L.6 Bordetella

Question 1

What is Bordetella pertussis?

Answer 1

Causative agent of pertussis or ‘whopping cough’

Question 2

What characterizes the cough associated with Bordetella pertussis?

Answer 2

Violent coughing spells called paroxysms

Question 3

Is Bordetella pertussis an exclusively human pathogen?

Answer 3

Yes

Question 4

What type of cells does Bordetella pertussis infect?

Answer 4

Ciliated bronchial epithelial cells

Question 5

How is Bordetella pertussis transmitted?

Answer 5

Via airborne droplets person to person

Question 6

Is pertussis a notifiable disease in Ireland?

Answer 6

Yes

Question 7

Who is particularly at risk from pertussis?

Answer 7

Young children who are not vaccinated

Question 8

What is the global impact of pertussis in terms of morbidity and mortality?

Answer 8

Significant morbidity + mortality worldwide where vaccination is unavailable

Question 9

How many deaths occur worldwide due to pertussis each year?

Answer 9

Over 300,000

Question 10

Is the pertussis vaccine part of the routine immunisation programme in Ireland?

Answer 10

Yes

Question 11

How many cases of pertussis were reported in Ireland in 2024?

Answer 11

514 cases

Question 12

How many cases of pertussis were reported in Ireland in 2023?

Answer 12

18 cases

Question 13

How often do cycles of pertussis infections occur?

Answer 13

Every ~5 years

Question 14

What percentage of pertussis cases occur in children 0-5 months old?

Answer 14

20%

Question 15

Fill in the blank: Bordetella pertussis is characterized by _______.

Answer 15

violent coughing spells

Question 16

True or False: Bordetella pertussis can infect both humans and animals.

Answer 16

False

Question 17

Fill in the blank: The vaccination against pertussis is part of the routine _______ programme in Ireland.

Answer 17

immunisation

Question 18

What is virulence?

Answer 18

The ability of a pathogen to enter the respiratory tract, adhere to epithelial cells, and release toxins that damage tissues.

Virulence factors are crucial for the establishment and progression of infections.

Question 19

What toxins aid in bacterial cell anchorage to epithelial cells?

Answer 19

• Filamentous haemagglutinin
• Pertactin
• Agglutinin

These toxins facilitate the attachment of bacteria to the host’s cells.

Question 20

What is the function of tracheal cytotoxin?

Answer 20

Paralyzes cilia, resulting in mucus accumulation and triggering severe coughing to clear airways.

Cilia are tiny hairlike projections that help clear mucus and trapped pathogens.

Question 21

What effects does pertussis toxin have?

Answer 21

• Aids bacterial adhesion
• Drives T cell proliferation in bloodstream
• Increases sensitivity of blood vessels in respiratory tract to histamine

This promotes tissue swelling and increases difficulty in breathing.

Question 22

What is the role of adenylate cyclase toxin?

Answer 22

Blocks phagocytes from reaching the site of infection and triggers apoptosis in those that do.

This helps the bacteria evade the immune response.

Question 23

What occurs during the incubation period of pertussis infection?

Answer 23

Bacteria are present in respiratory tract but have not yet multiplied enough to cause noticeable symptoms.

This period lasts about one week.

Question 24

What are the symptoms of the catarrhal phase of pertussis?

Answer 24

• Nasal congestion
• Mild cough
• Low-grade fever

This phase lasts about two weeks and is characterized by an increasing bacterial load.

Question 25

Why is the catarrhal phase considered very contagious?

Answer 25

Due to the large number of bacteria present in the body. ## Footnote This phase is critical for the spread of the infection.

Question 26

Describe the paroxysmal phase of pertussis infection.

Answer 26

Immune system begins to clear bacteria, significant airway damage occurs, resulting in characteristic coughing fits or 'paroxysms'. ## Footnote This phase can last from one to six weeks.

Question 27

What characterizes the coughing fits in the paroxysmal phase?

Answer 27

Rapid, consecutive coughs followed by a high-pitched 'whoop' when inhaling. ## Footnote This is a hallmark symptom of pertussis.

Question 28

What happens during the convalescent phase of pertussis?

Answer 28

Coughing gradually subsides, airway heals, and individual recovers. ## Footnote This phase lasts about two to three weeks.

Question 29

What are some complications of paroxysmal?

Answer 29

Complications include: * Vomiting * Rib fractures * Collapsed lungs * Small hemorrhages in the facial skin (petechiae) * Gasping, cyanosis, apnea, and life-threatening events in infants * Diminished oxygen levels leading to seizures and encephalopathy or death * Risk for pneumonia from other pathogens ## Footnote ALTEs refer to Apparent Life-Threatening Events in infants.

Question 30

What specimen is used for lab investigation on Day 1?

Answer 30

Specimen = nasopharyngeal swab (both nostrils), cough plates transported in charcoal medium ## Footnote Charcoal medium helps to preserve the viability of the bacteria during transport.

Question 31

What rapid identification methods are used in lab investigations?

Answer 31

Rapid identification methods include: * PCR to detect bacterial DNA * Direct fluorescent antibody testing to detect bacterial antigens * Serology to detect antibodies against B. pertussis ## Footnote These methods allow for quick diagnosis of Bordetella pertussis infection.

Question 32

What are the components of Bordet-Gengou (BG) agar?

Answer 32

BG agar contains: * Potato/starch base * Glycerol * Sheep blood * Antibiotics (e.g. penicillin) ## Footnote BG agar is selective for Bordetella pertussis and aids in visualization of colonies.

Question 33

At what temperature and for how long should Bordet-Gengou agar be incubated?

Answer 33

Incubate at 37C for 3-7 days ## Footnote This incubation period allows for growth of Bordetella pertussis colonies.

Question 34

What are the basic characteristics of Bordetella pertussis colonies on Day 2?

Answer 34

Basic characteristics include: * Smooth, raised, glistening colonies resembling ‘mercury drops’ * Gram negative coccobacilli * Catalase positive * Oxidase positive ## Footnote These characteristics help in the identification of Bordetella pertussis.

Question 35

What confirmatory tests are performed for Bordetella pertussis?

Answer 35

Confirmatory tests include: * Biochemical tests * Citrate utilization (positive = blue colour) * Antigen detection using direct fluorescence antibodies on nasopharyngeal smear * Molecular test = PCR ## Footnote These tests confirm the presence of Bordetella pertussis in the specimen.