New guidelines from the US Public Health Service deal with exposure to hepatitis B, hepatitis C, and HIV.
Mazen S. Bader, MD, MPH
Staff Physician, Department of Medicine, Hamilton Health Sciences, Juravinski Hospital and Cancer Centre; Department of Medicine, McMaster University, Hamilton, Ontario, Canada
Annie Brooks, BScPhm, PharmD
Clinical Pharmacist, Infectious Diseases & Antimicrobial Stewardship, Hamilton Health Services, Juravinski Hospital; Assistant Clinical Professor (Adjunct), Department of Medicine, McMaster University, Hamilton, Ontario, Canada
Deborah V. Kelly, PharmD, FCSHP, AAHIVP
School of Pharmacy, Memorial University of Newfoundland, St. John’s, Newfoundland and Labrador, Canada
Jocelyn A. Srigley, MD, MSc
Department of Pathology and Laboratory Medicine, BC Children’s & Women’s Hospitals; Director, Infection Prevention and Control, Provincial Health Services Authority; Clinical Assistant Professor, University of British Columbia, Vancouver, British Columbia, Canada
Address: Mazen S. Bader, MD, MPH, Juravinski Hospital and Cancer Centre, Department of Medicine, 711 Concession Street, Hamilton, Ontario L8V1C3 Canada; email@example.com
Anyone exposed to an infectious disease—whether a healthcare provider, patient, or contact of a patient—should be evaluated promptly and the source of the infection identified. A systematic response entails postexposure prophylactic therapy if available and indicated, infection control measures to prevent further transmission, counseling and educating those involved, and assessing those who may require work restriction or modification.
People who have been exposed to an infectious disease should be evaluated promptly and systematically, whether they are healthcare professionals at work,1 patients, or contacts of patients. The primary goals are to prevent acquisition and transmission of the infection, allay the exposed person’s anxiety, and avoid unnecessary interventions and loss of work days.1,2 Some may need postexposure prophylaxis.
Because postexposure management can be challenging, an experienced clinician or expert consultant (eg, infectious disease specialist, infection control provider, or public health officer) should be involved. Institution-specific policies and procedures for postexposure prophylaxis and testing should be followed.1,2
Postexposure management should include the following elements:
Postexposure management begins with an assessment to determine whether the exposure is likely to result in infection; whether the exposed individual is susceptible to the infection of concern or is at greater risk of complications from it than the general population; and whether postexposure prophylaxis is needed. This involves a complete focused history, physical examination, and laboratory testing of the potentially exposed individual and of the source, if possible.1,2
Postexposure prophylaxis should begin as soon as possible to maximize its effects while awaiting the results of further diagnostic tests. However, if the exposed individual seeks care after the recommended period, prophylactic therapy can still be effective for certain infections that have a long incubation period, such as tetanus and rabies.5,6 The choice of regimen should be guided by efficacy, safety, cost, toxicity, ease of adherence, drug interactions, and antimicrobial resistance.1,2
Exposed individuals are not all at the same risk of acquiring a given infection. The risk depends on:
Most people without symptoms who were exposed to most types of infections do not need to stay home from work or school. However, susceptible people, particularly healthcare providers exposed to measles, mumps, rubella, and varicella, should be excluded from work while they are capable of transmitting these diseases, even if they have no symptoms.11,12 Moreover, people with symptoms with infections primarily transmitted via the airborne, droplet, or contact route should be restricted from work until no longer infectious.1,2,7,9–15
Most healthcare institutions have clear protocols for managing occupational exposures to infectious diseases, in particular for blood-borne pathogens such as human immunodeficiency virus (HIV). The protocol should include appropriate evaluation and laboratory testing of the source patient and exposed healthcare provider, as well as procedures for counseling the exposed provider, identifying and procuring an initial prophylactic regimen for timely administration, a mechanism for formal expert consultation (eg, with an in-house infectious diseases consultant), and a plan for outpatient follow-up.
The next section reviews postexposure management of common infections categorized by mode of transmission, including the risk of transmission, initial and follow-up evaluation, and considerations for postexposure prophylaxis.
Blood-borne pathogens can be transmitted by accidental needlesticks or cuts or by exposure of the eyes, mucous membranes, or nonintact skin to blood, tissue, or other potentially infectious body fluids—cerebrospinal, pericardial, pleural, peritoneal, synovial, and amniotic fluid, semen, and vaginal secretions. (Feces, nasal secretions, saliva, sputum, sweat, tears, urine, and vomitus are considered noninfectious for blood-borne pathogens unless they contain blood.16)
Healthcare professionals are commonly exposed to blood-borne pathogens as a result of needlestick injuries, and these exposures tend to be underreported.17
When someone has been exposed to blood or other infectious body fluids, the source individual and the exposed individual should be assessed for risk factors for hepatitis B virus, hepatitis C virus, HIV, and other blood-borne pathogens.3,4,16,18 If the disease status for these viruses is unknown, the source and exposed individual should be tested in accordance with institutional policies regarding consent to testing. Testing of needles or sharp instruments implicated in an exposure is not recommended.3,4,16,18
Determining the need for prophylaxis after exposure to an unknown source such as a disposed needle can be challenging. Assessment should be made on a case-by-case basis, depending on the known prevalence of the infection of concern in the local community. The risk of transmission in most source-unknown exposures is negligible.3,4,18 However, hepatitis B vaccine and hepatitis B immunoglobulin should be used liberally as postexposure prophylaxis for previously unvaccinated healthcare providers exposed to an unknown source.3,4,16,18
Hepatitis B virus (Table 1) is the most infectious of the common blood-borne viruses. The risk of transmission after percutaneous exposure to hepatitis B-infected blood ranges from 1% to 30% based on hepatitis Be antigen status and viral load (based on hepatitis B viral DNA).1,2,4,16
Hepatitis B vaccine or immunoglobulin, or both, are recommended for postexposure prophylaxis in pregnant women, based on evidence that perinatal transmission was reduced by 70% to 90% when these were given within 12 to 24 hours of exposure.4,16,19
The risk of infection after percutaneous exposure to hepatitis C virus-infected blood is estimated to be 1.8% per exposure.16 The risk is lower with exposure of a mucous membrane or nonintact skin to blood, fluids, or tissues from hepatitis C-infected patients.16,18
Since there is no effective postexposure prophylactic regimen, the goal of postexposure assessment of hepatitis C is early identification of infection (by monitoring the patient to see if he or she seroconverts) and, if infection is present, referral to an experienced clinician for further evaluation (Table 1). However, data supporting the utility of direct-acting anti-hepatitis C antiviral drugs as postexposure prophylaxis after occupational exposure to hepatitis C are lacking.
The estimated risk of HIV transmission from a known infected source after percutaneous exposure is 0.3%, and after mucosal exposures it is 0.09%.20
If postexposure prophylaxis is indicated, it should be a three-drug regimen (Table 1).3,18 The recommended antiretroviral therapies have been proven effective in clinical trials of HIV treatment, not for postexposure prophylaxis per se, but they are recommended because they are effective, safe, tolerable, and associated with high adherence rates.3,16,18,21 If the source individual is known to have HIV infection, information about his or her stage of infection, CD4+ T-cell count, results of viral load testing, current and previous antiretroviral therapy, and results of any genotypic viral resistance testing will guide the choice of postexposure prophylactic regimen.3,18
The clinician should give the exposed patient a starter pack of 5 to 7 days of medication, give the first dose then and there, and arrange follow-up with an experienced clinician within a few days of the exposure to determine whether a complete 30-day course is needed.3,16,18
In the case of sexually transmitted infections, “exposure” means unprotected sexual contact with someone who has a sexually transmitted infection.22 People with sexually transmitted infections often have no symptoms but can still transmit the infection. Thus, people at risk should be identified and screened for all suspected sexually transmitted infections.23–25
Patients with sexually transmitted infections should be instructed to refer their sex partners for evaluation and treatment to prevent further transmission and reinfection. Assessment of exposed partners includes a medical history, physical examination, microbiologic testing for all potential sexually transmitted infections, and eligibility for hepatitis A virus, hepatitis B virus, and human papillomavirus vaccines.22 Ideally, exposed partners should be reassessed within 1 to 2 weeks to follow up testing results and to monitor for side effects of and adherence to postexposure prophylaxis, if applicable.
Public health departments should be notified of sexually transmitted infections such as gonorrhea, chlamydia, chancroid, and syphilis.22
Expedited partner therapy, in which index patients deliver the medication or a prescription for it directly to their partners, is an alternative for partner management where legally allowed by state and local health departments (see www.cdc.gov/std/ept/legal/).22
Recommended postexposure prophylactic regimens for sexually transmitted infections (Table 2) are based on their efficacy in the treatment of these infections.22,26–28 The regimen for HIV prophylaxis is the same as in Table 1.3,18,26
Chlamydia is the most commonly reported communicable disease in the United States. The risk of transmission after sexual intercourse with a person who has an active infection is approximately 65% and increases with the number of exposures.22,29
Infection with Neisseria gonorrhoeae is the second most commonly reported communicable disease in the United States. The transmission rate of gonorrhea after sex with someone who has it ranges from 50% to 93%.22 When prescribing postexposure prophylaxis for gonorrhea, it is essential to consider the risk of antimicrobial resistance and local susceptibility data.22
Risk of HIV transmission through sexual contact varies depending on the nature of the exposure, ranging from 0.05% to 0.5%.30
The risk of transmission of syphilis in its early stages (primary and secondary) after sexual exposure is approximately 30%. Transmission requires open lesions such as chancres in primary syphilis and mucocutaneous lesions (mucous patches, condyloma lata) in secondary syphilis.22
In cases of sexual assault, the risk of sexually transmitted infections may be increased due to trauma and bleeding. Testing for all sexually transmitted infections, including HIV, should be considered on a case-by-case basis.22
Survivors of sexual assault have been shown to be poorly compliant with follow-up visits, and thus provision of postexposure prophylaxis at the time of initial assessment is preferable to deferred treatment.22 The recommended regimen should cover chlamydia, gonorrhea, and trichomoniasis (a single dose of intramuscular ceftriaxone 250 mg, oral azithromycin 1 g, and either oral metronidazole 2 g or tinidazole 2 g), in addition to HIV if the victim presents within 72 hours of exposure (Table 2).22,26
Hepatitis B virus vaccine, not immunoglobulin, should be given if the hepatitis status of the assailant is unknown and the survivor has not been previously vaccinated. Both hepatitis B vaccine and immunoglobulin should be given to unvaccinated survivors if the assailant is known to be hepatitis B surface antigen-positive.22
Human papillomavirus vaccination is recommended for female survivors ages 9 to 26 and male survivors ages 9 to 21.
Emergency contraception should be given if there is a risk of pregnancy.22,26
In many jurisdictions, sexual assault centers provide trained examiners through Sexual Assault Nurse Examiners to perform evidence collection and to provide initial contact with the aftercare resources of the center.
Advice on medical management of sexual assault can be obtained by calling National PEPline (888–448–4911).
New guidelines from the US Public Health Service deal with exposure to hepatitis B, hepatitis C, and HIV.