A disseminated disease is a type of disease that has spread from its initial point of origin or contact in the body to other regions that were not its specific target of attack. Usually, it propagates through the blood supply or lymph system that carries white blood cells in plasma to fight infections. There are generally two types that are common in humans — those caused by cancer, where tumor cells spread throughout the body; and infectious diseases caused by bacteria, fungi, and viruses. Infections that are prone to becoming a form of disseminated disease include AIDS, tuberculosis, and subcutaneous skin infections like those that cause gangrene.
Cancer is considered to be a form of disseminated disease, as it uses the bloodstream of the body to perform metastasis, where it transfers copies of itself to other regions. Treating disseminated diseases involving cancer has been done since the 1950s by chemotherapeutic agents, which can kill off tumor cells as they spread. In the 1970s, some antibiotics were also discovered to have beneficial effects against cancer, such as actinomycin-D and bleomycin, so combinations of these agents along with chemotherapy treatments were begun. In combination treatments as of 1965, up to 70% of patients in the new regimen were showing positive reactions when the compound cisplatin was included. This is still a common treatment for cancer as of 2011, with new drug combinations resulting in a cancer-free state for 61% to 83% of patients depending on the cancer type.
Tuberculosis is a disease caused by the Mycobacterium tuberculosis bacteria carried by airborne water droplets that infect the lungs. In rare cases, tuberculosis will become a disseminated disease that spreads to many parts of the body, such as the bones, intestines, and lining of the heart. People most prone to the disseminated form of tuberculosis are those with weak immune systems, such as the elderly, HIV patients, and infants. As with cancer, the disseminated disease form of tuberculosis is treated with a combination of ten or more different chemical agents and antibiotics.
As of 2011, medical science has detected a specific range of infectious organisms that are known to be likely causes of disseminated disease. Amoebae, such as several species of Acanthamoeba can be responsible for causing a disseminated disease even though they don't require a human host to live like viruses do and don't have specific human or animal carriers. The bacteria of M. chelonae, M. avium-intracellulare, and M. abscessus are known to be responsible for pulmonary, soft tissue, and AIDS-related disseminated diseases, respectively. Fungi of the Hyalohyphomycoses group also cause disseminated disease conditions that are most common in immunosuppressed individuals and people who have recently had transplants. Examples of the most common species of fungi in this group that cause infectious diseases include Fusarium spp., Acremonium spp., and Paecilomyces spp.