Colorado State University Extension
SafeFood Rapid Response Network
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BEWARE OF BATHTUB CHEESE
by: Janice Mladonicky
CSU Public Health Graduate Student
“Bathtub Cheese” is the street name for queso fresco, or Mexican-style soft cheese. This cheese, a staple in many immigrant communities, is often made in bathtubs and backyard troughs using unpasteurized milk. It is also illegally imported from Mexico, sold door to door, and can often be found in small markets. Unpasteurized dairy products may be contaminated with Listeria monocytogenes, Brucella abortus, Campylobacter jejuni, Escherichia coli, Salmonella typhimurium, Mycobacterium tuberculosis, or Mycobacterium bovis. In the U.S. it is illegal to sell unpasteurized dairy products in 22 states, including Colorado. Because queso fresco is made with unpasteurized milk in unsanitary and unlicensed facilities, it poses a serious health threat to consumers, particularly the elderly, young, pregnant women, and immunocompromised individuals. Symptoms of foodborne illness can range from fever, aches, nausea and vomiting to septicemia, abortion, kidney failure, and death.
M. bovis is particularly concerning. This zoonotic pathogen can cause tuberculosis (TB) in both animals and humans. In the 1900s, M. bovis was eradicated from U.S. cattle. However, human consumption of raw dairy products has led to the re emergence of this pathogen. Unlike typical TB caused by M. tuberculosis, M. bovis is more likely to spread by consumption rather than through the respiratory route. This makes human to human transmission less likely with M. bovis, but still poses a danger because it is resistant to front-line therapy, complicating treatment. Studies have shown that adults with M. bovis are twice as likely to die when compared with those with M. tuberculosis infections before treatment is complete. Bathtub cheese may be one of the causes responsible for current TB infections, as most cases are seen in Hispanic communities where this food is common. A retrospective analysis of TB cases in San Diego, California, from 2001-2005 showed that almost all M. bovis cases were in persons of Hispanic ethnicity.
Outbreaks associated with bathtub cheese are not only observed in regions that border Mexico. From 2001 to 2004, 35 cases of human bovine TB were linked to queso fresco brought to New York City from Mexico. Other outbreaks associated with this type of cheese include Salmonella in New York, Illinois, Pennsylvania, and Washington; listeriosis in North Carolina, Texas, and Massachusetts; Campylobacter in Washington, Kansas, and Wisconsin; and brucellosis in California and Texas.
If produced under proper conditions and aged for the required time of 60 days, cheese from unpasteurized milk can be safe to eat, but that is not generally the situation with queso fresco. Individuals caught producing and selling unpasteurized cheese in unlicensed facilities can face misdemeanor or even felony charges. Despite legal and health implications, consumers still eat this cheese. If consumers want to decrease their chance of acquiring a foodborne illness, they should avoid buying unpasteurized cheese and only purchase dairy products from safe sources.
References and Resources:
- Aleccis, J. Tainted cheese fuels TB rise in California. 4 June 2008. MSNBC. Available at: http://www.msnbc.msn.com/id/24954041/.
- Becerra, H. LA crackdown on unpasterized Mexican cheese snares four. 28 August 2009. Los Angeles Times. Available at: http://articles.latimes.com/2009/aug/28/local/me-mexican-cheese28.
- Brito, J., Santos, E., Arcuri, E., Lange, C., Brito, M., Souza, G., Cerquerira, M., Soto-Beltran, M., Call, J., Yanhong, L., Porto-Fett, A., Luchansky, J. 2008. Retail survey of Brazilian Milk and Minas Frescal Cheese and a Contaminated Dairy Plant to Establish Prevalence, Relatedness, and Sources of Listeria monocytogenes Isolates. Applied and Environmental Microbiology. 74 (15): 4954-4961.
- MacDonald, P., Whitwam, R., Bogg, J., MacCormack, J., Anderson, K., Reardon, J., Saah, J., Graves, L., Hunter, S., Sobel, J. 2005. Outbreak of listeriosis among Mexican immigrants as a result of consumption of illicitly produced Mexican - style cheese. Clinical Infectious Diseases. 40(5): 677-682.
- Powell, Doug. "Cheese should not be made in a bathtub ." 25 October 2007. Barf Blog. 11 February 2010 http://barfblog.com/blog/137886/07/10/25/cheese-should-not-be-made-bathtub
- Rodwell, T., Moore, M., Moser, K., Brodine, S., Strathdee, S. 2008. Tuberculosis from Mycobacterium bovis in binational communites, United States. Emerging Infectious Diseases. 14 (6): 909-916.
