Can You Catch Tuberculosis by Sharing a Room with an Infected Person?

Tuberculosis (TB) is a contagious respiratory disease caused by Mycobacterium tuberculosis, and yes—spending time in the same room as someone with active TB can pose a risk of transmission. The bacteria primarily affect the lungs, though they can also involve the bronchi, trachea, and pleura. When an individual with active pulmonary TB coughs, sneezes, laughs, or speaks, they release tiny infectious droplets into the air. These airborne particles can remain suspended for several hours, and inhaling even a small number of them may lead to infection.

Understanding How TB Spreads Indoors

Close, prolonged contact in enclosed spaces significantly increases the risk of transmission. Poor ventilation allows contaminated air to linger, making shared bedrooms, living rooms, or kitchens potential hotspots for exposure. Unlike casual, brief interactions, continuous cohabitation—especially with a person who is actively shedding bacteria—creates conditions favorable for the spread of TB.

Who Is Most at Risk?

People with weakened immune systems, such as those with HIV, diabetes, or malnutrition, are more susceptible to developing active TB after exposure. Children and the elderly also face higher risks. However, not everyone exposed will become infected, and not all infections progress to active disease—some remain latent without symptoms.

Essential Preventive Measures for Households

If you live with someone diagnosed with active, contagious TB, taking proactive steps is crucial to protect yourself and others. Implementing proper hygiene and isolation practices can dramatically reduce the chance of transmission.

1. Ensure Proper Ventilation and Air Disinfection

The infected individual should ideally have a separate bedroom. Open windows at least twice daily—morning and evening—for 30 minutes each time to promote airflow. If available, use UV germicidal irradiation (UVGI) lamps for at least 30 minutes per day to kill airborne bacteria. Keep doors closed to limit air circulation between rooms.

2. Practice Safe Handling of Personal Items

Dishes, drinking glasses, and utensils used by the patient should be washed separately and boiled for a minimum of 15 minutes. Bed linens, blankets, and clothing should be sun-dried for at least six hours before laundering, as direct sunlight has natural disinfecting properties due to ultraviolet radiation.

3. Maintain a Clean and Sanitized Environment

Regularly disinfect high-touch surfaces like doorknobs, tables, and bathroom fixtures using diluted solutions of household bleach (such as sodium hypochlorite-based cleaners like "84 disinfectant") or hydrogen peroxide-based products like peracetic acid. Focus on common areas and the patient's room to minimize bacterial presence.

4. Manage Respiratory Secretions Safely

Sputum from TB patients contains high concentrations of bacteria. Encourage the patient to cover their mouth with a tissue when coughing. Used tissues should be immediately sealed in a covered container and disposed of through incineration whenever possible. Never discard them openly.

5. Use Masks and Maintain Physical Distance

Both the patient and healthy household members should wear well-fitted N95 respirators or surgical masks during close interactions. Maintain a distance of at least one meter (about three feet) whenever feasible. This simple measure greatly reduces inhalation of infectious droplets.

When to Seek Medical Advice

If you've had extended exposure to a TB patient, consult a healthcare provider for screening. Tests such as the tuberculin skin test (TST), interferon-gamma release assays (IGRAs), or chest X-rays can determine whether you've been infected—even if asymptomatic. Early detection allows for timely treatment or preventive therapy, reducing the risk of progression to active disease.

While sharing space with a TB patient does carry risk, informed precautions make it entirely possible to prevent transmission. With consistent hygiene, improved ventilation, and responsible care practices, families can support recovery while safeguarding their health.