194834 Epidemiology of Salmonella infections reported in a northern California county

Sunday, November 8, 2009

Catherine S. Sallenave, MD , Disease Control and Prevention, San Mateo County Health System, San Mateo, CA
Swati Deshpande, PhD , Disease Control and Prevention, San Mateo County Health System, San Mateo, CA
Amie DuBois, PHN , Disease Control and Prevention, San Mateo County Health System, San Mateo, CA
Background: In 2003, 43,657 cases of salmonellosis were reported in the USA. S. typhimurium and S. enteritidis were the serotypes most frequently isolated in 2000, accounting for 42% of all laboratory-confirmed cases. Since then, S. typhimurium has decreased in incidence. Methods: We reviewed the 2007 typhoidal and nontyphoidal Salmonella Confidential Morbidity Reports (CMRs) and abstracted specimen source, basic demographic information, clinical information, antibiotic/food/animal/water exposures, antibiotic resistance patterns along with travel and vaccine history for patients with S. typhi. Results: 116 nontyphoidal Salmonella and 11 typhoidal Salmonella infections were reported to our county. 2 asymptomatic typhoid carriers were identified. The mean age of typhoid cases was 25 years; 55% were hospitalized. 72% of cases presented with fever and headaches. 54% of infections occurred in foreign-born. Asian Pacific Islanders were disproportionately affected (45%). 55% had recently traveled abroad. None were vaccinated. The most common non-typhoidal serotype was S. enteritidis (23 cases), followed by newport (12) and typhimurium and heidelberg (10 each). 72% of these cases presented with diarrhea, often during spring/summer. Mean age was 33. 13% were hospitalized. The majority of newport cases occurred amongst Hispanics. Conclusions: S. typhi remains a disease of travelers and immigrants although contact with an asymptomatic chronic carrier is a risk factor. Vaccination rates remain low. Non-typhoidal infections remain common, demonstrating the need for education of the public regarding transmission mechanisms, including exposure to pets and contaminated food items. Newport was the 2nd most common serotype in our study possibly reflecting our county's large migrant worker population.

Learning Objectives:
Describe the epidemiology of the Salmonella infections reported to the San Mateo County Health Department over a one-year period.

Keywords: Data/Surveillance, Communicable Disease

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I have been involved in several clinical/epidemiological studies and surveillance projects previously as an Infectious Diseases Fellow and now as the Communicable Disease Controller for San Mateo County, CA.
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.