Risk factors

Factors that may increase your risk of salmonella infection include activities that may bring you into closer contact with salmonella bacteria and health problems that may weaken your resistance to infection in general.

Increased exposure

• International travel. Salmonella infection, including varieties that cause typhoid fever, is more common in developing countries with poor sanitation.
• Owning a pet bird or reptile. Some pets, particularly birds and reptiles, can carry salmonella bacteria.

Stomach or bowel disorders

Your body has many natural defenses against salmonella infection. For example, strong stomach acid can kill many types of salmonella bacteria. But some medical problems or medications can short-circuit these natural defenses. Examples include:

• Antacids. Lowering your stomach's acidity allows more salmonella bacteria to survive.
• Inflammatory bowel disease. This disorder damages the lining of your intestines, which makes it easier for salmonella bacteria to take hold.
• Recent use of antibiotics. This can reduce the number of "good" bacteria in your intestines, which may impair your ability to fight off a salmonella infection.

Immune problems

The following medical problems or medications appear to increase your risk of contracting salmonella by impairing your immune system.

• AIDS
• Sickle cell disease
• Malaria
• Anti-rejection drugs taken after organ transplants
• Corticosteroids