Anyone can contract TB at any age, but certain factors increase a person’s risk for contracting active TB, either on first exposure or when a latent TB infection overcomes the immune system to become active. These risk factors include:

• Extended close contact with someone with active TB.
• Older age, which lowers the effectiveness of the immune system.
• African, Asian, or Latin American nationality.
• Substance abuse, which tends to weaken immunity.
• Malnutrition, which prevents the immune system from working properly.
• Lack of medical care, making it harder to diagnose and treat TB.
• Living or working in a residential care facility, prison, refugee camp or anywhere there is overcrowding, poor ventilation, or unsanitary conditions.
• Health care work, which increases your chances of exposure to TB.
• International travel, which also increases the chances of exposure.
• Lowered immunity. Any factor that decreases the ability of your immune system to keep the TB bacteria in check increases the chances of active TB. Some factors include: having HIV/AIDS or diabetes, receiving treatment with corticosteroids, certain arthritis medications, or chemotherapy drugs.