Micro - Bordetella pertussis

Question 1

Most important takeaway from pertussis

Answer 1

Vaccines can be very effective; reduced the rate of pertussis by 80%

Question 2

(T/F): Someone vaccinated against Bordetella as a kid won’t get it as an adult

Answer 2

False - vaccine-generated immunity isn’t lifelong; they can get pertussis but it will be a milder form

Question 3

Bordetella pertussis is (G+, G-) (aerobic, anaerobic) (shape)

Answer 3

G- aerobic coccobacillus

Question 4

How does Bordetella cause damage?

Answer 4

Release toxin that paralysis cilia and causes inflammation of URT

Question 5

Can pertussis result in pneumonia?

Answer 5

Yes - Bordetella can get into alveolar macrophages

Question 6

4 Bordetella pertussis virulence factors

Answer 6

1. Pertussis toxin - inhibits IC pathways
2. Adenylate cyclase - inhibits ROS production in PMNs, macrophages, and lymphocytes
3. Filamentous hemagglutinin (FHA) - pili that binds cilia
4. Tracheal cytotoxin - paralyzes ciliated cells

Question 7

Most common presentation of pertussis

Answer 7

Mild annoying cough; can last up to 7 weeks if untreated

Question 8

If pertussis only causes an annoying cough in most patients, why is it important to treat them?

Answer 8

Can become a reservoir and pass Bordetella to unvaccinated people

Question 9

3 stages of pertussis infection

Answer 9

1. Catarrhal (inflammatory/common cold)
2. Paroxysmal (whooping cough)
3. Convalescent (cough subsides)

Question 10

How long does catarrhal stage last?

Answer 10

1-2 weeks

Question 11

Sx of catarrhal stage

Answer 11

Runny nose, no or low-grade fever, mild occasional cough, apnea (pauses in breathing) in infants

Question 12

What distinguishes pertussis in catarrhal stage from other URI?

Answer 12

Cough increases instead of diminishing

Question 13

How long does paroxysmal stage last?

Answer 13

2-6 weeks

Question 14

Sx of paroxysmal stage

Answer 14

Paroxysmal bursts of long series of cough sometimes followed by forced inspiratory effort against a closed glottis = characteristic sound of pertussis

Question 15

When is pertussis most contagious? When do most complications occur?

Answer 15

Catarrhal stage

Paroxysmal stage

Question 16

Sx of convalescent stage

Answer 16

Cough subsides over weeks to months; may present with another URI

Question 17

Even after pt recovers from pertussis, they may develop episodic coughing when:

Answer 17

They have another URI

Question 18

Who has atypical presentations of pertussis?

Answer 18

Vaccinated infants and children

Question 19

When is a vaccinated person more likely to develop pertussis?

Answer 19

During adolescence when immunity wanes –> causes “outbreak” cases

Question 20

Is pertussis transmitted human-to-human?

Answer 20

YES! Highly contagious; only found in humans

Question 21

How to diagnose pertussis?

Answer 21

H&P
Blood samples
Secretions from back of throat by going through nose
PCR
CXR to look for pneumonia and URI

Question 22

Why is culturing Bordetella pertussis difficult?

Answer 22

Must be grown on special media to tell it apart from other nasopharyngeal bugs

Question 23

Name of pertussis vaccine currently used

Answer 23

DTaP

aP = acellular pertussis