Feb 2019

1. ‫الرحيم‬ ‫الرحمن‬ ‫هللا‬ ‫بسم‬

2. PERTUSSIS ASSOCIATED COUGH
Ahmad Abu-Naglah
Prof of chest diseases
Al Azhar university

3. • Pertussis (whooping cough), caused by
Bordetella pertussis, is a highly contagious
respiratory tract infection
• It can be associated with significant morbidity
and mortality, particularly in young infants

4. • Infants less than 6 months of age are at
greatest risk of complications (apnoea, severe
pneumonia, encephalopathy) and are most
commonly infected by spread from family
members.

5. • It can occur in immunised children but the
illness is generally less severe.

7. Period of infectivity
• Pertussis is most infectious when patients are
in the catarrhal phase, but pertussis may
remain communicable for 3 or more weeks
after the onset of cough if untreated.

8. Period of infectivity
• Transmission requires close contact (exposure
within 1 metre for more than 1 hour) but can
be less for young infants

9. Diagnosis
• Clinical judgment plays an important role in
diagnosis.
• This is reflected in the clinical definitions used
by the WHO, CDC, and Public Health England

10. • Typically, the incubation period of pertussis
ranges from 3-12 days.
• Pertussis is a 6-week disease divided into
catarrhal, paroxysmal, and convalescent
stages, each lasting from 1-2 weeks

11. • Pertussis causes an acute cough that can often
become persistent
• classically associated with
paroxysms of coughing
inspiratory whooping
posttussive vomiting.

12. Older children, adolescents, and adults
• uninterrupted coughing, feelings of
suffocation , and headaches.
• Vaccinated adults usually develop only
prolonged bronchitis without a whoop
• Unvaccinated adults are more likely to have
whooping and posttussive emesis.

13. Laboratory diognosis
culture (100% specific),
polymerase chain reaction (88%- 100% )
serology (72%-100% specific),

14. PCR
• A nasopharyngeal aspirate/swab for PCR is the
investigation of choice.
• The test is usually negative after 21 days, or
5-7 days after effective antibiotic therapy has
been commenced.

15. Pertussis serology (IgA)
• Pertussis serology (IgA) may be detectable 2
weeks after the onset of the illness but rarely
affects clinical management.

16. Treatment
• There are several effective antibiotics
• These eliminate B pertussis but do not alter
the clinical course of the illness.

17. • Treatment should be initiated as soon as
possible after onset of illness to prevent
spread of the disease.
• The decision to treat with antibiotics is
therefore frequently based on a clinical
diagnosis rather than waiting for laboratory
confirmation

18. Indications of antibiotics
• Diagnosed in catarrhal or early paroxysmal
phase (may reduce severity)
• Cough for less than 14 days (may reduce
spread; reduces school exclusion period)
• Admitted to hospital
• Complications (pneumonia, cyanosis, apnoea)

19. Antibiotic options

20. Neonates
• Azithromycin 10 mg/kg oral daily for 5 days

21. • Clarithromycin liquid 7.5 mg/kg/dose (max
500mg) oral BD for 7 days
• Azithromycin (for children = 6 months old):
10mg/kg (max 500 mg) oral on day 1, then
5mg/kg (max 250mg) daily for 4 days

22. If macrolides are contraindicated:
• Trimethoprim-sulphamethoxazole (8mg-40mg
per ml) 0.5ml/kg (max 20ml) BD for 7 days

23. Vaccination
• Unimmunised or partially immunised children
diagnosed with pertussis should still complete
the pertussis immunisation schedule.

24. Recommendations of ACCP 2019

25. Clinically Diagnosing Pertussis-associated
Cough in Adults and Children
CHEST Guideline and Expert Panel Report
[ Evidence-Based Medicine ]
• Abigail Moore, BM, BCh; Anthony Harnden, MD; Cameron C. Grant, MD;
Sheena Patel, MPH; Richard S. Irwin, MD, Master FCCP; on behalf of the
CHEST Expert Cough Panel
• CHEST 2019; 155(1):147-154

26. Adult patients
For adult patients complaining of acute cough or
subacute cough the 4 key characteristics
paroxysmal cough
posttussive vomiting
inspiratory whooping
absence of fever

27. • The cough is likely to be caused by pertussis if
there is posttussive vomiting or is associated
with an inspiratory whooping sound.

28. • The cough is unlikely to be due to pertussis if
the patient has a fever or the cough is not
paroxysmal in nature

29. Children
• For children complaining of acute cough (< 4
weeks in duration) The 3 classical
characteristics
• paroxysmal cough
• posttussive vomiting
• inspiratory whooping.

30. The cough could be caused by pertussis if there
is posttussive vomiting

31. • For children complaining of acute cough
• The cough could be caused by pertussis if
there is paroxysmal cough or inspiratory
whooping. (Ungraded consensus-based
statement)

32. CONCLUSIONS
• In adults with acute (< 3 weeks) or subacute
(3-8 weeks) cough, the presence of whooping
or posttussive vomiting should rule in a
possible diagnosis of pertussis, whereas the
lack of a paroxysmal cough or the presence of
fever should rule it out.

33. • In children with acute (< 4 weeks) cough,
posttussive vomiting is suggestive of pertussis
but is much less helpful as a clinical diagnostic
test.

34. THANK YOU