TUBERCULOSIS
Paige Derouin
History
• Began infecting the first human ancestors as long as 500,000 years ago
• In 1882 – claimed the lives of 1 in 7 people • Ran rampant in crowded European and American cities• March 24 – Robert Koch discovers Mycobacterium
tuberculosis• Koch’s discovery allowed scientists to begin working on a
treatment and vaccine for TB.
• 1908 - Albert Calmette and Camille Guérin: BCG vaccineo First used in 1921 preventatively
History Cont’d
• 1943 - microbiologist Selman Waksman discovered streptomycin
• 1970s – Most people believe TB is completely irradiated
• 1998 – genetic sequencing of Mycobacterium tuberculosis
• 2006 – first case of extensively drug resistant TB in South Africa
• 2008 – 49 countries reported cases of extensively drug resistant TB
Incidence
• In 2008 highest incidence was in Southeast Asia
• 98% of TB related deaths occur in developing countries
• In the US, there were 4.2 cases per 100,000 people in 2008• Most of the US cases occurred in Florida,
Texas, California, and New York
World Incidence 2006
World map showing reported cases of tuberculosis per 100,000 citizens. Red = >300, orange = 200-300; yellow = 100-200; green 50-100; blue = <50 and grey = n/a.
Mycobacterium tuberculosis
• Rod shaped, gram positive bacterium
• Infection begins with phagocytosis into a macrophage
• can remain inside the host in a dormant form and reactivate later
Diagnosis
Diagnosis is based on: Symptoms
Producing cough, chest pain, night sweats, fatigue, fever
Medical history TB tests
Tuberculin Skin Test Blood Tests
Chest X-Rays Diagnostic microbiology
Sputum smear – acid-fast bacilli
TB Tests
Tuberculin Skin Test Injection of fluid into the skin of the lower arm 48-72 hours later – checked for a reaction Diagnosis is based on height of the skin
Blood Test Newer test Based white blood cells’ response to the test Results available in 24 hours http://www.youtube.com/watch?v=s3v8M2Q6A
GI&feature=channel
Treatment
• Latent TB• Not symptomatic or contagious • Usually treated with Isoniazid for 9 months• Confirmed with a chest X-Ray
• Infectious TB• Treatment is very expensive• Treated in phases - Isoniazid, Rifampicin,
Pyrazinamide and Ethambutol1. Usually 3 drugs2. 2 different drugs
Treating Drug Sensitive TB
Treating Drug Resistant TB
Treating Extensively Drug Resistant TB
Problems with Treatment
Very long treatment Large number of drugs is expensive Resistant Strains 3rd World countries
Steps to Prevention
WHO’s Stop TB Strategy DOTS – reduce deaths
from TB by 50% by 2015, eliminated by 2050
March 24 – World TB Day
Research for a new vaccine to replace or boost BCG
Works Cited
“I am stopping TB” image. : http://www.tac.org.za/community/files/stop-tb_medium.jpg
Treating extensively drug resistant TB: http://www.niaid.nih.gov/topics/tuberculosis/Understanding/WhatIsTB/ScientificIllustrations/Pages/extensivelyDrugResistantIllustration.aspx
Treating drug resistant TB: http://www.niaid.nih.gov/topics/tuberculosis/Understanding/WhatIsTB/ScientificIllustrations/Pages/multidrugResistantIllustration.aspx
Treating drug susceptible TB: http://www.niaid.nih.gov/topics/tuberculosis/Understanding/WhatIsTB/ScientificIllustrations/Pages/firstLineIllustration.aspx
Mycobacterium: http://www.students.stedwards.edu/aruiz5/interview.htm
World Incidence: http://commons.wikimedia.org/wiki/File:Tuberculosis_reported_cases_2006.PNG