Tuberculosis COPY Flashcards by Rassa Kapite

If you have what then you are more likely to get TB?

HIV

How well did you know this?

Not at all

Perfectly

Where are the TB incidence rates the highest?

Southern africa
Saharan africa
South east asia

How well did you know this?

Not at all

Perfectly

Causative organisms of TB

Mycobacterium tuberculosis
Mycobacterium bovis (bovine TB)
Mycobacterium avium-intracellulare (HIV)

How well did you know this?

Not at all

Perfectly

Transmission of mycobacterium tuberculosis

Respiratory droplets - coughing and sneezing

How well did you know this?

Not at all

Perfectly

Transmission of mycobacterium bovis

Consumption of infected cows milk - deposited in cervical and intestinal lymph nodes

How well did you know this?

Not at all

Perfectly

Pathology of TB

Infected with TB
Mycobacteria spread by lymphatics to draining hilar lymph nodes
Haematogenous seeding of mycobacteria to all organs of the body

How well did you know this?

Not at all

Perfectly

Presentation of TB

Usually no symptoms
Fever
Malaise
Erythema nodosum
Rarely chest signs
Initial lesion + local lymph node
Lesion may calcify

How well did you know this?

Not at all

Perfectly

Complications of TB

Primary focus continues to enlarge - cavitation
Enlarged hilar lymph compresses bronchi, lobar collapse
Enlarged lymph node discharges into bronchus (TB bronchopneumonia)

How well did you know this?

Not at all

Perfectly

In a small number (1%) 6 - 12 months after infection, after the infection…….

Miliary TB fine mottling on X ray, widespread small granulomata
Meningeal TB, severe, CSF high protein, lymphocytes
TB pleural effusion

How well did you know this?

Not at all

Perfectly

Possible causes post primary disease of TB

Reactivation of mycobacterium from latent primary infection spread by blood stream around the body
New reinfection from outside source, susceptible previously infected host

How well did you know this?

Not at all

Perfectly

What in the body can TB affect?

Pulmonary disease
Lymph nodes, usually cervical (scrofuloderma)
Renal
CNS (tuberculous meningitis)
Bone and joint; spine (vertebral bodies - potts disease), hip
GI tract
GU
Infertility
Van deferens and fallopian tube effects
Constrictive pericarditis, pericarditis
Ascites
Ileal TB - obstruction
Addisions disease
Lupus vulgaris

How well did you know this?

Not at all

Perfectly

When does post primary disease of TB occur?

1 - 5 years

How well did you know this?

Not at all

Perfectly

What is post primary TB?

Reactivation of latent disease

How well did you know this?

Not at all

Perfectly

Features of post primary TB

May occur at any age
May be no symptoms for months
Progressive and occur over several months

How well did you know this?

Not at all

Perfectly

Presentation of post primary TB

Cough
Sputum
Haemoptysis
Pleuritic pain
SOB
Malaise + weight loss + night sweats (systemically unwell)

How well did you know this?

Not at all

Perfectly

Who should you have a high index of suspicion of TB in?

Immunocompromised (HIV, corticosteroid therapy)
Malnutrition
Alcoholism
Vagrants
Previous gastric surgery
Malignancy
DM
Adolescence
Elderly
Recent immigrants from high prevalent countries

How well did you know this?

Not at all

Perfectly

What are the investigations of TB?

3 sputum specimens on successive days
- Sputum smear - Ziehl-Neilsen stain (ZN stain)
- Sputum culture
- Sputum PCR
CXR
- patchy (shadowing, often apices/upper zones or apex of lower lobes), often bilateral
- cavitation if advanced
- may calcify if chronic or healed TB
Further investigations if sputum -ve
- CT thorax
- Bronchoscopy with bronchoalveolar lavage
- pleural aspiration and biopsy if pleural effusion

How well did you know this?

Not at all

Perfectly

What is cavitation?

Formation of an empty space

How well did you know this?

Not at all

Perfectly

Different treatment regimes for treating TB

A) Rifampicin + Isoniazid + Ethambutol + Pyrazinamide for 2 MONTHS
B) Rifampicin + Isoniazid for 4 MONTHS

S/Es of rifampicin

Orange irn bru urine + tears
Deranged LFTs / Hepatitis
OCP ineffective

S/Es of isoniazid

Hepatitis
Peripheral neuropathy

S/Es of Ethambutol

Optic neuropathy

S/Es of pyrazinamide

Gout

What is the purpose of TB contact tracing?

Identify the source and identify transmission

What does the likelihood of infection with TB depend on?

Duration of contact Intensity ofinfection

Who should have no immunity to tuberculoprotein?

< 16 y/o no BCG

What is the vaccination against TB called?

BCG

What tests are done to screen for TB?

Mantoux test Heaf test Tuberculin test

If heaf +ve, what must be done next?

CXR

What must be done if heaf -ve?

Repeat after 6 weeks If still -ve, give BCG If +ve, Tx as recent infection

What is the 5 year survival with patients with cavitating disease?

25%

How long must TB drug treatment continue for?

At least 6 months

Types of TB disease

Primary Secondary

Features of primary TB

Non immune host exposed to the mycobacterium may develop primary infection of the lungs

What happens in primary TB?

Small lung lesion called Ghon focus develops Immunocompetent - healing by fibrosis Immunocompromised - may develop disseminated disease (miliary TB)

What is a ghon focus made up of?

Tubercle-laden macrophages

What is a Gohn complex?

Ghon focus and hilar lymph nodes

Features of secondary (post primary) TB

Host becomes immunocompromised the initial infection may be reactivated

Where does reactivation generally occur?

Apex of the lungs May spread to local or distant sites

Examples of causes of immunocompromise

Immunosuppressive drugs HIV Malnutrition

Where is the most common site for secondary TB?

Lungs

Main test used to screen for latent TB

Mantoux test

False negative tests in the Mantoux may occur when?

Miliary TB Sarcoidosis HIV Lymphoma Very young (e.g. < 6 months old)

Contraindications to BCG

Previous BCG Past history of TB HIV Pregnancy Positive tuberculin, heaf or mantoux

What test is offered to all patients with TB?

HIV testing

What can cause a reactivation of TB?

Immunosuppressant therapy such as chemo or biological treatments