Multistate Outbreak of Salmonella Newport and Salmonella Infantis Infections Linked to Imported Maradol Papayas (Final Update)

Posted November 3, 2017 3:00 PM ET

This outbreak appears to be over. This outbreak was one of four separate multistate outbreaks identified in 2017 linked to imported Maradol papayas from four different farms in Mexico. For information on the other outbreaks, please visit the Reports of Salmonella Outbreak Investigations from 2017 webpage.

Highlights
  • Read the Advice to Consumers, Restaurants, and Retailers>>
  • This outbreak appears to be over.
  • CDC, public health and regulatory officials in several states, and the U.S. Food and Drug AdministrationExternal investigated a multistate outbreak of Salmonella infections.
  • Epidemiologic and laboratory evidence indicated that the likely source of this outbreak was Maradol papayas from Rancho El Ganadero farm, distributed by Caraveo Produce in Colima, Mexico.
  • This outbreak included two types of Salmonella: Newport and Infantis. The same strains of these types of Salmonella were found in samples collected from papayas and from ill people.
  • Four people infected with the outbreak strains of Salmonella Newport (three) or Salmonella Infantis (one) were reported from four states.
    • Illnesses started on dates ranging from July 19, 2017 to August 7, 2017.
    • Two ill people were hospitalized. No deaths were reported.
Outbreak Summary

Introduction

CDC, public health and regulatory officials in several states, and the U.S. Food and Drug Administration (FDA)External investigated a multistate outbreak of Salmonella Newport and Salmonella Infantis infections linked to imported Maradol papayas from the Rancho El Ganadero farm in Colima, Mexico that were distributed by Caraveo Produce in Colima, Mexico.

Public health investigators used the PulseNet system to identify illnesses that may have been part of this outbreak. Four people infected with the outbreak strains of Salmonella Newport (three) and Salmonella Infantis (one) were reported from four states. A list of the states and the number of cases in each can be found on the Case Count Map page. Whole genome sequencing (WGS) showed that isolates from people infected with Salmonella were closely related genetically. This close genetic relationship means that people in this outbreak were more likely to share a common source of infection.

Illnesses started on dates ranging from July 19, 2017 to August 7, 2017. Ill people ranged in age from 40 to 82, with a median of 63. Two (50%) were female. Two (50%) of the four ill people were of Hispanic ethnicity. Two (50%) of the four ill people were hospitalized. No deaths were reported.

WGS did not identify antimicrobial resistance genes in isolates from four ill people and one papaya. Standard antibiotic susceptibility testing methods were used by CDC’s National Antimicrobial Resistance Monitoring System (NARMS) laboratory on a clinical isolate from one ill person in this outbreak. This isolate also was not resistant to any antibiotics tested.

Investigation of the Outbreak

Epidemiologic and laboratory evidence indicated that imported Maradol papayas from Mexico were the likely source of this multistate outbreak.

In interviews, ill people answered questions about the foods they ate and other exposures in the week before they became ill. All three (100%) people interviewed reported eating papayas. This proportion was significantly higher than results from a survey Cdc-pdf[PDF – 29 pages] of healthy Hispanic people in which 22% reported eating papayas in the week before they were interviewed during the summer months.

As a result of this summer’s outbreak investigation linked to papayas, FDA increased testing of papayas from Mexico to see if papayas from other farms were contaminated with Salmonella. Through this increased testing, FDA identified Salmonella Newport and Salmonella Infantis on papayas from Caraveo Produce in Tecomán, Colima, Mexico that were grown by Rancho El Ganadero. Investigators compared pulsed-field gel electrophoresis (PFGE) and WGS results of Salmonella isolates from the papayas to isolates from ill people in the CDC PulseNet database. These results showed the Salmonella Newport and Salmonella Infantis isolates from papayas shared the same DNA fingerprint as the Salmonella isolates from ill people. This result provided more evidence that people in this outbreak got sick from eating contaminated Maradol papayas.

FDA reportedExternal that the shipment of contaminated papayas was destroyed and was not distributed for sale in the United States. Papayas from this farm were distributed in the United States earlier in the summer, but FDA reported that no shipments of papayas from this farm were on the market in the United States when the outbreak was identified because the papayas were past their shelf life.

This outbreak appears to be over. This outbreak was one of four separate multistate outbreaks identified in 2017 linked to imported Maradol papayas from Mexico. For information on the other outbreaks, please visit the Reports of Salmonella Outbreak Investigations from 2017 webpage.

Previous Outbreak Announcements

Introduction

This outbreak is one of four separate outbreaks currently under investigation that are linked to imported Maradol papayas from Mexico.

CDC, public health and regulatory officials in several states, and the U.S. Food and Drug Administration (FDA)External are investigating a multistate outbreak of Salmonella Newport and Salmonella Infantis 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.

Investigation of the Outbreak

Since the last update on September 1 2017, one more ill person from one state was added to this investigation.

As of September 11, 2017, a total of 4 people infected with the outbreak strains of Salmonella Newport (3) and Infantis (1) have been reported from 4 states. A list of the states and the number of cases in each can be found on the Case Count Map page.

Illnesses started on dates ranging from July 19, 2017 to August 7, 2017. Ill people range in age from 40 to 82 years, with a median age of 63. Two (50%) are female. Two (50%) of the four ill people are of Hispanic ethnicity. Two (50%) of the four ill people have been hospitalized. No deaths have been reported.

In interviews, ill people answered questions about the foods they ate and other exposures in the week before they became ill. All three (100%) people interviewed reported eating papayas. This proportion was significantly higher than results from a survey Cdc-pdf[PDF – 29 pages] of healthy Hispanic people in which 22% reported eating papayas in the week before they were interviewed during the summer months.

This outbreak can be illustrated with a chart showing the number of people who became ill each day. This chart is called an epidemic curve or epi curve. Illnesses that occurred after August 18, 2017 might not be reported yet 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.

As a result of this summer’s outbreak investigation linked to papayas, FDA has increased testing of papayas from Mexico to see if papayas from other farms are contaminated with Salmonella. Through this increased testing, FDA identified Salmonella Newport and Salmonella Infantis on papayas from Caraveo Produce in Tecomán, Mexico that were grown by Rancho El Ganadero. Investigators compared PFGE and WGS results of Salmonella isolates from the papayas to isolates from ill people in the CDC PulseNet database. These results showed the Salmonella Newport and Salmonella Infantis isolates from papayas shared the same DNA fingerprint as the Salmonella isolates from ill people. This result provides more evidence that people in this outbreak got sick from eating contaminated Maradol papayas.

FDA reportsExternal that the shipment of papayas found to be contaminated was destroyed and was not distributed for sale in the United States. Papayas from this farm were distributed in the United States earlier this year, but FDA reports that no shipments of papayas from this farm are on the market in the United States because they are past their shelf life.

Because four separate outbreaks linked to papayas from different farms have been identified, CDC is concerned that papayas from other farms in Mexico might be contaminated with Salmonella and have made people sick. FDA continues testing papayas from Mexico to see if papayas from other farms are contaminated with Salmonella.

Investigations are ongoing to determine if additional consumer warnings are needed beyond the advice not to eat papayas from the specific farm given in this update, and from specific farms given in web postings about the other Salmonella outbreaks linked to Maradol papayas. CDC will provide updates when more information is available.

At A Glance
  • Case Count: 4
  • States: 4
  • Deaths: 0
  • Hospitalizations: 2
  • Recall: No
Photo of a papaya cut open

Maradol Papaya: Maradol papayas are a large, oval fruit that weighs 3 or more pounds, with green skins that turn yellow when the fruit is ripe. The flesh inside the fruit is salmon-colored.