Reported Pertussis-related Deaths to the National Notifiable Diseases Surveillance System (NNDSS) and the Centers for Disease Control and Prevention (CDC) in the United States, 2000–2005

Learning Objectives for this Presentation:
By the end of the presentation, participants will be able to understand the characteristics of pertussis-related deaths.

Background:
Despite childhood coverage rates >95% with five doses of pertussis vaccine, reported pertussis cases and pertussis-related deaths increased in the United States during the 1990s.

Objectives:
To describe the clinical characteristics and epidemiologic trends of pertussis-related deaths from 2000 to 2005.

Methods:
We analyzed data from NNDSS and available medical records for pertussis-related deaths reported to the CDC from 2000 through 2005.

Results:
From 2000–5, 140 pertussis-related deaths were reported to CDC compared to 103 deaths during 1990–9. Pertussis was considered positive by culture (49%), PCR (39%), DFA (6%), and epidemiologic linkage (10%). Overall, 54% fatal cases were females. One hundred and thirty one fatalities (94%) occurred among infants aged <1 year and 126 (90%) were aged <4 months; six deaths were aged >7 years and had preexisting co-morbidities. One hundred and thirty two cases (94%) were hospitalized and 72% required mechanical ventilation. Extracorporeal membrane oxygenation was performed in 40 infants (30%). Reported complications included pneumonia (92%), encephalopathy (5%) seizures (7%), co-infections (30%), and pulmonary hypertension (35%). Ninety-four percent cases were unvaccinated, 3% received >1 dose; vaccination status of 3% fatalities was unknown. Of 123 infants with ethnicity data, 49% were Hispanic. Mortality rate among Hispanic infants (7.2/100,000) was higher than among non-Hispanics (2.0/100,000). Among 101 infants with known gestational age, 39% were born at <37 weeks. The median maternal age was 22 years (range, 13-47, n=94). In 64 (49%) infant deaths, a parent, sibling or grandparent had an antecedent cough-illness in the household.

Conclusions:
Reported pertussis-related deaths increased during 2000-5 compared to the 1990s. Studies are needed to evaluate risk factors for fatal pertussis. Household contacts of infants should receive a dose of an age-appropriate pertussis vaccine to help protect infants from acquiring pertussis.