mycobacterium tuberculosis slide share ..

Editor's Notes

• #5: There are several other species and subspecies that are included in the Mycobacterium tuberculosis complex because of their close genetic relationship to tuberculosis: [Review the slide content] With the exception of M. pinnipedii, all of the species in the Mycobacterium tuberculosis complex have been shown to cause disease in humans; however, M. tuberculosis is by far the most prevalent Mycobacterium tuberculosis is the organism responsible for most of the tuberculosis infection and disease seen in the Caribbean Image Credit: CDC Public Health Image Library/Dr. George P. Kubica
• #7: Pose question to participants “How is TB transmitted?” Solicit their responses then proceed to review slide content Transmission is the spread of organisms, such as M. tuberculosis, from one person to another The primary mode of transmission for tuberculosis is through inhalation of infectious particles Less frequently, TB can be transmitted by:…[Review slide content] *Slide Animation Image Credit: Cartoon from clip art.; Graphic from CDC Core Curriculum. 2000.
• #12: Review the slide content Tuberculosis disease can develop very soon after infection or many years after infection In individuals without HIV co-infection, about 5% of people who have been recently infected with M. tuberculosis will develop TB disease in the first year or two after infection. Another 5% will develop disease later in their lives. The remaining 90% will stay infected, but free of disease for the rest of their lives It’s important to remember that not all patients with active TB disease will have a positive Mantoux TST (approx. 75% will have +TST and this percentage is lower in HIV infected patients). Never stop evaluating a patient for active TB simply because the Mantoux TST is 00mm! The chest X-ray will often show abnormalities suggestive of active TB but may be within normal limits for some patients with active disease, particularly if they also have HIV. This will be covered in more detail in Module 4 on Case Finding and Diagnosis Image Source: Centers for Disease Control and Prevention (CDC)
• #13: If the immune system is compromised, then the bacilli multiply and spread to other sites in the body. People who have TB infection but not TB disease are NOT infectious - in other words, they cannot spread the infection to other people Persons with LTBI have a low bacillary load (e.g., ≤~103) It is very important to remember that TB infection is not considered a case of TB Image Source: Centers for Disease Control and Prevention (CDC)
• #15: This next section describes the pathogenesis of TB (the way TB infection and disease develop in the body) At first, the tubercle bacilli multiply in the alveoli and a small number enter the bloodstream and spread throughout the body (dissemination) Bacilli may reach any part of the body, including areas where TB disease is more likely to develop. These areas include the upper portions of the lungs, as well as the kidneys, the brain, and bone Disseminated TB refers to TB that simultaneously involves multiple organs. While “miliary” is given as an example of disseminated TB, it really refers to a radiographic manifestation of disseminated TB. It’s important to note that not all patients with disseminated TB have a miliary pattern on CXR Image source: I-TECH
• #16: This slide shows different sites where TB has caused disease outside of the lungs Image Sources: Scrofula: http://farm1.static.flickr.com/110/283397827_f071de4335_m.jpg Radiographic images: Francis J. Curry National Tuberculosis Center