Outbreak of Pertussis in a School and Religious Community Averse to Healthcare and Immunizations – Columbia County, Florida 2013

BACKGROUND:  On August 30, 2013, the Florida Department of Health (FDOH) in Columbia County was notified of a positive PCR for Bordetella pertussis from an unimmunized child attending a local charter school in a religious community averse to healthcare and immunizations. Interviews confirmed a sibling with symptoms consistent with pertussis. By September 3, another child from the same school was confirmed with pertussis. On September 12, a declaration of communicable disease emergency was instituted by FDOH in Columbia County; children with cough were excluded from school and re-entry required an evaluation by a healthcare provider. Following laboratory confirmation of a fourth patient on September 27, FDOH in Columbia County requested epidemiologic assistance from the FDOH central office. An investigation was conducted to determine disease incidence and control the spread of pertussis within this community.  

METHODS:  Medical record review and household interviews were conducted for 130 children excluded or absent from the charter school for cough illness. Cases were classified using the FDOH case definition. A suspect case definition was created to capture persons with a cough illness of 7-13 days duration or who received treatment for pertussis without additional clinical details. Cases were examined to determine onset date, vaccination status, demographics, and attack rates.

RESULTS:  One hundred and nine individuals were classified as confirmed (8), probable (61), or suspect (40) cases within this community. Out of 316 students and 16 teachers, 94 (30%) students and 1 teacher met the case definition. Fourteen cases were household contacts of ill charter school students. Only one confirmed or probable individual reported receiving any vaccination against pertussis. The investigation identified 14 patients with symptom onset prior to the first reported case. Nearly 90% of the students and household contacts were evaluated and prescribed antibiotics by one pediatrician and laboratory testing was uncommon. Attack rates were highest among the youngest students (Pre-K=57.1%) and decreased with increasing age (8^th Grade=14.3%). 

CONCLUSIONS:  In vaccine-averse communities, controlling vaccine preventable disease outbreaks is challenging, particularly when susceptible community members have prolonged contact in multiple settings. The use of extraordinary outbreak control measures including a school-wide cough exclusion policy and a low threshold for prescribing household prophylaxis should be evaluated in communities low pertussis immunity. Physicians need to understand the importance of reporting presumptive pertussis cases without laboratory confirmation. In medically-averse communities, local public health agencies need to identify and collaborate with healthcare resources utilized by that community.