TUBERCULOSIS Paige Derouin. History Began infecting the first human ancestors as long as 500,000...

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