D. Tariq Jagnarine
Fam Med, Endocrinology/Diabetes
Tuberculosis (TB) is an airborne bacterial infection. TB prevention measures involve stopping the bacteria from spreading and treating asymptomatic infection before it progresses to active disease. Active TB disease without proper treatment can be life-threatening. Symptoms include chest pain, shortness of breath, and persistent cough. Sometimes, people can carry TB bacterium with no symptoms. This is known as latent TB or TB infection.
People with latent TB are at risk of developing TB disease. This may not happen for months or even years until something interferes with their immune system function and allows the bacteria in their lungs to multiply.
The infectious agent responsible is the bacterium Mycobacterium tuberculosis (M tuberculosis). A person with active TB disease can spread it with any action that causes the bacteria in their lungs and throat to become airborne. Examples include coughing, sneezing, singing, speaking, yelling, laughing, and playing a wind instrument
When another person inhales the bacteria, it enters their lung tissue, where it can cause active disease or remain latent. A person with latent TB cannot spread the bacteria to others.
M tuberculosis usually transmits from the lungs and throat. This means people cannot spread the bacteria from other locations such as their spine or kidneys. Since TB usually spreads through inhalation of M tuberculosis, a person cannot become infected through contact such as: handshakes, shared dishes, toilet seats or faucets.
TB infection is a reportable disease by law. Anyone with reason to believe a person has TB must report it to their local health officer or department.
PREVENT GETTING OR SPREADING TB
It is possible to control the spread of TB with some preventive measures.
Early diagnosis
TB testing can identify latent TB so a person can get prompt treatment. This may prevent their condition from progressing to active disease, during which the TB bacteria can spread to others. Treatment for latent TB is usually a daily dose of an antibiotic for 6–9 months.
Workplace prevention and control
Some jobs, such as health care, increase a staff member’s chances of TB exposure. Employers in these settings can maintain a TB prevention programme and support the timely identification of people who carry the TB bacteria.
Physical distancing
A person with active TB disease should stay away from others while there is a chance of M tuberculosis transmission. Transmission can occur when a person has active symptoms such as coughing and flu-like symptoms.
Household contacts are at high risk of TB infection, and doctors may recommend they receive preventive treatment. Screening may also be necessary. A doctor can monitor the effects of treatment to determine when the chance of bacteria spread has passed.
Air quality measures
A person with TB disease can reduce the number of bacteria in the air by: wearing a mask, ventilating rooms by opening windows, covering their mouth and nose when coughing or sneezing or using a high-efficiency particulate air (HEPA) filter.
UV light
An article from 2019 discusses how under controlled conditions, UV radiation may prevent the spread of M tuberculosis. It does this by changing the bacteria’s genetic material so it cannot reproduce. However, UV light can damage the skin and eyes. Installing the lamps out of sight in heating, ventilation, and air conditioning (HVAC) systems or high up in a room can reduce this risk, but technicians who service the lights should wear protective equipment.
UV air purifiers are another option. However, they can emit ozone layers, which may cause breathing difficulties. The California Air Resources Board has a list of electronic air cleaners that tests found to emit less than 0.05 parts per million of ozone.
RISK GROUPS
Anyone with exposure to TB bacteria can develop TB disease, but certain people are more likely to get sick sooner. They include:
Children under 5 years old
Older adults
People who have had TB infection in the last two years
Those who use injectable illegal drugs
People who have received incomplete TB treatment in the past
Those with low body weight
People receiving immunosuppressant therapy
Low-income or medically-underserved populations
Those who have had intestinal bypass or gastrectomy surgery
People who drink large quantities of alcohol
Certain medical conditions can also increase a person’s chance of becoming sick with TB, such as:
HIV
diabetes
certain cancers
chronic renal failure
silicosis, a type of lung disease
