Case scenario: A 31 year-old female who presented with a 2-week cough illness with paroxysms and post-tussive vomiting has pertussis confirmed by PCR. Her household contacts include a 3-month old daughter and a spouse who works in landscaping. She works in an office and shares a cubicle with a woman who is 37 weeks pregnant. She also carpools with a 52 year-old woman who lives alone. The infant, spouse, and carpool rider are all asymptomatic. The pregnant co-worker recently developed a runny nose and slight cough.

You are consulted by one or more of the exposed persons: Who should be tested and/or treated, including her spouse, daughter, co-worker, the carpool buddy, or all of them? For extra credit, who is not on this list yet but needs to be assessed as well?

Management of pertussis cases:  Treatment and post-exposure prophylaxis (PEP)

Confirmed cases:  All confirmed cases should (1) be treated with an appropriate antibiotic (see box) to prevent further spread of the illness and 2) avoid close contact with others until completion of 5 days of treatment with an appropriate antibiotic.

“High priority” contacts:  Public Health routinely recommends PEP for all “high priority” close contacts of pertussis cases. “High priority” contacts include:

The case’s spouse, 3-month old infant, and pregnant co-worker are “high-priority” contacts.  The pregnant, symptomatic co-worker should be tested and treated promptly without waiting for test results. Ideally, the clinician treating the case should arrange for treatment of the household contacts.

You get extra credit if you know that the HCWs who evaluated and tested the case need to be assessed as well.  PEP would be recommended if they did not use droplet precautions* (including wearing a mask) during the visit.

* Pertussis is spread through direct contact with infectious respiratory secretions by droplet transmission. Such droplets generally travel 3 feet or less when an infected person talks, coughs, or sneezes.

Other close contacts (not at increased risk of severe pertussis, such as the carpool rider), should be counseled about the signs and symptoms of pertussis, the availability of PEP treatment, and be advised to seek medical evaluation and testing if they become symptomatic within 21 days of exposure.  Clinicians may elect to treat “non-high-priority” contacts” in some circumstances.

Prevention

Health care providers should ensure that infants and children are up-to-date on their recommended immunizations including DTaP. The recommended age for Tdap should be 11 to 64 years of age to replace the next booster dose of Td. This is particularly important for adults who have close contact with infants < 12 months of age and HCW’s. Ideally women should have a dose of Tdap prior to becoming pregnant. Women who have not previously had Tdap should receive a dose in the immediate postpartum period, prior to hospital discharge.

Pertussis should be considered in the differential diagnosis of:  (1) patients with cough illness > 2 weeks duration, (2) patients with respiratory illness of any duration who have had contact with persons with a prolonged cough illness (or pertussis) and (3) infants <12 months of age with respiratory tract symptoms of any duration, even if the infant is immunized against pertussis or positive for RSV.

Pertussis testing is available at the Public Health - Seattle & King County Laboratory (206-744-8950) as well as local reference labs. Pertussis is immediately notifiable to Public Health upon suspicion at (206) 296-4774.