Tuberculosis

What Is It?

• Bacterial infectionBacterial infection• Caused by Caused by Mycobacterium Mycobacterium

tuberculosis tuberculosis (also called (also called tubercle tubercle bacillusbacillus))

• Damages a persons lungs or other Damages a persons lungs or other parts of the bodyparts of the body

• Fatal if not treated properlyFatal if not treated properly

Transmission

• Spreads through the air when a person Spreads through the air when a person with active TBwith active TB– CoughsCoughs– SpeaksSpeaks– LaughsLaughs– Sneezes Sneezes – SingsSings– Another person breathes in the bacteria and Another person breathes in the bacteria and

becomes infectedbecomes infected

Inside the Body

• Breath in infected air and bacilli go to Breath in infected air and bacilli go to lungs through bronchioleslungs through bronchioles

• Bacilli infect alveoliBacilli infect alveoli• Macrophages attack bacteria, but some Macrophages attack bacteria, but some

survivesurvive• Infected macrophages separate and Infected macrophages separate and

form tuberclesform tubercles• Dead cells form granulomasDead cells form granulomas

Active vs. Latent Infection

• Unhealthy personUnhealthy person– Bacilli overwhelm immune systemBacilli overwhelm immune system– Bacilli break out of tubercles in alveoli and Bacilli break out of tubercles in alveoli and

spread through bloodstreamspread through bloodstream– This is ≥active≤ TBThis is ≥active≤ TB

• Healthy personHealthy person– Initial infection controlled by immune systemInitial infection controlled by immune system– Bacilli remain confined in tubercles for yearsBacilli remain confined in tubercles for years– This is ≥latent≤ TBThis is ≥latent≤ TB

Symptoms

• Perpetual CoughPerpetual Cough• FeverFever• Weight lossWeight loss• Night sweatsNight sweats• Loss of appetiteLoss of appetite• FatigueFatigue• Swollen glandsSwollen glands• ChillsChills• Pain while breathingPain while breathing

Diagnosis

• Skin test- Mantoux testSkin test- Mantoux test• PPD injected in forearm and PPD injected in forearm and

examined 2-3 days laterexamined 2-3 days later• Red welt around injection indicates Red welt around injection indicates

infectioninfection• Examine medical history, x-rays, Examine medical history, x-rays,

and sputumand sputum

Most Susceptible

• People at higher risk of TB infection People at higher risk of TB infection – Close contacts with people with infectious TBClose contacts with people with infectious TB– People born in areas where TB is commonPeople born in areas where TB is common– People with poor access to health carePeople with poor access to health care– People who inject illicit drugsPeople who inject illicit drugs– People who live or work in residential People who live or work in residential

facilitiesfacilities– Health care professionalsHealth care professionals– The elderlyThe elderly

Most Susceptible

• People at higher risk of active TB People at higher risk of active TB diseasedisease– People with weak immune systems People with weak immune systems

(especially those with HIV or AIDS)(especially those with HIV or AIDS)– People with diabetes or silicosisPeople with diabetes or silicosis– People infected within the last 2 yearsPeople infected within the last 2 years– People with chest x-rays that show People with chest x-rays that show

previous TB diseaseprevious TB disease– Illicit drug and alcohol abusersIllicit drug and alcohol abusers

Treatments

• Take antibiotics for 6-12 monthsTake antibiotics for 6-12 months• Preventative drug to destroy Preventative drug to destroy

dormant bacteriadormant bacteria• For active TB, 4 medications: For active TB, 4 medications:

isoniazid, rifampin, ethambutol, and isoniazid, rifampin, ethambutol, and pyrazinamidepyrazinamide

• Vaccines (relatively ineffective Vaccines (relatively ineffective today)today)

Biological Effects on Humans

• Causes more deaths than any other Causes more deaths than any other infectious diseaseinfectious disease

• About 2 billion people infected About 2 billion people infected worldwideworldwide

• Major health problem in developing Major health problem in developing countriescountries

• Leading killer of youth and young adultsLeading killer of youth and young adults• Leading cause of death for women of Leading cause of death for women of

childbearing agechildbearing age