The World Health Organization (WHO) has achieved some success with improved treatment regimens, and a small decrease in case numbers. Some countries have legislation to involuntarily detain or examine those suspected to have tuberculosis, or involuntarily treat them if infected. Vaccines
The only available vaccine as of 2021 is bacillus Calmette-Guérin (BCG). In children it decreases the risk of getting the infection by 20% and the risk of infection turning into active disease by nearly 60%.It is the most widely used vaccine worldwide, with more than 90% of all children being vaccinated. The immunity it induces decreases after about ten years. As tuberculosis is uncommon in most of Canada, Western Europe, and the United States, BCG is administered to only those people at high risk. Part of the reasoning against the use of the vaccine is that it makes the tuberculin skin test falsely positive, reducing the tests usefulness as a screening tool. Several vaccines are being developed.Intradermal MVA85A vaccine in addition to BCG injection is not effective in preventing tuberculosis. Public health
Public health campaigns which have focused on overcrowding, public spitting and regular sanitation (including hand washing) during the 1800s helped to either interrupt or slow spread which when combined with contact tracing, isolation and treatment helped to dramatically curb the transmission of both tuberculosis and other airborne diseases which led to the elimination of tuberculosis as a major public health issue in most developed economies.
The cascade of person-to-person spread can be circumvented by segregating those with active ("overt") TB and putting them on anti-TB drug regimens. After about two weeks of effective treatment, subjects with nonresistant active infections generally do not remain contagious to others. If someone does become infected, it typically takes three to four weeks before the newly infected person becomes infectious enough to transmit the disease to others. Risk factors
A number of factors make individuals more susceptible to TB infection and/or disease. Active disease risk
The most important risk factor globally for developing active TB is concurrent HIV infection; 13% of those with TB are also infected with HIV. This is a particular problem in sub-Saharan Africa, where HIV infection rates are high. Of those without HIV infection who are infected with tuberculosis, about 5–10% develop active disease during their lifetimes; in contrast, 30% of those co-infected with HIV develop the active disease.Use of certain medications, such as corticosteroids and infliximab (an anti-αTNF monoclonal antibody), is another important risk factor, especially in the developed world.Other risk factors include: alcoholism, diabetes mellitus (3-fold increased risk), silicosis (30-fold increased risk), tobacco smoking (2-fold increased risk), indoor air pollution, malnutrition, young age, recently acquired TB infection, recreational drug use, severe kidney disease, low body weight, organ transplant, head and neck cancer, and genetic susceptibility (the overall importance of genetic risk factors remains undefined). Infection susceptibility
Tobacco smoking increases the risk of infections (in addition to increasing the risk of active disease and death). Additional factors increasing infection susceptibility include young age.