Tuberculosis Flashcards
What is TB?
An infection caused by mycobacterium tuberculosis
How is TB spread?
Spread from person to person via droplets in air released by person infected with TB when they cough/sneeze.
What are the two types of TB?
Pulmonary TB.
Extrapulmonary TB.
TB is subdivided into active TB and latent TB. What does each term mean?
Active - Evidence of symptomatic and progressive disease of lungs and/or other organs.
Latent - State of persistent immune response to stimulation by bacterium antigens but patient is asymptomatic and not infectious.
Who discovered mycobacterium tuberculosis as the causative agent of tuberculosis?
Dr Robert Koch.
Who is at risk of TB?
- born in high prevalence area.
- children under 5.
- close contact of infected individual.
- living conditions e.g. poor/crowded housing.
- untreated/inadequately treated TB.
- co-morbid conditions.
- poor health, hygiene, nutrition.
- immunosuppressed.
- deprived population.
What 3 factors can cause a poorer prognosis in individuals with TB?
Increasing age
More extensive disease
HIV co-infection
List the complications from TB.
Reduced quality of life. Transmission to others. Drug resistance. Post TB bronchiectasis, COPD, heart failure. Death.
Differentiate between extrapulmonary and pulmonary TB.
Pulmonary is TB which infects the lungs.
Extrapulmonary is TB which is present in locations outside of the lungs with symptoms specific to the site involved.
TB commonly grow in lungs - pulmonary TB. What are the signs and symptoms of this?
A bad cough that lasts 3 weeks or longer.
Pain in the chest.
Coughing up blood or sputum.
What are some non-chest related TB symptoms?
Weakness/fatigue Weightloss No appetite Fever Chills Sweating at night
What are the 5 ways TB can be diagnosed?
Rapid molecular test Mantoux test Microbiological investigation Chest X-Ray Interferon gamma release assay test (IGRA)
The classifications of TB = primary disease, latent infection and post primary disease. What is primary disease?
Defined as progression from sub-clinical infection to active disease within 5 years after infection.
The classifications of TB = primary disease, latent infection and post primary disease. How does post primary disease occur?
Following treatment, disease can return in a small number of people as not all bacteria have been killed.
- can happen due to interruptions in treatment.
List the 5 aims of treatment.
Cure without relapse. Prevent death. Stop transmission. Prevent drug resistance. Given by physicians with training and expertise.
Give 5 reasons as to why resistance develops.
Treatment interruptions. Lack of availability of high quality drug. Unreliable drug supply. Issues with compliance. Incorrect treatment regimen given.
Describe the initial phase of treatment of TB.
4 drugs used to reduce bacterial population as rapidly as possible and prevent emergence of drug resistant bacteria. This phase is continued for 2 months
Describe the continuation phase of treatment of TB.
After initial phase, treatment is continued daily for a further 4 months.
- longer treatment needed in meningitis, spinal cord involvement and drug resistance.
Define drug resistant TB.
Resistance to first line anti-TB drug.
Define multi-drug resistant TB (MDR-TB).
Resistance to isoniazid and rifampicin.
Define extensively drug resistant TB (XDR-TB).
Resistance to isoniazid, rifampicin, fluroquinolone and a second line injectable agent.
Who is at risk from getting MDR-TB?
- those who do not take medicine regularly.
- those who take the incorrect dose.
- those who develop TB again, after having TB treatment in the past.
- those who come from areas in which TB-drug resistance is common.
- those is close contact with someone with drug-resistance TB disease.
What is one side effect of each drug:
Rifampicin, Ethambutol, Pyrazinamide, Isoniazid.
Rifampicin = urine discolouration. Ethambutol = visual disturbances/impairment. Pyrazinamide = aggravated gout. Isoniazid = peripheral neuropathy.
Why is adherence to TB drugs a problem?
Duration of treatment No. of tablets used Side effects Social circumstances Lack of knowledge of medicine and disease
In what groups can adherence be an issue?
Prisoners Homeless History of poor compliance Alcoholics Drug abuse Mental Illness
What is the result of DOT?
Direct Observation Therapy
Improve adherence Better outcomes for the patient Reduce treatment failures Reduce drug resistance Reduce relapse Patient be monitored regularly for S/E’s and response to treatment Reduce transmission
