By: James Peacock

Health investigators are still investigating an outbreak of gastrointestinal illness connected to the Rifle Rodeo held on June 5. The Rifle Rodeo, held at the Garfield County Fairgrounds, was attended by about 200 people. About 6 hours after the event ended, people began to report symptoms of gastrointestinal illness, including nausea, cramping, and diarrhea. Since the Rodeo, dozens of people have reported being ill, and the Garfield County Public Health Department has launched an investigation. They have even reached out to the public through social media to ask victims to report their illnesses. Through interviews and sampling, the Garfield County Public Health Department has begun to narrow down the causes of the outbreak. Since the investigation began, investigators have been able to rule out airborne causes, waterborne causes, person-to-person transmission, E. coli, Salmonella, and Hepatitis A.

Also, coming with the investigation update was the news that the Consumer Protection Division of the Garfield County Public Health Department did not inspect the vendors prior to the start of the event, because they were not alerted about the event. Prior to 2008 temporary events were regulated by state officials, but after the Public Health Act of 2008 shifted that responsibility to local health officials. Local health officials are not necessarily notified of every event, though. Restaurants that wish to set up a booth at an event have to apply for a temporary event licensed prior to the event. The application for this license requires s depiction of the booth’s setup, and enumerates the requirements for proper food safety. Another event, Strawberry Days, is being held beginning on June 16 in Glenwood Springs. Garfield County Public Health is making sure that all proper procedures for inspection are being followed in the days leading up to this event.

With airborne, waterborne, and person-to-person transmission ruled out because of the investigation, there are only a few other options for the cause of the outbreak. The most likely of these are animal contact or contaminated food. Contact with cattle, sheep, goats, poultry, reptiles, amphibians, and rodents can all cause illness. Typically, outbreaks caused by animal contact involve the pathogens E. coli, Salmonella, Campylobacter, or Cryptosporidium. All of these pathogens are also common causes of foodborne illness. Because the investigation has also ruled out Salmonella, E. coli and Hepatitis A, the list of possible pathogens is much shorter.

Staphylococcus aureus is known to cause illness within the 6-hour window that this outbreak has. With an incubation period of only 1 hour in some cases, the 6-hour mark is actually on the tail end of when an aureus infection would begin to show symptoms. Staphylococcal food poisoning causes symptoms including sudden, severe nausea, vomiting, cramps, diarrhea, and potentially a fever. These infections will tend to end after a couple of days. This pathogen also appears to be transmitted via improperly refrigerated meats, potato and egg salads, and cream pastries. At least one attendee of the Rifle Rodeo has reported eating potato salad and a pork sandwich prior to being ill, which makes this pathogen a potential cause. However, nothing is confirmed until health officials do more testing.

The only other major foodborne illness causing pathogen that generally causes illness within a 6-hour window is Vibrio parahaemolyticus. These bacteria can cause illness anywhere between 4 and 96 hours after exposure. Symptoms of a Vibrio infection include diarrhea, vomiting, abdominal cramps, nausea, vomiting, and fever. These illnesses will usually stop between 2 to 5 days after symptoms appear, and will rarely cause hospitalization or a need for antibiotics. However, Vibrio poisoning is only connected to raw shellfish and other raw fish products and is typically only seen in coastal or tropical areas, making it less likely to appear in Colorado.

There are also a couple of pathogens that can cause illness just outside the 6-hour window present in this outbreak. However, the window for symptoms to appear provided by health officials is an estimate based on large amounts of data. Though unusual, it may be possible for an illness to begin producing symptoms outside of this window, either in less or in more time after exposure. One of these pathogens is Clostridium perfringens. C. perfringens is one of the most common causes of foodborne illness outbreaks in the United States, causing almost a million cases of illness per year in the United States. The illness can set in between 8 and 16 hours after exposure, and will usually come with symptoms including abdominal cramps and watery diarrhea. The illness will usually last for about 24 hours. What might make C. perfringens the cause of the outbreak is the way it usually causes illness. Perfringens outbreaks are usually caused by meats and poultry that have not been cooked at a proper temperature or were not properly maintained at the set holding temperatures that prevent contamination. C. perfringens infections are common in cafeterias, catered events, and other places where a large amount of food is prepared several hours prior to being served. A rodeo would likely fit this description.

Listeria is one of the less common forms of food poisoning, but it is still a very dangerous pathogen. In cases of gastrointestinal Listeria, symptoms can appear in as few as 9 hours. Causing about 1600 illnesses a year, as estimated by the CDC, Listeria poisoning can manifest itself in one of two forms. In those with relatively healthy immune systems, Listeria presents itself as a gastrointestinal illness, causing symptoms such as fever, muscle aches, nausea, vomiting, and diarrhea. In some cases of Listeria poisoning, and especially in the elderly and immunocompromised, Listeria can turn invasive, causing headache, stiff neck, confusion, loss of balance, and convulsions. Invasive Listeria is potentially fatal, as it can enter the nervous system and cause meningitis. Pregnant women are also at an increased risk of developing a serious case of Listeria poisoning. Listeria may cause a flu-like infection in pregnant women but can cause miscarriages and stillbirths. Symptoms of invasive Listeria usually take between 3 and 70 days to appear.  If you or a loved one begins to show the symptoms of Listeria poisoning, contact a medical professional.

Sources:

https://academic.oup.com/cid/article/43/12/1596/278637/Outbreaks-of-Enteric-Disease-Associated-with

http://www.postindependent.com/news/no-county-food-inspections-made-at-rifle-rodeo-last-week/

https://garfield-county.com/environmental-health/documents/Vendor-Flow-Chart.pdf

https://www.garfield-county.com/environmental-health/documents/2017-temporary-vendor-application.pdf