Knowledge, attitudes, and practices among border crossers during temporary enforcement of a formal entry requirement for Mexican-style soft cheeses, 2009.

The Food Safety Modernization Act of 2011 requires people and businesses that provide food to the public to take steps necessary to identify and control hazards that could make food unsafe (28). However, such laws and regulations must be enforced to assure their effectiveness as public health interventions (17). Although many hazards at large food production facilities can potentially be eliminated by mandates and enforcement of better manufacturing practices, foodstuffs imported in small quantities for noncommercial use are much more difficult to regulate (28). Mexican-style soft cheeses, typically referred to as queso fresco (QF), have been especially difficult to regulate. Often unpasteurized, QF is commonly made in small quantities by unregulated noncommercial processors, sold in small local markets in Mexico, and imported into the United States (14, 16, 18, 21). QF can be imported commercially into the United States if it is made from pasteurized milk, is otherwise in compliance with U.S. regulations, and makes formal entry with U.S. Customs and Border Protection (CBP) and the U.S. Food and Drug Administration (FDA). However, a significant proportion of the QF imported each year through border crossings between California and Mexico is transported by couriers or in personal baggage (16). FDA requirements for importation of food are based on chapter VIII of the Federal Food Drug and Cosmetic Act (21 US Code 381) (31). The Act makes no distinctions with regards to quantity, and the FDA exercises discretion in enforcement of noncommercial importation of cheese. Although upon entry to the United States QF is typically declared as being for personal use, experience in California suggests that much of this cheese is eventually sold commercially (20). The health risks of cheeses made from unpasteurized milk are well documented (2, 4–9, 11, 19, 25). For several years before 2009, surveys and enhanced surveillance operations conducted by the FDA, the CBP, and state health agencies at noncommercial ports of entry (POE) along the United States–Mexico border have revealed high violation rates for raw milk cheeses and evidence of pathogens in imported QF, including Salmonella, Escherichia coli O157:H7, Listeria spp., and Mycobacterium bovis (14, 16, 18, 21, 29). QF-associated disease is more common in Hispanic populations, among whom pregnant women and the elderly appear to be at increased risk (24, 27). Outbreaks and sporadic cases of salmonellosis, listeriosis, brucellosis, and M. bovis infections have been frequently associated with consumption of QF in Hispanic communities in California and throughout the United States (4–9, 11, 19, 25, 29). To test control measures aimed at decreasing unlawful importation of QF across the United States–Mexico border, the FDA and the CBP implemented a trial enforcement strategy requiring formal commercial entry for cheese imports in excess of 5 lb (2.3 kg) per border crosser. The requirement was fully enforced for 1 month starting 20 January 2009 with the assistance of the CBP who conducted systematic screening of border crossers at the two POE in San Diego, California (San Ysidro and Otay Mesa), and for another 2 months for QF detected during routine CBP inspections. The two POE were chosen because of the high volume of QF imported from Mexico and previous links between QF and foodborne illnesses in California. Outreach efforts were begun 30 days before the start of the enforcement period with educational materials containing information about the importation requirement and the risks of QF consumption. Posters were displayed at the two POE. Flyers and fact sheets were disseminated during routine vehicle inspections and in the pedestrian lane. Announcements were also provided through the U.S. media, including newspapers, television, and radio. During the enforcement period, the U.S. Centers for Disease Control and Prevention (CDC) conducted a survey of individuals crossing the border from Mexico into the United States to monitor changes in awareness of and compliance with the requirement. We measured variation among border crossers in their knowledge regarding health risks associated with consumption of unpasteurized QF and their consumption and importation practices.