The Tennessee Department of Health recently released a report from last Summer’s tragic E. coli O157:H7 Outbreak linked to goat contact. I sadly need to update www.fair-safety.com. Full disclosure, we are representing two families.
On Wednesday, June 22, the Tennessee Department of Health (TDH) was notified of an ill child hospitalized in Florida with Shiga Toxin-Producing E. coli (STEC) O157:H7 after attending a goat husbandry summer camp at a local farm in Rutherford County, Tennessee. The TDH received a second call on Saturday, June 25 from the same mother stating she knew of a 2-year-old patient hospitalized at Vanderbilt in Nashville, TN with hemolytic uremic syndrome (HUS) and reported that this child’s older brother had attended the same camp. The Foodborne and Enteric Diseases (FED) Program staff searched Vanderbilt Medical Center’s electronic medical records confirming the child had STEC and was admitted for HUS. On the morning of Monday June 27, the FED team initiated an outbreak investigation.
The farm hosting the summer camp, “Farm X,” included many attractions for families such as a petting zoo, pony rides, splash pad, walking trails, various fields and three food service establishments. During the summer months, Farm X held multiple five-day summer camps teaching animal husbandry for children ages 6-10. Among other activities, children pick out a baby goat and care for it the remainder of the camp. Children attended camp during the day and return home each afternoon. Three of these camps took place in 2022 prior to the TDH investigation: June 6-10 (Week 1), June 13-17 (Week 2), and June 20-24 (Week 3). Farm X typically hosts three weeks of camp followed by two weeks of no camp.
A list of 82 Summer Camp participants from weeks 1, 2 and 3 and their parent/guardians’ contact information was obtained from Farm X for case finding and exposure assessment. TDH staff sent an online survey to all parents/guardians on Friday, July 1 to provide information about the outbreak and conduct interviews. Questions included symptom profile and duration, illness outcomes, days/weeks of camp attendance, food history specific to lunches and other foods served at the camp, and camp activities. Cases were classified using the following case definitions:
o Primary Confirmed Case: A person who attended any of the three Farm X Summer Camps from 6/6/22 – 6/24/22 and tested positive for STEC with a specimen collection date after 6/6/22.
o Secondary Case: A household member or close contact of a Farm X Summer Camp attendee who tested positive for STEC with a specimen collection date after 6/6/22.
o Primary Probable Case: A person who attended Farm X Summer Camp and became ill with diarrhea* within 10 days of attending the Farm X Summer Camp without laboratory confirmation.
o Secondary Probable Case: A household member or close contact of a Farm X Summer Camp attendee that became ill with diarrhea* within 10 days after encountering a primary probable case.
*Diarrhea: Defined as at least 3 or more loose stools within a 24-hour period
Data were collected and stored in RED Cap. The survey was open from Friday, July 1 at 5PM to the afternoon of Friday, July 8. A reminder was sent to camp contacts on Tuesday, July 5 at noon. Odds ratios and Fisher’s exact p-values were calculated to help narrow down different possible exposures of interest on the farm and at the summer camp. If a person did not complete the survey, they were excluded from the analysis.
On June 28th and 29th, FED and Mid-Cumberland Region Environmental Health staff conducted an environmental assessment (EA) at Farm X. Property owners, management and several staff members were in attendance. The aims of EA activities included an onsite interview and observation, collection of camp attendee registration, goat assignment records, and environmental sampling.
A total of 28 environmental and water samples were collected by the TDH during the site visits (See Appendix II). All samples were delivered to the Tennessee State Public Health Laboratory (SPHL) on the same day of collection. Farm X also collected thirteen goat stool samples, independent of TDH sampling, for testing at Tennessee Department of Agriculture’s C.E. Kord Animal Health Diagnostic Lab (Kord Lab) and water samples for testing at a private laboratory in Nashville named Micobac.
Samples received at the SPHL were tested by polymerase chain reaction (PCR) and if PCR results were positive, isolation of the bacteria was attempted. If isolation was successful, the isolates were sent to the sequencing department for whole genome sequencing (WGS). After initial analysis by the Kord Lab, any specimens where STEC was isolated were sent to the SPHL for WGS. Samples initially tested by the SPHL that were unable to grow STEC were sent to the United States Department of Agriculture (USDA) Agroecosystem Management Research Unit for repeat testing, as this USDA laboratory specializes in animal and environmental STEC testing.
Eighty-two summer camp attendees were present at Farm X from 6/6/22 – 6/24/22. Fifty-three (65%) surveys were completed using an outbreak-specific questionnaire with twelve cases and fifty-eight controls included in the final analysis.
Twelve primary cases (2 confirmed, 10 probable) and two secondary cases (1 confirmed, 1 probable) were identified. Onset dates ranged from June 10 to June 21, 2022. The epidemiologic curve supports the likelihood most ill primary cases were exposed sometime during the week they attended camp; ten of twelve primary cases attended between June 6 and June 10. The median duration of illness was 4.5 days (Range: 2-20 days). Five cases (36%) were female. The median age among cases was 6 years. Two cases (one primary and one secondary case) went to the ER and were hospitalized. The secondary hospitalized case developed HUS and passed away. Fourteen (100%) cases reported diarrhea, seven (50%) reported stomach cramps, six reported fever (43%), and 5 (36%) reported nausea. The number of new cases peaked on June 13 with three cases stating they began feeling ill on this day.
Campers were served six food options and engaged in seventeen activities (see Appendix I for the full food and activity analysis). When comparing cases with controls (non-ill persons) who attended the camp, none of the food items or activities were statistically significantly associated with illness. Given the camp food and activity schedules were consistent between weeks and most campers ate every food and participated in almost every activity, it is difficult to make meaningful comparisons along these lines. The only statistically significant difference between cases and controls was that cases were more likely to attend camp during week one (OR: 13.1, 95% CI 2.59, 66.57) which is reflected in the epi curve (Figure 2).
On 6/25/22 Farm X voluntarily closed the facility. During the EA on 6/28/22 the food service aspect of the farm was not operating and general inquiries about food service and preparation were made. No ill food handlers, ill farm staff, or camper illnesses were reported to the farm owners during the three weeks of camp. There were no reports of foodservice system changes during this time and no disruptions in water, sewage, or power were reported. There were no maintenance activities reported for kitchen equipment and the kitchen was in good repair. Farm X owners reported that only pre-cooked food was served to campers and fresh watermelon was offered as an optional selection. Fresh raw, preformed beef burgers were prepared on Thursdays and Fridays and cooked to order but were not offered to campers. FED staff recommended cleaning and sanitizing all food contact surfaces in the kitchen and separating staff duties between farm/animal handlers from food handlers.
There were several handwashing and hand sanitizing stations throughout the facility. The outdoor handwashing stations observed were manually activated by depressing a foot bulb on ground and supplied with cold water (both municipal and chlorinated spring-sourced), soap, and towels. Farm X’s policy requires handwashing immediately following goat handling and prior to food service for campers. For smaller children, Farm X reported that step stools are provided, and staff assists them with pumping the water. Several porta-potty restrooms were provided throughout the facility and are maintained by the staff. Waste contents are removed by third-party, porta-potty vendor. No fecal incidents reported amongst campers during any week of camp.
On 6/28/22 investigators collected twenty environmental samples (See Appendix II Samples # 1-20) and on6/29/22 collected eight water samples (See Appendix II Samples 1.W–8.W). Farm X was able to provide investigators with the camp registration contact list, goat assignment records, lists of daily camp activities, and food service menu calendar. During the onsite visits the farm appeared to be in good repair and the animals seemed well cared for and healthy.
In response to the outbreak, Farm X expedited the already scheduled demolition of the barn housing the baby goats, euthanized two baby goats who had tested positive for STEC, moved the rest of the herd off the property, and indefinitely ceased the animal husbandry aspect of the summer camp. During the closure of the farm, Farm X reportedly consulted with veterinarians from the United States Department of Agriculture (USDA) and the Tennessee Department of Agriculture (TDA). Lastly, to better understand how similar operations address pathogen transmission risk reduction, Farm X reported consulting with other farming operations including visiting three petting zoos.
On 7/18/22 Farm X reopened for summer camp, without the goat husbandry component, and to the public on 7/21/22.
The SPHL received a total 33 environmental samples, eight water samples, and three clinical samples. One clinical specimen was collected in Florida and analyzed for whole genome sequencing by the Florida Department of Health State Laboratory. Of the 33 environmental samples one was a goat feed sample, seventeen were goat stool specimens, and fifteen were environmental swabs. Thirteen of the goat stool specimens were collected independently by the owner of Farm X and were initially analyzed at the Kord Lab. Fifteen of the environmental samples (one goat rectal swab and fourteen goat fecal samples) that initially were unable to grow STEC were sent to the USDA Agro ecosystem Management Research Unit for repeat testing. In total, 45 specimens were collected in response to this outbreak (see Appendix II: Table 2).
Of the 45 samples collected for this outbreak nine were positive for STEC representing three different serotypes: H14 (2 environmental), O157:H7 (3 clinical, 2 environmental), O26 (2 environmental) (See Appendix II: Table 2). One of the H14 specimens was collected by Farm X and initially tested at the KORD laboratory; neither of the H14 or O26 serotypes were associated with clinical illnesses in this outbreak. All five O157:H7 specimens were closely related by WGS. The two environmental samples were from a wooden post inside the barn where the baby goats resided (See Appendix II Sample #12) and from a runny stool (animal origin not confirmed) collected outside on the side of the barn where the baby goats would congregate (See Appendix II: Table 2, Sample #6). Sample 12 was isolated and sequenced by the SPHL and sample 6 was isolated by the USDA’s Agroecosystem Management Research Unit followed by sequencing at the SPHL. All five samples were closely related with a maximum of nine SNPs and average off our SNPs distance between isolates (Figure3). Innermost alleles, which more closely reflect the core genome, four of the five specimens were zero alleles apart (Figure 4). Allele information for the missing specimen is unavailable since it was collected in Florida and the two fecal samples (N22165515-01V and N22165515-01W) were isolates generated from the same specimen (See Appendix II: Table 2, Sample #6).
Discussion & Conclusion
It is well documented that Shiga Toxin-producing E.coli (STEC) resides in the gastrointestinal tract of ruminant animals such as cattle, goats, sheep, deer, and elk without causing illness (Source CDC1). STEC outbreaks have also been well documented specifically in the petting zoo environment both in the United States and globally (Austria 20152, Florida 20073, Virginia 20224, Connecticut 20165, Florida, and Arizona 2004 and 20056).
In June and July of 2022, the TDH investigated an outbreak of STEC E. coli O157:H7 associated with Farm X in Tennessee. Survey responses did not show any statistically significant results in terms of food or camp activity exposures, however attending during the first week of camp (June 6, 2022 – June 10, 2022) was significantly associated with illness. One explanation for this could be that this first week coincided with a period of increased STEC shedding in baby goats, which can happen due to increased stress or environmental changes (Factors Associated with STEC Shedding in Cattle7). Based on the laboratory and epidemiologic findings, this outbreak likely occurred due to close contact with baby goats during their time at the camp. Illness of others who did not attend camp were attributed to secondary exposure to their infected household member. This hypothesis is further strengthened by there being no reports of illness from general admission customers before, during, or after the three weeks of summer camps in question.
During the site visits at Farm X, we reviewed the National Association of State Public Health Veterinarians (NASPHV) Animal Contact Compendium and Resources (NASPHV Animal Contact Compendium8) document. Farm X had awareness of the Compendium and complied with the majority of recommendations potentially limiting additional transmission. Farm X voluntarily closed the farm for three weeks. Upon reopening they removed the baby goat care aspect from camp activities and increased risk communication language on their website and on signage throughout the farm.
STEC is naturally found in the intestinal tracts of healthy ruminant animals like cattle, sheep, and goats (Source CDC1). Proper hand washing is a key control measure to prevent infection with STEC and other harmful germs. The process of vigorously scrubbing the hands with running water and soap helps to remove germs. Use of alcohol-based hand sanitizer can reduce the number of germs on hands but does not replace washing with soap and water (Source CDC9).
TDH recommended they continue to provide an adequate number of accessible hand washing stations (supplied with soap, water, and paper towels), maintain appropriate educational signage throughout the facility, enhance educational messaging on their website, continue to explain this risk on their camp registration forms, and to complete a facility consultation with the University of Tennessee Extension agricultural professionals.
The TDH FED concluded that this outbreak was associated with direct contact with goats infected with STEC O157:H7 with secondary transmission from cases. Control measures in place at the farm to minimize transmission may have reduced additional illnesses and enhanced control measures to reduce risk were recommended.
Here is full Report: https://www.marlerblog.com/files/2022/10/TN22-023-Final-Outbreak-Report_9.29.22.pdf