Bloodborne pathogens can be transmitted by

It is very unlikely that you will become infected through everyday social contact with another worker who has a blood-borne virus (BBV). It is not thought that BBVs can be transmitted via the respiratory route, although this possibility cannot be dismissed entirely when, under laboratory conditions, (such as high titre in vitro cultures), BBVs are present in concentrations far exceeding that found in normal body fluids. BBVs are mainly transmitted sexually or by direct exposure to infected blood or other body fluids contaminated with infected blood. In the workplace, direct exposure can happen through accidental contamination by a sharp instrument, such as a needle or broken glass. Infected blood may also spread through contamination of open wounds, skin abrasions, skin damaged due to a condition such as eczema, or through splashes to the eyes, nose or mouth.

Routes of transmission

Blood-borne viruses (BBVs) are transmitted by blood, or other body fluids containing virus. This happens when the blood or fluids enter into the body of a susceptible person. The rate of viral transmission varies depending on how the person has been exposed to the virus (the route of transmission), the type of virus, how much of the virus the carrier has in their body and the immune status of the exposed person.

The more common routes of transmission include:

• sexual intercourse (common for HBV, HIV; inefficient for HCV);
  
• sharing injecting equipment;
• skin puncture by blood-contaminated sharp objects (eg needles, instruments or glass); and
• childbirth (ie the mother infects the child either before or during birth, or through breast-feeding).

Less common routes of transmission are:

• contamination of open wounds (eg blood injuries during sporting activities);
• contamination of skin lesions (eg eczema);
• splashing of the mucous membranes of the eye, nose or mouth; and
• human bites when blood is drawn (this may be more of a problem in certain occupations, eg prison and police service, where front line workers may be exposed to violent behaviour).

There is also a risk of acquiring a BBV infection via blood transfusion. However, in the UK, all blood donations are screened for HBV, HCV and HIV, meaning the risk is remote.

Photo by Brandy Sites

Sharps Injuries: Bloodborne Pathogens

Bloodborne pathogens and workplace sharps injuries

Human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) are three of the most common bloodborne pathogens from which health care workers are at risk. However, bloodborne pathogens are implicated in the transmissions of more than 20 other pathogens (Beltrami et al 2000external icon). Today, co-infection with multiple bloodborne diseases and multi-drug resistant organisms, including HIV, hepatitis B or C, Methicillin resistant Staphylococcus aureus (MRSA), and co-morbidities associated with diabetes means that occupational exposure to health care workers can carry an even greater risk than in years past.

Health care workers are potentially exposed to these diseases in one of two ways:

• A percutaneous injury in which a health care worker is injured by a sharps object
• A mucocutaneous exposure incident with contact of a mucous membrane or non-intact skin with blood, tissue, or other potentially infectious bodily fluids

When personal protective equipment is not readily available or accessible, employees are less likely to wear it.  This puts them at risk of exposure to blood and body fluids and vulnerability to bloodborne pathogens.

Overview

Hepatitis B virus can cause serious liver damage and death. Symptoms include jaundice, fever, nausea, and abdominal pain. Approximately five percent of adult patients develop chronic infection with hepatitis B, which carries an estimated 20 percent lifetime risk of dying from cirrhosis and 6 percent risk of dying from liver cancer. Individuals infected with HBV at birth have a much higher likelihood of chronic infection, with approximately 90 percent of infants and 25–50 percent of children aged one to five years remaining chronically infected with HBV after initial infection. According to the CDC, new cases of HBV have not been trending either up or down since 2012, but rather have been fluctuating at around 3,000 new cases per year. In 2016, there were 3,218 cases reported to CDC. After adjusting for under-ascertainment and under-reporting, the estimated number of new HBV infections in 2016 was 20,900.

Risk of injury and transmission

The chance of becoming infected with hepatitis B from a sharps injury is estimated to be between six and 30 percent.  National hepatitis surveillance data shows that approximately 400 health care workers became infected with HBV in 2001. This figure represented a 95 percent decline from the 17,000 new infections estimated in 1983. The decline was largely due to the widespread immunization of health care workers with hepatitis B vaccine and the use of universal precautions and other measures required by OSHA. As mentioned above, the CDC no longer collects post-exposure seroconversion data on occupationally acquired HBV.

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