According to a new study conducted by an OU Hudson College of Public Health faculty member in collaboration with colleagues in Denmark, Campylobacter infection, one of the most common foodborne illnesses in the Western world, can also be spread through sexual contact.
The study was published in Emerging Infectious Diseases, a journal published by the Centers for Disease Control and Prevention (CDC), and is the first known study to demonstrate this mode of transmission for Campylobacter. During a time when COVID-19 has dominated the news about infectious diseases, the study serves as a reminder that many other pathogens affect people all over the world on a daily basis. Katrin Kuhn, Ph.D., an assistant professor in the Department of Biostatistics and Epidemiology at the OU Hudson College of Public Health, led the research.
“This research is important for public health messaging and for physicians as they discuss the risks associated with sexual contact with their patients,” Kuhn said. “Although Campylobacter infection is usually not serious, it causes diarrhea, which can cause people to miss work, lose productivity, or even lose their job. It increases the risk for people who have pre-existing medical conditions.”
This is an interesting time because COVID-19 has raised awareness about the importance of monitoring infectious diseases in general, not just during a pandemic. Many infections, such as the one caused by Campylobacter, make people sick. It is critical that we raise awareness of the existence of these diseases and continue to conduct research on their effects and modes of transmission.
Katrin Kuhn
Campylobacter infections are most common when people consume undercooked chicken or when uncooked poultry juices contaminate other foods. Infections can also be contracted by consuming unpasteurized milk or water contaminated with the feces of infected animals. However, those didn’t account for all cases of infection, according to Kuhn, who wondered if there was another unproven route of transmission. An outbreak of Campylobacter infections in northern Europe among men who have sex with men prompted her to study that population of people in Denmark, where she was working at the time the research began.
According to the findings of the study, the rate of Campylobacter infection in men who have sex with men is 14 times higher than in control subjects. Although the study focused on men who have sex with men, the findings are applicable to people of any sexual orientation who engage in sexual behavior that may include fecal-oral contact, according to Kuhn.
In the study, two other bacteria, Salmonella and Shigella, were used as controls. Salmonella is primarily transmitted through contaminated foods, whereas Shigella can be transmitted through food or sexual contact. Salmonella has a high infectious dose, which means that people must consume a large amount of the bacteria before becoming ill. Shigella and Campylobacter, on the other hand, have low infectious doses, making transmission easier.
“That’s another reason we believe Campylobacter, like Shigella, can be transmitted through sexual contact,” Kuhn said, “because people can become infected even when only small amounts of the bacteria are present.”
Campylobacter infections are most likely more common than the figures indicate. Epidemiologists estimate that 20 more people are infected for every person who visits a doctor and is diagnosed, according to Kuhn. Although treatment is usually only required in severe cases, complications can occur, particularly in people with weakened immune systems. In some cases, infection can cause reactive arthritis, a condition in which the body’s immune system attacks itself, causing joint pain. Guillain-Barré Syndrome, a serious nerve disorder that can cause paralysis, can also be caused by infection.
“This is an interesting time because COVID-19 has raised awareness about the importance of monitoring infectious diseases in general, not just during a pandemic,” she said. “Many infections, such as the one caused by Campylobacter, make people sick. It is critical that we raise awareness of the existence of these diseases and continue to conduct research on their effects and modes of transmission.”
Kuhn worked as a senior infectious disease epidemiologist at Denmark’s Statens Serum Institut before joining the OU Hudson College of Public Health. Her work focused on food- and water-borne infections, and she was in charge of national Campylobacter and Shigella surveillance. She started this study in Denmark and finished it after moving to Oklahoma. Statens Serum Institut is the Danish national institute for infectious diseases and the primary institute for infectious disease surveillance and research in Denmark.
“A formal collaboration between the OU Hudson College of Public Health and the Statens Serum Institut will lay the groundwork for strengthening transatlantic research and, most importantly, improving the way we monitor, understand, and prevent infectious diseases in Oklahoma,” Kuhn said.
