Abstract
This policy addresses the global infection and disease burden from tuberculosis (TB) and the risk of exposure and illness among health workers. Worldwide, TB is the leading cause of infectious disease–related death. According to the World Health Organization, there were nearly 2 million deaths from TB in 2017, and an estimated 10 million individuals became ill. Global reduction of TB faces many obstacles, including delays in diagnosis and appropriate treatment, difficult treatment regimens, the concurrent HIV epidemic, poverty, and other economic and sociopolitical factors. The first-line drugs for treatment of TB have been in use since the mid-1940s; however, increasingly drug-resistant strains contribute to higher rates of morbidity and mortality. In addition to the disease itself, treatment, particularly for drug-resistant TB, may have severe consequences and may even be fatal. Those employed in the health care sector are at higher risk of infection than the general population as a result of their work exposures. Also, they are disproportionately affected due to inadequate workplace prevention and protection strategies. Infections among health workers further debilitate and diminish the overall health care resources needed to treat patients in affected communities. In addition to medical care, social services and support programs are essential to address the emotional cost and stigma many face and the common financial consequences. Resources and increased attention to prevention, early detection, and less toxic treatment options must be prioritized to address this public health emergency.
Relationship to Existing APHA Policy Statements
Problem Statement
In 2017, 10 million people developed tuberculosis (TB) worldwide, almost half of whom never received treatment, and 1.6 million people died.[1] The situation is worse for patients with multidrug-resistant TB and extensively drug-resistant TB. Only one in five people with drug-resistant TB received treatment, and only half were cured. Eighty-seven percent of TB cases occur in 30 high-burden countries, primarily in Southern Africa, various regions of Asia, the Russian Federation, and South America. These countries also tend to have more vulnerable populations and inadequate resources to address this crisis.[1–3] The concurrent epidemic of HIV in many countries contributes to the burden of TB deaths. HIV greatly enhances susceptibility to contracting TB and progressing from latent to active TB. According to the World Health Organization (WHO), the risk of developing active tuberculosis is estimated to be 16 to 27 times greater among those living with HIV than among those without HIV.[4] In some African countries, 80% of those with TB have HIV co-infection.[5] In low- and middle-income countries, an estimated 10% to 12% of TB cases occur among people living with HIV, and TB is the leading cause of HIV/AIDS-related deaths globally.[6] In the United States in 2017, 5.6% of people with TB were co-infected with HIV.[7,8]
Regardless of the tuberculosis burden in a given country, it is estimated that health workers have a 10 times higher TB incidence rate than the general population and a two- to three-fold higher incidence of active disease.[9–11] Globally, the percentage of health workers with occupationally acquired TB ranges from 27% to 81% depending on a country’s TB incidence.[9,11,12] While these figures are alarming, they are probably serious underestimates; diagnosis, surveillance system, and reporting problems still result in many cases being missed, making it difficult to measure the incidence of TB in most countries.[3]
TB transmission occurs through droplet nuclei, and therefore anyone in proximity to the breathing zone of an infected individual is susceptible. Adding to the ease with which TB is transmitted, the struggle to eliminate TB, particularly in high-burden countries, is complex and occurs in combination with weak health care systems; unmet funding needs; inadequate attention to prevention strategies, especially occupational health and safety measures; ineffective diagnostic and treatment options; and underlying socioeconomic conditions, primarily poverty. In addition, research on rapid diagnostic procedures, effective and less toxic treatment regimens, and improved prevention strategies, including a vaccine and better respiratory protection options, has lagged behind the magnitude of the epidemic. The strategy of WHO’s Global TB Programme to eliminate the disease is part of Sustainable Development Goal 3 identified by the United Nations General Assembly in 2015. The strategy addresses many of the high-level and critical issues needed to help communities address this epidemic, but resources must be provided to achieve these goals.[13]
As noted, health care workers (including all individuals employed in acute and long-term clinical care settings as well as community health workers, students, and volunteers) are at a particularly high risk of exposure to TB, subsequent infection, and, possibly, disease and death. TB has been identified as an occupational health care hazard since the 1950s[9]; however, it was not recognized by the International Labour Organization as an occupationally acquired infectious disease until the 1980s, and it was not specifically included in that category until 2010.[14,15] Guidance by the Centers for Disease Control and Prevention (CDC) first appeared in 1994,[16] with an update in 2005.[8] Health care workers face an increased risk of contracting TB as a result of occupational exposures to TB bacilli in their work environments and the communities where they live and work.[6,9,10] This is particularly true for health workers in countries with a high TB burden.[9,17] The risk for multidrug-resistant TB has been estimated to be five to 6 times higher among health care workers than among those not employed in health care,[18] and the risk is even greater in the case of extensively drug-resistant TB, for which there are very limited treatment options and consequently higher associated mortality rates. Health workers serving at the front lines of the TB and HIV epidemics often face obstacles to accessing TB diagnostic services and treatment. Some of the main barriers include stigma regarding TB and its associations with HIV, weak occupational health services, , concerns about discrimination, and fear of job loss.[19,20] This situation is compounded by a shortage of health workers in precisely those countries hardest hit by the dual epidemic. It has been estimated that the global needs-based shortage of health workers is about 17.4 million.[21] The high rates of TB among health workers have the potential to exacerbate this shortage and negatively affect health human resources. In addition, health workers may lack sufficient knowledge about TB and associated risks or may not receive the education and training they need to protect themselves.
Efforts to prevent occupationally acquired TB focus on the primary prevention triad, which comprises administrative controls, environmental controls, and personal protective equipment. Administrative controls include identifying people with TB symptoms who are not yet on effective treatment, separating those with symptoms, using rapid molecular diagnostics to screen for TB, and reducing time to treatment initiation. Environmental controls include improving ventilation through natural or mechanical means, while personal protective equipment includes fit-tested respirators. These efforts have been augmented by secondary prevention measures such as screening for and treating latent tuberculosis infection and active disease among health care workers. In low-resource settings, however, these measures are poorly implemented (if at all), and efforts at infection control tend to be fragmented or inadequate, including options for respiratory protection.[22–24] In addition, health workers may lack information about TB or have misunderstandings about the use of respirators.[25] If programs are to be successful, health workers must be included in the decision-making process as well as program implementation.[19,26]
There are real challenges in the application of preventive strategies in low-resource, high-burden settings, where most cases of occupational TB occur. These settings are characterized by high numbers of patients who remain undiagnosed, staff shortages, inadequate resources for triage and isolation, and lack of ventilation measures and respirators. Delays in diagnosis and treatment occur due to a lack of laboratory capacity and appropriate medications. Secondary prevention is also limited by a lack of available occupational health expertise and fears among staff members about providing care for TB patients.[27] Health care workers with TB may worry about the stigma of the disease and the resulting discrimination and possible threat to their job security.
The risk of occupationally acquired TB among health care workers varies depending on job activities, geographic location, and patient population.[11] As mentioned earlier, researchers have found that health workers are at least 10% higher risk of TB infection and possible disease than the general population.[9,10] Individuals at greatest risk of contracting occupational TB include those with repeated exposures to patients with TB, those engaged in high-risk occupational tasks, and those who are living with HIV or are immunosuppressed for other health reasons. An association has also been found between low staffing levels and a higher incidence of TB among health care workers.[28] Community health workers and those engaged in home-based care of TB patients are at high risk due to limited infection controls, unavailable or inappropriate respirators, and, above all, the lack of occupational safety and health training in many community care settings.[29,30]
The stigma of a TB diagnosis is of great concern for patients and health workers alike. Health care workers often seek care secretly to avoid possible backlash from colleagues who may fear becoming infected or to avoid loss of employment or other possible negative impacts on their career. Discrimination due to a TB diagnosis, often combined with fear of HIV, takes an emotional toll on individuals and their families.[20] At the same time, health care workers often perceive themselves to be at low risk of acquiring TB, possibly as a result of denial or lack of knowledge. Health care workers who have active TB and experience side effects from the toxic drugs typically used for multidrug-resistant and extensively drug-resistant TB require extensive support from family, friends, and community service programs. Stigma and its resulting isolation will compound and prolong unnecessary suffering.[20,31]
Evidence-Based Strategies to Address the Problem
Modern internationally accepted guidelines for prevention of hospital-acquired TB, based on public health infection control principles, stem from those outlined by WHO and the Centers for Disease Control and Prevention.[8,16,32] These guidelines established the primary prevention triad of administrative, environmental, and personal protective practices and were augmented by secondary prevention measures such as screening for and treating latent tuberculosis infection and active disease among health workers.
A strategy that focuses the attention of governments and national health systems on protection of health workers against tuberculosis needs to be informed by an occupational health approach in conjunction with infection prevention and control (IPC) strategies.[24] An occupational health approach must be an integral part of a community’s TB control program. It is impossible and counterproductive to maintain separate strategies for patients and health workers; such approaches must be implemented simultaneously in as coordinated a manner as possible. This will give due weight to primary prevention while also emphasizing surveillance of occupational TB and protection of students, volunteers, and community health workers. Primary prevention must incorporate training and education of health workers and students and include annual training on the nature, extent, and hazards of TB in health care settings; use of respirators; and environmental controls used to reduce and prevent the spread of infectious droplet nuclei.
Management of infected staff must maintain and strengthen workers’ rights via provision of medical treatment and care, paid sick leave and job protection, appropriate confidentiality, and wage replacement through compensation for those with temporary or permanent disabilities.
However, implementing these recommended measures in full to control transmission has been challenging in resource-poor, high-burden settings.[32,33] As a result, institutions tend to focus on prioritizing certain elements according to various factors such as expertise and resources. Therefore, in addition to IPC and occupational safety and health strategies, early detection and treatment will benefit patients and health workers alike. An example of an alternative clinical strategy is an intensified administrative approach to TB transmission control called FAST (Find cases Actively by cough surveillance and rapid molecular sputum testing, Separate safely, and Treat effectively based on rapid drug susceptibility testing). This approach is based on the assumption that most transmission occurs not from known TB patients on effective treatment but from individuals with unsuspected TB or inappropriate treatment.
Delays in diagnosing people with infectious TB lead to increased rates of transmission. Better education and triage regarding recognition of symptoms are essential. In addition, there are several relatively new diagnostic tests that will improve the timeliness and efficiency of diagnoses and result in reduced transmission. Patients most likely to be infectious with TB can be diagnosed via a rapid molecular sputum test that includes drug resistance (e.g., GeneXpert).[34] Another test that has been made available in limited circumstances is the urine test to detect lipoarabinomannan (LAM). LAM, an antigen produced in large quantities by Mycobacterium tuberculosis, can be identified in the urine for diagnostic purposes. Its implementation is limited to those who are also infected with HIV and who have TB symptoms or are hospitalized.[35] Although cost is a constraint, new technologies should be made available more widely as they are essential for early diagnosis and treatment to stem the continued spread of the disease. Ultimately, prevention will be less costly than treatment and will save more lives. There is a need for further investment in research on and development of new diagnostic tests.
Studies in some settings suggest that implementation of preventive occupational health and IPC measures can reduce occupational TB risks in both low- and high-burden settings,[36,37] underscoring the importance of respiratory protection as a preventive measure. However, respiratory protection measures must be effectively and efficiently implemented if they are to result in real protection, as studies suggest that, particularly in high-burden countries, respirators are not always used correctly or adequately fit tested.[38]
Policies that support training and education programs are essential for health workers and students to protect themselves. Such programs must include increased awareness of the population-specific prevalence of TB, an understanding of TB signs and symptoms, elements of the respiratory protection program (e.g., the importance of when and how to use respirators), and other elements of occupational health and infection control programs. However, respirator use with identified TB patients is insufficient to prevent all occupational infections because many infections are contracted from patients prior to their diagnosis or appropriate treatment. Reducing occupational infections requires implementation of a comprehensive TB control program, including early identification and investigation of people with symptoms of TB .[39] This is a challenge even in high-resource countries, where TB is often not recognized during initial contact with a patient.[40–42]
In addition, efforts must be made to encourage health care workers to report symptoms of TB, and strategies to protect confidentiality and reduce the stigma associated with a possible diagnosis must be in place. Compensation systems must be available and responsive to workers living with TB to provide sufficient financial support during treatment and recovery so that they are not further debilitated or lost to the workforce altogether. In many instances, health care workers lack information regarding their eligibility for and access to workers’ compensation benefits, contributing further to financial hardship.[43]
Opposing Arguments/Evidence
Opposing arguments stem from the cost required to prevent and ultimately eliminate TB, particularly in high-burden but low-resourced countries. Primary, secondary, and tertiary prevention efforts will require increased funding and development of better resources and culturally responsive training and education. Ultimately, this will involve a commitment to shift priorities to address such needs. As with most health issues, and occupational health in particular, prevention at all levels will be less costly than the status quo, which is likely to worsen over time without serious dedication to this urgent issue. It is also likely that there are arguments emphasizing one approach over others (e.g., IPC over occupational health or occupational hygiene). Evidence for the effectiveness of any one measure is scarce, and thus the use of a number of elements simultaneously will yield the best results. However, often employers prefer prioritization of available strategies given potential difficulties in introducing new approaches.
There are some who believe that health workers should not need special or targeted interventions to prevent TB transmission in the workplace because community-wide programs may capture them as well. This implies that there are active and effective community-based programs, which is an unrealistic expectation given that screening for latent TB infection is not routinely done in countries with a high prevalence of the disease.[1] Countries with a high TB burden tend to also have limited resources for managing latent TB infection. As a result, individuals who become ill and need to be treated at a clinical facility or seen in a community setting can expose other workers to infection until the appropriate treatment has been initiated and the infectious state has subsided. In countries such as the United States, by and large those with latent or infectious TB are primarily found in immigrant populations, and targeted programs for these groups will probably not reach most health workers. Workplace screening for latent TB infection among health workers in countries such as the United States is likely to be a useful measure to help reduce disease, particularly because many workers may also be immigrants from countries with a higher TB prevalence. However, there is no precedent, guideline, or recommendation suggesting that workplace prevention strategies are unnecessary, and such a position has never been put forward for TB, influenza, or any other airborne transmissible disease.
Screening measures such as tuberculin skin testing and blood assays for M. tuberculosis represent only a single element of a comprehensive occupational health and infection control program, and such measures are useful in identifying infections but not in preventing them. In fact, the 2005 CDC guidelines stipulated decreases in the use of serial TB screening among certain health workers.
Two key sets of guidelines — the U.S.-based CDC guidelines of 2005 and the more global WHO guidelines of 2009 — focus on a similar list of administrative controls, environmental controls, and respiratory protection controls. All of these controls are essential in preventing the spread of TB, and each relies on facility-specific needs and the availability of resources, expertise, and motivation. The WHO guidelines clearly refer to CDC guidance for more detailed and specific recommendations. In addition, WHO has a greater emphasis than the CDC on addressing specific recommendations regarding co-infection with HIV, reflecting the difference between disease profiles in the United States and those elsewhere in the world.
As an example of shifting commitments and resources, it was recently reported that the CDC will decrease its funding for global disease outbreaks by 80%.[44] This will have implications for many of the needs identified herein. In addition, some of those currently directing TB policies in the United States are minimizing the problem of occupational infections. The 2005 TB guidelines included a risk matrix that defined a "low-risk" facility as any 200-bed hospital treating fewer than six TB cases per year and recommended no medical surveillance beyond an initial screening, even though individuals may be at risk when they encounter patients with TB.[8] Furthermore, such hospitals did not need a respiratory protection program even though health workers were assigned to care for these patients.[45] These assessments document procedures that appear to be contradictory regarding employee risk and that are in conflict with established health risk recommendations.[46] To resolve this issue, a basic health risk assessment should be considered in order to determine which facilities and/or employees need to be included in any program designed to prevent infection or disease. A number of resources are available to help guide occupational health and infection control strategies intended to protect workers (e.g., Appendix B of the 2005 CDC guidelines and a strategy described by Verkuijl and Middelkoop[8,47]).
Action Steps
Political commitment by all sectors of society is necessary to address this public health crisis. Funding by the U.S. Congress to the Centers for Disease Control and Prevention to maintain and bolster existing programs combating TB and other infectious diseases both nationally and globally initiatives is crucial.
To successfully implement WHO recommendations,[36,48] CDC guidelines,[8] the Moscow Declaration,[49] and the declaration of the UN General Assembly’s high-level meeting on the fight against TB[50] (approved by the General Assembly on September 26, 2018), APHA calls on UN agencies, national and state governments, global health funders, worker representative organizations, and all employers of health workers to protect health workers from occupational TB by addressing the recommendations listed below.
Specifically, APHA urges:
References
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18. O’Donnell MR, Jarand
