Tuberculosis (TB) Overview

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Questions and Answers

What is the primary causative agent of tuberculosis (TB)?

Mycobacterium tuberculosis (correct)

Escherichia coli

Pseudomonas aeruginosa

Streptococcus pneumoniae

In which of the following ways can tuberculosis NOT be transmitted?

Direct contact with infected skin

Inhalation of aerosols

Through contaminated water (correct)

Ingestion of infected meat

What characteristic of tuberculosis bacteria helps them resist disinfectants?

Production of spores

High lipid content in the capsule (correct)

Gram-positive cell wall

Presence of flagella

Which cells first respond to the presence of tuberculosis bacilli in the body?

Neutrophils Signup and view all the answers

What purpose does the inhibitory migratory factor serve in tuberculosis infection?

Inhibits movement of macrophages Signup and view all the answers

Which of the following statements is true regarding TB's symptom development?

Granulomas develop slowly over time Signup and view all the answers

What are the primary clinical signs associated with the disease characterized by swollen soun and muzzle?

Procy salivation and blue tongue edema Signup and view all the answers

What is the pathogenesis process leading to edema in the described disease?

Increase in vascular permeability due to endothelial damage Signup and view all the answers

What are the potential routes through which TB can be transmitted?

Inhalation, ingestion, skin contact Signup and view all the answers

Which immune cells aggregate in response to tuberculosis bacilli and resemble epitheloid cells?

Langerhans cells Signup and view all the answers

Which stage in the poxvirus pathogenesis signifies the typical forms that result in lesions?

Formation of pastules with pus Signup and view all the answers

Which organism is NOT typically associated with poxvirus transmission among species?

Felines Signup and view all the answers

What is the most notable color change observed in the blood due to the disease affecting the endothelium?

Blue from the increase of plasma and proteins Signup and view all the answers

What cells are primarily involved in the formation of a granuloma?

Fibroblasts Signup and view all the answers

What characterizes the proliferative action of a granuloma?

Presence of new cells spreading Signup and view all the answers

Which type of infection occurs when bacilli enter the body for the first time?

Primary infection Signup and view all the answers

How does the severity of primary infection differ between young and adult individuals?

Primary infection is mild to moderate in young individuals Signup and view all the answers

What does dormant infection refer to in the context of the immune system?

Bacilli are resistant due to strong immunity Signup and view all the answers

Which lymphatic condition is associated with the presence of macrophages?

Lymphangitis Signup and view all the answers

In which scenario is a secondary infection likely to occur?

In previously exposed organs and lymph nodes Signup and view all the answers

What is Ghon's disease primarily characterized by?

Granuloma under the pleura Signup and view all the answers

What characterizes Closed T.B in comparison to Open T.B?

It has no fibrosis. Signup and view all the answers

In which organ does T.B cause nodules that may lead to ulceration?

Intestine Signup and view all the answers

What is a common method of infection by actinomyces bovis?

Ingestion Signup and view all the answers

What does the appearance of a central yellow area in actinomycosis indicate?

Abscess formation Signup and view all the answers

What distinguishes actinobacillosis from actinomycosis?

It arises from the umbilical cord. Signup and view all the answers

What is a consequence of the pus formed in actinomycosis?

It causes destruction of surrounding tissues. Signup and view all the answers

What complication can arise from infections that cause abscess formation in soft tissues and lungs?

Septicemia Signup and view all the answers

Which anatomical structure is a typical site for T.B lesions in the liver?

Capsule Signup and view all the answers

Which symptom is most indicative of Rift Valley Fever in infected animals?

Focal coagulative necrosis Signup and view all the answers

What occurs as a result of the neutrophils surrounding colonies in actinomyces infection?

Formation of abscesses Signup and view all the answers

What primary route of transmission is associated with Rift Valley Fever?

Mosquito bites Signup and view all the answers

What is the characteristic symptom of Blue Tongue disease?

Cyanotic mucous membranes Signup and view all the answers

What is the significance of hepatic tropism in Rift Valley Fever?

It causes liver damage and necrosis. Signup and view all the answers

What is a key clinical sign of wooden tongue as a result of actinobacitus infection?

Hardening of the tongue Signup and view all the answers

Which animal is primarily affected by Blue Tongue disease?

Sheep Signup and view all the answers

What is a common consequence of Rift Valley Fever in sheep?

Stormy abortion Signup and view all the answers

Study Notes

Tuberculosis (TB)

Transmitted through direct contact, primarily from infected animals to humans.
Bacteria found in infected meat and milk, making it essential to boil for about an hour to completely destroy the bacteria.
Symptoms include granuloma formation in the lungs and other internal organ infection.
Characterized by a chronic granulomatous disease, developing gradually over time.
Caused by Mycobacterium tuberculosis.
Highly resistant to disinfectants, requiring ultraviolet light for effective destruction.
Has a lipid capsule, making it strong and difficult to eradicate.
Contains two parts: Cho and Protein.
Cho attracts neutrophils and polymorphic neutrophils.
Protein attracts lymphocytes.
Macrophages engulf the bacilli.
Lymphocytes produce lymphokines, including INHIPI, which prevents macrophage movement.
Infected macrophages clump together, forming a granulomatous structure similar to an epithelioid cell.
Ribroblasts create collagen fibers around these cells, leading to granuloma development.

Caseous Necrosis

Occurs in the center of the granuloma, caused by bacteria entering the area and initiating necrosis.
The quantity of caseous is directly proportional to the amount of cytotoxic factor secreted by lymphatic glands.
Granuloma exhibits two types of action:
- Proliferative action: Characterized by the presence of new cells spreading.
- Exudative action: Characterized by the secretion of a large amount of fluid.
Located around the lung, often causing pleurisy.

Classification of TB Infection

Primary infection: The first time Mycobacterium tuberculosis enters the body.
Secondary infection: Occurs when an individual is infected a second time after previously having the infection but with no symptoms.
Exogenous: Occurs when Mycobacterium tuberculosis enters the body for the first time.
Endogenous: Occurs when the immune system is strong and resists the bacteria.
Dormant: Mycobacterium tuberculosis remains dormant, only appearing when the immune system weakens.

Primary Infection

In young individuals: The disease is mild to moderate, characterized by a smaller number of T-cells and Mycobacterium tuberculosis, resulting in a smaller amount of caseation.
In adults: The disease is more severe, due to prolonged exposure, leading to a larger number of T-cells and Mycobacterium tuberculosis, and a larger amount of caseation.
Migration to organs:
- In young: Typically localized to the lymph nodes.
- In adults: It can be present in various organs.
Infection in lymph vessels:
- Localized infection in lymph vessels and lymph nodes.
- The most common form in adults because they have been previously exposed to TB.
Lymphatic system:
- Macrophages: Present in the lymphatic system, causing lymphangitis and lymphadenitis.
- TB complex: Can occur in organs and lymph nodes.

Secondary Infection

Occurs in organs previously exposed to Mycobacterium tuberculosis and the corresponding lymph nodes.

TB Manifestations in Different Organs and Lesions

1. Lungs

Ghon's disease:
- A granuloma that forms under the pleura.
- The center fills with caseous material, becoming irregular and later surrounded by fibrous tissue, forming a cavity.
- Blood vessels and Mycobacterium tuberculosis enter bronchioles to create new muscles.
- Lung infection spreads through blood vessels created by the bronchioles and the bronchi.

Closed TB

No fibrosis, leading to disease spread.

Open TB

Has fibrosis, confining the infection to the lungs and preventing disease spreading.

2. Liver

Found in nodules inside liver cells or on the liver surface capsule.

3. Kidneys

Similar to the liver.

4. Intestines

Mycobacterium tuberculosis nodules form in the intestinal wall, causing ulceration.
Associated with ulceration, wall perforation, and the natural area affected is Peyer's patch in the intestine.
A grating sound can be heard during the slaughtering process due to the presence of caseous material.

Actinomycosis

A chronic bacterial infection caused by Actinomyces bovis.
Forms granules due to its suppurative nature, meaning it forms pus.
Associated with suppurative osteomyelitis.
Mainly affects bones but can also affect wounds.

Route of Infection

Ingestion
Inhalation
Wounds

Pathogenesis of Actinomyces bovis

Primarily affects facial tissues and bones.
It enters bone but not wounds, forming colonies in the center.
Colonies form a sulfur-like yellow central area surrounded by pus.
This can result in abscess formation.
Granules: bacteria proliferate, releasing pus, which is mainly composed of destroyed tissue, dead neutrophils, and colonies.
Granules expand and become larger, surrounded by fibro-tissue and neutrophils.
After some time, the skin surrounding the bone is destroyed, resulting in the release of pus.
The outcome is direct contact or granulation tissue.

Actinobacillosis

Caused by Actinobacillus lignieresii.
Found inside the umbilical cord, leading to abscess formation.
Can cause death or spread to different organs causing septicemia.

Pools

Occur primarily in newborn cattle due to the presence of blood in the umbilical cord.
Infection enters slowly through hard objects, creating wounds in the buccal or oral cavities.
If it's present in soft tissue or the lungs, it can cause abscesses with surrounding colonies.
One hard consequence: Wooden tongue, causing the tongue to harden.

Clinical Signs of Actinobacillosis

Animal refuses food.
No regurgitation of food.
Loss of body weight.

Rift Valley Fever (RVP)

Belongs to the Phlebovirus group, part of the Bunyaviridae family.
Transmitted from infected animals to humans through direct contact.
Primarily transmitted through mosquitoes, but can also be transmitted by inhalation or through contaminated blood and fluids.
Found in sheep, cattle, and Anopheles mosquitoes.
Main route of transmission: Anopheles mosquitos. Minor route: secretions.
Mosquitos inject the virus into the blood, which then migrates to the liver, causing tropism.

Pathogenesis of RVP

Causes liver tropism, leading to focal coagulative necrosis.
Causes Icterus (jaundice), manifesting as yellowing of the animal.
Leads to hemorrhagic poeci in sheep, characterized by bloody diarrhea.
Causes stormy abortion in sheep.
Causes hemorrhagic poeci in lambs and calves.
Causes hemorrhagic poeci, intestine problems, and hemorrhagic diarrhea.
Main focuses:
- Hepatic tropism
- Focal necrosis in the liver.
- Stormy abortion in sheep.

Blue Tongue Disease

Named after its symptoms, as it causes anosis in the mouth, lips, and tongue of infected animals, primarily sheep and cattle.
Caused by Blue Tongue Virus, a member of the Reoviridae family.
Transmitted through arthropods.

Pathogenesis of Blue Tongue Disease

The virus enters blood capillaries, damaging the endothelium, causing pore formation.
Leads to increased permeability and edema.
Edema is caused by increased leukocyte infiltration in the blood.
Red blood cells leave the blood, causing increased plasma and protein levels and turning the blood blue, giving the disease its name.

Clinical Signs

Excessive salivation.
Fever: Appears on the third day of infection.
Liver inflammation.
Nasal discharge: Turns into mucopurulent discharge when secondary bacterial infection occurs.
Coronitid
Lameness, recumbancy.
Obstruction.
Blue tongue edema: The most important clinical sign of this disease.

Poxvirus

Spread amongst different species, including cows, sheep, and humans.
Highly contagious.
Epitheliotropic, meaning it targets the epithelium, causing associated lesions.
Infections can become systemic, spreading to other organs but returning to the skin's epithelium.

Pathogenesis of Poxvirus

Causes characteristic forms that consist of four stages:
- Erythema: Erythematous vacuolated spots.
- Papules.
- Vesicles: Contain fluid, called cell-walled fluid-filled areas.
- Pustules: Contain pus due to secondary bacterial infection.
- Pus: White in color, and ruptures.
- Ulceration.
- Healing with scar formation.
Pustules have a depressed center, giving them a pock shape.
Skin becomes raised above the normal level by the pustules.

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Description

Explore the critical aspects of Tuberculosis (TB), a chronic granulomatous disease caused by Mycobacterium tuberculosis. This quiz covers transmission, symptoms, and the body's immune response to the infection. Understand the importance of hygiene and treatment in controlling this resilient disease.