Outbreak-Related Disease Burden Associated with Consumption of Unpasteurized Cow's Milk and Cheese, United States, 2009-2014.
Level 4 - case-series / case-control
Epidemiological modeling based on surveillance and survey data (by design analogy, non-clinical CEBM)
PubMed 28518026 · doi:10.3201/eid2306.151603
What was done
An epidemiological modeling study estimating US outbreak-related illnesses and hospitalizations (2009–2014) from cow's milk and cheese contaminated with Campylobacter spp., Listeria monocytogenes, Salmonella spp., and Shiga toxin-producing Escherichia coli. The authors used publicly available outbreak surveillance data combined with population consumption estimates.
What was found
Dairy-related outbreaks caused an average of 760 illnesses/year and 22 hospitalizations/year, primarily from Salmonella spp. and Campylobacter spp. Although consumed by only 3.2% (milk) and 1.6% (cheese) of the population, unpasteurized dairy caused 96% of dairy-associated outbreak illnesses. Unpasteurized dairy products caused 840 (95% CrI 611–1,158) times more illnesses and 45 (95% CrI 34–59) times more hospitalizations than pasteurized products. A doubling of unpasteurized dairy consumption was projected to increase outbreak illnesses by 96%.
Why it matters
This study quantitatively demonstrates that despite very low population consumption rates, unpasteurized dairy accounts for the overwhelming majority of dairy-related outbreak illnesses and hospitalizations in the United States.
Limits
The study relied solely on reported outbreak surveillance data, excluding sporadic (non-outbreak) foodborne infections and suffering from surveillance underreporting. Population consumption rates relied on survey estimates without direct individual-level exposure tracking.
Cited by
- supports Hospitalizations resulting from bacterial contamination of raw milk in the United States since the mid-1990s are in the hundreds.