Occupational Exposures to Blood-Borne Viral Infections

Chapter: Occupational Exposures to Blood-Borne Viral Infections
McMaster Section Editor(s): Mark Loeb
Section Editor(s) in Interna Szczeklika: Piotr Zaborowski, Jerzy Stefaniak, Miłosz Parczewski, Weronika Rymer, Agnieszka Wroczyńska
McMaster Author(s): Fiona Smaill
Author(s) in Interna Szczeklika: Weronika Rymer, Brygida Knysz, Jacek Juszczyk
Additional Information

The key blood-borne pathogens are hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV).

Infection Risk AssessmentTop

The risk of infection following exposure depends on the type of exposure, type of potentially infectious biological material, susceptibility to infection of the exposed individual, etiologic agent, and status of the source patient (infected vs not infected, level of infectiousness).

1. Types of exposure (incidents that pose a risk of virus transmission):

1) Skin injury with infected sharp objects (needle, scalpel).

2) Contact of mucosa (conjunctiva, oral mucosa) or nonintact skin (skin with lacerations, abrasions, inflammatory lesions, wounds) with a potentially infectious material: the source patient’s blood, tissues, or body fluids (risk of infection is minimal if the skin is intact).

3) Each direct contact with a concentrated viral stock of HBV, HCV, or HIV in research facilities.

4) Very rarely, a human bite (both the bitten and the biting individual can be the source of infection).

2. Infectious material is a biological material containing the minimal amount of infectious particles required for transmitting infection that has been described as potentially infectious. The highest risk of transmitting HBV, HCV, and HIV is through blood. Other infectious materials include cerebrospinal fluid (CSF), synovial fluid, pleural fluid, peritoneal fluid, pericardial fluid, amniotic fluid, unfixed tissue, virus culture, saliva (only in HBV infection following percutaneous exposure [bite]), vaginal secretions, and semen. In clinical practice, noninfectious material (ie, material that does not contain a particular microorganism or risk of transmission has not been described) is defined as feces, urine, vomit, sputum, nasal discharge, tears, and sweat, unless blood-stained.

3. Etiologic factors:

1) HBV: In individuals susceptible to HBV infection, the risk of infection due to needlestick or another sharp object injury depends on the serologic status of the source patient (source of exposure) (Table 8.10-1):

a) In the case of HBsAg(+) and HBeAg(+), the risk of clinically overt hepatitis B is from 22% to 31%, and the risk of asymptomatic hepatitis B is from 37% to 62%.

b) In the case of HBsAg(+) and HBeAg(−), the risk of clinically overt hepatitis B is from 1% to 6%, and the risk of asymptomatic hepatitis B is from 23% to 37%.

2) HCV: The risk of infection following occupational exposure to blood is relatively low—on average 1.8% after needlestick injury and even lower after mucosal exposure. No infection through nonintact or intact skin has ever been reported. The risk of transmitting the disease via body fluids other than blood is very low.

3) HIV: Apart from blood, HIV may be present in saliva, tears, urine, and other body fluids; however, infections in medical personnel following occupational exposure to these biological materials have not been documented. Similarly, there were no reports of infections transmitted through vomit or through aerosols that may be generated during certain procedures (dental, surgical, autopsy).

The risk of HIV infection:

a) By needlestick or injury with other sharps (eg, scalpel) is ~0.3%.

b) As a result of mucosal or intact skin contact with blood is ~0.1%.

c) If the source patient is adequately treated (suppressed HIV viral load on antiretroviral treatment), the risk is ≥79-fold lower than after exposure to the blood of an untreated patient.

High-risk factors include high viral load in the source patient (detectable prior to seroconversion and in late-stage HIV infection), deep injury, blood visible on the object that caused injury, and injury with a large-diameter hollow-bore needle.

Postexposure ProphylaxisTop

Every health-care worker, including a trainee, who is in contact with patients or potentially infectious body fluids (particularly blood) and has a negative history of HBV infection should receive a hepatitis B vaccination series (3 doses) together with evaluation of the immune response to vaccination.

Protocols for nonspecific protection against potential occupational infections in health-care facilities should be strictly implemented. They include, among others, proper storage and disposal of equipment, avoiding unnecessary contact with blood and blood-contaminated objects (eg, designated sharps containers, disposal of needles without recapping them, following relevant procedures), using personal protective equipment (gloves, masks, safety eyewear), maintaining good hand hygiene, and disinfecting objects and surfaces contaminated with body fluids.

General Postexposure Recommendations

1. We recommend that the site of the needlestick injury is cleaned by washing it with soap and large amounts of water without attempting to stop the bleeding or squeezing the wound. Do not use disinfectants. Mucosa exposed to potentially infectious material should be flushed with 0.9% saline or water. The incident should be reported to the designated responsible individual and appropriate assessment and management should be provided by a clinician with expertise in postexposure procedures.

2. The risk of infection should be assessed on the basis of (1) type of exposure (injury with a needle or other contaminated object, contamination of mucosa or injured skin, bite resulting in bleeding); (2) type of potentially infectious material (blood, blood-stained body fluid, other potentially infectious fluids or tissues, highly concentrated viral stock).

3. We recommend, where feasible, to check the source patient for infection (if exposure was associated with a significant infection risk) on the basis of (1) clinical and epidemiologic data; (2) serum HBsAg, HCV antibody, and HIV antibody levels. Do not test the sharps (eg, needle, scalpel) that caused the injury for HBV, HCV, or HIV.

4. It is good practice to examine the exposed worker: Assess the worker’s HBV immunity status (vaccination status, anti-HBs levels 1 or 2 months after completing a full vaccination series) and take history of current illnesses, medications, pregnancy, and breastfeeding.

5. We recommend to start appropriate prophylaxis if the risk of infection is significant. The exposed individual should be provided with appropriate recommendations and monitoring appointments and follow-up tests should be scheduled.

Specific Management

1. HBV: We recommend, where feasible, to measure HBsAg in the source patient and perform serologic tests in the exposed individual to evaluate the susceptibility to infection (HBsAg, anti-HBc; in the case of previously immunized persons, anti-HBs levels if they were not measured after the primary vaccination). Prophylaxis involves use of HBV vaccine, HBV vaccine and hepatitis B immunoglobulin (HBIG), or HBIG alone. The choice of prophylaxis depends on the vaccination history of the exposed individual and the availability of the exposure source and their serologic status (Table 8.10-1). Prophylaxis should be instituted as soon as possible, optimally within 24 hours and not later than after 7 days of exposure. If active-passive prophylaxis is indicated, it is recommended to administer HBV vaccine and HBIG on the same day. The exposed worker at risk of HBV infection should be monitored by measuring anti-HBc 6 months after the exposure.

2. HCV: There is no specific postexposure HCV prophylaxis; no vaccine or specific anti-HCV immunoglobulin is available. Human polyclonal immunoglobulins and antiviral drugs are not recommended for postexposure HCV prophylaxis.

Management:

1) It is good practice to assess serum HCV antibody levels in the exposed individual on the day of exposure (to exclude previously undiagnosed hepatitis C); if there is a risk of infection, it is recommended to repeat the tests after 3 and 6 months, or earlier if the patient develops symptoms suggestive of acute hepatitis C. A positive result of the HCV antibody test should be confirmed by qualitative polymerase chain reaction detecting serum HCV RNA. One can also measure HCV RNA levels within 4 to 6 weeks of exposure instead of performing serologic tests.

2) If the exposed individual develops acute hepatitis C, you may consider antiviral treatment in consultation with appropriate specialist (see Acute Hepatitis C).

3. HIV:

1) We recommend consultation with an expert in HIV treatment for complicated cases: An HIV-exposed individual should consult a specialist with expertise in HIV treatment within a few hours of exposure, particularly in complicated cases (eg, underlying health issues or pregnancy in the exposed individual, resistant strain of virus in the source patient).

2) An HIV antibody blood test should be offered to the exposed individual to establish the baseline serologic status. In addition to HIV antibody testing in the source patient, consideration may be given to plasma HIV RNA testing of the source patient in certain settings, such as possible acute seroconversion or an inconclusive HIV antibody result.

3) Where there is a risk of HIV transmission (depending on the type of exposure and underlying probability of HIV in the source patient) (Table 8.10-2), it is recommended to start a postexposure prophylaxis antiviral regimen as soon as possible (optimally within 1-2 hours, but not later than 48 hours after the exposure, or 72 hours in exceptional cases). Our current practice is to use a 3-drug antiretroviral regimen: a 2 nucleoside/nucleotide analogue reverse transcriptase inhibitor combination (eg, tenofovir + emtricitabine) + an integrase inhibitor as a preferred choiceEvidence 1Strong recommendation (benefits clearly outweigh downsides; right action for all or almost all patients). Low Quality of Evidence (low confidence that we know true effects of the intervention). Quality of Evidence lowered due to the observational nature of data and extrapolation from animal studies. Kuhar DT, Henderson DK, Struble KA, et al; US Public Health Service Working Group. Updated US Public Health Service guidelines for the management of occupational exposures to human immunodeficiency virus and recommendations for postexposure prophylaxis. Infect Control Hosp Epidemiol. 2013 Sep;34(9):875-92. doi: 10.1086/672271. Erratum in: Infect Control Hosp Epidemiol. 2013 Nov;34(11):1238. Dosage error in article text. PubMed PMID: 23917901.; alternative regimens may also be considered in special circumstances by specialists or if certain drugs are not available. Medications included in an HIV postexposure prophylaxis regimen should be selected to optimize adverse-effect and toxicity profiles and a convenient dosing schedule to encourage completion of the regimen.

4) If the exposed individual may be pregnant, it is recommended to obtain a pregnancy test. It is currently recommended that dolutegravir be avoided in pregnant women early in their pregnancy or in women who may become pregnant (eg, sexually active without effective birth control). It is good practice to perform a complete blood count (CBC) and tests of kidney function at baseline and repeat them at 2 and 4 weeks if any abnormalities were detected.

5) It is recommended to perform serologic tests for HIV on the day of exposure and then after 6 weeks, 3 months, and 6 months using a fourth-generation HIV Ag/Ab assay. Follow-up testing for HIV RNA is not generally recommended but may be considered in cases of clinical features suggestive of acute retroviral syndrome.

6) A follow-up visit should be scheduled within the first 72 hours of starting drug prophylaxis to provide for modification of the treatment according to incoming results (eg, anti-HIV test results in the source patient).

7) The exposed individual should be considered infectious until HIV infection has been excluded. To minimize the potential risk of transmission, we recommend that the exposed individual should refrain from sexual contacts (or use condoms); refrain from blood, sperm, and organ donation; and refrain from becoming pregnant, or stop breastfeeding, if applicable.

8) Postexposure prophylaxis should be discontinued if HIV infection has been excluded in the source patient.

9) Treatment should be continued for 4 weeks if the source patient is positive or the HIV status of the source patient is unknown.

TablesTop

Table 8.10-1. Recommended HBV postexposure prophylaxis

Vaccination status of exposed individual and immunity induced by hepatitis B vaccine

Decision on further management based on HBsAg status of source patienta

HBsAg(+)

HBsAg(–)

Exposure source unknownh or HBsAg measurement not feasible

History of HBVb or ongoing infection (HBsAg[+] in exposed person)

No need for additional specific prophylaxis

No need for additional specific prophylaxis

No need for additional specific prophylaxis

Unvaccinated

1 dose of HBIGc + start hepatitis B vaccine seriesd

Start hepatitis B vaccine seriesd

Start hepatitis B vaccine seriesd

Consider HBIG if source considered at high risk (eg, drug use history, men who have sex with men)

Vaccinated with response to vaccination evaluated 1-2 months after scheduled vaccination

 

Sufficient serologic responsee

No need for additional specific prophylaxis

No need for additional specific prophylaxis

No need for additional specific prophylaxis

Insufficient serologic responsef

1 dose of HBIGc + start hepatitis B vaccine seriesd

No need for additional specific prophylaxisg

Administer booster dose of vaccine

Consider HBIG if high risk

Multiple vaccinations with confirmed lack of response to vaccination

2 doses of HBIG at 1-month interval

No need for additional specific prophylaxis

No need for additional specific prophylaxis

If clinical and epidemiologic data indicate high risk of HBV infection, follow guidelines for exposure to HBsAg(+) blood

Vaccinated without evaluation of response to vaccination 1-2 months after scheduled vaccination; in such cases measure anti-HBs as part of qualification for prophylaxis

 

Anti-HBs ≥10 mIU/mL

No need for additional specific prophylaxis

No need for additional specific prophylaxis

No need for additional specific prophylaxis

Anti-HBs <10 mIU/mL

Booster dose + 1 dose of HBIG

No need for additional specific prophylaxis

Administer booster dose of vaccine; consider HBIG if high risk

Recommendations presented in this table are graded as strong recommendations based on low quality of evidence.Evidence 2Strong recommendation (benefits clearly outweigh downsides; right action for all or almost all patients). Low Quality of Evidence (low confidence that we know true effects of the intervention). Quality of Evidence lowered due to the observational nature of data. Schillie S, Murphy TV, Sawyer M, et al; Centers for Disease Control and Prevention (CDC). CDC guidance for evaluating health-care personnel for hepatitis B virus protection and for administering postexposure management. MMWR Recomm Rep. 2013 Dec 20;62(RR-10):1-19. PubMed PMID: 24352112.

a Measure HBsAg in patients whose blood or body fluids were the source of infection.

b Individuals who have recovered from an earlier HBV infection acquire sustained immunity and require no postexposure prophylaxis.

c IM or IV, depending on the preparation (dosage as per manufacturer’s prescribing information), as soon as possible after exposure, preferably within 12 hours. HBIG should be administered simultaneously with the first dose of hepatitis B vaccine (IM preparations should be injected in separate sites).

d As soon as possible (preferably within 12-24 hours). Safe in pregnant and breastfeeding women. Vaccination schedule: month 0, 1, then month 6; or month 0, 1, and 2, then month 12.

e Serum anti-HBs levels ≥10 mIU/mL in individuals tested within 1-2 months of completion of a primary (scheduled, pre-exposure) vaccination series.

f Serum anti-HBs levels <10 mIU/mL in individuals tested within 1-2 months of completion of a primary (scheduled, pre-exposure) vaccination series, without a repeated vaccination dose.

g A repeated scheduled vaccination should be administered 1-2 months following the last dose. Serologic response should be evaluated.

Anti-HBs, serum antibodies against HBsAg; HBIG, hepatitis B immunoglobulin; HBsAg, HBs antigen; HBV, hepatitis B virus; IM, intramuscular; IV, intravenous.

Table 8.10-2. Types of occupational HIV exposure in which postexposure prophylaxis is recommended

Type of exposure

Serologic status of source patient

Percutaneous exposure (needlestick, cut)

HIV(+) or status unknown but HIV infection risk factors present (eg, multiple sexual partners, history of IV drug use, highly endemic country)

Contact with mucosa or nonintact skin: a small amount of infectious material (a few drops)

HIV(+)

Contact with mucosa or nonintact skin: a large amount of infectious material or prolonged time of contact (>15 min)

HIV(+) or status unknown but HIV infection risk factors present

HIV, human immunodeficiency virus; IV, intravenous.

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