Campylobacter infects more than 1.3 million Americans each year. Campylobacter is among the most common forms of foodborne illness in the United States. The Centers for Disease Control and Prevention note that Campylobacter is the third most common foodborne infectious pathogen in the U.S.
Why are Campylobacter infections so common? Campylobacter food poisoning is so common because it takes so few Campylobacter bacteria to infect someone. In fact, it can take as little as a single drop of juice from a raw chicken contaminated with Campylobacter in it for a person to contract severe food poisoning.
What is Campylobacter?
Campylobacter is a type of bacteria. Scientists have discovered 17 different species of Campylobacter. According to the World Health Organization, one particular strain of Campylobacter, Campylobacter Jejuni, most frequently causes human illness. In the United States, Campylobacter infections cause an estimated 8,463 hospitalizations each year. And each year, 76 Americans die from Campylobacter infections. In terms of loss of life, Campylobacter is the fifth most deadly form of severe food poisoning in the United States.
The Foodborne Diseases Active Surveillance Network (FoodNet) estimates that 14 Campylobacter cases are diagnosed for every 100,000 people each year. But many more cases go undiagnosed or unreported. Of the Campylobacter infections that are reported, most are reported as isolated cases and are not known to be connected to widespread outbreaks. This is partly due to the fact that, currently, most bacteria are detected though live culture testing, and Campylobacter bacteria are particularly difficult to culture. But as disease investigators shift from live culture testing towards Whole Genome Sequencing testing (WGS), it is becoming easier for scientists to see the connections between Campylobacter cases. What once looked like unconnected individual cases may actually have been part of a larger outbreak. Importantly for consumers, better detection methods will enable scientists to identify outbreaks sooner, companies to recall contaminated products sooner, and stores to remove contaminated food from their shelves. Faster recalls will prevent outbreaks from spreading further.
Where is Campylobacter found?
Campylobacter is found in the intestinal tracts of cats, dogs, poultry, cattle, rodents, monkeys, wild birds, and even some humans. In some rare cases, the bacteria have also been found in shellfish. Most recently, there was a major national outbreak linked to puppies purchased from a chain-pet store. Most of the time, an infected animal will not show any signs of illness. Animals rarely show symptoms when infected with Campylobacter.
Most often, Campylobacter can be carried in the intestines, liver, and giblets of animals. It can cross-contaminate other edible parts of an animal during the slaughter process. Oftentimes, the bacteria are introduced to the environment through fecal matter and can also be found in untreated water. According to PetMD, up to 45% of stray cats carry Campylobacter. Though the bacteria are uncommon is adult house cats, kittens under six months old are susceptible to the pathogen – as are animals kept in kennels, where they may become exposed to infected pets. According to the same site, “up to 49 percent of dogs carry Campylobacteriosis, shedding it into their feces for other animals to contract.”
How does Campylobacter cause infection?
Humans typically become infected with Campylobacter through eating or drinking a contaminated product, such as undercooked meat or raw milk. The National Antimicrobial Resistance Monitoring System (NARMS) published their findings in 2014 that Campylobacter was found on 33% of raw chicken purchased from retailers. Milk or produce can also become contaminated through the transmission of the bacteria from manure exposure to the product.
But eating undercooked meats or raw milk are not the only ways someone can become sick. Some other sources of Campylobacter infections include:
- Contaminated water, either consumed or contacted via recreational activities, can also cause Campylobacter
- Improperly cleaned cutting boards may contain Campylobacter bacteria which could then be transferred to other foods prepared on that same surface, such as fruits or salad.
- Improper slaughtering methods increase the risk of Campylobacter bacteria in retail meat sales.
- In rare cases, a person can become infected through a blood transfusion.
- As the CDC confirms, humans can also contract Campylobacter from the feces of pets, such as a cat or dog.
The infection is also concerning for those who travel abroad. The CDC notes that 1 in 5 Campylobacter infections reported to the Foodborne Diseases Active Surveillance Network (FoodNet) are associated with international travel. This is likely due to the fact that Campylobacter is even more common in the developing world than in the United States.
In the past, outbreaks of Campylobacter infections have most often been linked poultry, raw (unpasteurized) dairy products, untreated water, and produce.
What are the symptoms of Campylobacter infection?
An infected person will typically show signs and symptoms of a Campylobacter infection within 2-5 days after eating or drinking a contaminated product or other exposure. But in some infections, it can take up to 10 days for symptoms to show. The most common symptoms include:
- diarrhea (often with blood in the stool)
- abdominal pain
These symptoms typically subside anywhere from 3 to 6 days. It is important to note that some infected people may not show any symptoms at all.
Those most susceptible to infection include the elderly, very young children, and those with immunosuppression or suffering from another serious disease. Although death is rare, Campylobacter could spread to the bloodstream and cause a life-threatening infection.
What are the possible long-term effects of Campylobacter infection?
Campylobacter infections can cause serious complications, especially those who are in the high-risk group. These complications may include:
- Reactive arthritis (temporary, painful inflammation of the joints)
- Irritable bowel syndrome
- Guillain-Barre syndrome (As many as 40% of cases in the United States may be triggered by Campylobacter infection)
- Some incidents of miscarriage have also been reported
How is Campylobacter infection treated?
Many people can recover from this type of infection without antibiotics and just through supportive care (i.e. plenty of fluids, rest, etc.) However, people with weakened immune systems may be given a course of antibiotic during their recovery to help avoid long-term complications.
Campylobacter infection is diagnosed when a laboratory test detects Campylobacter bacteria in stool, body tissue, or fluids. The test could be a culture that isolates the bacteria or a rapid diagnostic test that detects genetic material of the bacteria.
Is Campylobacter Antibiotic-Resistant?
It can be. In some cases, doctors prescribe antibiotics, such as azithromycin and ciprofloxacin, to treat patients with severe Campylobacter infections. But some infections are resistant to antibiotics. In fact, high rates of resistance to fluoroquinolones have limited their usefulness in treating Campylobacter infections. According to the CDC, Campylobacter infections with antibiotic-resistant bacteria are often harder to treat, can last longer, and may result in more severe illness.
What can restaurants and home cooks do to prevent Campylobacter infection?
According to the USDA Food Safety and Inspection Services (FSIS), “Meat and poultry can contain Campylobacter. However, the bacteria can be found in almost all raw poultry because it lives in the intestinal tract of healthy birds.” For this reason, proper kitchen safety and cleanliness is a must-have to prevent infection. As the FSIS notes, “Campylobacter bacteria are extremely fragile and are easily destroyed by cooking to a safe minimum internal temperature.” In addition to cooking meat thoroughly, it is vital that meat be refrigerated properly. Food should be thawed in cold water on in the microwave, not at room temperature. Frequent hand-washing reduces contamination risk as does the proper washing of dishes and utensils. All cooking surfaces and cutting boards should be cleaned in hot, soapy water to reduce the risk of cross contamination.
What can food processing plants and retails store do to prevent Campylobacter infection?
Food processing plants need to follow up-to-date manufacturing practices that minimize the likely of Campylobacter infection. Hygienic, regulated slaughtering practices reduce the contamination of carcasses. Retail establishments should report any health concerns present in their products.