Tuberculosis Andrea Eden-Shingleton Concordia University, Nebraska MPH 500 Introduction to Public Health Professor Rebecca Toland 10/21/2014

Biomedical/ Biostatistical Principles What is Tuberculosis? Biomedical/ Biostatistical Principles Definition Cause Symptoms Transmission Pathophysiology Treatment History

What is Tuberculosis? Definition Tuberculosis, commonly known as TB, is a contagious and potentially fatal airborne disease caused by a bacterial infection. TB typically affects the lungs, but it also may affect any other organ of the body. (cdc.gov, 2013) Terms Latent TB infection- Persons with latent TB infection do not feel sick and do not have any symptoms. They are infected with M. tuberculosis, but do not have TB disease. The only sign of TB infection is a positive reaction to the tuberculin skin test or TB blood test. Persons with latent TB infection are not infectious and cannot spread TB infection to others. (cdc.gov, 2013) Multi drug resistant TB (MDR TB) is a form of drug-resistant TB in which TB bacteria can no longer be killed by at least the two best antibiotics, isoniazid (INH) and rifampin (RIF), commonly used to cure TB. As a result, this form of the disease is more difficult to treat than ordinary TB and requires up to 2 years of multidrug treatment. (cdc.gov, 2013)

What is Tuberculosis? Cause Mycobacterium tuberculosis is a slow growing; aerobic, rod-shaped, acid fast bacterium that only lives in humans. As shown below on an Acid Fast Bacilli smear. (cdc.gov, 2013) Signs and Symptoms Cough with bloody sputum Fever Weakness and fatigue Weight loss (loss of appetite) Positive Tuberculin Skin Test Positive acid fast smear and cultures Chest x-ray (see photo above, left x-ray image is TB, right is normal)

What is Tuberculosis? Transmission Spread by aerosol Mycobacterium Tuberculosis is breathed in droplets expelled during coughing Pathophysiology Inside the lungs the immune system will kill off some bacilli and then wall off the rest into small, calcified lesions which remain dormant(latent TB infection.) Unknown to scientists, a small percentage of infected people develop active TB soon after exposure. In an active case of pulmonary TB, the bacilli grow in the lungs, causing breakdown of lung tissues. (cdc.gov, 2013)

What is Tuberculosis?

Anti TB drugs for TB Disease Anti TB drugs for Latent TB What is Tuberculosis? Anti TB drugs for TB Disease Isoniazid (INH)  Rifampin (RIF) Pyrazinamide (PZA)  Ethambutol (EMB) TB disease must be treated for at least 6 to 9 months. In some cases, treatment can last 18 to 24 months or longer to treat multidrug-resistant TB (MDR TB).  (cdc.gov, 2013) Phases of treatment initial phase of 2 months, most tubercle bacilli are killed continuation phase of either 4 or 7 months. there are still active bacilli in the body, to kill remaining bacilli Anti TB drugs for Latent TB 3 choices  Isoniazid (INH) daily for 9 months combination regimen of isoniazid (INH) and rifapentine (RPT) given in 12 once-weekly doses under directly observed therapy (DOT). Rifampin (RIF) given daily for 4 months(cdc.gov, 2013)

History of Tuberculosis Found in spines of 4000 yr old Egyptian mummies 460BCE consumption or phthisis described by Hippocrates 1679 Sylvius identifies pathological lung changes 1854 first successful public health initiative, Isolation in Sanatoriums (see photo) 1882 Robert Koch discovered Mycobacterium Tuberculosis 1906 Bacille Calmette-Guerin vaccine 1947 first anti-TB drug therapy (Persson, 2010)

How prevalent is TB? Epidemiological Principle World wide incidence United States incidence Risk Factors Social and Behavioral Environmental

How prevalent is TB? The National Institute of Allergy and Infectious Diseases reports, worldwide, a new person is infected every second, killing between 2-3 million people globally each year. (niaid.nih.gov, 2010) The WHO (2013) accounts around 1.3 million TB-related deaths worldwide in 2012; emphasizing that TB is a leading killer of people who are HIV infected (320, 000 of the total deaths.)

How prevalent is TB?

How prevalent is TB in the US? With 9,945 total cases, representing a case rate of 3.2 cases per 100,000 persons, 2012 had the lowest number of reported TB cases since reporting began in 1953. (84,304 cases/ 52.6) (cdc.gov, 2013). In 2013, the CDC reported that foreign born Hispanics and Asians account for 79% of the new cases and 50% of the national case total. In 2013, the CDC estimated 6% of all TB cases and 10% of TB cases among people aged 25–44 occurred among people who were HIV-positive.

How prevalent is TB? United States: new cases reported in every state in 2012

How prevalent is TB? High Risk Groups Foreign-born Asian Hispanic Native Hawaiian or Pacific Islander Black or African American

How prevalent is TB in the US? High risk Gender: Males, all adult age groups Age 24-44 yrs. combined with 45-64 yrs. is 62% of all reported cases in 2012

How prevalent is TB? Social/Behavioral Factors Gender Race Income Education Alcohol/Substance abuse HIV positive Poor nutrition Lack of healthcare (cdc.gov, 2013) Environmental Factors Crowding (prison) Urban dwelling Low Social Economic Status (Poverty) Unemployment Homelessness Healthcare workers (cdc.gov, 2013)

Stopping Tuberculosis Policy and Infection control

Stopping Tuberculosis TB Prevention laws are authorized by various levels of government (typically state governments) to regulate and establish TB control programs. (cdc.gov, 2009) Federal agencies prevent infected individuals from traveling on commercial aircraft; names of these individuals are placed on a Do Not Board list. (Schneider, 2014, p. 165) A similar list, managed by the CDC and Homeland Security, is distributed to border patrol authorities in order to prevent diseased persons from entering the U.S. via seaport or land border. (Schneider, 2014, p. 165)

Stopping Tuberculosis The CDC (2013) TB infection control program should be based on a three control measures: Administrative measures Environmental controls Use of respiratory protective equipment For suspected exposure: The Mantoux tuberculin skin test (TST) is the standard method of determining whether a person is infected with Mycobacterium tuberculosis. Reliable administration and reading of the TST requires standardization of procedures, training, supervision, and practice. (cdc.gov, 2013)

References cdc.gov. (2013, October). Retrieved September 10, 2014, from cdc.gov: http://www.cdc.gov/tb/statistics/reports/2012/pdf/report2012.pdf niaid.nih.gov. (2010, August 10). Retrieved September 10, 2014, from http://www.niaid.nih.gov/topics/tuberculosis/Understanding/history/pages/historical_killer.aspx Persson, S. (2010). Smallpox, syphilis and salvation: medical breakthroughs that changed the world. Auckland, New Zealand: ReadHowYouWant. Schneider, M. J. (2014). Introduction to public health. (4th ed.). Burlington, MA: Jones & Bartlett Learning. WHO.int. (2013). Retrieved September 10, 2014, from Global Tuberculosis Report 2013: http://apps.who.int/iris/bitstream/10665/91355/1/9789241564656_eng.pdf?ua=1