Types of Infectious Disease

Infectious disease is a broad term that describes an illness caused by a specific type of bacterium, parasite, virus, or fungus. Most of these organisms don’t pose a threat to health, but those that do can cause an array of illnesses, which range from mild to life-threatening. Harmful organisms can be transmitted from person to person, through animal bites, or by consuming contaminated food or water. Infectious diseases can affect anyone, although people with compromised immune systems are at a greater risk of acquiring an infection. 

Here is a brief overview of the main infectious disease types:

  • Bacterial infections – Bacteria is responsible for a broad variety of infectious diseases, from strep throat and urinary tract infections to meningitis and tuberculosis. Many skin rashes are also caused by bacteria.
  • Bone infections – An infection that affects a bone is referred to as osteomyelitis. It is most commonly caused by bacteria that enters the body through a deep wound or surgical incision, but fungi may also be to blame for a bone infection.
  • Fungal infections – There are roughly 300 types of fungi known to cause infectious diseases. Commonly occurring fungal infections include ringworm, pneumocystis pneumonia, blastomycosis, and histoplasmosis. Localized fungal infections (such as toenail fungus) also occur frequently in the United States.
  • Joint infections - Bacterial joint inflammation, or bacterial/septic arthritis, most frequently affects the knee joint. Most cases are caused by the bacterium Staphylococcus aureus (staph), although viral or fungal infections can also cause joint infections.
  • Tropical diseases – Experienced largely by the world’s poorest populations, the most common tropical diseases include elephantiasis (lymphatic filariasis), river blindness (onchocerciasis), snail fever (schistosomiasis or bilharzia), and trachoma. 
  • Parasitic infections – The majority of parasitic infections affect countries in the tropics and subtropics, but these infections also occur in the United States. Prevalent parasitic infections include malaria, Chagas disease, and toxocariasis.
  • Viral infections – Like bacteria, viruses can cause many different infectious diseases. The common cold develops from a virus, as does more complex diseases like the flu, mononucleosis, smallpox, and HIV/AIDS.

Led by experienced physicians who utilize the latest advances in medical technology, Tampa General Hospital provides individualized treatment for a full range of infectious disease types. Please use our PhysicianFinder to identify an infectious disease specialist.