Background 

There are three stages of clinical pertussis: catarrhal, paroxysmal, and convalescent. Clinical presentation, complications, and risk of death can differ based on age and vaccination status.

• Pertussis has an insidious onset with catarrhal symptoms that are indistinguishable from those of minor respiratory tract infections.
• Next is the paroxysmal stage characterized by numerous, rapid coughs.
• The final stage is the convalescent stage, which can take weeks to months to resolve.
• Transmission is usually person to person through respiratory droplets.
• Previously vaccinated adolescents, adults, and children may become infected with B. pertussis but may have milder disease than infants and young children.
• Protection from vaccination has been shown to wane over time.

Recommendations  

Reporting: Health care providers must report by telephone the suspected or confirmed case to the local health department (LHD) in which the patient resides. Within 24 hours, health care providers should report the case online through the Wisconsin Electronic Disease Surveillance System (WEDSS) or by fax using an Acute and Communicable Disease Case Report.

Testing: PCR testing is the preferred method. Obtain a nasopharyngeal (NP) swab as soon as pertussis is suspected, preferably within 21 days of cough onset and prior to the initiation of antibiotic therapy. Many clinical labs and the Wisconsin State Laboratory of Hygiene perform this testing.

Treatment/Prophylaxis: Recommended antimicrobial treatment and post-exposure for pertussis should be initiated upon suspicion of disease for the patient and household contacts. The recommended antibiotic is azithromycin; clarithromycin, erythromycin and TMP-SMX may be used. See the DHS guidance for clinicians or the AAP Redbook for more specifics.

Exclusion: Exclude and isolate the patient until five days of appropriate antibiotic therapy has been completed. If the patient has been coughing for more than 21 days (or more than 42 days in an infant aged less than 12 months), isolation and exclusion is not necessary.

Prevention

The best available methods for the prevention of pertussis include:

• Vaccinate with DTaP and Tdap according to the CDC recommended schedule.
• Recommend Tdap vaccine for pregnant individuals with each pregnancy, ideally between 27 and 36 weeks’ gestation to provide protection to the newborn.
• Appropriately use post-exposure antimicrobial prophylaxis.
• Encourage good personal hygiene, including proper hand hygiene, disposal of used tissues, and covering cough.

DHS has released a new communicable diseases case reporting and investigation guidance for clinicians.

Further information regarding pertussis vaccines, disease and case reporting can be found on the DHS website.

 Questions 

Questions regarding this health alert may be directed to the Bureau of Communicable Disease at dhsdphbcd@dhs.wisconsin.gov.  

About the Wisconsin Health Alert Network  

The content of this message is intended for public health and health care personnel and response partners who have a need to know the information to perform their duties. The HAN will be the primary method for sharing urgent and time-sensitive public health information with clinical and public health partners. For more information about the HAN, including how to subscribe and unsubscribe, visit DHS' HAN webpage.