key: cord-0943711-4s0ptvho
authors: Bader, Mazen S.; Brooks, Annie A.; Srigley, Jocelyn A.
title: Postexposure management of healthcare personnel to infectious diseases
date: 2015-03-01
journal: Hosp Pract (1995)
DOI: 10.1080/21548331.2015.1018091
sha: 7b51c265906b873195b13b62e34b894cb13ab8ff
doc_id: 943711
cord_uid: 4s0ptvho

Healthcare personnel (HCP) are at risk of exposure to various pathogens through their daily tasks and may serve as a reservoir for ongoing disease transmission in the healthcare setting. Management of HCP exposed to infectious agents can be disruptive to patient care, time-consuming, and costly. Exposure of HCP to an infectious source should be considered an urgent medical concern to ensure timely management and administration of postexposure prophylaxis, if available and indicated. Infection control and occupational health departments should be notified for management of exposed HCP, identification of all contacts of the index case, and application of immediate infection control measures for the index case and exposed HCP, if indicated. This article reviews the main principles of postexposure management of HCP to infectious diseases, in general, and to certain common infections, in particular, categorized by their route of transmission, in addition to primary prevention of these infections.

Healthcare personnel (HCP) are at risk of exposure to various pathogens through their daily tasks. They may serve as a reservoir for ongoing nosocomial transmission, particularly highly contagious infections such as varicella and measles [1] . Nosocomial transmission can result in infection of susceptible patients, outbreaks, work and patient care disruption, and increased cost [2, 3] . An occupational exposure is defined as an exposure of HCP to a material containing an infectious agent in a healthcare setting [1] . The exposure can occur in inpatient settings (e.g. patient rooms and laboratories), in outpatient settings (e.g. medical offices and dialysis units), and in nontraditional facilities (e.g. emergency medical and skilled nursing facilities) [1] . HCP include all paid and unpaid persons working in healthcare settings who can potentially be exposed to patients and/or to infectious materials, including body substances (e.g. blood, tissue, and specific body fluids), contaminated medical supplies and equipment, contaminated environmental surfaces, or contaminated air [1] . The infectious organism can be transmitted to HCP from a patient, another HCP, hospital visitor, or the environment by several routes (Table 1 ) [1] .

There are several strategies to prevent infections among HCP. These include vaccination of HCP who are at risk of infection and are close to or in frequent contact with highrisk patients; education and implementation of infection prevention and control measures (Table 1) ; and timely delivery of postexposure prophylaxis (PEP) to susceptible HCP in the event of exposure [4, 5] . PEP involves administration of anti-infective agents, vaccines, or immunoglobulin as soon as possible to HCP potentially exposed to a pathogen in order to reduce the risk of infection [1, 4] . Management of HCP exposure to infectious agents is paramount not only to prevent or attenuate the infection in the HCP but also to prevent secondary transmission to their contacts [1] . Airborne precautions a,c Wash hands with soap and water or alcoholbased hand disinfectant before and after patient contact, before aseptic procedures, and after contact with body fluids, mucous membranes or non-intact skin.

Wear gloves if contact with blood, any body fluids or contaminated items. Wear gowns during procedures and patient-care activities if contact with blood, body fluids, secretions, or excretions is anticipated.

Wear masks, goggles, face shields, and combinations during procedures and patient-care activities that are likely to generate splashes or sprays of blood, body fluids, secretions, and excretions.

Cough etiquette (cover nose or mouth when coughing, promptly dispose used tissues, and practice hand hygiene after contact with respiratory secretions).

Safe disposal or cleaning of instruments and linen.

Isolate patients in a single room or cohort those with same active infection or colonized with the same organism. Wear nonsterile gloves for all patient contact. Wear gowns during direct patient contact or contact with contaminated material or surfaces. Use dedicated equipment for a single patient or clean and disinfect prior to use for another patient.

Isolate patients in a single room or cohort with patients who have the same active infection or are colonized with the same organism. Wear a surgical mask and eye protection within 6-10 feet of the infectious patients. Infectious patients must wear a surgical mask during transport.

Isolate patients in a single room with special air handling and ventilation systems (e.g. monitored negative pressure, at least 6-12 air exchanges per hour, exhaust must be appropriately discharged outdoors or passed through a high-efficiency particulate arrestance filter before recirculation within the hospital).

Wear a fit-tested certified N95 or higher-level respirator before entering the room of infectious patients. Infectious patients must wear a surgical mask during transport.

Recommended for all patients Certain procedures can generate droplets and aerosols including administration of aerosolized or nebulized medication, diagnostic sputum induction, bronchoscopy, airway suctioning, endotracheal intubation, positive pressure ventilation via facemask, high frequency oscillatory ventilation, grinding, centrifugation, and vigorous shaking of laboratory specimens, and bone-sawing during autopsy. b Contact precautions also are required for infectious patients with respiratory viruses such as influenza, and iGAS infections.

c Contact precautions required for infectious patients with varicella, disseminated herpes zoster, smallpox, SARS-associated coronavirus, and MERS-CoV. d Contact and droplet are the main routes of transmission for smallpox, SARS-associated coronavirus, and MERS-CoV. e Patients with Ebola should be placed in a single private room with a closed door and a private bathroom. HCP entering the room should wear a single-use fluid-resistant or impermeable gown that extends to at least mid-calf or coverall without integrated hood, a single-use nitrile examination double gloves with extended cuffs, a single-use fluid-resistant or impermeable boot covers that extend to at least mid-calf or single-use shoe covers, and fit-tested N95 respirator in combination with a single -use surgical hood extending to shoulders and a single -use full face shield or powered air-purifying respirator exposure, extent and type of exposure, susceptibility of the HCP to the infectious disease of concern, and whether the exposed HCP is at a greater risk of complications than the general population [1, 4] . Vaccines should be given to the exposed HCP even if they present beyond the time indicated for PEP administration. All nonimmune HCP should be vaccinated against hepatitis B virus (HBV), seasonal influenza, measles, mumps, rubella, pertussis, and varicella [4, 5] .

The HCP should be counseled on risk of infection acquisition and transmission to others, particularly if they decline PEP, benefits of treatment, importance of adherence to the drug regimen, possible adverse effects of the PEP regimen, and follow-up plan [1, 4 ]. The exposed HCP should be counseled to immediately stop working or not to report to work, notify infection control and occupational health, and seek prompt medical attention if they develop fever or symptoms and signs of the infection of concern. They should comply with work restriction or exclusion until they are no longer deemed infectious to others by the occupational health department [1, 4] .

Healthcare institutions should have protocols available to HCP for the management of occupational exposures to infectious diseases. Federal law requires covered employers to ensure that all medical evaluations and procedures, vaccines, and PEP are made available to the employee within a reasonable timeframe, at a reasonable location, and at no cost to the employee [1, 4, 6] . The employer is responsible for establishing and implementing policies to protect the confidentiality of both the exposed employee and the source [6] .

In the following section, we will review postexposure management of common and serious infectious agents encountered in the healthcare setting, categorized by route of transmission. We will discuss initial assessment and testing, PEP regimen and its adverse effects, follow-up testing, and work restriction. We will also briefly discuss primary prevention, infection prevention and control precautions and vaccination for each infection.

Percutaneous injuries sustained by hospital-based HCP occur at a rate of 19.5 injuries per 100 occupied beds [7] . Exposure of HCP to blood-borne pathogens commonly occurs as a result of needlestick injuries, with operating rooms, patient rooms, and emergency departments being the most common sites [7] . Exposures that pose a risk of transmission of bloodborne pathogens include percutaneous (e.g. needlestick), ocular, mucous membrane, or non-intact skin (e.g. human bites, traumatized skin) exposures to blood, tissue, or other potentially infectious body fluids. There are several pathogens that can be transmitted following exposure to blood [8] . Other body fluids that can transmit blood-borne pathogens are cerebrospinal, pericardial, pleural, peritoneal, synovial, amniotic fluid; semen, cervical, or vaginal secretions; and visibly bloody fluids, excretions, or secretions. Feces, nasal secretions, saliva, sputum, sweat, tears, urine, and vomitus cannot transmit blood-borne pathogens unless they contain blood [1, 9, 10] .

We will discuss the management of exposure to HBV, hepatitis C virus (HCV), and HIV since they are the most commonly encountered [8] .

Following exposure to blood-borne pathogens, the exposed area should be immediately washed with soap and water and cleansed with an antiseptic (e.g. chlorhexidine gluconate). The exposed mucous membranes should be flushed with copious amounts of water and the eyes irrigated with saline or water [1] .

The risk factors and baseline status for HIV, HBV, HCV, and other blood-borne pathogens should be assessed in both the source and the exposed HCP. It is not necessary to test the source patient if the status of HIV, HBV, or HCV is known to be positive [9] [10] [11] . If the status for these infections is unknown through history and medical records, testing to determine the disease status of both source and exposed HCP should be performed promptly. The recommended tests are hepatitis B surface antigen (HBsAg), hepatitis C antibodies, and HIV antibodies. It is not recommended to test needles or sharp instruments implicated in the exposure [9] [10] [11] .

PEP for HIV and HBV, if nonimmune, should be given to HCP as early as possible while waiting for further information or test results if the exposure is associated with risk of transmission [9] [10] [11] . However, hepatitis B vaccine should be given to nonimmune exposed HCP who are at future exposure risk even if presenting >7 days after exposure [9, 11 ].

The exposed HCP should be counseled about modifying sexual practices (for HIV), avoiding breastfeeding and pregnancy (HIV), and refraining from donating blood, plasma, organs, tissue, or semen until these infections have been ruled out [9] [10] [11] .

The average risk of HIV transmission after percutaneous and mucocutaneous exposure to HIV-infected blood in healthcare settings is approximately three and one per 1000 exposures, respectively [12] . The risk of transmission of HIV after percutaneous exposure to HIV-infected blood is increased with deep injury, visible blood on the device, procedures involving a needle in an artery or vein, and high HIV viral load. Low level of HIV viral load in the blood and the use of antiretroviral therapy (ART) are associated with a reduction of the risk of HIV transmission [13] .

Selection of a three-drug regimen for HIV PEP should be guided by proven efficacy, tolerability and side effect and toxicity profiles, ease of administration, and known or suspected resistance of the source virus to ART [9, 11] . The preferred HIV PEP regimen is tenofovir, emtricitabine, and raltegravir, based on their proven efficacy in treatment of HIV infection and tolerability (Table 2) [9, 11, 14, 15] .

HIV PEP should be continued until the result of HIV testing is available. If the source patient is known or confirmed to be HIV-infected, PEP should be continued for 28 days. If HIV antibody testing is negative in the source patient, PEP There is no need for work restriction or modification for exposed asymptomatic noninfected HCP.

c HIV-infected source who has confirmed positive HIV antibody by EIA assay with HIV1/HIV2 antibody differentiation immunoassay, rapid HIV testing, or positive HIV RNA (>5000-10,000 c/mL, if the source patient has been at risk of HIV exposure in the previous 6 weeks). d ARV drugs that should be avoided due to severe drug adverse effects and toxicity include efavirenz, nevirapine, abacavir, stavudine, didanosine, nelfinavir, indinavir, tipranavir, and enfuvirtide. e This is the preferred HIV PEP regimen, whereas others are considered alternative regimens. should be discontinued and no follow-up HIV testing for the exposed HCP is required. However, if the source patient is at a risk of HIV exposure in the previous 6 weeks and acute retroviral syndrome is clinically suspected, plasma HIV RNA testing is recommended. PEP should be continued until results of the plasma HIV RNA assay are available [9, 11] . Rapid HIV testing is the recommended test to be utilized in decision-making regarding PEP, if the HIV status of the source is unknown. A fourth-generation HIV antigen/antibody combination test is the preferred serologic screening test, if the rapid HIV test is positive, and as a follow-up test for the exposed HCP. All positive HIV antibody tests should be confirmed by supplemental tests such as the HIV1/HIV2 antibody differentiation immunoassay [9, 11, 16] .

Exposed HCP should be followed in an outpatient clinic 3 days after initial assessment, every 1-2 weeks until the end of PEP treatment and for blood testing ( Table 2 ). If the exposed HCP develop an acute illness consistent with primary HIV infection such as febrile or mononucleosis-like illness, testing for HIV with a fourth-generation enzyme immunoassay and HIV RNA assay is recommended [9, 11] . If HIV antibody testing is positive at baseline or at any time during follow up, HCP should be referred to a clinician experienced with HIV care for further management and treatment, and the incident should be reported to the local health department if occupationally acquired [9, 11] .

The risk of HBV transmission after percutaneous exposure to blood from an HBV-infected patient is approximately 23%-62% [17] .The need and type of PEP for HBV is based on type of exposure, HBsAg status of the source patient, disease status of the exposed HCP, and vaccination status and vaccine-response status of the exposed HCP (Table 2) [4, 10] . HBV vaccine and hepatitis B immunoglobulin are 70%-90% effective in preventing HBV infection if given within 12-24 hours of exposure [18, 19] .

The risk of transmission of HCV following percutaneous exposures to blood from HCV-infected source patients is estimated to be 1.8% per exposure [8, 11] . Since there is no effective PEP regimen to prevent HCV transmission, the goal is early identification of infection and, if present, referral for follow up, and evaluation of treatment options with an experienced clinician (Table 2) [11, 20] . If the serum alanine aminotransferase level is elevated at follow up, HCP should be tested for HCV RNA to assess for acute HCV infection; if the HCP become acutely infected with hepatitis C, immediate referral to a specialist experienced in the treatment of hepatitis C is strongly recommended [11, 20] .

Primary prevention of occupational infection with bloodborne pathogens can be achieved by preventing exposures to blood and body fluids through infection control precautions, use of safety devices, safer work practices and engineering controls, improved surgical techniques, education of HCP on prevention of needlestick injury, and postexposure care and vaccination against HBV [6, 10] .

Person-to-person transmission of these air-borne infections occurs via inhalation of droplet nuclei (airborne particles 1-5 mm in diameter) containing infectious agents that remain infective over time and distance. These droplets are usually generated by infectious patients through coughing, sneezing, and shouting, in addition to other sources such as aerosolgenerating procedures (Table 1 ) [1, [21] [22] [23] .

Tuberculosis HCP are at higher than average risk of acquiring tuberculosis (TB), particularly in TB-prevalent areas. The estimated latent TB infection (LTBI) rates among HCP in countries with low, intermediate, and high TB incidence are 3.8%, 6.9%, and 8.4%, respectively [24] . Patients with unrecognized TB disease who are not promptly placed in appropriate airborne precautions are the major risk factor for transmission of Mycobacterium tuberculosis in healthcare settings [21] . The risk of transmission is higher following contact with patients with cavitary pulmonary or laryngeal TB, acid-fast bacilli (AFB) smear positive sputum, cough, and those who are not on effective anti-TB treatment or have just initiated treatment [21] .

When a new case of infectious TB is identified in the healthcare setting, all contacts prior to implementing infection control measures should be identified and evaluated for TB disease and LTBI [21] . The highest priority for contact evaluation should be given to HCP with medical risk factors for TB disease (e.g. HIV infection or immunocompromised) and those present during aerosol-producing procedures (e.g. bronchoscopies, sputum induction, or autopsies) ( Table 3 ) [21] . Any HCP exposed to a potentially infectious TB source should be evaluated promptly with a symptom screen for TB and a tuberculin skin test (TST) or IFN-g release assay (IGRA). TST or IGRA should not be performed in exposed HCP who have had a previous positive test result or a history of treatment for LTBI or TB disease [21] . The TST or IGRA and symptom screen should be repeated 8-12 weeks later, if the initial TST or IGRA result is negative and HCP is asymptomatic. Repeating TST is not contraindicated, unless the test was associated with severe ulceration or anaphylactic shock; in such cases, IGRA is the recommended test. IGRA is also preferred in previously Bacillus Calmette-Gue rin (BCG) vaccinated HCP [21, [25] [26] [27] .

The choice of the cut point for a positive TST result after exposure to an active TB index case will depend on the baseline TST result if known and whether the exposed HCP has an immunocompromising condition. Prior BCG vaccination status should not be used in the interpretation of TST in the setting of contact investigations [25] [26] [27] . The result of the TST should be read by a designated and trained clinician 48-72 hours after the TST is placed and should be Close contact is defined as being within~6 feet or within the room or care area for a prolonged period of time (not a brief interaction such walking by) or having direct contact with infectious secretions such respiratory while not wearing PPE.

n High-risk exposures include: percutaneous (e.g. needle stick) or mucous membrane exposure to blood, body fluids (vomitus, urine, feces), or tissues from an infected symptomatic patient; direct skin contact with skin, blood, body fluids from an infected symptomatic patient; processing blood or body fluids from an infected symptomatic patient without appropriate PPE; direct contact with a dead body of an infected patient. Low-risk exposures include: HCP in facilities with infected patients who have been in care areas of infected patients without recommended PPE.

o Close contact, particularly if at high risk of complications of avian influenza, within 6 feet with a confirmed or probable case during bronchoscopy or intubation; while performing tracheal suctioning, delivering nebulized drugs, or handling inadequately screened or sealed body fluids without use of recommended PPE; or following a recognized breach in PPE procedure or a laboratory workers with unprotected exposure to a virus-containing sample. If PEP cannot be started within 48 hours of exposure, antiviral treatment with oseltamivir 75 mg orally twice daily for 7 days can be given.

Abbreviations documented in millimeters, not simply as negative or positive. A positive TST in a contact of a known infectious TB patient is defined as ‡5 mm in HCP with a previous TST result of 0 mm or an increase of ‡10 mm in HCP with a previous TST result between 0 mm and 10 mm. In immunocompromised HCP, a TST ‡5 mm on baseline or follow-up testing is considered positive [21, [25] [26] [27] ]. All exposed HCP with positive TST or IGRA should be evaluated by screening for symptoms and signs of TB disease and chest radiography to rule out TB disease. If TB disease is ruled out, treatment for LTBI should be considered [21] . Treatment of LTBI significantly reduces the risk of progression from infection with M. tuberculosis to TB disease by 60%-90% (Table 3 ) [28] [29] [30] [31] .

Exposed immunocompromised HCP (e.g. HIV infection, organ transplantation) should be evaluated by screening for symptoms and signs, TST or IGRA, and chest-X-ray; if all the tests are normal, they should be started on treatment for LTBI due to the high risk of developing active disease. If the repeat TST or IGRA at 8-12 weeks is negative, treatment for LTBI can be discontinued. Clinicians may choose to complete the treatment course for LTBI in that situation since TST and IGRA may not be reliable in severely immunocompromised conditions [21] .

If exposed HCP develop symptoms or signs of TB (e.g. fever, weight loss, hemoptysis) during follow up, chest X-ray and AFB smear and culture should be performed and the HCP should be treated for TB disease if indicated [21] .

Prevention of TB among HCP can be accomplished through education regarding TB symptoms, transmission, and prevention, and by providing training in the proper donning and doffing of personal protective equipment (PPE) such as respirators and N95 masks. In addition, annual screening for symptoms or signs of TB disease, baseline (for all HCPs in low-and medium-risk settings) and annual (for medium-risk settings) TB screening for HCP with negative TST or IGRA, and treatment of HCP who have LTBI is recommended [21, [25] [26] [27] .

Varicella, caused by varicella-zoster virus (VZV), is highly contagious, with secondary attack rates up to 90%. It is transmitted via direct contact with vesicles and inhalation of aerosols from vesicular fluid or respiratory tract secretions of a patient with varicella or disseminated herpes zoster (HZ) [22] . HZ is much less contagious than varicella [22, 32] . Varicella can still occur in vaccinated exposed persons, but the infection is usually milder and less infectious than in the unvaccinated ones [22] . Nosocomial transmission, which is uncommon, is usually due to delay in the diagnosis, incorrect diagnosis, or late implementation of infection control precautions [4, 22, 32] .

PEP regimens for varicella and HZ include varicella vaccine, varicella zoster immune globulin (VariZIG), and oral antiviral agents (Table 3) [22, 32, 33] .

Varicella vaccine, not zoster vaccine, is effective in prevention of varicella infection (risk reduction of 60%-90%) and development of severe disease due to vaccine-induced VZV-specific T-cell proliferation if given within 3-5 days of exposure to an index case of varicella or zoster [34] . The disease is usually mild in vaccinated persons who did not seroconvert or who lost detectable antibody and developed varicella after exposure to VZV [4, 35] . Any HCP who develops vaccine-related rash should avoid contact with susceptible patients until resolution of the rash [4, 22] .

VariZIG is effective in prevention and disease modification of varicella in exposed susceptible persons if given ideally within 96 hours, and up to 10 days, of exposure [36, 37] .

It should be noted that none of the PEP regimens are completely effective in preventing the disease after exposure and breakthrough infections have been reported [22] .

Measles is a highly contagious disease with a secondary attack rate of 90%. The majority of measles cases occur in either unvaccinated HCP or HCP with unknown vaccination status. It still can occur in immunized persons after exposure to an index case [4, 38, 39] .

Measles vaccine may prevent and attenuate the severity of the disease if given within 3 days of exposure in limited contact settings such as schools, childcare, and medical offices [40, 41] . Immunoglobulin products are effective in preventing and modifying the infection, in addition to reducing the mortality by 75%, in persons who are nonimmune if administered within 7 days of exposure [42] .

Measles, mumps, and rubella vaccine is highly effective in primary prevention of measles, with a two-dose vaccine effectiveness of 99% [4, 39, 43] .

Ebola is an infection caused by Ebolavirus, part of the family Filoviridae. Although the natural reservoir host is unknown, the virus can be transmitted from person-to-person and can result in outbreaks. There are 20,129 cases of Ebola with 7879 deaths in the current outbreak of Ebola in West Africa [44] .

The virus is transmitted through direct contact (through broken skin or mucous membranes) with blood, body fluids, tissues, or skin of symptomatic infected patients or persons who have died of the disease. The risk of transmission is particularly high during the later stages of infection, when viral loads are high. Transmission is not possible during the incubation period when the patient is asymptomatic [45] [46] [47] . HCP caring for Ebola patients are in the highest risk of infection if not wearing appropriate PPE.

Unfortunately, there is no available PEP for Ebola. Exposed HCP should stop working immediately and report to occupational health and their supervisors. They should monitor their temperature twice daily for 21 days after the last exposure and report any temperature >101 F (38.3 C) or symptoms/signs of Ebola infection. Clinicians should follow the updated information available at Centers for disease control and prevention, World Health Organization, and other health organization websites [45] [46] [47] .

Postexposure management of avian influenza and Middle East respiratory syndrome coronavirus are summarized in Table 3 [48] [49] [50] [51] [52] .

Droplet transmission occurs when respiratory droplets carrying infectious agents travel directly from the respiratory tract of the infectious person to susceptible mucosal surfaces of the exposed person. Respiratory droplets are >5 mm in diameter, do not remain suspended in air, are generated mainly during coughing, sneezing, and talking by the infectious person or during procedures such as suctioning, and are typically transmitted across short distances (3-6 feet) from the infectious person (Table 1 ) [1] .

Healthcare-associated severe group A streptococcal (GAS) infection occurs at rate of 5%-12%. Surgical, obstetrics and gynecology, and burn units are the wards most commonly involved in hospital outbreaks of GAS infections [53] [54] [55] . The issue of treating the contacts of invasive GAS (iGAS) index cases is debated because it is unknown if antibiotic therapy will decrease risk of acquiring GAS infection. It is generally agreed that PEP should not be routinely given to all contacts of iGAS cases. The decision to use PEP for contacts will be based on clinician's assessment of the risk associated with each HCP and guidance from local institutions (Table 4 ) [53] [54] [55] .

All HCP in contact with an index case of iGAS infection should be screened for GAS if they develop sore throat, skin infection, skin lesions, vaginitis, or pruritus within 7 days of contact with the index case [55] . In outbreaks of GAS infection, the infection control department may decide to screen asymptomatic HCP for GAS. Screening for GAS should be performed from throat and skin lesions and, if negative, from nose, anus, and vagina. Screened HCP found to be positive for GAS should receive antibiotic eradication therapy (Table 4 ). Screening for GAS should be repeated 7-10 days after completion of therapy and, if still positive for GAS, HCP should be retreated and their household contacts should be screened [53] [54] [55] .

Nosocomial transmission of N. meningitidis is rare due to adherence to infection control practices. HCP can acquire the organism through contact with respiratory secretions of infected patients or in laboratory settings [4, 56] . Antibiotic therapy used as PEP is effective in preventing infection after exposure and eradicating nasopharyngeal carriage of N. meningitidis (Table 4 ) [57] .

Quadrivalent (A, C, W-135, Y) meningococcal polysaccharide vaccine (MPSV4) and conjugate meningococcal vaccines (MenACWY-D, MenACWY-CRM) protect against 75% of disease among adults by induction of detectable bactericidal antibodies, which decline 3-5 years post-vaccination [4, 56] . Meningococcal vaccines can be used in the routine vaccination schedule of high-risk HCP (Table 4 ) and during institutional outbreaks (defined as the occurrence of ‡2-3 confirmed or probable primary cases of meningococcal disease caused by the same serogroup in £3 months). During an outbreak, HCP should be vaccinated with a meningococcal vaccine that contains the responsible serogroup [4, 56] . The recently approved meningococcal vaccine for serogroup B is indicated for individuals 10-25 years of age and its role for HCP vaccination is not clear [58] .

Pertussis is a highly contagious disease with a secondary attack rate of 80%, which may turn into an outbreak [4, 59] . Pertussis is most communicable in the first 2 weeks of illness during the catarrhal and early paroxysmal stages. Transmission is negligible after about 3 weeks of untreated infection or 5 days after initiation of effective antibiotic therapy [59] .

The benefits of PEP for exposed HCP to pertussis are not well supported with strong evidence (Table 4 ) [4, [60] [61] [62] . However, it is generally recommended that unvaccinated HCP with significant exposure to an infectious patient should be given PEP. On the other hand, vaccinated HCP can be given the option of either taking PEP or monitoring for symptoms for 21 days after last contact with infectious index patient. Providing PEP is preferred for vaccinated HCP at high risk of severe disease or HCP working with patients at high risk of severe disease, such as neonates or pregnant women [60, 63] .

Effectiveness of pertussis-containing vaccines (e.g. tetanus-diphtheria-acellular pertussis, diphtheria-tetanus-acellular pertussis) for primary prevention of pertussis ranges from 66% to 78% but the duration of immunity is unknown [4, 5, 59, [63] [64] [65] .

Influenza is a large burden in healthcare settings since it is a common infection and can cause outbreaks of severe respiratory illness among hospitalized patients and long-term-care residents [4, 66] . Viral shedding typically occurs from 1 day before symptom onset until 5-10 days after onset, although young children and immunocompromised patients may shed virus for longer durations [67] . Antiviral agents have been shown to be effective as PEP after unprotected exposure to influenza and particularly in outbreak situations. However, because of concern of antiviral resistance, it is usually preferred to watch the exposed HCP and to initiate treatment early if symptoms develop [67] [68] [69] . If it is decided to give PEP, it should be for HCP contacts who are at high risk of influenza complications or in contact with persons at high risk of influenza complications (Table 4 ) [67] .

The effectiveness of influenza vaccine to prevent influenza varies and depends on the age and health status of the person and the match between the circulating strains and the strains included in the vaccine for that season [68, 70] . The influenza vaccine is~90% serologically effective in HCP but the vaccine impact on clinical illness among HCP and their contacts is not well established [71] [72] [73] [74] . Postexposure management of other infections transmitted by the droplet route are summarized in Table 4 [39, [75] [76] [77] [78] [79] [80] .

Postexposure management of infections transmitted by the contact route Direct contact transmission occurs when infectious agents are transferred from an infected person to another person without a contaminated intermediate object or person. Indirect contact transmission occurs when infectious agents are transferred from an infected person to another through a contaminated intermediate object or person (e.g. hands of HCP, shared patient-care devices such as electronic thermometers and glucose monitoring devices, or inadequately cleaned instruments such as endoscopes and surgical instruments) [1] .

There are several organisms that can be transmitted by this route (Table 1) . Unfortunately, there is no effective PEP regimen for the majority of these organisms. Therefore, standard precautions including hand hygiene are the cornerstone of prevention and control of these infections [1] .

Scabies, which is caused by the mite Sarcoptes scabiei, has resulted in many outbreaks in different healthcare settings [81] . Scabies is transmitted primarily by skin-to-skin contact with an infested person. Crusted scabies, in which millions of mites infest a single host, is more contagious than scabies and can be transmitted by casual contact, such as holding hands, or through fomites, such as clothing and linens [82] . PEP should not be given for exposed HCP who lack signs of infestation. In case of a continuing outbreak, PEP for scabies can be given to asymptomatic HCP contacts in consultation with the infection control and occupational health departments (Table 5) [1, 83, 84] .

Postexposure management of other infections transmitted by the contact route is summarized in Table 5 [1, [85] [86] [87] [88] [89] .

Postexposure management is the responsibility of the HCP, occupational health provider, and employer, and is made possible through awareness of the risks and potential interventions both before and after exposure. There are several challenges in the postexposure management of HCP to infectious sources. These include evaluation of an unknown source patient or a source patient who refused testing, difficulties in determining levels of risk of transmission for exposure incidents, availability of a rapid diagnostic test for source patient testing, sensitivity and specificity of diagnostic tests, disclosure of related information of the source individual, unavailability of PEP regimens, development of drug-resistant pathogens (e.g. TB), and adherence of exposed HCP to clinic visits and to the prescribed PEP regimen. There is an urgent need for PEP for serious infections such as HCV and Ebola. Ig should be used as PEP for nonimmune exposed HCP who are >40 years of age, or who are deemed immunocompromised, have chronic liver disease, or have severe allergic reaction to hepatitis A vaccine.

b

Exposed areas of skin that have abrasions, minor cuts, or other lesions are the most commonly affected sites in exposed HCP.

c The decision will depend on the extent, location, and severity of HSV infection in the HCP and the risk of serious disease in the patients taken care of by the HCP (e.g. immunocompromised, severely malnourished, patients with severe burns or eczema, and neonates). Having established protocols for postexposure management, a multidisciplinary team approach, and accessible expert consultation may solve some of these challenges.

Guideline for isolation precautions: preventing transmission of infectious agents in health care settings

Surveillance Network of Catalonia Spain TM. Implications of health care personnel in measles transmission: The need for updated immunization status in the move towards eradication of measles in Catalonia

The economic burden of sixteen measles outbreaks on United States public health departments

Advisory Committee on Immunization Practices. Centers for Disease Control and Prevention. Immunization of health-care personnel: recommendations of the Advisory Committee on Immunization Practices (ACIP)

Advisory Committee on Immunization Practices. Advisory committee on immunization practices recommended immunization schedule for adults aged 19 years or older: United States

OSHA bloodborne pathogens and needlestick prevention

University of Virginia Health System. International healthcare worker safety center

Infection risks following accidental exposure to blood or body fluids in health care workers: a review of pathogens transmitted in published cases

Updated US Public Health Service guidelines for the management of occupational exposures to human immunodeficiency virus and recommendations for postexposure prophylaxis

Centers for disease control and prevention(CDC). CDC guidance for evaluating health-care personnel for hepatitis B virus protection and for administering postexposure management

HIV prophylaxis following occupational exposure

Risk of HIV-1 transmission for parenteral exposure and blood transfusion: a systematic review and meta-analysis

Centers for Disease Control and Prevention Needlestick Surveillance Group. A case control study of HIV seroconversion in health care workers after percutaneous exposure

Raltegravir, tenofovir DF, and emtricitabine for post-exposure prophylaxis to prevent the sexual transmission of HIV: Safety, tolerability, and adherence

Assessment of adverse events associated with antiretroviral regimens for postexposure prophylaxis for occupational and nonoccupational exposures to prevent transmission of human immunodeficiency virus

Centers for Disease Control and Prevention. Laboratory testing for the diagnosis of HIV infection: updated recommendations

Accidental hepatitis-B-surface-antigen-positive inoculations: use of e antigen to estimate infectivity

Prevention of perinatally transmitted hepatitis B virus infections with hepatitis B immune globulin and hepatitis B vaccine

Hepatitis B immune globulin for accidental exposures among medical personnel: final report of a multicenter controlled trial

Testing for HCV infection: an update of guidance for clinicians and laboratorians

Guidelines for preventing the transmission of Mycobacterium tuberculosis in health-care settings

Prevention of varicella: recommendations of the Advisory Committee on Immunization Practices (ACIP)

Aerosol generating procedures and risk of transmission of acute respiratory infections to healthcare workers: a systematic review

Tuberculosis among health care workers

Interferon-gamma release assays versus tuberculin skin test for targeting people for tuberculosis preventive treatment: an evidence-based review

Interferon-gama release assays for tuberculosis screening of healthcare workers: a systematic review

Updated guidelines for using Interferon Gamma Release Assays to detect Mycobacterium tuberculosis infection -United States

Treatment of latent tuberculosis infection: a network Meta-analysis

Antibiotic prophylaxis for preventing post solid organ transplant tuberculosis

Rifamycins (rifampicin, rifabutin and rifapentine) compared to isoniazid for preventing tuberculosis in HIV-negative people at risk of active TB

Recommendations for use of an isoniazid-rifapentine regimen with direct observation to treat latent Mycobacterium tuberculosis infection

Advisory Committee on Immunization Practices, Centers for Disease Control and Prevention. Prevention of herpes zoster: recommendations of the Advisory Committee on Immunization Practices (ACIP)

Vaccines for preventing herpes zoster in older adults

Vaccines for post-exposure prophylaxis against varicella (chickenpox) in children and adults

Persistence of immunity to varicella-zoster virus vaccination among health care workers

Updated recommendations for use of VariZIG-United States

Evaluation of varicella-zoster immune globulin: protection of immunosuppressed children after household exposure to varicella

A global perspective of vaccination of healthcare personnel against measles: systematic review

Prevention of measles, rubella, congenital rubella syndrome, and mumps, 2013: summary recommendations of the Advisory Committee on Immunization Practices (ACIP)

MMR immunization after contact with measles virus

Post-exposure passive immunization for preventing measles

Current efficacy of postexposure prophylaxis against measles with immunoglobulin

Measles, mumps, and rubella-vaccine use and strategies for elimination of measles, rubella, and congenital rubella syndrome and control of mumps: recommendations of the Advisory Committee on Immunization Practices (ACIP)

Infection prevention and control recommendations for hospitalized patients with known or suspected Ebola hemorrhagic fever in u.s. hospitals

Interim guidance for healthcare workers providing care in west african countries affected by the ebola outbreak: limiting heat burden while wearing personal protective equipment (PPE)

Review of Human-to--Human Transmission of Ebola Virus

Interim infection prevention and control recommendations for hospitalized patients with Middle East Respiratory Syndrome coronavirus (MERS-CoV

Middle East Respiratory Syndrome coronavirus (MERS-CoV)

Interim guidance for infection control within healthcare settings when caring for patients with confirmed, probable, or cases under investigation of avian influenza A(H7N9) virus infection

Interim guidance for follow-up of contacts of persons with suspected infection with highly pathogenic avian influenza A (H5N1) virus

Interim guidance on the use of antiviral medications for chemoprophylaxis of close contacts of persons with avian influenza A (H7N9) virus infection

Public Health Agency of Canada. Guidelines for the prevention and control of invasive group A streptococcal disease

Prevention of invasive group A streptococcal disease among household contacts of case patients and among postpartum and postsurgical patients: recommendations from the Centers for Disease Control and Prevention

Guidelines for prevention and control of group A streptococcal infection in acute healthcare and maternity settings in the UK

Prevention and control of meningococcal disease: recommendations of the Advisory Committee on Immunization Practices (ACIP)

Antibiotics for preventing meningococcal infections

Updated recommendations for use of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine in adults aged 65 years and older -Advisory Committee on Immunization Practices (ACIP)

National Immunization Program CDC. Recommended antimicrobial agents for the treatment and postexposure prophylaxis of pertussis: 2005 CDC Guidelines

Antibiotics for whooping cough (pertussis). Cochrane Database Syst Rev

A comparison of 2 strategies to prevent infection following pertussis exposure in vaccinated healthcare personnel

American College of Occupational and Environmental Medicine Medical Center Occupational Health Section Task Force On Pertussis Vaccination Of Health Care Workers. Pertussis vaccination of health care workers: ACOEM medical center occupational health section task force on pertussis vaccination of health care workers

Updated recommendations for use of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap) in pregnant women-Advisory Committee on Immunization Practices (ACIP)

Effectiveness of adolescent and adult tetanus, reduced diphtheria, and acellular pertussis vaccine (Tdap) against pertussis

Disruption of services in an internal medicine unit due to a nosocomial influenza outbreak

Antiviral agents for the treatment and chemoprophylaxis of influenza -recommendations of the Advisory Committee on Immunization Practices (ACIP)

Expert Panel of the Infectious Diseases Society of America. Seasonal influenza in adults and children -diagnosis, treatment, chemoprophylaxis, and institutional outbreak management: clinical practice guidelines of the Infectious Diseases Society of America

Neuraminidase inhibitors for preventing and treating influenza in healthy adults and children

Centers for Disease Control and Prevention. Prevention and control of seasonal influenza with vaccines: recommendations of the Advisory Committee on Immunization Practices (ACIP) -United States, 2014-15 influenza season

Antibody response to influenza A(H1N10 pdm09 among healthcare personnel receiving trivalent inactivated vaccine: effect of prior monovalent inactivated vaccine

Effect of influenza vaccination of healthcare personnel on morbidity and mortality among patients: systematic review and grading of evidence

Vaccination of healthcare workers to protect patients at increased risk of acute respiratory disease: summary of a systematic review

Influenza vaccination for healthcare workers who care for people aged 60 or older living in long-term care institutions

Mumps postexposure prophylaxis with a third dose of measles-mumps-rubella vaccine

Prevention of plague: recommendations of the Advisory Committee on Immunization Practices (ACIP)

Doxycycline or ciprofloxacin prophylaxis and therapy against experimental Yersinia pestis infection in mice

Plague as a biological weapon: medical and public health management. Working Group on Civilian Biodefense

Human rabies prevention -United States, 2008: recommendations of the Advisory Committee on Immunization Practices

Use of a reduced (4-dose) vaccine schedule for postexposure prophylaxis to prevent human rabiesrecommendations of the Advisory Committee on Immunization Practice

Control of scabies outbreaks in an Italian hospital: an information-centered management strategy

Scabies outbreak in an intensive care unit with 1,659 exposed individuals-key factors for controlling the outbreak

Interventions for preventing the spread of infestation in close contacts of people with scabies

Interventions for treating scabies

Hepatitis A vaccine versus immune globulin for postexposure prophylaxis

Effectiveness of immune globulins in preventing infectious hepatitis and hepatitis A: a systematic review

Disease-modifying effects of postexposure hepatitis A active immunization

Prevention of hepatitis A through active or passive immunization: recommendations of the Advisory Committee on Immunization Practices (ACIP)

Head lice

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.