Tuberculosis (TB) Mycobacterium Flashcards
What shape can TB be classified as, shape wise?
1 - spheres (cocci)
2 - rods (bacilli)
3 - spirals
4 - none of the above
- bacillus (rod shaped)
Is TB aerobe or anaerobe?
- aerobe, hence why is likes the lungs
Does TB possess a cell wall?
- yes
- gives bacterial its waxy surface (mycolyic acid)
- but no phospholipid outer membrane
Does TB divide quickly or slowly?
- slowly
- every 16-20 hours
Mycobacterium tuberculosis (TB) is an aerobic pathogenic bacteria, hence its affinity for the lungs. Is TB Gram + or Gram -?
- typically a weak Gram + due to the waxy cell coating
- mycolic acid in cell wall gives TB waxy coating
Atypical non-mycobacteria is a part of mycobacterium family (cousin of TB and is an opportunistic bacteria. Does atypical non-mycobacteria infect as many people as standard TB?
- no
- typically affects effect immunocompromised patients
Is there an interaction between TB and HIV?
- yes
- immunocompromised patients are more likely to be infected with TB
- HIV patients have low CD4+ T cells
- HIV patients are unable to mount an immune response against TB
Why is TB more common in big cities?
1 - more close to close contact
2 - TB can undergo genetic drift and infect more people
3 - larger diversity from all parts of the world
4 - all of the above
3 - larger diversity from all parts of the world
- more diversity means more people from all over the world
- majority of TB patients in UK, are born outside UK
All of the following patients are at greater risk of developing TB, EXCEPT which ones?
1 - deprivation (malnourished, overcrowding) - 2 - alcoholics
3 - prison inmates
4 - females
5 - immunocompromised (elderly, infants)
6 - high risk groups/jobs (airport staff)
4 - females
- men and women are equally affected
How is TB transmitted?
1 - sexual contact
2 - aerosols and direct contact
3 - shared food only
4 - dirty water
2 - aerosols and direct contact
- 80% affects lungs
Once inside the lungs TB is able to spread through a specific type of immune cell. Which immune cell is this?
1 - B cells
2 - dendritic cells
3 - CD4 T cells
4 - macrophages
4 - macrophages
- engulf TB and attempt to phagocytose
- if no phagocytosis, TB replicates in endosome
Mycobacterium tuberculosis (TB) is an aerobic pathogenic bacteria, hence its affinity for the lungs. What is the estimated global incidence of TB?
1 - 9 / 100,000
2 - 90 / 100,000
3 - 900 / 100,000
4 - 9000 / 100,000
1 - 9 / 100,000
- estimated to affect 10 billion/year
Mycobacterium tuberculosis (TB) is an aerobic pathogenic bacteria, hence its affinity for the lungs. What age does the TB occurrence peak in?
1 - 20-30
2 - 20-40
3 - 30-50
4 - 50-60
4 - 50-60
Mycobacterium tuberculosis (TB) is an aerobic pathogenic bacteria, hence its affinity for the lungs. Does TB affect more men or women?
- both equally affected
How many people each year are estimated to die from TB each year?
1 - 1500
2 - 15,000
3 - 150,000
4 - 1.5,000,000
4 - 15,000,000
- 1.5 billion die from TB each year
Are patients with TB, active or inactive infectious?
- no
- latent = non-infectious
- active = infectious
If you suspect a patient has active TB, what disease must also be screened for?
1 - diabetes
2 - SLE
3 - HIV
4 - vasculitis
3 - HIV
- TB affects those who are immunocompromised
Although TB affects lots of people, what % of TB is actually active?
1 - 40-50%
2 - 20-30%
3 - 10-20%
4 - 5-10%
4 - 5-10%
Once TB has been inhaled into the lungs there are lots of host defences that try to eradicate TB. Which of the following are innate host defences against TB?
1 - mucocillary escalator
2 - turbulent air flow causes TB to get stuck in mucus
3 - macrophages
4 - all of the above
4 - all of the above
Once inside the lungs, if the macrophages are unable to phagocytose TB, the patient now has primary TB. Do they present with symptoms immediately?
- no
- some patients can be asymptomatic and others can have mild flu like symptoms
Once inside the lungs, if the macrophages are unable to phagocytose TB, the patient now has primary TB. After aprox 3 weeks after being infected, cell mediated immunity begins and does what to the TB?
1 - immune cells kill off all TB cells
2 - immune cells surround TB and form a granuloma without caseous necrosis
3 - immune cells surround TB and form a granuloma with caseous necrosis
4 - all of the above
3 - immune cells surround TB and form a granuloma with caseous necrosis
Once inside the lungs, if the macrophages are unable to phagocytose TB, the patient now has primary TB. After aprox 3 weeks after being infected, cell mediated immunity begins and immune cells surround TB and form a granuloma with caseous necrosis. What is this called?
1 - hyperplasia
2 - ghon focus
3 - TB cyst
4 - pleural effusion
2 - ghon focus
TB can affect which lymph nodes in the thoracic cavity?
1 - intercostal lymph nodes
2 - juxtavertebral lymph nodes
3 - hilar lymph nodes
4 - brachiocephalic lymph nodes
3 - hilar lymph nodes
- could affect any lymph nodes but these are the most commonly affected
Is bilateral hilar lymphadenopathy specific to TB or sarcoidosis?
- present in both
If a ghon complex is found in the hilar lymph nodes, what is this called?
1 - hyperplasia
2 - TB cyst
3 - ghon complex
4 - pleural effusion
3 - ghon complex
- most commonly occur in lower lobes
- causes fibrosis and calcification
If a ghon complex is found in the hilar lymph nodes, the ghon complex in the hilar lymph nodes is called a ghon complex. Inside the ghon complex there may be fibrosis and/or calcification. What is this calcification called on imaging?
1 - ranke complex
2 - reed sterling complex
3 - kimmelstiel-Wilson lesion
4 - pleural effusion
1 - ranke complex
When TB is surrounded by the granuloma, do they always die?
- no
- can die OR become latent, but still viable
When TB is surrounded by the immune cells, they can either be killed off or just remain viable but latent. Which of the following occasions would allow the latent TB to overpower the surrounding granuloma and begin infecting the host again?
1 - ageing
2 - patient is infection with AIDs
3 - diabetes
4 - all of the above
4 - all of the above
- all of these involve an immunocompromised host
If a patients TB becomes active again, it can begin spreading to the rest of the lungs. Which lobe does TB prefer spreading to?
1 - upper lobes
2 - lower lobes
3 - middle lobe
4 - doesn’t make a difference
1 - upper lobes
- TB is an aerobe and greater oxygenation in upper lobes
If a patients TB becomes active again, it can begin spreading to the rest of the lungs, with preference to the upper lobes due to increased oxygenation. In response T cells secrete cytokines in an attempt to control the TB. What does this then lead to?
1 - small cell lung cancer
2 - pleural effusion
3 - atelectasis
4 - caseous necrosis
4 - caseous necrosis
- these areas form cavities allowing TB to spread and can cause broncho pneumonia
When TB is active and it spreads throughout the body, what is it called?
1 - homogenous TB
2 - systemic miliary TB
3 - system organ failure TB
4 - sepsis TB
2 - systemic miliary TB
If a patient has active TB in the lungs, which of the following are constitutional symptoms?
1 - fever: usually gradual onset and low-grade.
2 - night sweats: maybe drenching.
3 - weight loss and/or anorexia
4 - malaise
5 - all of the above
5 - all of the above
If a patient has active TB in the lungs, which of the following is NOT a lung specific symptom?
1 - dyspnoea
2 - cough over 2-3 weeks, dry then productive
3 - haemoptysis (sometimes)
4 - pleuritic chest pain
5 - crackles, bronchial breath sounds, or maybe normal
6 - expiratory wheeze
6 - expiratory wheeze
- more common in asthma
If TB is able to spread it can affect other organs. If it spreads to the CNS, what can it cause?
1 - clade equine
2 - encephalitis
3 - meningitis
4 - pituitary adenoma
3 - meningitis
If TB is able to spread it can affect other organs. If it spreads to the kidneys, what can it cause?
1 - sterile pyuria (high WBC in urine)
2 - nephrotic syndrome
3 - nephritis syndrome
4 - tubular necrosis
1 - sterile pyuria (high WBC in urine)
If TB is able to spread it can affect other organs. If it spreads to the vertebral column, what can it cause?
1 - kyphosis
2 - spondylosis
3 - scoliosis
4 - potts disease
4 - potts disease
- results in damage and destruction of bone
If TB is able to spread it can affect other organs. If it spreads to the adrenal glands, what can it cause?
1 - Graves disease
2 - Addison’s disease
3 - Kawasaki disease
4 - Cushings disease
2 - Addison’s disease
- causes a lack of cortisol and aldosterone
If TB is able to spread it can affect other organs. If it spreads to the liver, what can it cause?
1 - hepatitis
2 - NAFLD
3 - liver cancer
4 - cirrhotic liver
1 - hepatitis
If TB is able to spread it can affect other organs. If it spreads to the cervical lymph nodes, what can it cause?
1 - Leukaemia
2 - Scrofula
3 - Hodgkins disease
4 - Multiple myeloma
2 - Scrofula
- infection in >1 lymph nodes
In a patient who has no symptoms, but has latent TB, which 2 of the following tests is best to diagnose them?
1 - chest X-ray
2 - mantoux test
3 - PCR
4 - interferon-gamma release assays
2 - mantoux test
- patient injected intradermally with tuberculin, part of TB
- if patient has TB they will have a positive immune reaction (memory T cells) within 48-72 hours
4 - interferon-gamma release assays
- IGRAs detected in the blood specific to TB
- POSITIVE tests tells us if patients has had TB
- best in patients who have had their BCGs
Are Mantoux (Tuberculin test) and Interferon gamma release assay (IGRA)/T-spot test able to distinguish between active and latent TB?
- no
- both will show as positive
The mantoux test can be used to inject tuberculin, part of TB into patients who may have latent TB. If they have a response in 48-72h then they have latent TB. What type of hypersensitivity reaction is this?
1 - type 4
2 - type 3
3 - type 2
4 - type 1
1 - type 4
In an y patient who is suspected of having TB. should receive all of the following tests, EXCEPT which one?
1 - blood culture
2 - 3 separate sputum tests for microscopy and culture
3 - chest X-ray
4 - nucleic acid amplification testing (NAAT)
1 - blood culture
- not routinely done
- sputum culture is the gold standard, but takes up to 6 weeks for results
Which of the following is the most effective staining to identify if TB is present?
1 - chocolate agar
2 - gram staining
3 - ziehl-Neelson acid based stain
Because of this waxy cell wall, they’re “acid-fast”, meaning that they can hold on to a dye in spite of being exposed to alcohol, leaving it bright red colored when a Ziehl–Neelsen stain is used. The wall also makes them incredibly hardy, and allows them to resist weak disinfectants and survive on dry surfaces for months at a time
3 - Ziehl-Neelson acid based stain
- alcohol can hold onto waxy cell wall
- TB therefore appears as a bright colour
When a sputum sample is taken for patients with suspected TB, which 2 of the following can be performed?
1 - TB growth if present in sample
2 - viral load in patient
3 - antibiotic sensitivity if TB is present
4 - strain of TB present
1 - TB growth if present in sample
3 - antibiotic sensitivity if TB is present
When analysing sputum samples will TB be present in active and latent TB?
- active = TB present
- latent = TB absent
When trying to diagnose TB, all of the following differentials should be considered, EXCEPT which one?
1 - pneumonia
2 - infective endocarditis
3 - lung cancer
4 - sarcoidosis
5 - lymphoma
6 - lung abscess (epithelial lined open space filled with pus)
2 - infective endocarditis
- all others must be rules out, but can present with similar symptoms
In patients with latent TB, once active TB has been rules out (reduce resistance), which of the following medications can be given to patients for 9 months?
1 - Isoniazid
2 - Entecavir
3 - Rifampicin
4 - Succinylcholine
1 - Isoniazid
- inhibits the synthesis of mycoloic acids, an essential component of the bacterial cell wall
- induces TB death
In patients with latent TB, once active TB has been rules out (reduce resistance), Isoniazid can be given to patients for 9 months. As an alternative option, which of the following could be given for 4 months?
1 - Vancomycin
2 - Entecavir
3 - Rifampicin
4 - Succinylcholine
3 - Rifampicin
- inhibiting RNA synthesis
- irreversibly binds RpoB, the beta-subunit of the bacterial DNA-dependent RNA polymerase
In a patient with confirmed active TB, they will receive 4 of the following drugs for 2 months, called the intensive phase. Which drug is NOT part of the quadruple therapy?
1 - Vancomycin
2 - Isoniazid
3 - Rifampin
4 - Pyrazinamide
5 - Ethambutol
1 - Vancomycin
- Isoniazid - inhibits cell wall synthesis
- Rifampin = inhibit RNA synthesis
- Pyrazinamide = inhibits TB growth
- Ethambutol = inhibits cell wall synthesis
Which 2 of the following are common adverse effects of the quadruple therapy in TB?
1 - CKD
2 - hepatotoxicity
3 - peripheral neuropathy
4 - CHF
2 - hepatotoxicity
3 - peripheral neuropathy
In a patient with confirmed active TB, they will receive quadruple therapy, which includes Isoniazid, Rifampin, Pyrazinamide and Ethambutol. Which 2 of these 4 drugs will then be continued for a further 4 months as part of the continuation therapy?
1 - Isoniazid
2 - Rifampin
3 - Pyrazinamide
4 - Ethambutol
1 - Isoniazid
2 - Rifampin
While patients are taking their medications for TB, they will need monthly sputum samples analysed for microscopy and culture. How many consecutive sputum samples need to be negative before a patient is told they are TB free?
1 - just 1
2 - >2
3 - >4
4 - >6
2 - >2
What is the main risk of not giving the patient the correct type and dose of drugs?
1 - increased costs as patients need to take longer doses of the drugs
2 - drug resistance
3 - increased risk of TB spreading
4 - all of the above
2 - drug resistance
- multi drug resistant TB
- normally due to poor adherence
- multi drug resistant TB can be transmitted
In patients with multi drug resistant TB, what is the danger to public health?
- high risk of contamination
- patients are normally isolated
- given longer dose of antibiotics
What is the curative effective of TB treatment?
1 - 25%
2 - 50%
3 - 75%
4 - 100%
4 - 100%
- it is curable
What is an index case?
1 - patient who is currently infected
2 - patient who has come into contact with someone with TB
3 - patient who has been out of the country
4 - patient who has TB
4 - patient who has TB
- could then spread to others
When screening for latent TB who needs to be screened?
1 - anyone who has travelled internationally
2 - anyone who is immunocomprimised
3 - anyone who as come into contact with TB
4 - all of the above
3 - anyone who as come into contact with TB
- close contacts of index case
- pre-employment in healthcare
A 72 year old man with background history of multiple myeloma presents to the emergency department with shortness of breath, sore throat runny node and a cough. He had chemotherapy 4 days previously.
Observations: HR 118 bpm, BP 90/60 mmHg, temperature 38.2°C, respiratory rate 25 /min, O2 saturation 75% on air..
Blood results:
Hb 96 g/L
WBC 0.9 x109/L
CRP 115 mg/L
U&E: normal
Urinalysis: 1+ blood and 1+ protein, nitrite -ve
His CXR is shown. In this patient, which aspect of the history is most likely to help in making the diagnosis?
1 - Exposure to asbestos
2 - Exposure to domestic pets
3 - Smoking history
4 - Travel abroad
5 - Vaccination for polio
4 - Travel abroad
Most likely to be TB
ESR is typically raised in all of the following, EXCEPT which one?
1 - TB
2 - malignancy
3 - pleural effusions
4 - connective tissue disorders
3 - pleural effusions
