Mycobacterium Tuberculosis

Shelbi Arnold

Northern Arizona University

Background image of M. tuberculosis. scanning electron microscope

courtesy of CDC

Epidemiology of Tuberculosis

• Tuberculosis is a infectious disease produced by a pathogenic microorganism caused by the inhalation or ingestion of the bacteria Mycobacterium tuberculosis (M. tuberculosis)

• Tuberculosis is transmitted via microscopic airborne droplets when an infected person coughs, sneezes, breathes or speaks

Background Information

The primary site of TB is in the lungs

Infection can spread to other systems– Musculoskeletal– Genitourinary– Central nervous– Integumentary

• TB thrives in overpopulated, developing countries, and among drugs users, the homeless and immunosuppressed individuals.

Strands of Tuberculosis

• Inactive or latent– Person is infected with the disease, but has no signs or

symptoms

• Active– Person is infected and is experiencing signs and symptoms

such as fever, loss of appetite, hemoptysis, cough, night sweats, and fatigue (Gavrilut & Pop, 2012).

• Multi-drug Resistant TB– Person is infected and is resistant to drugs used to treat the

infection• Either due to prior noncompliance of drug regimens or specific

strands of TB

Clinical Diagnosis

• Radiological exams– Chest xray or chest CT scan• Presents as pulmonary scarring,

cavitary lesions, infiltrates,

pleural effusions and atelectasis

• Bacteriological exams– Consecutive collection of sputum for the testing of

blood presence

• Bacterial testing of biopsied tissue from lungs

Recovery, Disability or Death

Outcomes of those infected with Tuberculosis:• Recovery with no disability• Regimens of antibiotics or chemotherapy• Surgical resection of affected lobe of lung or

lung in its entirety• If drug regimens are not followed or TB has

progressed into multi-drug resistant strands, recovery is unlikely

• Death

Demographics and Health Statistics United States 2011

Nationally• Age

– Those 65 and older are the most highly affected

• Gender– Globally the ratio of male to female cases of reported TB stands at 1:1.5-2.1,

males are reported almost twice as many times as females (Nur, Ozsahin, Arslan, Sumer, 2009).

• Race – Pacific Islanders the most affected race/ethnicity

• Geographic location– High Tuberculosis burdens occur in large cities such as New York, Florida,

Texas and California• Account for more than 50% of the national TB cases (Reported Tuberculosis in the

United States, 2010, p. 3).

Nationally, TB cases continue to decline

TB MorbidityUnited States, 2005 - 2010

Year Number Rate per 100,000 populations

2005 14,068 4.8

2006 13,732 4.6

2007 13,286 4.4

2008 12,905 4.2

2009 11,537 3.8

2010 11,182 3.6

(Reported Tuberculosis in the United States, 2011, p. 101)

Trends and Patterns

CDC (2011). Tuberculosis Surveillance Slides

National Impact- Prevalence rate

As of 2011, there were an estimated 4.7 per 100,000 populations infected with TB (Global Tuberculosis Report, 2012)

Epidemiologic Measures

International Impact• Incidence rate (past 10 years)

– Between 2010 and 2000 incidence rates declined from 141 per 100,000 populations to 128 per 100,000 populations (Bachh, Gupta, Hag & Varudkar, 2012, p. 83)

• Prevalence rate– As of 2012, there were an estimated 12,000,000 people

living with TB (Global Tuberculosis Report, 2012, p. 10)

• Mortality rate (past 10 years)– Between 2000 and 2010 mortality rates declined from 22

per 100,000 populations to 15 per 100,000 populations (Barnes et. al., 2011, p. 141)

International Impact

• The WHO’s Global Tuberculosis Report, 2012 states that as of 2011 there were an estimated 12,000,000 people living with Tuberculosis worldwide (p. 10).

• One-third of the world’s population is latently infected with TB (McShane, 2003).

• The 1990 WHO report on the Global Burden of Disease ranked tuberculosis as the seventh most morbidity-causing disease in the world, and expected it to continue in the same position up to 2020 (Bachh, Gupta, Hag, & Varudkar, 2010).

Demographics and Trends in India

“India is highest tuberculosis (TB) burden country globally, accounting for more than one-fifth of the global incidence” (Ananthakrishnan, Jeyaraj, Palani, & Sathiyasekaran, 2012). • In 2011, males ages between 35 and 44 were the highest

reported group of newly notified cases by age and gender• In 2011, females ages between 35 and 44 were the

highest reported group of newly notified cases by age and gender

Globally, TB cases continue to decline

India

• Percentages of risk of contracting tuberculosis based on geographic location in India in the year 2004– Urban areas (2.2%; 1.8%−2.6%) – Rural areas (1.3%; 1.0%−1.5%) (38) – North (1.9%; 1.3%−2.5%) – West (1.6%; 1.0%−2.2%)– East (1.3%; 1.0%−1.6%) – South (1.0%; 0.7%−1.4%)

(A brief history of tuberculosis control in India, 2004, p. 7).

New Case Notifications in 2011South East Asia

MalesAge New cases

0-14 6,490

15-24 114,254

25-34 136,142

35-44 141,636

45-54 135,592

55-64 106,420

65+ 72,640

Females Age New cases

0-14 10,654

15-24 85,376

25-34 84,383

35-44 64,868

45-54 50,920

55-64 36,755

65+ 21,593

Global Tuberculosis Report 2012

Disease Prevention and Management

• The Stop TB Partnership sector of the WHO called DOTS (directly observed therapy, short-course), has a goal to bring the global incidence of active TB to less than one case per 1,000,000 population per year by 2050

(Onozaki & Raviglione, 2010)

• DOTS goal components– Sputum smear microscopy

(SSM)– Directly observed treatment

with standardized short-course chemotherapy

– A system to deliver drugs without interruption and free of charge

– Standardized recording and reporting of cases

– National political commitment (Keeler et al., 2006)

Globalization

• Due to the spread of the infection via airborne transmission, globalization is a high topic of concern for the spread and containment of the disease

• Dangers include:– Tight, closed quarters– Poorly ventilated environments– Noncompliant infected individuals

• Ultimately the health and safety of others is the responsibility of the infected individual to obey physicians orders and remain isolated if infected

Economic Impact• Financing TB control in the US in 2012 and 2013 estimates a

total budget of $140 million (Global Tuberculosis Report 2012).• “Between 2002 and 2009, the annual budget for TB control in

India grew from US$ 36 million to US$ 100 million” (A brief history of Tuberculosis control in India, 2010, p. 5)

• Costs can include– Transportation to treatment facilities– Diagnosis and consecutive medical treatment– Expenses from work and time missed from school

In India, some TB patients spend 20% to 40% of their annual family income being treated for TB (A brief history of Tuberculosis control in India, 2010)

References• A brief history of tuberculosis control in India. (2010) World Health

Organization. Retrieved from

http://whqlibdoc.who.int/publications/2010/9789241500159_eng.pdf

• Ananthakrishnan, R., Jeyaraj, A., Palani, G., & Sathiyasekaran, B. C. (2012).

Socioeconomic impact of TB on patients registered within RNTCP and their

families in the year 2007 in Chennai, India. Lung India, 29(3), 221-226.

Doi:10:4103/0970-2113.99103

• Bachh, A. A., Gupta, R., Hag, I., & Varudkar, H. G. (2010). Diagnosing

sputum/smear-negative pulmonary tuberculosis: Does fibre-optic bronchoscopy

play a significant role? Lung India, 27(2), 58-62. doi: 10.4103/0970-2113.63607.

• Barnes, R. W., Moore, M., Garfein, R. S., Brodine, S., Strathdee, S. A., &

Rodwell, T. C. (2011). Trends in Mortality of Tuberculosis Patients in the United

States: The Long-Term Perspective . Annals Of Epidemiology, 21(10), 791-795.

• CDC. Reported Tuberculosis in the United States, 2011. Atlanta, GA: U.S.

Department of Health and Human Services, CDC, October 2012.

References• Găvrilut, A. I., & Pop, C. M., (2012). Study of correlation between several diagnostic

tests for latent tuberculosis. Analele Societatii Nationale De Biologie Celulara, 17(2),

125-129.

• Keeler, E., Perkins, M. D., Small, P., Hanson, C., Reed, S., Cunningham, J., Aledort, J.

E., Hillborne, L., Rafael, M. E., Girosi, F., & Dye, C. (2006). Reducing the global

burden of tuberculosis: The contribution of improved diagnostics. Nature, p. 49-57.

doi:10.1038/nature05446.

• McShane, H. (2003). Susceptibility to tuberculosis: The importance of the pathogen as

well as the host. Clinical and Experimental Immunology, 133(1), 20-21. doi:

10.1046/j.1365-2249.2003.02194.x

• Nur, N., Ozsahin, L., Arslan, S., & Sumer, H. (2009). An evaluation of gender

differences in the epidemiology to tuberculosis. Heatlhmed, 3(4). 352-358.

• Onozaki, I., & Raviglione, M. (2010). Stopping tuberculosis in the 21st century: Goals

and strategies. Respirology, 15(1), 32-42. doi: 10.1111/j.1440-1843.2009.01673.x.

• WHO. Global Tuberculosis Report, 2012. Switzerland, Information Resource Center,

WHO, 2012.