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Posted in E. coli,Our Blog,Raw Milk on May 2, 2023
Cow-Share Arrangement Sickens 2 Infants Recent CDC Report Discusses Two Infants Sickened with Serious E. coli Infection – Concerns with Raw Milk Ecoli.
A recent report published in the Center for Disease Control and Prevention describes a case study from 2022 where two infants contracted a serious form of E. coli known as Shiga Toxin-Producing Escherichia coli O157:H7 or STEC.
The infants both lived in households that consumed raw milk acquired from the same cow-share program. According to the report, at least one infant had reportedly consumed raw milk.
The Outbreak
According to the report, the Tennessee Department of health (TDH) identified two cases of STEC infection on August 9, 2022. The two cases were two infants, aged 10 months, that began experiencing diarrhea on July 25 and August 1, 2022.
Stool samples were tested and both infants tested positive for STEC by a genetic analysis (Polymerase Chain Reaction or PCR) of bacteria present in the stool.
One infant developed Hemolytic Uremic Syndrome (HUS); a type of kidney disease often associated with STEC infection. That child was hospitalized for 27 days and required hemodialysis – a type of treatment that removes waste from the blood.
The second infant was hospitalized for 1 day and did not develop HUS.
Both infants lived in households that consumed raw milk acquired from the same cow-share program. The household was not a direct participant in the cow-sharing program but received the milk from a participant.
According to the report, at least one of the sickened 10-month-olds actually consumed the raw milk.
Investigating the Source
The investigation began with a site visit to the cow-share dairy farm. The farm was in an area so rural that there was no phone service or electricity at the farm.
A TDH employee visited the dairy farm to inform the owner of the investigation and to start gathering contacts of cow-share participants.
On August 15, another site investigation and environmental assessment was conducted.
What is a Cow-Share
Direct sale of raw milk is not allowed in the state of Tennessee. But some have found ways around it. That is where a “cow-share” or “herd-share” comes in. Participants “buy into” the farm and are thus part owners. They pay the farmer to feed and care for the cow or portion of the herd, and in turn can partake of the raw, unpasteurized milk.
Samples Obtained
The dairy farm in question included seven to ten cows that were hand-milked daily. Several observations were made.
Several possible routes of fecal contamination during the milking process were observed. Additionally, milk storage was higher than recommended. The milk cooling was facilitated by mechanical circulation of cool spring water followed by immersion of milk containers in ice-filled coolers.
Testing and Analysis
Samples were taken from eight sites on the farm. This included the milk filter, a collection pail, barn posts, four manure locations, and a sample of raw milk.
A United States Department of Agriculture (USDA) Laboratory identified two isolates of STEC O157:H7 from a single cattle manure sample in the dairy farm’s milking barn. The bacteria was analyzed using whole genome sequencing to determine the genetic makeup (strain) of the bacteria.
The same was performed on the patient’s stool samples. Unfortunately, only one of the infant stool samples could be tested due to delayed specimen collection for testing by TDH Laboratory Services. However, the infant stool sample that was analyzed showed that it was highly related to cattle stool STEC isolates. The strain of bacteria was the same.
A source was declared!
Additional Cases Possible
More cases of STEC illnesses are possible. The cow-share list consisted of 125 participants across the states of Georgia, Tennessee, and North Carolina. TDH reached out to 109 of the participants that had phone numbers on file and successfully reached only 50 participant households, which included 112 persons.
Three participants from a single household were identified as probable cases. This is based on interviews with the individuals. According to interviewees, the self-described symptoms began on July 20, 2022, and resolved on their own. No samples were taken for laboratory confirmation.
STEC infection symptoms vary from person to person, but often include severe stomach cramps, diarrhea (often bloody), and vomiting. Some people may experience a low-grade fever (less than 101 °F) and generally recover between 5 and 7 days. Cases range from very mild to severe and even life-threatening. Symptom onset can be anywhere from 1 to 10 days after exposure.
Around 5 to 10% of those diagnosed with STEC develop a potentially life-threatening complication known as HUS. This was the complication that hospitalized one of the infants for 27 days. HUS often develops about 7 days after the first symptoms appear, when diarrheal symptoms begin to include. Those developing HUS will often experience decreased urination, feeling tired, and losing color in cheeks and inside the lower eyelids. Most people with HUS recover within a few weeks, but for some the outcome could be permanent damage or even death.
Observations
This particular outbreak highlights the risk for severe illness associated with cow-share arrangements for the consumption of raw milk, especially among young children, who are among the higher risk population for STEC related HUS.
This outbreak also demonstrated that households who are not formally participating in cow-share arrangements may be affected by potential contamination.
According to the report, “increasing awareness of inherent health risks of raw milk products in Tennessee could prevent further morbidity.”
As the sharing of raw milk through cow-share arrangements is legally permitted in Tennessee, and the dairy farm intends to continue raw milk distribution through the cow-share program, TDH requested that the nearby University of Tennessee Extension’s Agriculture and Natural Resources Team visit the dairy to educate the farm concerning best practices to reduce the risk of milk contamination.
Households who participate in the cow-share were also included in this educational campaign. They were mailed an educational letter about the risk of foodborne illness associated with raw milk.
Potential Risk of Raw Milk
Many Americans are taking a look at the foods they consume and opting for foods that are less processed. As a result, many are choosing to drink raw milk, which comes with certain risks.
Raw milk consumption is associated with many outbreaks and cases of foodborne illnesses across the country. Certain populations, such as the very young (children under 5 years of age), older adults (over 65 years of age), and those with a weakened immune system from medication, underlying condition, or other factors are at greatest risk for severe illness following exposure to contaminated raw milk.
Pasteurization reduces the risk of illness associated with consuming dairy products. According to the CDC, “when milk pasteurization began in the early 1900’s, deaths and diarrheal illnesses in young children declined dramatically.” Despite this, raw milk regulation still varies from state to state and by point of sale.
Make smart choices when it comes to your dairy consumption. Always choose sources that are regulated by a safety organization or choose something pasteurized.
By: Heather Van Tassell