24 sick in 16 states: Salmonella Typhimurium infections linked to clinical and teaching microbiology laboratories

The U.S. Centers for Disease Control (CDC) and public health officials in several states have identified a multistate outbreak of Salmonella Typhimurium infections linked to various clinical, commercial, and college and university teaching microbiology laboratories.

Public health investigators used the PulseNet system to identify illnesses that may be part of this outbreak. PulseNet, coordinated by CDC, is the national subtyping network of public health and food regulatory agency laboratories. PulseNet performs DNA fingerprinting 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.

Twenty-four people infected with the outbreak strain of Salmonella Typhimurium have been reported from 16 states, including California, Colorado, Florida, Georgia, Iowa, Maine, Michigan, Missouri, North Carolina, New Hampshire, New Jersey, New Mexico, New York, Oklahoma, Texas, and Washington. WGS showed that the strain of Salmonella Typhimurium causing illness in this outbreak is closely related genetically to a strain from an outbreak in 2014 and an outbreak in 2011, both of which were linked to microbiology laboratories. As a result of the 2011 outbreak, several laboratory professionals across the country developed a set of guidelines for handling microorganisms safely in a teaching laboratory.

Among people for whom information was available, illnesses started on dates ranging from March 17, 2017 to June 22, 2017. Ill people ranged in age from less than one year to 57 years, with a median age of 24. Seventy-five percent of ill people were female. Among 21 people with available information, six (29%) were hospitalized. No deaths were reported.

In interviews, ill people answered questions about different exposures in the week before they became ill. Nine (69%) of 13 ill people had laboratory exposures. Ill people in this outbreak reported behaviors while working in the laboratory that could increase the risk of Salmonella infection. These included not wearing gloves or lab coats, not washing hands, and using the same writing utensils and notebooks outside of the laboratory.

This outbreak highlights the potential risk of Salmonella infection associated with working in microbiology laboratories.

All students and staff in clinical and teaching microbiology laboratories should receive laboratory safety training. Either nonpathogenic or attenuated bacterial strains should be used when possible, especially in teaching laboratories. This practice will help reduce the risk of students and their family members becoming ill.

More Hep A means more human shit where fish swim

REO Speedwagon was a terrible band.

The U.S. Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC), are assisting state and local officials in assessing the risk of hepatitis A virus exposure from contaminated frozen tuna sourced from Sustainable Seafood Company, Vietnam, and Santa Cruz Seafood Inc., Philippines. If unvaccinated consumers have consumed the recalled product within the last two weeks, post-exposure prophylaxis may help prevent hepatitis A virus infection.

Prior to FDA’s announcement, Hilo Fish Company alerted its customers and distribution partners directly to let them know about the company’s voluntary recall of certain tuna products on May 18. The FDA received records from the company or its distribution partners indicating that they sold frozen tuna to the establishments listed on the FDA’s website. The FDA is working with Hilo and other distributors to ensure that the companies remove product from the market. The table containing the names of establishments have been updated.

It is the responsibility of the Hilo Fish Company to notify its customers about the voluntary recall. It is also the responsibility of any company that received a recall notice from Hilo Fish Company to notify its customers. The establishments identified on the FDA’s website should have received a notice from Hilo Fish Company or their direct supplier. If they have not, they should reach out to their suppliers for more information. Any company that has questions about the voluntary recall or has affected product and did not receive notice should contact the FDA at 1-800-SAFEFOOD.

Kids, kids: Foodnet report is out

It’s my favorite day of the year: The annual U.S. Foodnet report, where data is presented, mulled over, and then crammed into politically suitable food safety fairytales.

When a scientific report leads with, “The incidence of infections transmitted commonly through food has remained largely unchanged for many years,” isn’t it time to try something different?

The U.S. Centers for Disease Control reports reducing foodborne illness depends in part on identifying which illnesses are decreasing and which are increasing. Yet recent changes in the use of tests that diagnose foodborne illness pose challenges to monitoring illnesses and progress toward preventing foodborne disease, according to a report published today in CDC’s Morbidity and Mortality Weekly Report.

Rapid diagnostic tests help doctors diagnose infections quicker than traditional culture methods, which require growing bacteria to determine what is causing illness. But without a bacterial culture, public health officials cannot get the detailed information needed to detect and prevent outbreaks, monitor disease trends, and identify antibiotic resistance.

The MMWR article includes the most recent data from CDC’s Foodborne Diseases Active Surveillance Network, or FoodNet, which collects data on 15% of the U.S. population. It summarizes preliminary 2016 data on nine germs spread commonly through food. In 2016, FoodNet reported 24,029 infections, 5,512 hospitalizations, and 98 deaths. This is the first time the numbers used for calculations of trends include bacterial infections diagnosed only by rapid diagnostic tests as well as those confirmed by traditional culture-based methods. Previously, these calculations used only those bacterial infections confirmed by culture-based methods. The most frequent causes of infection in 2016 were Salmonella and Campylobacter, which is consistent with previous years.

 Incidence and Trends of Infections with Pathogens Transmitted Commonly Through Food and the Effect of Increasing Use of Culture-Independent Diagnostic Tests on Surveillance — Foodborne Diseases Active Surveillance Network, 10 U.S. Sites, 2013–2016

Marder EP, Cieslak PR, Cronquist AB, et al.

MMWR Morb Mortal Wkly Rep 2017;66:397–403. DOI: http://dx.doi.org/10.15585/mmwr.mm6615a1

https://www.cdc.gov/mmwr/volumes/66/wr/mm6615a1.htm?s_cid=mm6615a1_e#suggestedcitation

The incidence of infections transmitted commonly through food has remained largely unchanged for many years. Culture-independent diagnostic tests (CIDTs) are increasingly used by clinical laboratories to detect enteric infections.

What is added by this report?

Compared with the 2013–2015 average annual incidence, the 2016 incidence of confirmed Campylobacter infections was lower, incidences of confirmed Shiga toxin-producing Escherichia coli (STEC), Yersinia, and Cryptosporidium infections were higher, and incidences of confirmed or CIDT positive–only STEC and Yersinia infections were higher. However, CIDTs complicate the interpretation of surveillance data; testing for pathogens might occur more frequently because of changes in either health care provider behaviors or laboratory testing practices. A large proportion of CIDT positive specimens were not reflex cultured, which is necessary to obtain isolates for distinguishing pathogen subtypes, determining antimicrobial resistance, monitoring trends, and detecting outbreaks.

What are the implications for public health practice?

Some information about the bacteria causing infections, such as subtype and antimicrobial susceptibility, can only be obtained for CIDT positive specimens if reflex culture is performed. Increasing use of CIDTs affects the interpretation of public health surveillance data and ability to monitor progress toward prevention measures.

Foodborne diseases represent a substantial public health concern in the United States. CDC’s Foodborne Diseases Active Surveillance Network (FoodNet) monitors cases reported from 10 U.S. sites* of laboratory-diagnosed infections caused by nine enteric pathogens commonly transmitted through food. This report describes preliminary surveillance data for 2016 on the nine pathogens and changes in incidences compared with 2013–2015. In 2016, FoodNet identified 24,029 infections, 5,512 hospitalizations, and 98 deaths caused by these pathogens. The use of culture-independent diagnostic tests (CIDTs) by clinical laboratories to detect enteric pathogens has been steadily increasing since FoodNet began surveying clinical laboratories in 2010 (1). CIDTs complicate the interpretation of FoodNet surveillance data because pathogen detection could be affected by changes in health care provider behaviors or laboratory testing practices (2). Health care providers might be more likely to order CIDTs because these tests are quicker and easier to use than traditional culture methods, a circumstance that could increase pathogen detection (3). Similarly, pathogen detection could also be increasing as clinical laboratories adopt DNA-based syndromic panels, which include pathogens not often included in routine stool culture (4,5). In addition, CIDTs do not yield isolates, which public health officials rely on to distinguish pathogen subtypes, determine antimicrobial resistance, monitor trends, and detect outbreaks. To obtain isolates for infections identified by CIDTs, laboratories must perform reflex culture; if clinical laboratories do not, the burden of culturing falls to state public health laboratories, which might not be able to absorb that burden as the adoption of these tests increases (2). Strategies are needed to preserve access to bacterial isolates for further characterization and to determine the effect of changing trends in testing practices on surveillance.

FoodNet is a collaboration among CDC, 10 state health departments, the U.S. Department of Agriculture’s Food Safety and Inspection Service, and the Food and Drug Administration. FoodNet personnel conduct active, population-based surveillance for laboratory-diagnosed infections caused by Campylobacter, Cryptosporidium, Cyclospora, Listeria, Salmonella, Shiga toxin-producing Escherichia coli (STEC), Shigella, Vibrio, and Yersinia for 10 sites covering approximately 15% of the U.S. population (an estimated 49 million persons in 2015). Confirmed bacterial infections are defined as isolation of the bacterium from a clinical specimen by culture. Confirmed parasitic infections are defined as detection of the parasite from a clinical specimen by direct fluorescent antibody test, polymerase chain reaction, enzyme immunoassay, or light microscopy. CIDTs detect bacterial pathogen antigen, nucleic acid sequences, or for STEC, Shiga toxin or Shiga toxin genes, in a stool specimen or enrichment broth.§ A CIDT positive–only bacterial infection is a positive CIDT result that was not confirmed by culture. Hospitalizations occurring within 7 days of specimen collection are recorded. The patient’s vital status at hospital discharge (or 7 days after specimen collection if not hospitalized) is also recorded. Hospitalizations and deaths occurring within 7 days of specimen collection are attributed to the infection. FoodNet also conducts surveillance for physician-diagnosed postdiarrheal hemolytic uremic syndrome (HUS), a potential complication of STEC infection, by review of hospital discharge data through a network of nephrologists and infection preventionists. This report includes HUS cases among persons aged <18 years for 2015, the most recent year with available data.

Incidence of infection for each pathogen is calculated by dividing the number of infections in 2016 by the U.S. Census estimates of the surveillance area population for 2015. Incidence is calculated for confirmed infections alone and for confirmed or CIDT positive–only infections combined. A negative binomial model with 95% confidence intervals (CIs) was used to estimate changes in incidence of confirmed bacterial and parasitic infections and confirmed or CIDT positive–only bacterial infections in 2016 compared with 2013–2015, adjusting for changes in the surveillance population over time. For STEC, incidence is reported for all STEC serogroups combined because it is not possible to distinguish between serogroups using CIDTs. Insufficient data were available to assess change for Cyclospora. For HUS, the 2015 incidence was compared with incidence during 2012–2014.

Cases of Infection, Incidence, and Trends

During 2016, FoodNet identified 24,029 cases, 5,512 hospitalizations, and 98 deaths caused by confirmed or CIDT positive–only infections. The largest number of confirmed or CIDT positive–only infections in 2016 was reported for Campylobacter (8,547), followed by Salmonella (8,172), Shigella (2,913), STEC (1,845), Cryptosporidium (1,816), Yersinia (302), Vibrio (252), Listeria (127), and Cyclospora (55). The proportion of infections that were CIDT positive without culture confirmation in 2016 was largest for Campylobacter (32%) and Yersinia (32%), followed by STEC (24%), Shigella (23%), Vibrio (13%), and Salmonella (8%). The overall increase in CIDT positive–only infections for these six pathogens in 2016 was 114% (range = 85%–1,432%) compared with 2013–2015. Among infections with a positive CIDT result in 2016, a reflex culture was attempted on approximately 60% at either a clinical or state public health laboratory. The proportion of attempted reflex cultures differed by pathogen, ranging from 45% for Campylobacter to 86% for STEC and 88% for Vibrio. Among infections for which reflex culture was performed, the proportion of infections that were positive was highest for Salmonella (88%) and STEC (87%), followed by Shigella (64%), Yersinia (59%), Campylobacter (52%), and Vibrio (46%).

The incidence of confirmed infections and of confirmed or CIDT positive–only infections per 100,000 persons was highest for Campylobacter (confirmed = 11.79; confirmed or CIDT positive–only = 17.43) and Salmonella (15.40; 16.66), followed by Shigella (4.60; 5.94), Cryptosporidium (3.64; N/A**), STEC (2.85; 3.76), Yersinia (0.42; 0.62), and lowest for Vibrio (0.45; 0.51), Listeria (0.26; N/A), and Cyclospora (0.11; N/A). Compared with 2013–2015, the 2016 incidence of Campylobacter infection was significantly lower (11% decrease) when including only confirmed infections, yet was not significantly different when including confirmed or CIDT positive–only infections. Incidence of STEC infection was significantly higher for confirmed infections (21% increase) and confirmed or CIDT positive–only infections (43% increase). Similarly, the incidence of Yersinia infection was significantly higher for both confirmed (29% increase) and confirmed or CIDT positive–only infections (91% increase). Incidence of confirmed Cryptosporidium infection was also significantly higher in 2016 compared with 2013–2015 (45% increase).

Among 7,554 confirmed Salmonella cases in 2016, serotype information was available for 6,583 (87%). The most common serotypes were Enteritidis (1,320; 17%), Newport (797; 11%), and Typhimurium (704; 9%). The incidence in 2016 compared with 2013–2015 was significantly lower for Typhimurium (18% decrease; CI = 7%–21%) and unchanged for Enteritidis and Newport. Among 208 (95%) speciated Vibrio isolates, 103 (50%) were V. parahaemolyticus, 35 (17%) were V. alginolyticus, and 26 (13%) were V. vulnificus. Among 1,394 confirmed and serogrouped STEC cases, 503 (36%) were STEC O157 and 891 (64%) were STEC non-O157. Among 586 (70%) STEC non-O157 isolates, the most common serogroups were O26 (190; 21%), O103 (178; 20%), and O111 (106; 12%). Compared with 2013–2015, the incidence of STEC non-O157 infections in 2016 was significantly higher (26% increase; CI = 9%–46%) and the incidence of STEC O157 was unchanged.

FoodNet identified 62 cases of postdiarrheal HUS in children aged <18 years (0.56 cases per 100,000) in 2015; 33 (56%) occurred in children aged <5 years (1.18 cases per 100,000). Compared with 2012–2014, in 2015, no significant differences in incidence among all children or children aged <5 years were observed.

Discussion

The number of CIDT positive–only infections reported to FoodNet has been increasing markedly since 2013, as more clinical laboratories adopt CIDTs. Initially, increases were primarily limited to Campylobacter and STEC; followed by substantial increases in Salmonella and Shigella beginning in 2015 (6). The pattern continued in 2016, with large increases in the number of CIDT positive–only Vibrio and Yersinia infections. When including both confirmed and CIDT positive–only infections, incidence rates in 2016 were higher for each of these six pathogens. The increasing use of CIDTs presents challenges when interpreting the corresponding increases in incidence. For example, the incidence of confirmed Campylobacter infections in 2016 was significantly lower than the 2013–2015 average. However, when including CIDT positive–only infections, a slight but not significant increase occurred. For STEC and Yersinia, the incidence of confirmed infections alone and confirmed or CIDT positive–only infections in 2016 were both significantly higher than the 2013–2015 average; the magnitude of change approximately doubled when analyzing CIDT positive–only infections.

Because of the ease and increasing availability of CIDTs, testing for some pathogens might be increasing as health care provider behaviors and laboratory practices evolve (2). Among clinical laboratories in the FoodNet catchment, the use of CIDTs to detect Salmonella, for which the only CIDTs available are DNA-based gastrointestinal syndrome panels, increased from 2 per 460 laboratories (<1%) in 2013 to 59 per 421 laboratories (14%) in 2016 (FoodNet, unpublished data). This increased use paralleled significant increases in incidence of Cryptosporidium, STEC, and Yersinia, and slight but not significant increases in incidence of Campylobacter, Salmonella, Shigella, and Vibrio, all of which are also included in these panel tests. The increase in STEC incidence is driven by the increase in STEC non-O157, which is not typically included in routine stool culture testing because it requires specialized methods. Routine stool cultures performed in clinical laboratories typically include methods that identify only Salmonella, Campylobacter, Shigella, and for some laboratories, STEC O157 (4,5). The increased use of the syndrome panel tests might increase identification, and thus, improve incidence estimates of pathogens for which testing was previously limited.

Results are more quickly obtained using CIDTs than traditional culture methods (3). Because of this, health care providers might be more likely to order a CIDT than traditional culture (2). Increased testing might identify infections that previously would have remained undiagnosed. However, sensitivity and specificity vary by test type. Evaluations of DNA-based syndrome panel tests have indicated high sensitivity and specificity for most targets (3). However, among pathogens for which antigen-based CIDTs are often used, such as Campylobacter and Cryptosporidium, sensitivity and specificity have varied more widely, with a large number of false positive results (7,8). Including CIDT positive infections to calculate incidence, some of which could be false positives, might provide an inaccurate estimate. When interpreting incidence and trends in light of changing diagnostic testing, considering frequency of testing, sensitivity, and specificity of these tests is important. The observed increases in incidence of confirmed or CIDT positive–only infections in 2016 compared with 2013–2015 could be caused by increased testing, varying test sensitivity, an actual increase in infections, or a combination of these reasons.

These changes in testing are also important to consider when monitoring progress toward Healthy People 2020 objectives.†† The current objectives were created before the use of CIDTs and were based on confirmed infections. In the future, just as incidence measures should adjust for these changes, objectives should also be evaluated in light of changing diagnostics.

CIDTs pose additional challenges because they do not yield the bacterial isolates necessary for essential public health surveillance activities, such as monitoring trends in pathogen subtypes, conducting molecular testing, detecting outbreaks and implicating vehicles, and determining antimicrobial susceptibility. Reflex culture performed to yield an isolate places an additional burden on laboratories’ budgets, personnel, and time. Specimen submission requirements differ by state and pathogen, and this responsibility often falls to state public health laboratories (9). As CIDT use increases and more pathogens are affected, state public health laboratories will be challenged to sufficiently increase their testing capacity and will likely have to prioritize specimens on which to perform reflex culture (10). Clinical laboratories should review state specimen submission requirements and the Association of Public Health Laboratories guidelines§§ for reflex culture and submission of CIDT positive specimens.

The findings in this report are subject to at least two limitations. First, the changing diagnostic landscape with unknown changes in frequency of testing, varying test performance, and decreasing availability of isolates for subtyping make interpreting incidence and trends more difficult. Second, changes in health care–seeking behavior, access to health services, or other population characteristics might have changed since the comparison period, which could affect incidence.

Foodborne illness remains a substantial public health concern in the United States. Previous analyses have indicated that the number of infections far exceeds those diagnosed; CIDTs might be making those infections more visible (11). Most foodborne infections can be prevented, and substantial progress has been made in the past in decreasing contamination of some foods and reducing illness caused by some pathogens. More prevention measures are needed. Surveillance data can provide information on where to target these measures. However, to accurately interpret FoodNet surveillance data in light of changes in diagnostic testing, more data and analytic tools are needed to adjust for changes in testing practices and differences in test characteristics. FoodNet is collecting more data and developing those tools. With these, FoodNet will continue to track the needed progress toward reducing foodborne illness.

Acknowledgments

Foodborne Diseases Active Surveillance Network staff members, Emerging Infections Program; Brittany Behm, Staci Dixon, Elizabeth Greene, Jennifer Huang, Clare Wise, and FoodNet Fast Development Team, Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, CDC.

‘We meet all standards’ Fresh Express uses Pinto defense after dead bat found in salad

The U.S. Centers for Disease Control and Prevention (CDC) are working with the Florida Department of Health and the U.S. Food and Drug Administration (FDA) to support an investigation of a dead bat that was found in a packaged salad purchased from a grocery store in Florida. Two people in Florida reported eating some of the salad before the bat was found. The bat was sent to the CDC rabies lab for laboratory testing because bats in the United States sometimes have been found to have this disease. The deteriorated condition of the bat did not allow for CDC to definitively rule out whether this bat had rabies.

Transmission of rabies by eating a rabid animal is extremely uncommon, and the virus does not survive very long outside of the infected animal. CDC is supporting Florida local and state health officials in evaluating the people who found the bat in the salad. In this circumstance, the risk of rabies transmission is considered to be very low, but because it isn’t zero, the two people who ate salad from the package that contained the bat were recommended to begin post-exposure rabies treatment. Both people report being in good health and neither has any signs of rabies. CDC is not aware of any other reports of bat material found in packaged salads.

On April 8, 2017, Fresh Express issued a recall of a limited number of cases of Organic Marketside Spring Mix. The salads were sold in a clear container with production code G089B19 and best-if-used-by date of APR 14, 2017 located on the front label. The recalled salads were distributed only to Walmart stores located in the Southeastern region of the United States. All remaining packages of salad from the same lot have been removed from all store locations where the salad was sold.

The company said in a statement it worked quickly with officials to remove the entire batch of salads from store shelves, and only one line of its products had been affected.

“Fresh Express takes matters of food safety very seriously and rigorously complies with all food safety regulations including the proscribed Good Agricultural Practices.”

Maybe install bat filters as the lettuce goes through a wash?

94 sickened: Sprouted chia seed powder – USA and Canada, 2013–2014

Salmonella is a leading cause of bacterial foodborne illness. We report the collaborative investigative efforts of US and Canadian public health officials during the 2013–2014 international outbreak of multiple Salmonella serotype infections linked to sprouted chia seed powder.

The investigation included open-ended interviews of ill persons, traceback, product testing, facility inspections, and trace forward.

Ninety-four persons infected with outbreak strains from 16 states and four provinces were identified; 21% were hospitalized and none died. Fifty-four (96%) of 56 persons who consumed chia seed powder, reported 13 different brands that traced back to a single Canadian firm, distributed by four US and eight Canadian companies.

Laboratory testing yielded outbreak strains from leftover and intact product. Contaminated product was recalled. Although chia seed powder is a novel outbreak vehicle, sprouted seeds are recognized as an important cause of foodborne illness; firms should follow available guidance to reduce the risk of bacterial contamination during sprouting.

 

Truffle oil fingered: 159 sickened with Salmonella at Fig & Olive in 2015

In the summer of 2015, some 150 people were stricken with Salmonella at uppity Fig and Olive restaurants in Washington, D.C. and Los Angeles.

The salmonella outbreak shut down the City Center, DC location for six days in Sept. 2015. The Food and Drug Administration and local health authorities never definitively determined the exact source of the salmonella, but truffle mushroom croquettes were a common denominator among Fig & Olive diners who got sick. Components of the dish were pre-prepared at a Long Island City commissary that supplied Fig & Olive’s restaurants around the country with already-made sauces, dressings, and more, and has since been closed.

Six months and a round of layoffs later, one former mid-level executive told Jessica Sidman of Washington City Paper, “They’re an image conscious-first company. They don’t care about the guest. They care about their image, and they care about the bottom line … It’s just not a good company.”

The U.S. Centers for Disease Control has now weighed in on the source of the Salmonella – without naming the restaurant.

During July–September 2015, a total of 159 patrons reported gastrointestinal illness after eating at a single District of Columbia restaurant. Forty-one persons (40 restaurant patrons and one employee) were infected with an indistinguishable Salmonella Enteritidis strain on the basis of pulsed-field gel electrophoresis (XbaI pattern JEGX01.0008). Results from a case-control study using restaurant patron data identified a novel food vehicle, truffle oil, as the likely source of Salmonella Enteritidis infection in this outbreak. Approximately 89% of case-patients reported eating truffle oil–containing items, compared with 57% of patrons who did not report gastrointestinal illness (p<0.001).

Public health officials and consumers should be aware that truffle oil has been implicated as the likely source of a Salmonella Enteritidis outbreak and could possibly harbor this pathogen. Timely engagement of the public, health care providers, and local and federal public health officials, is particularly critical for early recognition of outbreaks involving common foodborne pathogens, such as Salmonella Enteritidis.

Resistant Salmonella causes 6,200 illnesses a year in US

Chris Dall of the Center for Infectious Disease Research Policy reports the U.S. Centers for Disease Control and Prevention (CDC) has published new estimates of the incidence of antibiotic-resistant Salmonella infections in the United States, putting the burden at about 6,200 cases annually.

ab-res-salmIn a report in Emerging Infectious Diseases, CDC researchers estimate the overall incidence of resistant salmonella infections as roughly 2 for 100,000 persons per year from 2004 to 2012They also determined that clinically important resistance was linked to four specific Salmonella serotyopes: Enteritidis, Newport, Typhimurium, and Heidelberg.

Nontyphoidal Salmonella causes an estimated 1.2 million foodborne illnesses and about 450 deaths each year, according to the CDC. While most people who get Salmonella infections recover within a week and do not require antibiotics, more severe infections are generally treated with either ampicillin, ceftriaxone, or ciprofloxacin. Resistance to these drugs can result in increased hospitalization, invasive illnesses, and death.

The new estimates are based on data from the US Census Bureau and from two surveillance systems the CDC uses to track Salmonella and drug-resistant Salmonella: The National Antimicrobial Resistance Monitoring System (NARMS) and the Laboratory-based Enteric Disease Surveillance (LEDS) system. NARMS monitors resistance in Salmonella by testing isolates from infected individuals and determining the percentage of isolates that show resistance. LEDS collects Salmonella surveillance data, including serotypes, from state and territorial public health labs.

The researchers defined three mutually exclusive categories of resistance for the study: ampicillin-only resistance, ceftriaxone/ampicillin resistance, and ciprofloxacin nonsusceptibility.

According to the LEDS data, there were 369,254 culture-confirmed Salmonella infections from 2004 through 2012. Four primary serotypes—Enteritidis, Typhimurium, Newport, and Heidelberg—accounted for 52% of all fully serotyped isolates. NARMS tested 19,410 isolates from 2004 through 2012, and overall resistance was detected in 2,320 isolates. Ampicillin-only resistance was the most common resistance pattern detected, followed by ceftriaxone/ampicillin resistance and ciprofloxacin nonsusceptibility.

Using these data, the researchers determined that from 2004 to 20012 there were approximately 6,200 resistant culture-confirmed infections annually. Overall incidence was 1.93/100,000 person-years for any clinically important resistance, 1.07 for ampicillin-only resistance, .51 for ceftriaxone/ampicillin resistance, and .35 for ciprofloxacin nonsusceptibility.

The authors note that while Enteritidis, Typhimurium, Newport, and Heidelberg account for only half of all culture-confirmed Salmonella infections, the four serotypes accounted for 73% of the Salmonella infections that involved clinically important resistance.

The predominance of these four serotypes, they write, reflects their ability to persist in food animals, be transmitted through the food system, and cause illness. It also suggests that strategies to reduce Salmonella infections caused by these four serotypes could have an impact on the incidence of resistant infections overall.

“The 4 major serotypes that have been driving the incidence of resistant infections should continue to be high priorities in combating resistance,” the authors write.

The report also notes that two of these serotypes—Typhimurium and Newport—have been associated with outbreaks of drug-resistant Salmonella infections linked to contaminated meat, which highlights the need for NARMS to continue monitoring emerging resistance patterns by serotype.

The authors caution, however, that while this estimate of resistant Salmonella infection incidence will help define the magnitude of the problem and guide prevention efforts, it might be telling only part of the story. That’s because it relies on culture-confirmed infections only.

The CDC has estimated that for every culture-confirmed case of Salmonella, there may as many as 29 undetected cases. That could put the annual US incidence as high as 180,000 cases.

Plague in domestic cats — Idaho, 2016

The U.S. Centers for Disease Control and Prevention reports in May 2015, Yersinia pestis, the bacterium that causes plague, was identified in dead Piute ground squirrels (Urocitellus mollis) reported through the Idaho Department of Fish and Game’s wildlife mortality monitoring program; in June 2015, the Idaho Division of Public Health (DPH) sent an advisory to veterinarians in four southwestern Idaho counties requesting that they notify their local public health officials of suspected plague in animals.* Y. pestis was not confirmed in any pets during 2015.

yersinia-pestisDuring May 30–July 26, 2016, local veterinarians notified public health officials that five dogs and 12 cats were being evaluated for possible plague. Local veterinarians also performed necropsies, when applicable, to establish the diagnosis. Idaho’s Central District Health Department and Eastern Idaho Public Health coordinated with DPH on submission of specimens to the DPH Bureau of Laboratories for Y. pestis testing and interviewed veterinary staff and pet owners. Specimens from blood, spleen, liver, and lymph nodes were screened using real–time polymerase chain reaction and confirmed by culture and phage lysis testing.

sorenne-cats-aug-15Among evaluated animals, Y. pestis was isolated from six of 12 cats; five of the six were from areas in southwestern Idaho where dead ground squirrels with confirmed Y. pestis had been reported in May 2016, and one was from from eastern Idaho. Among these six cats, specimen collection occurred during May 31–July 12, 2016; cats ranged in age from 10 months to 14.5 years (median = 4 years), four (67%) were male, five (83%) resided both indoors and outdoors, and one resided outdoor only. All six cats were domestic shorthair breed and had been neutered or spayed. Fever and lymphadenopathy (n = 4, 67%) were the most commonly reported signs of illness. None of the cats had known pulmonary involvement. Three of the six cats were treated with appropriate antibiotics (1); of these, two survived and one was euthanatized. The three other cats had died or had been euthanatized. All six cats reportedly had contact with ground squirrels and other wild rodents or rabbits before becoming ill; one had flea control administered before illness onset.

Cat owners, their household members, and veterinary staff were advised to be alert for fever and other plague symptoms (2) in themselves and other pets that might have had contact with the ill cats. Veterinary staff members were reminded about methods to prevent occupational exposure when managing pets suspected of having plague (1). In June 2016, an updated plague advisory was sent to veterinarians in four southwestern Idaho counties and eight eastern Idaho counties. Local public health districts used the Idaho Health Alert Network to enhance situational awareness among health care providers and issue guidance on management and reporting of plague cases. Public communication strategies to raise awareness about the risk for and prevention of Y. pestistransmission to persons and pets included an online map of plague-affected areas, warnings posted in affected public areas, and press releases advising residents about preventive measures. No human plague cases were reported.

Cat-associated human plague cases, including fatalities, have been reported in the western United States since 1977 (3). Compared with dogs, cats are highly susceptible to plague illness and can transmit disease to humans directly through exposure to respiratory droplets and infectious body fluids associated with bites or scratches (1). Cats could also carry infected fleas into households. Y. pestis–infected cats usually develop fever, anorexia, lethargy, and lymphadenitis (submandibular in approximately 75% of cases); approximately 10% of cases are pneumonic (4) and present the most risk to pet owners and veterinary staff members. During 1926–2012, six (43%) of all primary pneumonic cases of human plague that occurred in the United States had contact with domestic cats (5). No plague vaccine for pets is available.

Veterinarians should consider the diagnosis of plague in pets, including cats, with compatible signs and exposure to rodent habitats, rodents, or ill pets in areas where plague is endemic or epizootic. Suspicion of plague should trigger the following actions by veterinary staff: 1) implementation of personal protective measures, including wearing masks and gloves; 2) isolation of the ill pet; 3) assessment of pulmonary involvement; 4) initiation of diagnostic testing for Y. pestis; 5) prompt administration of antibiotic therapy; 6) implementation of flea control for affected animals and the hospital environment; 7) provision of advice on household flea control to pet owner; and 8) notification of public health officials (1). Pet owners can reduce the risk for plague in pets by controlling pet roaming, implementing a flea control program, and minimizing rodent habitats and food sources inside and outside the home. Additional information on prevention of plague is available at http://www.cdc.gov/plague/prevention/index.html.

Not the 4-H: 21 confirmed sick with Salmonella in 8 US states from contact with dairy bull calves

The U.S. Centers for Disease Control (CDC) is working with Wisconsin health, agriculture, and laboratory agencies, several other states, and the U.S. Department of Agriculture Animal and Plant Health Inspection Service (USDA-APHIS) to investigate a multistate outbreak of multidrug-resistant Salmonella Heidelberg infections.

Portrait of the cute baby bull calf

Portrait of the cute baby bull calf

Public health investigators used the PulseNet system to identify illnesses that may have been part of this outbreak. PulseNet, coordinated by CDC, is the national subtyping network of public health and food regulatory agency laboratories. PulseNet performs DNA fingerprinting 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.

Twenty-one people infected with an outbreak strain of Salmonella Heidelberg have been reported from eight states.

Among 19 people with available information, illnesses started on dates ranging from January 11, 2016 to October 24, 2016. Ill people range in age from less than 1 year to 72, with a median age of 21. Sixty-two percent of ill people are female. Among 19 ill people with available information, 8 (42%) reported being hospitalized, and no deaths have been reported.

WGS showed that isolates from ill people are closely related genetically to one another. This close genetic relationship means that people in this outbreak are more likely to share a common source of infection.

Epidemiologic, traceback, and laboratory findings have identified dairy bull calves from livestock markets in Wisconsin as the likely source of infections. Dairy bull calves are young, male cattle that have not been castrated and may be raised for meat. Dairy bull calves in this outbreak have also been purchased for use with 4-H projects.

In interviews, ill people answered questions about any contact with animals and foods eaten in the week before becoming ill. Of the 19 people interviewed, 15 (79%) reported contact with dairy bull calves or other cattle. Some of the ill people interviewed reported that they became sick after their dairy bull calves became ill or died.

One ill person’s dairy calves were tested for the presence of Salmonella bacteria. This laboratory testing identified Salmonella Heidelberg in the calves. Further testing using WGS showed that isolates from ill people are closely related genetically to isolates from these calves. This close genetic relationship means that the human infections in this outbreak are likely linked to ill calves.

As part of routine surveillance, the Wisconsin State Laboratory of Hygiene, one of seven regional labs affiliated with CDC’s Antibiotic Resistance Laboratory Network, conducted antibiotic resistance testing on clinical isolates from the ill people associated with this outbreak. These isolates were found to be resistant to antibiotics and shared the same DNA fingerprints, showing the isolates were likely related to one another.

dairy-male-calves-salmonellaWGS identified multiple antimicrobial resistance genes in outbreak-associated isolates from fifteen ill people and eight cattle. This correlated with results from standard antibiotic resistance testing methods used by CDC’s National Antimicrobial Resistance Monitoring System (NARMS) laboratory on clinical isolates from two ill people in this outbreak. The two isolates tested were susceptible to gentamicin, azithromycin, and meropenem.  Both were resistant to amoxicillin-clavulanic acid, ampicillin, cefoxitin, ceftriaxone, chloramphenicol, nalidixic acid, streptomycin, sulfisoxazole, tetracycline, and trimethoprim-sulfamethoxazole and had reduced susceptibility to ciprofloxacin. Antibiotic resistance limits treatment options and has been associated with increased risk of hospitalization, bloodstream infections, and treatment failures in patients.

Traceback information available at this time indicates that most calves in this outbreak originated in Wisconsin. Wisconsin health and agriculture officials continue to work with other states to identify herds that may be affected.

 

1 dead, 4 sick in 2014: Miami cheese producer jailed for 15 months

On August 4, 2014, Oasis Brands, Inc. voluntarily recalled quesito casero (fresh curd) due to possible Listeria monocytogenes contamination.

oasis-listeria-oct_-14On October 6, 2014, Oasis Brands, Inc. recalled cuajada en hoja (fresh curd) after the U.S. Food and Drug Administration isolated Listeria monocytogenes from environmental samples collected from the production facility.

Whole-genome sequences of the Listeria monocytogenes strains isolated from recalled quesito casero cheese produced by Oasis Brands, Inc. were found to be highly related to sequences of Listeria strains isolated from one person who became ill in September 2013 and four persons who became ill during June through October 2014.

These five ill persons were reported from four states: Georgia (1), New York (1), Tennessee (2), and Texas (1).

Four of the five ill persons were hospitalized. One death was reported in Tennessee. Three illnesses were related to a pregnancy – one of these was diagnosed in a newborn.

All ill persons were reported to be of Hispanic ethnicity and reported consuming Hispanic-style soft cheese. Two persons who were able to answer questions about specific varieties of Hispanic-style soft cheeses reported consuming quesito casero, though neither could remember the brand.

According to Andrea Torres of ABC Channel 10, after making promises to the feds, Christian Rivas knew he was distributing cheese with listeria and did so anyway.

Rivas was in federal prison Nov. 11, 2016 and faced 15 moths in prison after federal prosecutors armed with the results of CDC tests and FDA inspections were ready to show consumers were “fraudulently led to believe” the cheese was safe to eat when it wasn’t. 

Before the criminal case, authorities recalled 15 of their “Lacteos Santa Martha ” products targeting Central American migrants in Florida, Georgia, Tennessee, Virginia and North Carolina. The list included the “Queso Seco Olanchano,” the “Queso Seco Hondureno,” the  “Queso Cuzcatlan,” and the “Crema Guatemalteca.”

Rivas plead guilty to charges that he acted with an “intent to defraud and mislead, delivered cheese processed and packed at the Oasis facility into interstate commerce that was adulterated,” according to the U.S. Department of Justice. 

U.S. District Judge Robert N. Scola sentenced Rivas to 15 months in prison.  

Wifredo A. Ferrer, United States Attorney for the Southern District of Florida, and Justin Green, Special Agent in Charge, U.S. Food and Drug Administration, Office of Criminal Investigations (FDA-OCI), Miami Field Office, announced the sentencing

“We will continue to pursue and bring to justice those who put the public’s health at risk by allowing contaminated foods to enter the U.S. marketplace,” Green said.