Tuberculosis, or TB, is a deadly infectious disease caused by strains of the parasitic organism Mycobacterium tuberculosis. In 1 to 3 percent of TB cases the disease spreads widely, riddling the lungs with 1 to 5 mm lesions, and infecting other organs including the liver and spleen in some cases. In cases such as these, the disease is referred to as disseminated TB, according to MedlinePlus.
Transmission
Disseminated TB is transmitted from person to person predominantly via coughing and sneezing of infected individuals, creating particulates of mycobacterium-infested water droplets, which are breathed in by others. The disease spreads more rapidly in densely populated areas, and is more likely to affect people with a poor diet, who are living in unsanitary conditions, according to an October 2008 article published on the Merck Online Medical Library.
Disease Progression
Rapid proliferation of the TB parasite occurs in lesions formed in the lungs, from which the mycobacteria spread to other organs through the bloodstream. The pathogen gains access to the bloodstream in many cases due to erosion of the pulmonary vein caused by TB infested lesions. Mycobacteria can also spread from the lungs to other organs via the lymphatic system, a network of vessels that carry a clear fluid called lymph throughout the body, according to Medline plus.
Symptoms
A patient with disseminated TB often presents with a slight fever, cough, swollen lymph nodes and an enlarged liver. Patients with this condition suffer multiple organ dysfunctions, and have problems maintaining the normal balance of hormones in the body due to failure of the adrenal glands, which produce these important molecules, according to a January 2009 published in the "American Journal of Medicine."
Treatment
The TB pathogen is extremely resistant to many types of antibiotics, due in part to the composition of the mycobacterium cell wall. Standard treatment includes the antibiotics isoniazid and rifampicin, which are administered for at least six months, in combination with antibiotics ethambutol and pyrazinamide for the first two months. Treatment is extended to 12 months if there is evidence of meningitis, a common complication associated with disseminated TB, according to a February 2003 article published in "American Journal of Respiratory Critical Care Medicine."
Mortality
If left untreated, the mortality rate of disseminated TB is close to 100 percent, but can be reduced below 30 percent if appropriate treatment is administered early. Many deaths occur due to delayed diagnosis and treatment of the disease, according to an April 2004 article published in "The International Journal of Tuberculosis and Lung Disease."
References
- MedlinePlus: Disseminated tuberculosis
- Merck Online Medical Library: Tuberculosis
- "The International Journal of Tuberculosis and Lung Disease"; Clinical Characteristics of 110 Miliary Tuberculosis Patients from a Low HIV Prevalence Country; S. Hussain; April 2004
- "American Journal of Medicine"; Acute forms of Tuberculosis in Adults; J. Jacob et al; January 2009
- "American Journal of Respiratory Critical Care Medicine"; Treatment of Tuberculosis; H. Blumburg et al; February 2003
