A21 - General pathogenesis of tuberculosis

Question 1

Draw the steps of pathogensis og tuberculosis

TIP: Easier to draw and then expain on the exam

Answer 1

Question 2

Name the phases of tuberculosis, that we can distinguish:

Answer 2

1. Primary phase/complex
2. Postprimary phase
3. Breakdown phase

The three phases can only be seen in cattle and humans !!

Question 3

Infection

Answer 3

Upon infection, the pathogen needs to enter the host causing the primary phase and lesions

Question 4

What is the site of the primary phase in the different species?

Answer 4

Cattle= Lungs, sometimes GI-tract
Calf= Mostly liver, sometimes lungs and GI-tract
Small RU= Lungs
Swine= GI-tract
Horse= GI-tract
Carnivores= Lungs and GI-tract
Poultry= GI-tract

Question 5

Primary complex

Answer 5

Following the infection, there is alwasy predominantly exudative tuberculosis, because this is where the bacteria and host meets for the first time.

The primary complex has two different forms

Question 6

Name the two different forms of primary complex, and what happens in them

Answer 6

1. Complete primary complex = We see comlete lesions on both the sire of injury and at the regional lymph nodes

2. Non-complete primary complex = We see only lesions in the lymph nodes

Question 7

Healing after primary complex

Answer 7

In some cases the immune system kill the bacteria. The lesions are absorbed and the necrotic zone is replaced by connective tissue and scars.

Question 8

Reinfection after healing

Answer 8

In this case a new infection starts all over again, and is NOT different from the original/first one.

Question 9

Post primary phase