Border Infectious Disease Surveillance - Queso Fresco
The Centers for Disease Control and
Prevention (CDC) estimate there are approximately 48 million cases of foodborne
illness per year
in the United States. Unpasteurized (raw) milk and certain derived products can
harbor pathogens that would have otherwise been eliminated through the process
of pasteurization. According to the CDC, more than 1,500 people became sick
from drinking unpasteurized milk or eating cheese made from raw milk between
1993 and 2006 in the United States.
Certain groups are considered at risk of
contracting a foodborne illness, including people with weakened immune systems,
pregnant women, and the elderly.
BIDS aims to identify if
unpasteurized cheese consumption is playing a role in the spread of disease in San Diego County.
The purpose of the Queso
Fresco Enhanced Surveillance is to assess the burden of enteric illnesses that could be attributed to unpasteurized queso fresco and other Mexican-style soft cheeses.
Disease investigators complete an additional questionnaire if queso fresco was
consumed by the individual during the exposure period for their illness. The
enteric illnesses monitored are those caused by Shiga toxin-producing E. coli (including O157), Salmonella, Shigella, Listeria, Brucella, and Hepatitis A. The questionnaires are
designed to obtain detailed
exposure information, including the source and location of purchase.
In 2017, there were 63 cases of foodborne
illness included in enhanced surveillance for queso fresco. Instances of
homemade cheese were identified in some of the cases, which helped BIDS
identify opportunities for outreach and educational campaigns. The results of
enhanced surveillance are also shared in quarterly meetings of the Queso Fresco
Task Force. The task force is comprised of officials from the Office
of Border Health and Department of Environmental Health of San Diego County,
the California Department
of Food and Agriculture, CDC US-Mexico Unit, and Customs
and Border Protection, among others.