Sick Kids, Dairy Calves, and Antibiotics That Don't Work: Dr. Megin Nichols's Story

At a glance

After having contact with dairy calves, many adults and young children became sick with multidrug-resistant Salmonella. Learn how to prevent getting sick from contact with animals.

Dr. Megin Nichols who worked on multidrug-resistant Salmonella outbreak


You may know that the germ Salmonella lurks in some foods and can make you sick. But did you know that animals can also carry Salmonella even if they don't look sick?

People can get sick from touching animals such as cows and chickens that carry Salmonella germs. For example, contact with dairy calves and other cattle likely sparked a 2017 outbreak of multidrug-resistant Salmonella Heidelberg that sickened 56 people in 15 states. More than one-third of those who got sick were children younger than age 5, and more than one-third were hospitalized. Young children are more likely to get a Salmonella infection because their immune systems are still developing.


"What we started to see is that children who worked with cattle—and these were kids who participated in 4-H events or other types of agricultural activities—were getting sick with this really severe strain of Salmonella," said Megin Nichols, a CDC veterinarian who investigates outbreaks of human illness linked to petting zoos, small turtles, and livestock with strains of multidrug-resistant Salmonella. "A lot of these kids were hospitalized."

Nichols said they discovered that all the children had been exposed to young dairy calves.

"So we looked into this a little bit more and found out that the dairy calves were also sick with the exact same strain of Salmonella," she said. "One of the things that this outbreak really showed us is that the health of animals and the health of people are very closely related."

More than half of the sick people who were interviewed reported contact with dairy calves or other cattle. Some of those interviewed said that they got sick after their calves became sick or died. Investigators learned that calves in several states were infected with the outbreak strains of multidrug-resistant Salmonella Heidelberg.

Antimicrobial-resistant infections can be more severe, and antibiotics normally used to treat infections may not work. Sick people may need to go to the hospital or to spend more time there.

"As a veterinarian, one of the things I learned from this outbreak is how important it is for veterinarians and human doctors to use antimicrobials responsibly," Nichols said. "We must make sure that we preserve the power of the antibiotics to treat infections in both people and animals."

Antimicrobial resistance affects the health of humans, animals, and the environment, which makes it a One Health issue.


Nichols recommended ways to protect against getting an infection from animals:

  • Wash your hands with soap and water after any contact with animals or their environment.
  • Use dedicated clothes, shoes, and work gloves when working with livestock. Store these items outside your home.
  • Work with your veterinarian to keep animals healthy and prevent disease.

"Those in the agriculture community should get to know their state public health veterinarian because they have resources that can help keep people and animals safe and healthy," she said.

Even if you are just visiting a farm, wash your hands after being around animals and help young children wash their hands. Everyone has a role to play in preventing disease and preserving the power of antimicrobials to treat infections in people and animals.