, MD, FAAEM, Attending Physician, Department of Emergency Medicine, Long Island College Hospital
Coauthor(s): Peter B Richman, MD, Consulting Staff, Department of Emergency Medicine, Morristown Memorial Hospital; Richard Dee Shih, MD, Associate Professor, Department of Surgery, New Jersey Medical School, University of Medicine and Dentistry of New Jersey; Program Director, Department of Emergency Medicine, Morristown Memorial Hospital; Attending Physician, New Jersey Poison Center, Newark Beth Israel Medical Center;
Contributor Information and Disclosures

Updated: Nov 11, 2009

Introduction

Background

Occupational transmission of blood-borne infections may occur through parenteral, mucous membrane, and nonintact skin exposure. The greatest risk for transdermal transmission is via a skin penetration injury sustained with a sharp hollow-bore needle that was recently removed from a blood-contaminated source. Although many infections may be transmitted by such contact, the most consequential are hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV). In addition, skin and soft tissue infection at the site of inoculation through introduction of staphylococcal species is an issue of concern and must not be neglected. Tetanus prophylaxis is also an important issue of concern. Another important concept is the fact that many clinical pathways adopt plans for management primarily of health care personnel but are woefully lacking when faced with the outside individual at risk for significant exposure.

Pathophysiology

When intact, the integumentary system serves as an effective physical barrier to the entry of infectious elements into the body. However, a special situation exists in terms of mucous membranes. Across these membranes, lies a layer of mucus secreted by specialized columnar cells that are closely associated with each other through gap junctions, which are little more than specialized cell surface projections that allow intercellular communication. The presence of a moist mucous layer tends to prolong the viability of fragile viruses, such as HIV and HBV, which cannot survive long in drier environments. However, HBV has been demonstrated to survive in dried blood for extended periods.

Higher vascularity coupled with a relatively permeable cellular layer gives rise to a presumed heightened risk of transmission of HBV, HCV, and HIV across this organ system and into the bloodstream. Still, at least for occupational HIV exposures, transmission rarely occurs. Intact, keratinized skin does not possess these characteristics and is virtually impermeable unless disrupted. Viral transmission here is not readily possible, hence the association with transmission caused by needlestick injury or (less frequently) through open wounds.

In terms of blood and body fluids, semen and vaginal secretions with visible blood should be considered potentially infectious vehicles. Similarly, cerebrospinal fluid, amniotic fluid, pleural fluid, synovial fluid, and peritoneal and pericardial fluids carry a high suspicion of risk for transmission. In addition, unless blood is present, saliva, sputum, sweat, tears, feces, nasal secretions, urine, and vomitus carry a low risk of transmission of HBV, HCV, and HIV.

Frequency

United States

Sharps injuries occur at a rate of 1.8 per year per physician and 0.98 per year per nurse, while working on the same medical ward. Statistically, twice as many nurses as doctors have been reported with occupationally acquired HIV infection. Whether this is a functionality of the significance of the exposure (ie, severity of the stick) or the route of exposure remains to be studied. If the inoculum were blood and positive for both hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg), the risk for developing clinical hepatitis due to HBV infection may lie somewhere between 22% and 31%. The risk for developing HIV remains around 0.3%.

In a retrospective study of first responders presenting to an ED for body fluid or blood exposure, the incidence was 23.29 ED visits per 100,000 ambulance runs.¹

Mortality/Morbidity

• Health care workers who have a significant exposure (ie, inoculation with an open-bore needle from a source known to have active HBV disease) to HBV but have not previously received hepatitis B vaccine and do not receive postexposure prophylaxis have a 6-30% risk of becoming infected.
• The risk of HCV transmission from a known HCV-positive source by a sharps injury is 2-7%. The vast majority of individuals who develop HCV infection progress to become long-term carriers of the virus, and about two thirds have elevated liver enzyme levels.
• The rate of HIV transmission from a known infected individual via a sharps injury is 0.3%. The rate is higher if the injury was sustained by a hollow-bore needle, if the injury was deeply penetrating, or if blood was injected during injury. Risk to the injured health care worker is greater if the source patient has a high HIV viral load and/or lower CD4 count.

Clinical

History

Patients present with a history of exposure. Typically, this is a splash-type exposure to mucosal or nonintact skin or a needle-stick injury to intact skin. Patients may often report exposures to intact keratinized skin out of uninformed concern or they are aware of some preexisting injury and may be predisposed to infection. Reassurance through awareness of the risks for viral transmission in various scenarios is of significant importance to both the health care provider and the patient.

• Health care personnel includes employees, volunteers, attending clinicians, students, contractors, and any public safety workers whose activities involve contact with patients and their environment such that exposure to blood or other body fluids can occur.
• Non–health care personnel may also be exposed by way of social interaction, sexual encounters, trauma scenarios, or intentional inoculations consistent with contemporary terrorist activity. Note that any postexposure program that does not provide for management and follow-up of nonhospital personnel is woefully inadequate for the needs of a given community.

Physical

During the physical examination, be sure to assess body area of exposure and depth of any wounds. The neurovascular status in the setting of extremity wounds is an important and often omitted element. The clinician should remain suspicious of occult injury, such as paper cuts or abrasions, which may threaten the integrity of the skin. For mucosal exposures, especially on the face, keep in mind that the exposure may not be limited to only one area, and it may occur simultaneously in nasal, mucosal, and conjunctival mucosae.

Causes

Most exposures are the result of a departure from universal precautions on some level—whether it is the result of recapping, failure to use personal protective equipment, or the unintentional sharp left in an inappropriate container for disposal. When dealing with blood and body fluid exposures, document whether the exposure represents a departure from universal precautions, Occupational Safety and Health Administration (OSHA) standards, or a true accident (eg, projectile vomiting, precipitous labor with spontaneous rupture of membranes). This information is vital to the institutional safety committee whose function is to monitor the safety of the environment for the entire facility and make recommendations for upgrades and changes in policy.

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