Pertussis clinician fact sheet

Pertussis
Clinician Fact Sheet
Agent: Bordetella pertussis, a fastidious Gram-negative bacterium.
Symptoms:
• Initial presentation as a mild upper respiratory tract infection • Progresses to cough, which may develop to paroxysms of cough (in children with characteristic inspiratory whoop), and commonly followed by vomiting • Minimal or absent fever • Symptoms wane gradually over weeks to months (duration typically 6-10 weeks) In children under 6 months: atypical presentation including apnea; whoop often absent. In older children and adults: atypical presentation generally prolonged cough; whoop is absent. Severity of Disease:
Disease is most severe in unimmunized or under-immunized children under the age
of 12 months. Watch for seizures, pneumonia, encephalopathy, or death.
Differential Diagnosis:
In adults, the clinical presentation is similar to viral respiratory infections, which
are generally far more common. Other possibilities include Bordetella
parapertussis, Mycoplasma pneumoniae, Chlamydia trachomatis, Chlamydia
pneumoniae, and Bordetella bronchiseptica. Pertussis should be considered in
differential diagnosis of chronic cough, especially when pertussis is known to
be circulating in the community.
Clinical case definition:
A cough illness lasting around 2 weeks with one of the following: paroxysms of
coughing, inspiratory “whoop,” or post-tussive vomiting, without other apparent
cause.
Laboratory criteria for diagnosis
• Isolation of Bordetella pertussis from clinical specimen or • Positive polymerase chain reaction for B. pertussis Surveillance Case classification
Probable: meets the clinical case definition, is not laboratory confirmed, and
is not epidemiologically linked to a laboratory-confirmed case
Confirmed: a case that is culture positive and in which an acute cough illness of
any duration is present; or a case that meets the clinical case definition and is confirmed by positive PCR; or a case that meets the clinical case definition and is epidemiologically linked directly to a case confirmed by either culture or PCR Epidemiology:
• Humans are the only host. • Transmission is by close contact via aerosol droplets. Pertussis • Incubation period ranges from 6-21 days, average of 7-10 days. • Immunity wanes approximately 5-12 years following vaccination OR natural infection, therefore older children and adults form the susceptible reservoir. • Pertussis is highly contagious and as many as 80% of non-immune household contacts will acquire the disease. • Patients are most infectious during the initial presentation and during the first Diagnostic Testing:
In children, the inspiratory “whoop” of pertussis is characteristic of this disease.
Children with the classical presentation of paroxysmal cough, inspiratory “whoop”
and subsequent vomiting can be considered to have pertussis and treated.
However, adults and children with atypical presentations should have the
diagnosis of pertussis verified through laboratory testing in order to reduce the
amount of antibiotics incorrectly prescribed for viral conditions.
• PCR - Currently, this test is the best option in most clinical
circumstances. This test provides acceptable sensitivity in children and
adults, has a relatively short turnaround time, and is available at most
commercial reference laboratories.
o Collect a nasopharyngeal sample on Dacron NP swab. Transport o Note: NP swabs have thin wire shafts and are flexible. You
cannot collect an NP specimen with a throat swab. Throat
swabs and cough plates are not acceptable specimens.
• Culture – The sensitivity of this test varies widely. However, the length of
time to obtain results makes it unacceptable for determining patient therapy. Generally this test could be used when: o Testing children (sensitivity in adult patients is unacceptable) o Using an on-site laboratory (transport decreases yield) o Patients have not started taking antibiotics o Patients are within two weeks of symptom onset o Determining possible antibiotic resistance o Collect a nasopharyngeal aspirate or nasopharyngeal swab (on Dacron or rayon NP swab), plate directly to culture media. o Note: NP swabs have thin wire shafts and are flexible. You
cannot collect an NP specimen with a throat swab. Throat
swabs and cough plates are not acceptable specimens.
• DFA – While the speed of this test is appealing to determine antibiotic
therapy, the sensitivity and specificity of this test are unacceptable. • Serology – This requires paired acute and convalescent sera and
therefore it is not recommended due to the wait for convalescent sera. Treatment:
If treatment is started early in disease, it should limit disease spread and may
reduce the duration of illness. If treatment is started late in disease, it should limit
disease spread but may not affect the course of the illness.
Recommended Antimicrobial Therapy and Postexposure Prophylaxis for Pertussis in Infants,
Children, Adolescents, and Adultsa – Pink Book 2009
TMP indicates trimethoprim; SMX, sulfamethoxazole a Centers for Disease Control and Prevention. Recommended antimicrobial agents for the treatment and postexposure prophylaxis of pertussis. MMWR Recommendations and Reports 2005; 54(RR-14): 1-16 b Preferred macrolide for this age because of risk of idiopathic hypertrophic pyloric stenosis with erythromycin. Resistance to macrolides is rare. Penicillin-class drugs, and first/second generation cephalosporins are not effective. Management of People Exposed to Pertussis:
Vaccination:
• All household and close contacts of pertussis cases who are <7 years of age and: o who have not completed the four-dose primary series should complete the series with the minimal time intervals between doses. o whose last dose of DtaP or DTP was more than 3 years ago For close contacts (10-18 years of age) of pertussis cases: • Recommend vaccination with Tdap • A 5-year interval between TD and Tdap is safe, but may cause a higher risk of local or systemic reactions; Tdap may be given after a shorter interval when the risk of transmission outweighs the risk of a reaction • Adolescents with history of pertussis should still receive the vaccine • Note: There is only one vaccine approved for 10 year olds. For close contacts (>18 years of age) of pertussis cases: • Advise people of the availability of a licensed vaccine for adults • ACIP recommends adults receive a single dose of Tdap to replace a single dose of Td for booster immunization
Prophylactic antibiotics:
Prophylactic antibiotics may reduce secondary transmission in household and
other settings. Most experts recommend prophylactic antibiotics be given to all
close and household contacts of a pertussis case, especially when there is a
child under the age of one in the household.
Exclusion from School or Daycare:
Symptomatic persons with pertussis should be excluded from school or childcare
settings until they have received five days of appropriate antibiotic therapy, or if not
treated until 21 days after onset of symptoms.
It is recommended that adults with pertussis refrain from public activities and the
workplace for the first 5 days of a full course of antimicrobial treatment. Persons
with pertussis who do not take antimicrobial treatment should refrain from public
activities and the workplace for 21 days from onset of cough.
Outbreaks:
Additional measures to limit transmission may be appropriate in outbreak
settings. Please consult with your local health department or the Communicable
Disease and Epidemiology Program, DPHHS, if you suspect an outbreak.
Vaccine/ Immunization
For up to date information on pertussis vaccines, including possible adverse
events and reporting, please consult http://www.cdc.gov/vaccines/vpd-
vac/pertussis/default.htm

References:
1. Red Book: 2009 Report of the Committee on Infectious Diseases, Elk Grove Village, IL, American Academy of Pediatrics; 2009, pages 504-519. This book contains detailed recommendations for treatment, vaccination, and prophylaxis of children. 2. Control of Communicable Diseases Manual (19th Edition), David Heymann, Ed., 2008. 3. Manual of Clinical Microbiology (8th Edition), Murray et.al., Eds., 2003 4. Principles and Practice of Infectious Diseases (5th Edition), Mandell et.al., Eds., 2000. 5. Manual for the Surveillance of Vaccine-Preventable Diseases (4th Edition), 2008-2009 6. Centers for Disease Control and Prevention. Guidelines for the Control of Pertussis Outbreaks (2005). Centers for Disease Control and Prevention: Atlanta, GA, 2000. http://www.cdc.gov/vaccines/pubs/pertussis-guide/guide.htm Montana Department of
Public Health and Human
Services
Communicable Disease and
Epidemiology Program
Update October 2010

Source: http://www.dphhs.mt.gov/publichealth/immunization/documents/PertussisClinicianFactSheet.pdf