Online Program

Shigella sonnei waterborne transmission in a state park--New Jersey 2012

Tuesday, November 5, 2013 : 3:15 p.m. - 3:35 p.m.

Miranda Chan, MPH, Communicable Disease Service, New Jersey Department of Health, Trenton, NJ
Rebecca Greeley, MPH, Communicable Disease Service, New Jersey Department of Health, Trenton, NJ
Lisa A. McHugh, MPH, Communicable Disease Service, New Jersey Department of Health and Senior Services, Trenton, NJ
Barbara Carothers, LPN, Communicable Disease Service, New Jersey Department of Health, Trenton, NJ
Michelle Malavet, MSA, Communicable Disease Service, New Jersey Department of Health, Trenton, NJ
Background: On June 24, 2012 an emergency department physician called the New Jersey Department of Health (NJDOH) to report two unrelated families being evaluated for diarrheal illnesses. These patients tested positive for Shigella sonnei and reported swimming in the same lake at a NJ state park. NJDOH investigated to identify additional cases and to determine possible infection sources. Methods: We reviewed reported gastrointestinal illnesses to identify additional associated cases. We defined (1) confirmed cases as gastrointestinal illnesses with positive cultures for S. sonnei and lake exposure, (2) probable cases as gastrointestinal illnesses and lake exposure, and (3) secondary cases as gastrointestinal illnesses epidemiologically linked to a confirmed case. Cases were interviewed with a developed targeted questionnaire. The lake's facilities- a concession stand, septic system, potable water system, and swimming area- were inspected. Results/Conclusions: We identified 12 confirmed, 13 probable and 3 secondary cases. For confirmed cases, illness onset dates range from June 21-24 and lake exposure from June 20-22. Investigation findings ruled out septic system breaches, failure of potable water system and contamination of concession food items. Findings suggested that Shigella bacteria were most likely introduced into the lake by a fecal contamination from visitors. Due to warm weather and staff shortage, a high volume of visitors were confined to a small area of the lake and likely facilitated disease transmission which was interrupted by the lake's weather-related closure on June 21. This outbreak underscores the importance of recognizing recreational waterborne illnesses and promoting appropriate measures to limit and prevent such illnesses.

Learning Areas:

Protection of the public in relation to communicable diseases including prevention or control

Learning Objectives:
Define outbreak case definition for waterborne Shigellosis Describe the epidemiological characteristics and public health investigation for a waterborne gastroenteritis outbreak

Keyword(s): Outbreaks, Infectious Diseases

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: As a CDC/CSTE Applied Epidemiology Fellow, I played an integral role in this outbreak investigation. I aided in the response to the initial outbreak report, the development of the case-interview questionnaire and the environmental inspection of the state park.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.