Most recent first. Note that original articles may no longer be available.

Journal article published in: Journal of Clinical Microbiology

Published date: February 2014

Link to article:(external link)

Nosocomial outbreak of Salmonella enterica serovar Typhimurium primarily affecting a pediatric ward in South Africa in 2012

By Anthony Smith, 1 February 2014


This study described a nosocomial outbreak of diarrheal disease caused by extended-spectrum β-lactamase producing multidrug-resistant Salmonella enterica serovar Typhimurium, focused on a pediatric ward in South Africa. The outbreak peaked between May 2012 and July 2012. Person-to-person transmission was the most likely mechanism of spread of the infection, expedited due to the presence of a breakdown in hand-washing and hygiene, suboptimal infection control practices, overcrowding of hospital wards and an undesirable nurse to patient ratio


Journal article published in: Journal of Medical Microbiology

Published date: September 2011

Link to article:(external link)

International collaboration tracks typhoid fever cases over two continents from South Africa to Australia

By Anthony Smith, 1 September 2011


This study investigated a cluster of Salmonella Typhi cases in Pretoria, South Africa, 2010. All isolates showed an indistinguishabe pulsed-field gel electrophoresis pattern, suggesting that all isolates were the identical strain of bacteria. A single restaurant was linked to the outbreak and we speculate that the restaurants barman may have been the index case and the source of the typhoid fever outbreak in Pretoria. Furthermore, this investigation saw the outbreak strain tracked from South Africa to Australia.


Reported: 20 May 2011



Read original (external link)

Human Salmonella Typhimurium Infections Associated with Aquatic Frogs --- United States, 2009--2011

From CDC Morbidity and Mortality Weekly Report, May 20, 2011
Investigation of human Salmonella Typhimurium infections associated with African

Investigation of human Salmonella Typhimurium infections associated with African dwarf frogs

CDC is collaborating with state and local public health departments in an ongoing investigation of human Salmonella Typhimurium infections associated with African dwarf frogs (ADFs) (1(external link)). ADFs are aquatic frogs of the genus Hymenochirus commonly kept in home aquariums as pets. From April 1, 2009 to May 10, 2011, a total of 224 human infections with a unique strain of S. Typhimurium were reported from 42 states. The isolates are indistinguishable by pulsed-field gel electrophoresis and multiple-locus variable-number tandem repeat analysis. This outbreak likely includes considerably more than the 224 laboratory-confirmed cases reported to CDC; only an estimated 3% of Salmonella infections are laboratory confirmed and reported to surveillance systems (2). Surveillance for additional cases continues through PulseNet, the national molecular subtyping network for foodborne disease surveillance.


Reported: 26 Feb 2010


Read original(external link)

PDF Copy of original

Ref: PN1012

Salmonella Typhimurium and Pet Turtle Exposure (USA 2008)

From CDC Morbidity and Mortality Weekly Report, February 26, 2010
Malayan Box Turtle picture by M Noth, wikimedia commons

Malayan Box Turtle picture by ©(external link) M Noth, wikimedia commons

On September 4, 2008, the Philadelphia Department of Public Health and the Pennsylvania Department of Health notified CDC of an outbreak of possible turtle-associated human Salmonella Typhimurium infections detected by identifying strains with PulseNet.

Turtles and other reptiles have long been recognized as sources of human Salmonella infections, and the sale or distribution of small turtles has been prohibited in the United States since 1975.

CDC and state and local health departments conducted a multistate investigation during September-November 2008, identifying 135 cases in 25 states. Of these, 45% were in children aged 5 or younger. Read original(external link)


Reported: 8 Dec 2009

Washington Post

Read original(external link)

PDF Copy of original

Ref: PN1001

The Unusual Suspects

By Arthur Allen Tuesday, December 8, 2009
The Unusual Suspects

The Unusual Suspects

As food production and preparation moves farther afield, tainted items become hard to avoid. The PulseNet system reveals how a centralized food system can allow a single batch of contaminated food to hurt people across the country. Read original(external link)


Reported: 9 Feb 2009


Read original(external link)

PDF Copy of original

Ref: PN1002

Cracking the poison processed peanuts case

Group called ‘Team Diarrhea’ helped track salmonella outbreak to plant

The Associated Press, Feb. 9, 2009


Solving the case of the poison processed peanuts took marathon work by federal scientists, clues in Canada, Oregon, Ohio and Connecticut, and a breakthrough in Minnesota at the hands of public health hotshots known as Team Diarrhea.
So labyrinthian has the nation's food production and distribution network become that a salmonella outbreak that has sickened 575 people in 43 states and resulted in the recall of more than 1,500 foods is traced to one plant making a mere 1 percent of the country's peanut products.

jar of peanut butter

Jar of peanut butter

... The peanut case quickened the pulse of federal scientists on Nov. 12, more than a month after people started getting sick, when the federal Centers for Disease Control detected a cluster of salmonella cultures with an unusual genetic fingerprint reported from 12 states.
That was "a blinking light," Dr. Ali Khan, assistant surgeon general, told Congress.

PulseNet, a national network for finding patterns in widely dispersed foodborne bacterial illness, offered additional clues when four more states reported the cluster.

To solve a whatdunit, public health officials need to know what type of salmonella has caused an outbreak and what food is carrying it. There are more than 2,500 kinds of salmonella, each divided into subtypes.

... Gabrielle Meunier, whose 7-year-old son Christopher spent nights in the hospital sick from the outbreak in Vermont, told lawmakers the mystery poison might have been identified much sooner if the government had a secure Web site where victims could communicate with each other.
... As well as tracing the contamination back to the source, officials have to follow serpentine trails forward to try to figure out all the final destinations. The list of recalls, and possibilities, keeps growing. Recalls now include cookies, crackers, cereal, candy, ice cream, pet treats and much more. Read original(external link)


Reported: 28 Jan 2009


Read original(external link)

PDF Copy of original

Ref: PN1003

Drug-resistant salmonella? Maybe next time.

By JoNel Aleccia, January 28, 2009


Even as the list of peanut products linked to a national salmonella scare continued to expand, and the number of strains of bacteria associated with the outbreak climbed to four, federal health officials winding up an investigation said they may well have dodged a bullet. You could say that, said Dr. Peter Gerner-Smidt, chief of the Enteric Diseases Laboratory Response Branch for the Centers for Disease Control and Prevention. The salmonella strain that has sickened more than 500 people and contributed to eight deaths does not appear to be resistant to frontline antibiotics. Read original(external link)


Reported: 11 Nov 2008

Rocky Mountain News
(Denver, Colorado.)

Read original(external link)

PDF Copy of original

Ref: PN1004

E. coli outbreak traced to elk droppings

By Bill Scanlon, November 11, 2008
Two elk in a field

Two elk in a field

Elk droppings in the Evergreen area tested positive for the same strain of E. coli that sickened eight children. The mystery behind the E. coli outbreak southwest of Denver started clearing up when all eight sickened children said they liked playing outdoors in elk country.

"We track every case of E. coli 0157:H7," Gayle Miller, senior epidemiologist with Jefferson County Health and Environment, said. "Usually, the outbreaks are so sporadic that no useful links can be made." ... she and her staff used a relatively new test, Pulse Field Gel Electrophoresis, and found that not only was the strain the same, but each child's E. coli had almost identical genetic markers.... The E. coli in the elk had the same genetic markers as the E. coli in the sickened kids. "That means the kids got the E. coli from the elk," she said. Read original(external link)


Reported: 27 Dec 2007

Milford Daily News
(Massachusetts, USA)

Read original(external link)

PDF Copy of original

Ref: PN1005

Two dead from Whittier Farms milk contamination

By... December 27, 2007

The Department of Public Health (DPH) has issued a warning to consumers not to drink any milk products from Whittier Farms in Shrewsbury because of listeria bacteria contamination, which has contributed to the death of two people.

... DNA fingerprinting conducted by the State Laboratory Institute showed that the bacteria causing these infections came from a common source....

Four cases of listeriosis infection have been identified by DPH, according to a statement released by the state department late this afternoon. The cases occurred in June, October and two in November. The four cases involved three elderly residents and a pregnant woman from Worcester county. Two of the people have died. They have not been identified.

DNA fingerprinting conducted by the State Laboratory Institute showed that the bacteria causing these infections came from a common source. Samples collected showed product contamination. Read original(external link)


Reported: 13 Jul 2006

Japan Journal of Infectious Diseases

Read original(external link)

PDF Copy of original

Ref: PN1011

International outbreak of Shigella sonnei associated with air travel to Hawaii in 2004

By multiple authors, Japan Journal of Infectious Diseases,
July 13, 2006
Jumbo jet

Jumbo jet

In September 2004, investigations of two outbreaks of Shigella sonnei took place simultaneously in Japan and the United States. The collaboration through PulseNet International linked both outbreaks to the same source: air travel to Hawaii. In the United States, the Hawaii Department of Health contacted the Minnesota Department of Health (MN) to inform them of a potential outbreak of S. sonnei associated with domestic and international air travel to Hawaii. PulseNet USA participants in the MN laboratory alerted the rest of PulseNet USA via the PulseNet listserv by posting two different S. sonnei patterns digested with XbaI that were obtained from patients who had recently traveled to Hawaii. In response to the posting, the public health laboratories in Hawaii, Michigan, New Jersey and Texas reported similar patterns, all of which were associated with Hawaii travel. Concurrently, investigators in Japan investigated a similar S. sonnei outbreak, and alerted PulseNet USA about it due to a suspected link to travel to Hawaii. The link was microbiologically confirmed through exchange of PFGE patterns and strains between the countries using PulseNet International. The epidemiological investigation pointed to salad served on-board the associated airplanes leaving from Hawaii as the most likely source of the outbreak. PulseNet data was instrumental in providing the microbiological evidence for a link between Japanese and US shigellosis cases. This outbreak illustrates how the increase in world travel increases the opportunity for dispersion of bacterial disease. It is also a good example of the key role that PulseNet International plays in the investigation of foodborne disease outbreaks with global implications.   Read original(external link)

Last modified: