Health Care Workers in the Developing World: Disease Transmission Risk and Mitigation

Abstract & Commentary

By Michele Barry, MD, FACP, and Brian G. Blackburn, MD

Dr. Barry is the Senior Associate Dean for Global Health at Stanford University School of Medicine. Dr. Blackburn is Clinical Assistant Professor in the Division of Infectious Diseases and Geographic Medicine at Stanford University School of Medicine.

Dr. Barry is a retained consultant for the Ford Foundation and has received research or grant support from Johnson & Johnson Corporate Foundation, the Doris Duke Foundation, and the National Institutes of Health. Dr. Blackburn reports no financial relationships related to this field of study.

Synopsis: The recent explosion of overseas training opportunities for health care workers and medical researchers brings with it unique risks and exposures, such as to needlestick injuries, hemorrhagic fever viruses, tuberculosis, and severe respiratory viruses. These issues require special measures for risk mitigation.

Source: Kortepeter MG, et al. Health care workers and researchers traveling to developing-world clinical settings: Disease transmission risk and mitigation. Clin Infect Dis 2010;51(11):1298-1305.

Only limited data are available regarding the epidemiology of infectious diseases that occur among traveling health care workers (HCWs) or medical researchers. Providing prophylaxis and vaccinations, bringing protective personal equipment, and having medical countermeasures such as post-exposure antiretroviral blister packs and antibiotics are reviewed. Four special areas are targeted: needlestick injuries, hemorrhagic fever viruses, emerging severe respiratory viral infections (such as SARS-CoV and H1N1 influenza), and drug-resistant tuberculosis.

Regarding needlestick exposures, the authors suggest a pre-travel discussion of management and prevention. HCWs are advised to set up a "sharps" container, even using a soda can or plastic laundry detergent bottle. Not only can HIV and hepatitis viruses be contracted by needlestick, but Ebola and Lassa viruses, syphilis, dengue, and even malaria may be contracted in this way; fatal cases of malaria have occurred after needlestick exposure.1 The authors suggest administration of hepatitis B immunoglobulin if an injury is sustained by a non-immune HCW. They also suggest considering administration of hepatitis B immunoglobulin for non-immune HCWs prior to travel. Those who suffer needlestick injuries also should be followed for the possibility of hepatitis C infection.

Needlestick transmission of HIV should be addressed with post-exposure prophylaxis initiated preferably immediately, and not later than three days after exposure.This should be continued for 4 weeks; the World Health Organization recommends two nucleoside reverse-transcriptase inhibitors, and 3 drugs if there is >15% antiretroviral resistance in the community. The CDC recommends a 3-drug regimen if the source patient is known to be infected with HIV and the source device is a hollow-bore needle or has visible blood contamination; they recommend zidovudine, stavudine, or tenofovir plus emtricitabine or lamivudine, and when a third drug is added, both the CDC and the WHO recommend a ritonavir-boosted protease inhibitor. Follow-up for needlestick injury should include serologic testing for HIV, viral hepatitis, and syphilis at 3 months and HIV RNA testing at 2, 6, 12, and 24 weeks as well as with any acute febrile illness post-needlestick injury.

The WHO and CDC have developed viral hemorrhagic infection-control recommendations for African health care settings.2 In a post-exposure setting, treatment or prophylaxis measures can be instituted with specific antivirals directed at certain hemorrhagic fever viruses.2

Infection with some respiratory viruses such as SARS-CoV or influenza (H5N1 and H1N1) can cause severe infections in HCWs. Protective measures to mitigate risk include contact and respiratory precautions, diligent hand-washing, and N95 respirators when high-risk procedures that generate aerosols, such as intubation, are undertaken. Influenza vaccination for HCWs is recommended, and chemoprophylaxis with neuraminidase inhibitors may be indicated in certain settings.

Drug-resistant tuberculosis is a potential threat, and extensively drug-resistant (XDR)-TB has been reported in 58 countries, and both multidrug resistant and XDR-TB represent serious occupational risks to HCWs working overseas. Before departure, the risk of tuberculosis at the destination should be assessed, and the authors recommend that HCWs should be screened for latent tuberculosis by an interferon gamma release assay (IGRA). If the assay is negative, the authors recommend considering BCG immunization 2-6 months before departure. Rescreening the HCW with a repeat IGRA two months after return is recommended as well. The authors strongly suggest fit testing with a disposable filtering facepiece respirator, as negative air pressure rooms are unlikely to be available overseas. When latent tuberculosis is diagnosed after travel to high-risk areas, the authors emphasize that infection with MDR- or XDR-TB should be considered and treatment might consist of either ethambutol or pyrazinamide plus levofloxacin or moxifloxacin for 6-12 months.

Commentary

With the explosion of global health programs in the United States, the number of HCWs and researchers traveling abroad has increased dramatically. The authors suggest that this type of travel exposes HCWs to different risks than the usual traveler experiences. Although this review provides practical guidance to mitigate potential occupational infectious disease transmission, a few of the recommendations are controversial or difficult to administer in a low-resource setting. For example, BCG vaccination has never been shown to be effective in adults, but the authors and certain advisory boards recommend using it for HCWs in high-risk areas. In addition, although seronegative HCWs may remain at risk for hepatitis B if exposed, it would be highly unlikely that hepatitis B immunoglobulin would be available in a low-resource setting after a needlestick injury.

References

  1. Tarantola A, Rachline A, Konto C, et al. Occupational Plasmodium falciparum malaria following accidental blood exposure: A case, published reports and considerations for post-exposure prophylaxis. Scand J Infect Dis 2005;37:131-140.
  2. World Health Organization and CDC infection control for viral hemorrhagic fevers in the African health care setting. http://www.cdc.gov/ncidod/dvrd/spb/mnpages/vhfmanual.htm.
  3. Advisory Council for the Elimination of Tuberculosis; The Role of BCG in the Prevention and Control of Tuberculosis in the United States. MMWR 1996;45(RR-4):1-18.