Tuberculosis (TB) bacteria's lifespan varies significantly depending on its location and environment.
TB Bacteria Lifespan Outside the Body
In the air, under certain conditions, TB bacteria can survive for 3-4 months. A humid and dark environment can extend this survival time to up to 3 months. However, direct sunlight significantly reduces viability. One source notes that if protected from direct sunlight, the bacilli can survive up to six months outside the body. 10 Another study indicates that TB bacteria can survive in cockroach feces for 8 weeks. 4 Importantly, TB is not spread through contact with surfaces; it's primarily transmitted through airborne droplets produced by coughing or sneezing from an infected individual. 2
TB Bacteria Lifespan Inside the Body
Inside the human body, the story is quite different. TB bacteria can remain dormant (latent) for a very long time, even decades, without causing illness. 6 In this latent stage, the individual is not contagious. However, if the bacteria become active (active TB disease), the length of the infection and its effects will depend on a number of factors and will require treatment which may last for several months. 7 Untreated, active TB can significantly reduce life expectancy. 8
Summary
The lifespan of TB bacteria is greatly influenced by location. Outside the body, survival times are measured in months, significantly reduced by sunlight, and are not a primary route of transmission. Inside the body, the bacteria can persist in a dormant state for many years, even decades. Active TB disease requires treatment and the length of treatment depends on various factors.
References:
[1]: TB bacteria can survive for a long time in the air from about 3-4 months In a humid and dark environment, TB bacteria can survive for up to 3 months. TB bacteria are aerobic bacilli, so in clinical cases, TB bacteria are most often found in the largest numbers in TB caves with bronchioles, which are rich in oxygen.
