Outbreak Investigation Updates by Date
Published on July 5, 2019 at 4:30 PM ET
CDC, public health and regulatory officials in several states, and the U.S. Food and Drug Administration are investigating a multistate outbreak of Salmonella Uganda infections.
Public health investigators are using the PulseNet system to identify illnesses that may be part of this outbreak. PulseNet is the national subtyping network of public health and food regulatory agency laboratories coordinated by CDC. DNA fingerprinting is performed on Salmonella bacteria isolated from ill people by using techniques called pulsed-field gel electrophoresis (PFGE) and whole genome sequencing (WGS). CDC PulseNet manages a national database of these DNA fingerprints to identify possible outbreaks. WGS gives a more detailed DNA fingerprint than PFGE. WGS performed on bacteria isolated from ill people showed that they were closely related genetically. This means that ill people in this outbreak are more likely to share a common source of infection.
As of June 26, 2019, a total of 62 people infected with the outbreak strain of Salmonella Uganda have been reported from 8 states. A list of the states and the number of cases in each is on the Map of Reported Cases page.
Illnesses started on dates ranging from January 14, 2019, to June 8, 2019. Most illnesses have occurred since April 2019. Ill people range in age from 1 to 86 years, with a median age of 60. Fifty-three percent of ill people are female. Of 35 people with available information, 23 (66%) have been hospitalized. No deaths attributed to Salmonella have been reported. Of 33 ill people with available information, 22 (67%) reported being of Hispanic ethnicity.
Illnesses might not yet be reported due to the time it takes between when a person becomes ill and when the illness is reported. This takes an average of 2 to 4 weeks. Please see the Timeline for Reporting Cases of Salmonella Infection for more details.
Whole genome sequencing analysis of 40 isolates from ill people predicted antibiotic resistance to streptomycin and sulfisoxazole. Testing of three clinical isolates using standard antibiotic susceptibility testing methods by CDC’s National Antimicrobial Resistance Monitoring System (NARMS) is currently underway. This resistance will not affect the choice of antibiotic used to treat most people.
Investigation of the Outbreak
Epidemiologic evidence and early product distribution information indicate that whole, fresh papayas imported from Mexico and sold in Connecticut, Massachusetts, New Jersey, New York, Pennsylvania, and Rhode Island, are a likely source of this outbreak.
In interviews, ill people answered questions about the foods they ate and other exposures in the week before they became ill. Of 21 people who were interviewed, 16 (76%) reported eating papayas. This proportion was significantly higher than results from a survey pdf icon[PDF – 787 KB] of healthy Hispanic people in the months of January through June in which 13% reported eating papayas in the week before they were interviewed.
Two people who lived in different households got sick in Connecticut after eating papayas purchased from the same grocery store location in the week before becoming ill. This provides additional evidence that papayas are a likely source of this outbreak. One ill person in Florida had traveled to Connecticut in the week before they got sick. Officials are working to gather more information about an ill person in Texas.
The FDA and regulatory officials in several states are collecting records to determine the source of the papayas that ill people ate. Early product distribution information available at this time indicates that papayas that made people sick were imported from Mexico. This traceback investigation is ongoing.
Consumers in Connecticut, Massachusetts, New Jersey, New York, Pennsylvania, and Rhode Island should not eat whole, fresh papayas imported from Mexico until we learn more about this outbreak. This investigation is ongoing, and CDC will provide updates when more information is available.