Investigation Update: Salmonella Outbreak, Pet Bearded Dragons - June 2024

June 14, 2024

CDC and public health officials in several states are collecting different types of data to investigate a multistate outbreak of Salmonella Cotham infections.

Epidemiologic and laboratory data showed that contact with pet bearded dragons made people sick in this outbreak.

Epidemiologic Data

As of June 14, a total of 15 people infected with the outbreak strain of Salmonella Cotham were reported from 9 states (see map). Illnesses started on dates ranging from January 8, 2024, to May 16, 2024 (see timeline).

The true number of sick people in an outbreak is likely much higher than the number reported, and the outbreak may not be limited to the states with known illnesses. This is because many people recover without medical care and are not tested for Salmonella. In addition, recent illnesses may not yet be reported as it usually takes 3 to 4 weeks to determine if a sick person is part of an outbreak.

Public health officials collect many different types of information from sick people, including their age, race, ethnicity, other demographics, and the animals they came into contact within the week before they got sick. This information provides clues to help investigators identify the source of the outbreak.

The table below has information about sick people in this outbreak ("n" is the number of people with information available for each demographic).

State and local public health officials are interviewing people about the animals they came into contact with during the week before they got sick. Of the 12 people interviewed, 7 (58%) reported contact with a bearded dragon before getting sick. Most people had contact at home while caring for bearded dragons such as touching the animals or their enclosures, feeding them, and putting them on their laps, heads, or shoulders. At least one child did not touch the bearded dragons and might have been exposed through indirect contact from a reptile in the household. For example, after a reptile was allowed to roam freely in the home.

Laboratory and Traceback Data

Public health investigators used the PulseNet system to identify illnesses that may be part of this outbreak. CDC PulseNet manages a national database of DNA fingerprints of bacteria that cause gastrointestinal illnesses. DNA fingerprinting is performed on bacteria using a method called whole genome sequencing (WGS).

WGS showed that bacteria from sick people's samples are closely related genetically. This means that people in this outbreak likely got sick from the same type of animal. WGS also showed that this Salmonella Cotham strain is genetically closely related to a Salmonella Cotham strain which caused an outbreak from 2012–2014 and was linked to bearded dragon exposure. More information on this previous outbreak can be found here.

People in this outbreak reported purchasing bearded dragons at multiple retail locations.

WGS analysis of bacteria from 13 people's samples did not predict resistance to any antibiotics. Two people's samples predicted resistance to ciprofloxacin, gentamicin, and streptomycin. More information is available at the National Antimicrobial Resistance Monitoring System (NARMS) site. Most people with Salmonella illness recover without antibiotics. However, if antibiotics are needed, some illnesses in this outbreak may be difficult to treat with some commonly recommended antibiotics and may require a different antibiotic choice.

Public Health Actions

CDC advises that you always take steps to stay healthy around bearded dragons:

• Wash your hands after handling bearded dragons, their food, or items in their environment.
• Don't kiss or snuggle bearded dragons.
• Keep bearded dragons out of the kitchen or anywhere that food is prepared, stored, served, or eaten and away from areas where young children play.
• Keep its supplies and habitat clean.
• Limit young children's contact with bearded dragons.