Tuberculosis Flashcards
Tuberculosis
- Mycobacterium tuberculosis- acid fast rod; transmitted from human to human
- M. bovis-
Tuberculosis: the organism
- acid- fast rods; slow growing
- resistant to drying
- found to survive weeks in dried sputum
- resistant to antiseptics and disinfectants
- important to use effective treatments at the correct concentration and for the correct period of time
- spread by respiratory route
- exposure to others with active case of TB most common
TB- test
- spread by respiratory
- may be active or latent
- infections can be detected by tuberculin skin test, x-rays, sputum samples and Xpert MTB/RIF test
TB- effected
- 1/3 of the world population may be infected
- 2013, 9 million fell ill with TB and 1.5mil died from the disease
- over 95% of TB deaths occur in low and middle income countries
- TB is the leading killer of people with HIV –> causing a quarter of the deaths
TB- latent and active
- minimum infectious dose is 10cells
- latent TB infection- primary infection
- tubercules
- caseous lesions
- positive skin test
- no active disease
TB disease- development of active disease, also called consumption
dissemination
- extra-pulmonary TB (lymph nodes, kidneys, bones, gentile tract, brain and meninges)
Sites of TB disease
-Pulmonary TB- Lungs
-Extra pulmonary TB- places other then lungs
- larynx, lymph nodes, pleura, brain, kidneys, bones and joints
Miliary TB- carried to all parts of the body, through bloodstream
TB- signs and symptoms
symptoms in the lungs-
- bad cough that last 3 weeks or longer
- weight loss
- coughing up blood or mucus
- weakness or fatigue
- fever and chills
- night sweats
Pathogenesis of tuberculosis
- breathe in bacteria then they go in alveolus then attach to macrophage
- M. Tuberculosis is able to produce compounds to inhibit the fusion of the phagosome and the lysosome to make the phagolysosome. bacteria don’t get digested and survive in the macrophage
- early immune response
- TB may become dominant at this point
- in some people the disease progresses
TB skin test
-pokes arm and if inflames then TB is present
TB treatment
- treatment requires multiple drugs for 6-9 or more months
-very difficult
-non-compliance common which leads to resistance
DOTS- directly observed therapy
Paul Farmer, M.D
- partners in health (PIH)- Boston
- paul farmer, Jim Kim and Opthelia Dahl
- worked in Haiti
- Developed the concept of DOTS
- success in treating MDR TB (multi drug resistance)
Drug- Resistant TB
- caused by M. tuberculosis organisms resistant to at least one TB treatment drug below
- isoniazid (INH)
- Rifampin( RIF)
- Pyrazinamide (PZA)
- Ethambutol (EMB)
- resistant means drugs can no longer kill the bacteria
Resistant TB
MDR-TB- multidrug resistant tuberculosis
- bacteria resistant to at least isoniazid and rifampin which are the most effective drugs in use
- treatable but requires long treatment
XDR-TB- Extensively drug resistant tuberculosis
- bacteria resistant to the 1st line drugs and the 2nd line drugs
- high mortality rate
- 30% cure rate
- doesn’t respond to many antibiotics
Primary and Secondary Resistant TB
primary- caused by person to person transmission of drug resistant organisms
secondary- develops during TB treatment:
- patient was not given appropriate treatment regimen or
- patient did not follow treatment regimen as prescribed
DOTS= directly observed therapy
- DOTS is the most effective strategy available for controlling the worldwide TB epidemic today
- Patients are registered into a program where the drugs are supplied on a daily basis
- patient is observed taking the medication by health worker or responsible family member
- assures compliance with treatment plan
