Charles Stewart MD EMDM Professor of Emergency Medicine

Introduction: Everyone gets/can get Pertussis Immunity from vaccination is not 100% California is seeing more cases than before vaccination started in Increased testing? Increased # of cases

Differences: Bronchiolitis Brief - Few days max Progress to lower respiratory tract involvement PE - Lower tract involvement Pertussis Longer No progression to lower tract involvement More classic ‘whooping’ cough - rare very sick

One of the most common childhood illnesses in the U.S. in the 20th century Before vaccination > 200,000 cases/year Since vaccination in 1940's, > 80% decreased incidence Still an endemic infection in the U.S. (not "vaccine eradicatable") Increasingly prevalent *Highest morbidity in young children

Why does it matter now? Significantly increasing prevalence in the U.S., particularly in certain states (such as California) Pertussis usually manifests itself slowly, like a mild cold, with a runny nose or mild cough but can steadily progress into coughing fits resulting in its telltale “whoop.

California... The anti-vaccination folks had a real ‘win’ here!

Pertussis In Adolescents and Adults Often milder than in infants and children May be asymptomatic, or may present as classic pertussis Persons with mild disease (we never know they have it) may transmit the infection to others Older persons often the source of infection for children

Pertussis In Adolescents and Adults Reported (perhaps not actual) incidence by age decreases as age goes up Highest (reported) incidence in young children Decreased (reported) incidence decreases with each DTaP vaccination ( months)

Symptoms...

Diagnosis of Pertussis High clinical suspicion (but only the right patients) Cough > 2 weeks No significant fever Post-tussive emesis Close contact with others with prolonged cough Looks fine in the ED (no sig. sx's) -- i.e. DO NOT CLINICALLY HAVE BRONCHIOLITIS

Testing Culture is gold standard, though expensive and time- consuming PCR is faster with good sensitivity Classic WBC elevation with lymphocytosis only occurs in infants and is unreliable (DO NOT CHECK CBC TO ESTABLISH OR SUPPORT DX.)

Testing Who to Test? Cough > 2 weeks Coughing "fits" No significant fever Post-tussive emesis Close contact with others with prolonged cough Looks fine in ED

Testing No rapid test for Pertussis exists. Test only on good clinical suspicion while waiting the results to come back. Who to Treat (while awaiting PCR result) --*Difficult question Under 6 months(?), due to risk of immediate complications if treatment delayed (unlike older children and adults High likelihood of disease

Treatment of Pertussis Supportive care Azithromycin (standard treatment) Trimethoprim-Sulfamethoxazole (alternative to azithromycin) Antibiotics do NOT shorten the course of illness, they only (potentially) reduce contagion

TDaP Tetanus, Dipthera, Pertussis All persons > 10 years old considered susceptible to pertussis due to waning immunity unless given single dose of TDaP *Single dose of TDaP should now replace Td booster

TDaP Special emphasis on adults with close contact with infants (including childcare and ALL healthcare personnel, and parents) The purpose of giving everyone TDaP over age 10 is to decrease the spread of asymptomatic carriers in the community Vaccination rates of at least 93% are needed to ensure herd immunity against pertussis, which prevents the disease from spreading quickly to unvaccinated individuals.

TDaP Hispanic infants under six months are most affected by the epidemic of pertussis that affect California, authorities said Monday health. The epidemic has already caused the deaths of eight babies, mostly Hispanic, said the Department of Public Health of California (CDPH, in English), reporting that cases identified in California totaled more than 200 in the last week, surpassing the 3,300 so far this year (article date Aug 2010). Immunization is lacking in this group.

Recent studies have also suggested some mutated strains of the disease may be resistant to the vaccine, including a paper published in Emerging Infectious Diseases earlier this year. Kurniawan J, Maharjan RP, Chan W-F, Reeves PR, Sintchenko V, Gilbert GL, et al. Bordetella pertussis clones identified by multilocus variable-number tandem-repeat analysis. Emerg Infect Dis [serial on the Internet] Feb [accessed 12 Jan2011]. Available from

Summary Far more common than usually suspected Must be considered to be diagnosed Matters mostly for infants Dramatically increasing in (reported) incidence throughout the U.S. You are likely to see it if you look for it! Does NOT look like bronchiolitis

Further Info s/Public%20Health%20Departme nt%20(DEP)/attachments/Health _Alert_Pertussis_ pdf s/Public%20Health%20Departme nt%20(DEP)/attachments/Health _Alert_Pertussis_ pd © Illustration Bruno Laporte