Health Care Workers, Including Public Health Researchers & Medical Laboratorians

Risks For Health Care Workers Practicing During Travel Outside the United States

Health care workers practicing outside the United States face unique health hazards, including infectious disease risks associated with patient contact or handling clinical specimens. Any type of health care worker working in clinical areas or handling specimens may be at risk, including physicians, nurses, ancillary clinical staff, trainees (for example, students on international rotations), researchers, and public health workers.

Health care workers can be exposed to infections spread through blood and bodily fluids (such as HIV or hepatitis B) or through airborne or respiratory droplet routes (such as tuberculosis [TB] or influenza). Risks vary depending on the duties of the worker, the geographic location, and the practice setting. Of note, health care workers working overseas can have increased risk of exposure to patients with certain uncommon, highly pathogenic, or emerging infectious diseases such as extensively drug-resistant tuberculosis (XDR-TB), Middle East respiratory syndrome (MERS), and Ebola virus disease.

Risks encountered while performing medical work outside the United States can be due to multiple factors, including:

  • Less stringent safety regulations or infection control standards.
  • Limited availability of personal protective equipment (PPE), safety-engineered devices, or postexposure management resources.
  • Unfamiliar practice conditions, equipment, or procedures.
  • Challenging practice conditions that can prevent providers from adhering to standard precautions (such as extremely resource-limited settings, natural disasters, or conflict zones) (see Box 9-1).
  • Higher prevalence of transmissible infections (such as HIV, hepatitis B virus [HBV], hepatitis C virus [HCV], or TB), with potentially increased transmission risk from untreated source patients.

Box 9-1. Health care workers in extreme circumstances

Health care workers regularly provide care in a range of extreme circumstances, which may be characterized by: limited or absent medical and public health infrastructure; lack of fundamental hygiene supplies (such as soap and water for handwashing); increased infectious disease transmission; extreme environmental conditions; and high levels of violence. In 2016, there were 158 attacks against aid workers; 101 were killed.

Because of these increased risks and consequences of severe disease or injury, adequate prevention and preparation are essential. Health problems for the health care worker can have serious implications, both for the person and for those who depend on the health care worker for provision of health care. Detailed instructions on how to prepare for travel or work in developing countries or humanitarian environments is covered in detail in other sections, but additional key considerations for the health care worker include:

  1. Having reliable communication equipment: usually satellite phone, ensuring service provider contract for duration of the mission. Consider portable solar recharging capabilities unless there is a guaranteed power supply, which is rare in most extreme circumstances.
  2. Acquiring evacuation insurance and having a plan if ill or injured: deploying organizations may not provide evacuation insurance (see Chapter 6, Travel Insurance, Travel Health Insurance & Medical Evacuation Insurance) or a detailed evacuation contingency plan. However, both are critical, and the health care worker should be familiar with all details.
  3. Considering underlying health conditions: the provider’s health should be monitored closely and treatment initiated early, if necessary. Any indication that a potentially serious condition is not responding to treatment should warrant rapid planning for potential medical evacuation.
  4. Being psychologically stable and knowing whom to contact if problems arise: providers in conflict and disaster zones typically work long hours in dangerous conditions and are exposed to profound suffering. These experiences can be intensely stressful, leading to increased rates of depression, posttraumatic stress disorder, and anxiety. Before deployment, providers should think about coping strategies and, as much as possible, stay in contact with a support network of family and friends.
  5. Inquiring about availability of antidotes to chemical warfare: although rare, health care workers may be exposed to chemical warfare agents while caring for patients, as recently documented in Syria. If exposure to these agents is a possibility, antidotes (such as atropine) should be immediately available.

Pretravel Vaccination and Screening

In addition to vaccinations specifically indicated for the country visited and routine age-appropriate vaccines, all health care workers should be up-to-date on all recommended vaccinations for employment in health care settings. These include vaccinations (or documented immunity) for the following:

  • Measles, mumps, and rubella
  • Influenza
  • Varicella
  • Tetanus, diphtheria, and pertussis
  • Hepatitis B

For hepatitis B, postvaccination serologic testing for antibody to hepatitis B surface antigen (anti-HBsAg) is recommended. Health care workers without documented response to vaccination should receive 1 more additional dose of hepatitis B vaccine followed by anti-HBsAg testing to assess protection.

Regular screening for latent TB infection with tuberculin skin test or interferon-γ release assay is recommended for health care workers at increased risk of TB exposure. Testing before and after travel should be considered when the provider is working in a country with a high prevalence of TB infection or in a setting of high TB exposure, such as in prisons, refugee camps, and health facilities (see Chapter 4, Tuberculosis). Routine vaccination of health care workers with bacillus Calmette-Guérin (BCG) is not recommended in the United States; however, BCG vaccination may be considered for some health care workers who will work in settings with high TB transmission risk and a high prevalence of strains resistant to isoniazid and rifampin.

Baseline testing for HIV and hepatitis C is not routinely recommended, although it should be considered if risk of exposure will be high and reliable testing will not be available locally in the event of an exposure. Inactivated polio vaccine (given as an adult booster dose) or meningococcal vaccine may be indicated for specific locations experiencing high incidence or outbreaks of these infections.

Personal Protective Equipment and Infection Control

Health care workers should consistently follow standard precautions and, if possible, apply other precautions (contact, droplet, or airborne) as needed. For details, guidelines, and training materials on standard precautions and personal protective equipment (PPE), see PPE, including gloves, gowns, aprons, surgical masks, fit-tested N95 respirators, and protective eyewear, may be necessary to achieve personal protection. Workers untrained in infection-control practices should not participate in patient care or activities with risk of exposure to infectious materials. Specialized PPE and infection-control techniques might be indicated for certain infections that pose high risk to health care workers, such as MERS, avian influenza, and Ebola virus (see disease-specific websites at for the most up-to-date epidemiology and infection control recommendations).

Health care workers should be properly trained for all anticipated procedures, considering the locally available equipment. Health care workers should maintain strict safety standards, even if local practices are less stringent. Needlestick injuries are a common mode of percutaneous exposure to bloodborne pathogens, and practices known to increase risk of needlestick injuries, such as recapping syringes or using needles to transfer a bodily fluid between containers, should be avoided whenever possible. Safety-engineered medical devices and biosafety equipment such as sharps containers might not be available. Local infection-control practices and supplies should be determined in advance. If the local supply of PPE is questionable, bringing one’s own supply can be important.

Infections Transmitted by Airborne or Droplet Routes

Although some airborne or respiratory droplet–transmitted infections are vaccine preventable (such as measles, seasonal influenza, and varicella), vaccines are not routine or available for many others, including TB, MERS, and pneumonic plague. TB is a particular concern for health care workers working overseas in high-incidence areas, and BCG vaccination might be considered for health care workers going to areas with high risk of exposure to multidrug resistant–TB.

Since equipment and facilities for airborne isolation are limited or unavailable in many countries, bringing a personal supply of PPE including N95 respirator masks might be prudent. However, identifying the situations where their use is indicated can be difficult, especially when TB is highly prevalent and isolation of patients is suboptimal. Enhanced PPE recommendations may apply for emerging respiratory pathogens, such as MERS or avian influenza.

Infections Transmitted through Blood or Bodily Fluids

Health care workers are at risk for numerous infections transmitted through blood or body fluids via percutaneous, mucous membrane, or nonintact skin exposures. These include bloodborne pathogens such as HIV, HBV, and HCV. The risk of HIV transmission is approximately 0.3% after a percutaneous exposure to HIV-infected blood and approximately 0.09% after a mucous membrane exposure. Health care workers who have received hepatitis B vaccine and have developed immunity to the virus are at virtually no risk for infection. Based on limited studies, the estimated risk for HCV transmission after a needlestick or cut exposure to HCV-infected blood is approximately 1.8%. Other bodily fluids that may transmit HIV and hepatitis viruses include cerebrospinal fluid, synovial fluid, pericardial fluid, pleural fluid, peritoneal fluid, amniotic fluid, semen, and vaginal secretions. Saliva, urine, sputum, nasal secretions, tears, feces, vomitus, and sweat are not considered infectious for HIV and HCV unless they are visibly bloody. Numerous other infections have also been transmitted to health care workers via blood or bodily fluids, including many that are uncommon or not endemic to the United States, such as viral infections (including Ebola virus, dengue), parasitic infections (including malaria), and brucellosis.

Typically, exposures occur as a result of percutaneous exposure to contaminated sharps, including needles, lancets, scalpels, and broken glass (from capillary or test tubes). Infection risk is considered increased after percutaneous exposures to larger blood volumes (visible blood on the injuring device, hollow-bore needles, deeper injuries, or procedures that involved direct cannulation of an artery or vein). Skin exposures to potentially infectious bodily fluids are only considered to be at risk for bloodborne pathogen infection if there is evidence of compromised skin integrity (for example, dermatitis, abrasion, or open wound). Higher circulating viral load in the source patient is also thought to increase the risk of transmission, and this can be of particular concern in resource-poor settings where treatments for HIV and viral hepatitis are limited.

Health care workers with occupational exposures to blood or bodily fluids should perform the following steps immediately:

  • Wash the exposed area with soap and water thoroughly. If mucous membrane exposure has occurred, flush the area with copious amounts of water or saline.
  • If possible, assess the HIV and HCV status of the source patient. Rapid HIV testing of the source patient is preferred. Exposures originating from source patients who test HIV negative are considered not to pose HIV transmission risk, unless they have clinical evidence of primary HIV infection or HIV-related disease. HBV testing of the source patient may be indicated if the health care worker is not a documented responder to hepatitis B vaccination.
  • Baseline HIV (and potentially HCV and HBV) testing of the exposed health care worker should be performed immediately after the exposure.
  • Seek qualified medical evaluation as soon as possible to guide decisions on HIV PEP (see below).

Postexposure Prophylaxis (PEP)

PEP after percutaneous and mucous membrane exposures to potentially infectious bodily fluids from patients with known or potential HIV infection is recommended to reduce the chance of transmission. A number of medication combinations are available for PEP (see the Updated US Public Health Service Guidelines for the Management of Occupational Exposures to HIV and Recommendations for Postexposure Prophylaxis at

The decision of whether or not to initiate PEP must weigh numerous factors. These include the timing, nature, and source of the exposure; regimen choice as affected by drug availability; the exposed person’s medical history; potential drug interactions; and the possibility of exposure to a drug-resistant strain. Expert consultation is important when considering PEP. When expert advice is not immediately available, the National Clinicians’ Postexposure Prophylaxis Hotline (PEPline) can be reached toll-free at 888-448-4911 (11 am to 8 pm Eastern Time daily) for assistance in managing occupational exposures to HIV and HBV and HCV (

Other considerations when initiating HIV PEP include the following:

  • Initiate HIV PEP as soon as possible after exposure.
  • PEP can be stopped if new information changes the decision to treat.
  • PEP recipients should be counseled regarding drug toxicities, drug interactions, and the importance of adherence.

Other potentially infectious exposures in the source material might require specific interventions. For example, if the health care worker is not a documented serologic responder to hepatitis B vaccination or is incompletely vaccinated, postexposure testing of the source patient and health care worker may be indicated, as well as PEP with hepatitis B immune globulin and vaccination.

Postexposure Testing and Counseling

Postexposure testing and counseling are important follow-up measures for exposed health care workers, whether or not HIV or HBV PEP have been administered. This may include:

  • Advice to take precautions to avoid secondary transmission (such as abstaining from sexual contact, using condoms or other barriers to prevent transmission, avoiding blood or tissue donations, and breastfeeding, if possible) during the first 12 weeks after exposure.
  • Psychological counseling is considered essential since the emotional effect of occupational exposures can be substantial and exacerbated by stressors inherent to the overseas work environment.
  • Baseline and follow-up testing for HIV at 6 weeks, 3 months, and 6 months (follow-up at 6 weeks and 4 months is acceptable if a fourth-generation combination HIV p24 antigen-HIV antibody test is used). Extended HIV follow-up testing for up to 12 months is recommended for those who become infected with HCV after exposure to a source coinfected with HIV and HCV.
  • Baseline and follow-up testing for HCV for those with known or potential exposure to HCV. Perform a baseline test for HCV antibody and if positive perform confirmatory RNA test. Follow-up testing should include either a test for HCV RNA at ≥3 weeks after exposure or a test for HCV antibody at ≥6 months after exposure with a confirmatory RNA test if positive.
  • Baseline and follow-up testing for HBV for those with known or potential exposure to HBV if the health care worker is not a documented serologic responder to hepatitis B vaccination or is incompletely vaccinated. Baseline testing of total antibodies to hepatitis B core antigen (anti-HBc) should be performed as soon as possible after exposure with follow-up testing HBsAg and anti-HBc 6 months after exposure.


  1. Aid Worker Security Database (AWSD): figures at a glance [database on the Internet]. Humanitarian Outcomes; 2015 [cited 2018 Mar 29]. Available from:
  2. CDC. Healthcare-associated infections (HAIs). Atlanta: CDC; 2018 [cited 2018 May 13]. Available from:
  3. CDC. Hepatitis C and health care personnel. 2018 [cited 2018 May 13]. Available from:
  4. CDC. Tuberculosis: testing health care workers. 2018 [cited 2018 May 13]. Available from:
  5. Clinicians Consultation Center. Post-exposure prophylaxis (PEP): timely answers for urgent exposure management. San Francisco: UCSF; 2014 [cited 2018 May 13]. Available from:
  6. Connorton E, Perry MJ, Hemenway D, Miller M. Humanitarian relief workers and trauma-related mental illness. Epidemiol Rev. 2012 Jan;34(1):145–55.  [PMID:22180469]
  7. Grinnell M, Dixon MG, Patton M, Fitter D, Bilivogui P, Johnson C, et al. Ebola virus disease in health care workers—Guinea, 2014. MMWR Morb Mortal Wkly Rep. 2015 Oct 2;64(38):1083–7.  [PMID:26421761]
  8. Human Rights Watch, Safeguarding Health in Conflict Coalition. Under attack: violence against health workers, patients, and facilities. 2014 [cited 2016 Sep. 27]. Available from:
  9. Kuhar DT, Henderson DK, Struble KA, Heneine W, Thomas V, Cheever LW, et al. 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.  [PMID:23917901]
  10. Lee R. Occupational transmission of bloodborne diseases to healthcare workers in developing countries: meeting the challenges. J Hosp Infect. 2009 Aug;72(4):285–91.  [PMID:19443081]
  11. Lyon RM, Wiggins CM. Expedition medicine—the risk of illness and injury. Wilderness Environ Med. 2010 Dec;21(4):318–24.  [PMID:21168784]
  12. Mohan S, Sarfaty S, Hamer DH. Human immunodeficiency virus postexposure prophylaxis for medical trainees on international rotations. J Travel Med. 2010 Jul–Aug;17(4):264–8.  [PMID:20636600]
  13. Schillie S, Vellozzi C, Reingold A, Harris A, Haber P, Ward JW, et al. Prevention of hepatitis B virus infection in the United States: recommendations of the Advisory Committee on Immunization Practices. MMWR Recomm Rep 2018;67(RR-1):1–31.  [PMID:29939980]
  14. Vaid N, Langan KM, Maude RJ. Post-exposure prophylaxis in resource-poor settings: review and recommendations for pre-departure risk assessment and planning for expatriate healthcare workers. Trop Med Int Health. 2013 May;18(5):588–95.  [PMID:23461554]


Henry M. Wu, Alan G. Czarkowski, Eric J. Nilles