Lake City) - Public health agencies in Utah, in coordination with the Utah
Department of Agriculture and Food, have been investigating a cluster of
Salmonella Newport cases in which it appears that the common link is queso
fresco, a Mexican-style soft cheese. Officials don't believe the
contaminated cheese is being produced or sold commercially. Epidemiologic
investigations point to queso fresco that is being made in private homes
and then either sold to neighbors or given away. A sample of queso fresco
produced and distributed by a non-commercial, private source was obtained
by Utah Department of Agriculture and Food and tested at the Utah Public
Health Laboratory. Salmonella Newport was recovered from the sample.
Public health officials are still uncertain how the cheese is getting
contaminated with Salmonella bacteria, but believe the cheese is either
being contaminated from ingredients used to make the queso fresco (such as
unpasteurized/raw milk), or from cross-contamination of the cheese (e.g.
through using a bowl to prepare or hold raw chicken, and then using that
same bowl without cleaning it to make the cheese).
Health officials understand that many people enjoy making food from scratch
and sharing it with others, especially in these tough economic times.
"I am sure that those who make queso fresco in the home and share it
with those in the neighborhood don't intend to make other people sick. It
is important that we teach people about proper food handling practices, and
that it is against the law to sell privately produced products
door-to-door, if they are potentially hazardous," stated Marilee
Poulson, a Foodborne Disease Epidemiologist with the Utah Department of
While this current investigation is focused on individuals infected with
Salmonella bacteria, public health officials warn that other dangerous
bacteria can also be spread through contaminated queso fresco, such as
Listeria, Campylobacter, E. coli, and Brucella. Public health agencies in
Utah are currently investigating another cluster of illnesses due to the
bacteria Campylobacter which may be associated with contaminated cheese
made with raw or unpasteurized milk.
There is no way to detect Salmonella or other bacteria in food without
laboratory testing; it cannot be detected by sight, taste, or smell.
Salmonella bacteria are commonly transmitted by eating or drinking
contaminated food or water. Salmonellosis can also be spread by direct
contact with an infected person or animal. Symptoms include: headache,
stomach pain, diarrhea, nausea, vomiting and almost always fever; symptoms
last between three and seven days.
Making homemade queso fresco can be done safely by following a few simple
steps that will help prevent bacterial contamination:
Use only pasteurized milk to make queso fresco. Queso fresco made from milk
that has not been pasteurized can cause severe illness. This is especially
dangerous for children, the elderly, and pregnant women. Eating queso
fresco made with pasteurized milk will help pregnant women protect
themselves and their unborn babies from getting a serious infection.
do not recommend that you use unpasteurized milk to make queso fresco.
However, if you choose to do so, it may be less dangerous to use milk from
a licensed seller. To obtain a list of licensed sellers of unpasteurized
milk, call Utah Department of Agriculture and Food at 801-538-7156.
milk refrigerated. Use proper food handling practices to avoid
cross-contamination when making queso fresco, such as:
Separate raw meats from other foods
Use separate countertop space, cutting boards, utensils, etc. for raw meats
cooked meat or other raw or prepared foods;
Don't place food in a dish (e.g. a plate or bowl) that previously held raw
meats or raw eggs without first cleaning that dish with soap and water.
Don't buy queso fresco from street vendors or door-to-door sellers.
If you buy queso fresco, make sure it comes from the refrigerated area of
the grocery store or market, and that it is sealed and labeled for
If you have questions or would like more information, contact the Utah
Department of Health at 801-538-6191 or the Utah Department of Agriculture
and Food at 801-538-7156, or visit www.health.utah.gov/epi.