What to do after an Exposure to Potential Blood Borne Infections

Blood borne pathogens are infectious viruses present in blood or other body fluids that can cause disease in humans. These pathogens include:

  • Hepatitis B Virus
  • Hepatitis C Virus
  • Human Immunodeficiency Virus

People exposed to blood borne pathogens are at possible risk for getting these infections. Risks are calculated based on:

  • The type of body fluids
  • The type of injury
  • The severity of the injury
  • Length of exposure
  • If the source person is known to be infected with Hepatitis B, Hepatitis C or Human Immunodeficiency Virus

Risks include:

  • Puncture wounds with contaminated needle or other sharp object
  • Splash of body fluids into the mouth
  • Splash of body fluids into the eyes
  • Human bite which breaks the skin
  • Prolonged skin exposure when skin is in poor condition (examples are open wounds, cuts, cracked hands, abrasions and rashes).

Assessing the Risk

The estimated risks that after a needle stick injury that the exposed person will be infected unless previously vaccinated (according to the Ontario Hospital Association – Blood-Borne Diseases Surveillance Protocol for Ontario Hospitals – November 2018):

  • Hepatitis B Virus – 6 to 30%
  • Human Immunodeficiency Virus – 0.3%
  • Hepatitis C Virus – 1.8%

Talk to your designated officer or health care provider to help assess your risks.

Treatment at the Emergency Room

First Steps:

  1. Let the wound bleed freely and do not apply direct pressure.
  2. The wound should be gently and thoroughly cleaned with antiseptic or soap and water as soon as possible.
  3. If the exposure happens to mucous membranes including the eyes, nose and mouth, the area should be flushed immediately with water or saline for 10 to 15 minutes.

At the Emergency Room:

  • The emergency department will take your blood to create a “baseline” for you.
  • Baseline blood work determines your Hepatitis B, Hepatitis C and Human Immunodeficiency Virus status currently.
  • These results identify if you had these infections prior to the injury. Doing this blood work also helps determine if you have protection against Hepatitis B Virus.
  • It also helps you with any future claims for compensation if you get an occupationally-acquired infection of Hepatitis B, Hepatitis C or Human Immunodeficiency Virus.
  • Not doing this baseline blood work may jeopardize any future work related claims.
  • Your health care provider may obtain these results by calling the main Public Health Laboratory customer service line at 1-877-604-4567 or you may request the hospital medical records department to forward copies of your results to your family doctor.

Hepatitis B

  • The emergency room staff will ask whether you have previously been vaccinated against Hepatitis B (in school or before travel) in order to determine whether any further vaccine is needed.
  • If you have never received the Hepatitis B vaccine, it may be recommended that you get Hepatitis B Immune Globulin and start the Hepatitis B vaccine.
  • Hepatitis B Immune Globulin is human immune globulin prepared from plasma of donors who have high antibody levels to Hepatitis B. It provides temporary, but immediate immunity. It is also recommended that you complete the Hepatitis B vaccine series.
  • If a person is immune to Hepatitis B, no further Hepatitis B testing is required.

Hepatitis C

You will not receive any treatment to prevent Hepatitis C since there is no current preventative treatment or vaccine.


  • Although tetanus is not a blood borne infection, you may be treated with a vaccine as a part of regular first aid for injuries to skin.
  • Emergency room staff will ask when your last tetanus vaccine was given.
  • It may be recommended that you get a tetanus vaccine, especially if the wound was dirty or deep.

Human Immunodeficiency Virus Post Exposure Prophylaxis

  • The Emergency Room Physician may prescribe medications that may help prevent Human Immunodeficiency Virus infection.
  • The decision to start post exposure prophylaxis will be based on the on a number of factors including:
    • the type and severity of the exposure
    • the source’s Human Immunodeficiency Virus status and risks
    • the preference of the patient and the physician, and
    • post exposure prophylaxis treatment is based on limited but supportive studies
  • Treatments may be discontinued after more information becomes available; however, delaying the start of post exposure prophylaxis is not recommended.
  • Ideally, post exposure prophylaxis should be started one to two hours after exposure, but needs to be started within six hours from exposure to be effective.
  • The long term toxicity of post exposure prophylaxis appears minimal; however, data is limited.
  • Side effects may include nausea, headache, diarrhea, fatigue, anemia, and pancreatitis.
  • One month of post exposure prophylaxis is required.
  • For the treatment to be effective, you must comply with the medication regimen (right dose at the right time for the prescribed amount of time).

Repeat Blood Tests

Additional blood work will be required. It is important to repeat these blood tests as certain infections may take longer to show up. For example, Hepatitis may take up to six months to show up in a blood test and Human Immunodeficiency Virus may take up to 12 weeks.

Recommended Blood Tests

  • Baseline – Human Immunodeficiency Virus, Hepatitis B (HBsAg, anti HBs and anti HBc), Hepatitis C, and liver function tests
  • Six weeks – Human Immunodeficiency Virus, Hepatitis B (if required), and Hepatitis C
  • Three months – Human Immunodeficiency Virus, Hepatitis B (if required), and Hepatitis C and liver function tests
  • Six months – Human Immunodeficiency Virus, Hepatitis B (if required), and Hepatitis C and liver function tests

Preventing Infection During the Window Period

Precautions should be taken to prevent possible spread of infections, especially following a significant exposure and the source person has Hepatitis B, Hepatitis C or Human Immunodeficiency Virus. This means living for the next six months as if you may have the infections. This period of time is known as the window period, the time for signs of infections to show up in the blood.

In the next six months, you should:

  • practice safer sex – use a condom
  • avoid pregnancy or have further consultation if taking post exposure prophylaxis for Human Immunodeficiency Virus
  • refrain from donating any blood, semen or organs
  • avoid sharing razors, toothbrushes or nail clippers and files, as trace amounts of blood may be on them.

These precautions should be followed until your health care provider advises you that they are no longer required.

Source Testing

Ideally, testing the source person is the most effective method to assess risk. When an injury has happened and the source is known, the health care provider can explain to this person that it is important to complete blood testing (for Hepatitis B, Hepatitis C, and Human Immunodeficiency Virus) so that the injured person can make medical decisions for him or herself (for example post exposure prophylaxis medication).

Consent is needed for:

  • the drawing of the blood
  • and sharing the test results with the Physician of the exposed person.

If the source refuses to consent to blood work and, or sharing of the results, the exposed person can initiate the Mandatory Blood Testing Act process.

Information adapted with permission from the Grey Bruce Health Unit