Whooping Cough

Question 1

what is the cause of whooping cough?

Answer 1

Bordetella pertussis
Gram negative coccobacilli
Transmisted via sneeze or cough

Question 2

what is the cycle of infection of whooping cough?

Answer 2

Infection
Incubation period (1 week)
Catarrhal Phase (2 weeks)
Paroxysmal phase (1-6 weeks)
Convalescent Phase (days to months)

Question 3

what occurs in the incubation period of whooping cough?

Answer 3

Bacteria in resp tract but not multiplied
Releases toxins to help anchoring/prevent removal - filamentous haemagglutinin, pertactin, agglutinin
Releases toxins to stop immune response - pertussis toxin, adenlylate cyclase

Question 4

what occurs in the catarrhal phase of whooping cough?

Answer 4

o Eventual damage causes nasal congestion, cough, low grade
o Symptoms of coryza
o Very infectious

Question 5

what occurs in the paroxysmal phase of whooping cough?

Answer 5

symptoms persist, worse at night, development of cough
o symptoms persist
o present day and night but symptoms worse at night
 breathing paroxysms in machine gun bursts
 as patient tries to catch breath = then a whooping noise from air passing partially closed glottis

Question 6

what occurs in the convalescent phase of whooping cough?

Answer 6

o Cough slowly improves (100 day)
o Paroxysms and whooping fade
o Airway heals

Question 7

what are the complications of whooping cough?

Answer 7

• Adenovirus
• Atypical pneumonia i.e. Mycoplasma pneumonia
• Chlamydophilia pneumoniae
• Bordetella parapertussis
• Protracted bacterial bronchitis
• Asthma
• Post-infectious cough

Question 8

what are the differentials of whooping cough?

Answer 8

• Pneumonia
• Apnoea
• Seizures
• Encephalitis
• Bronchiectasis

Question 9

what is the treatment of whooping cough?

Answer 9

• Pertussis Vaccine – avoid disease or lessen symptoms
• Macrolide antibiotics – azithromyxin (catarrhal or early paroxysmal phase)
• Prevent transmission especially in infants and immunocompromised

Question 10

what phases of whooping cough are investigations most beneficial?

Answer 10

catarrhal phase - can be treated in this phase

Question 11

what are the different tests used for whooping cough diagnosis?

Answer 11

• Nasal Pharngeal Swab – Pertussis PCR Swabbing then culture, or PCR
• Direct fluorescent antibody – detects Bordetella pertisus antigens
• Pertussis serology – looking for antibody response
• FBC – lymphocytosis

Question 12

what are the consequences of spasmodic paroxysms in whooping cough?

Answer 12

Adults - vomiting, collapsed lung, broken rib, petechiae, epistaxis, subconjunctival haemorrhage,
Absence of fever or wheeze
In infants – gasping, cyanosis, apnea, ALTE, decreased o2 = seizures

Question 13

what does the pertussis toxin do in whooping cough?

Answer 13

helps anchoring, causes increase in lymphocyte (T cell)
• Stimulates T cells to divide
• Blocks them from leaving blood and migrating
• Helps cells be more receptive to histamine – airway swells up

Question 14

what does adenylate cyclase do in whooping cough?

Answer 14

• Blocks phagocytes from reaching site of infection
• Stops them engulfing
• Induces phagocytes to undergo apoptosis