تعليق
In general, only 5–10% of people infected with M. tuberculosis will develop TB disease at some time in their life, but the risk is much higher for some groups, such as people with HIV, very young contacts and people who have recently acquired infection. As treatment always carries some risk of adverse drug reactions, it is important that individual benefits and potential harms be evaluated before TPT is administered. Routine testing and treatment should be limited to groups with a demonstrated risk of progression from TB infection to TB disease. Indiscriminate population-wide TPT is not recommended.
TPT is given to people who are not ill and not infectious. This basic difference from treating TB disease alters the ethical obligations that are imposed when a condition threatens the health of an affected individual and their community (174). A decision to take TPT must therefore always be an individual choice, made with full information and without coercion. People offered TPT should feel empowered to opt out or to stop TPT once started. Provision of TPT must always be based on human rights and respect for people (108). The absence of an immediate risk of transmission makes it unethical to restrict the movements of someone with TB infection who refuses treatment.
WHO guidance on TB ethics clearly states that taking TPT should never be compulsory (174). National programmes should strengthen counselling services for eligible people to ensure effective, adequate communication on protective benefits, uncertainties and likely adverse events. The risks and uncertainties should be communicated in a culturally appropriate way. Regular feedback should be invited to guide programme implementation. Counselling and informed consent of TPT recipients should be documented and monitored systematically to ensure effective implementation. Proactive measures, including routine clinical and laboratory monitoring (when indicated), should be an integral part of PMTPT to ensure that those treated remain safe throughout TPT.
9.1 Informed consent
Explicit consent is generally required for TPT, as the person does not pose an immediate risk to others, and the potential benefits are highly context-specific and may be outweighed by a risk of harm for some individuals. The provider usually has a professional obligation to obtain consent. Whether this is documented in writing or not depends on local practice. Informed consent requires adequate, effective communication about the possibility of adverse drug reactions and the prospect of TB risk reduction. Key messages that should be conveyed to a person considering TPT are:
- In the absence of specific risk factors, most individuals with TB infection will not progress to TB disease.
- The poor predictive value of current tests in determining who will progress from TB infection to disease decreases the certainty of the effectiveness of TPT at individual level.
- There are currently no tests for establishing that TPT has been successful for an individual.
- There is a very low risk of emergence of drug resistance when TPT is given to people with TB disease.
- While TPT protects people from disease due to an existing TB infection, a person may be re-infected after completing TPT.
Nurses and other front-line health-care workers can be trained to counsel people on TPT and treatment options and to interpret the results of testing for TB infection or TB disease. The information should include not only the benefits and risks for individuals but also the implications of TPT for a person’s family and community. All messages should be provided in a culturally and linguistically appropriate manner.
9.2 Equity, stigmatization and human rights
Person-centred TPT care must be provided in an equitable fashion, without disadvantage to marginalized and vulnerable populations. It should encompass the human rights aspects of TPT interventions, with appropriate safeguards in law, policy and practice to minimize additional stigmatization, discrimination, violation of bodily integrity or restrictions on freedom of movement. People who are offered testing and treatment should understand the uncertainties well enough to be able to participate in decisions on care options.
The risk of TB disease is higher among population groups who are marginalized and who are likely to live in crowded places with poor infection control. Access to TB screening and TPT for these groups should be prioritized to ensure equity, human rights and solidarity. Efforts must be made to address any inequities in access to services and to uphold human rights, so that the vulnerability of target groups does not impede their access to screening and treatment or violate their rights.
TPT may increase the psychological burden and anxiety of a person taking the treatment. In addition, they might experience stigmatization or discrimination (175). TPT also has financial implications for households – for testing, adherence to treatment and care. Therefore, any TPT services, particularly those for vulnerable groups such as people in prisons, should include measures to minimize the risk of stigmatization, protect the confidentiality of personal data and ensure informed consent; support might also be required to cover social and economic costs associated with screening and treatment. Other interventions can contribute to minimizing the burden on a person on TPT, such as requiring only one visit to a health-care setting or community-based care and access to a shorter, safer TPT regimen.
9.2.1 Mandatory TB screening at borders
Migrants who are screened for TB disease may also be screened for TB infection. Screening for either should always be done with the intention to provide appropriate medical care and not to deport or deny entry to the country. As TB infection indicates a potential future risk to a small number of people, denying or deferring immigration according to infection alone is unjustified and unethical. Whether the individual tests positive for TB infection or is receiving TPT should not affect the immigration procedure. This should be reflected in laws or other policy regulations. People should be tested for TB infection and receive TPT in strict adherence to human rights and ethical considerations.
9.2.2 Screening of health-care workers
Health-care workers are at increased risk of acquiring TB infection and/or disease when infection control measures are not effective. Health workers have the right to work in a safe work environment. They are also under a professional obligation to behave in such a way as to minimize the risk of harm to people in their care. Any consideration of mandatory screening should include both the burden on health-care workers and potential risks for others. Policies should be based on an evaluation of the likelihood of transmission (e.g. for health-care workers in a clinical or ambulatory setting with greater exposure of themselves or their patients) and the likelihood that patients will develop TB disease (e.g. for health-care workers who work with immunosuppressed patients who are at higher risk of developing TB disease after infection). If health-care workers are exposed occupationally to TB or undergo screening and TB treatment or TPT, the health system is obliged to alleviate their burdens as much as possible, such as by offering free screening and TPT. In addition, it is important to invest in infection control measures to reduce the risks of health-care workers, patients and the wider community. Any decision to implement periodic screening for TB infection and/or TB disease among health-care workers should be based on high-quality evidence of the risk of transmission and on the benefit to both health-care workers and others who may be affected.
9.2.3 Community engagement
Engaging affected communities in the development and evaluation of policy can ensure that their views and experiences are considered and that they are prepared for any unexpected effects of the policy. Affected communities, including people who have taken TPT and people who have had TB previously, can also contribute to TPT communication strategies and to disseminating knowledge about TPT. Policy should always be based on current and relevant evidence.