After considering these issues, it was concluded that any tuberculosis infection in a health-care-facility worker[1] due to occupational transmission should be considered unacceptable. Infection of health-care-facility workers with tuberculosis, whether with or without clinical disease, constitutes a preventable impairment of the health of these workers. Additionally, chemoprophylaxis of tuberculosis-infected workers with isoniazid (INH+) poses further significant risks due to isoniazid-related hepatitis and other potential side effects.
The rationale for isoniazid chemoprophylaxis for both those infected and not infected with tuberculosis is to reduce the probability that infected persons will develop active tuberculosis (75,76):
When taken as prescribed, isoniazid preventive therapy is highly effective in preventing latent tuberculous infection from progressing to clinically apparent disease. In controlled trials conducted by the Public Health Service in ordinary clinical and public health settings, isoniazid preventive therapy reduced the incidence of disease by 54%-88%. The main reason for the variation in efficacy appears to have been the amount of medication actually taken during the year in which isoniazid was prescribed.
Others have described the limitations of isoniazid prophylaxis as follows (64):
Aside from toxicity, which is infrequent but potentially serious, the inconvenience and the lack of motivation for an apparently healthy person to accept long-term medication [6 to 12 months] pose formidable obstacles to preventive therapy programs. . . .
Preventive therapy is inefficient. Among newly infected persons, only about 10% will develop disease during a lifetime, but there is currently no reliable way to distinguish the 10% who will develop disease from the 90% who will not. Thus, 10 or more persons must be given preventive therapy to prevent one future case of tuberculosis.
- ↑ The term health-care-facility workers refers to all persons working in a health-care setting-including physicians, nurses, aides, and persons not directly involved in patient care (e.g., dietary, housekeeping, maintenance, clerical, and janitorial staff, and volunteers) (1).
