Archive for ‘Outbreaks’

President Creates Food Safety Working Group. Why Not a Review Board?

By Bala Swaminathan, 16 March, 2009, No Comment

In his radio address yesterday, President Obama announced the creation of a Food Safety Working Group. It will consist of cabinet secretaries and senior officials and will advise the President on how antiquated food laws can be updated for the 21st century, how coordination between various federal agencies can be improved and how current and new food laws and regulations can be effectively enforced.

While this is definitely a step in the right direction, I wish the President had gone further. It is time to create a National Food Safety Review Board to continually review the workings of the various federal agencies involved in food safety and advise the President. An ideal NFSRB would be composed of members who are not presently associated with the executive branch but have extensive previous experience in different aspects of food safety: food laws and regulations, food policy, foodborne disease surveillance and epidemiology, public health microbiology and food microbiology, food production and processing, food sanitation and hygiene and inspection of food processing facilities). The tasks outlined by the President for his Food Safety Working Group will be more effectively performed by an independent review board than a group comprised of the secretaries of the agencies involved in foods safety and the senior officials from those departments.

Specifically, a NFRSB should have the following responsibilities:

  • Periodic review of the priorities of each agency involved in food safety and how effectively they are implementing actions to address these objectives
  • Review whether additional food safety funds requested by the President and appropriated by the Congress are being used for the purposes for which they were provided and whether the implementation has had a measurable positive impact on food safety
    • Example 1: If the Food and Drug Administration is provided additional funding for more food inspectors, the NFSRB will determine how many additional inspections of national and international food processing facilities were conducted and what was the demonstrable public health impact of these increased inspections
    • Example 2: If the Centers for Disease Control and Prevention is provided additional funding to improve surveillance and accelerate outbreak recognition and investigations, the NFSRB will assess the impact of any new programs implemented by CDC to ensure that these steps have resulted in a measurable positive impact
  • During the investigation of major foodborne disease outbreaks by the public health agencies and food regulatory agencies, the NFSRB will have a facilitation and coordination role and will ensure that all critical and relevant data are being shared between the agencies in a timely manner.
  • Within a reasonable period after the acute phase of an outbreak investigation is completed, the NFSRB will conduct a thorough review of the investigation with respect to the performance of the agencies involved. The NFSRB will issue a report within a specified time period indicating what was done right and what could be improved.
  • The NFSRB will work with the federal agencies to make sure that information about the outbreak investigation is released to the interested parties and the general public in a timely manner.
  • The NFSRB will assess the funding needs of the agencies involved in food safety and provide input to the President for the next budget

Where Federal Funds Should Go to Avoid Another Outbreak

By Bala Swaminathan, 12 February, 2009, No Comment

It doesn’t look like food safety is going to make it into the economic stimulus bill that President Obama will likely sign before week’s end. As we mentioned earlier, a number of politicians, however, have called for reform. As the United States Congress works to appropriate additional funds to enhance food safety and prevent the recurrence of the peanut butter fiasco, here are a list of priority needs that I wrote up with the help of my friend Craig Hedberg of the University of Minnesota. (I am excited to announce that Craig will soon be contributing to our humble blog.):

1. FDA’s Food Protection Plan is built around the concepts of prevention, intervention and response. Although no amount of inspectors will ever provide an absolute guarantee for the safety of food, more are needed for FDA’s Office of Regulatory Affairs (ORA) in order to ensure that food processing establishments are checked out on a regular basis.  Beyond more inspectors, a broader scope to the inspection process is needed: Regular inspections that were informed by knowledge of the 2007 outbreak of salmonella in peanut butter and included reviews of critical control point-monitoring records and environmental and product test results might have prevented or at least limited the impact of the Peanut Corporation of America outbreak. Interestingly, the ORA website doesn’t express our concern about the need for more inspection resources:

The FDA’s ability to protect the public health has been enhanced by additional resources authorized by Congress in the wake of the Sept. 11, 2001, terrorist attacks. The FDA hired 655 new ORA employees, 600 of whom strengthen food safety, 35 enhance the safety of animal drugs and feed, and 20 are part of the drug, biologic and device programs. About 420 of the new inspectors and other employees either are stationed at border locations or are working specifically on imports. All of the new hires will be trained in both import and domestic operations to help ensure adequate coverage of both domestically manufactured and imported products.

Obviously, that wasn’t enough to conduct inspections of the Peanut Corporation of America’s manufacturing operations.

2. Timely intervention and response requires ongoing surveillance that can identify potential outbreaks early and investigate them rapidly.

a. Because public health surveillance is primarily conducted at the state and local levels, CDC needs funding to enhance epidemiological capacity at state and local health departments. This should be directed to ensure that food history questionnaires will be administered to persons contracting foodborne diseases in a timely manner. The “Team Diarrhea” concept pioneered by the Minnesota Department of Health has proven to be an efficient and cost-effective model for accomplishing this objective. CDC, with assistance and input from the Minnesota Department of Health and University of Minnesota School of Public Health, should use these additional funds to create a series of regional centers for surveillance based on the “Team Diarrhea” model. Standardized questionnaires should be developed to allow for electronic data collection and transmission to a national database that could be linked to PulseNet.

b. Funding for CDC should be increased and directed to assure rapid DNA “fingerprinting” of foodborne disease-causing bacteria and viruses by state and local health departments and timely submission of the DNA “fingerprint” patterns to the national PulseNet database maintained by CDC. CDC and the state and local health departments should be adequately funded so that they can use the best available technologies to obtain the most accurate possible information on disease clusters in a timely manner. States must be encouraged to make appropriate changes to their existing laws to ensure that foodborne pathogen isolates are submitted to the local or state health department as soon as possible for DNA “fingerprinting.”

c. CDC and the state health departments should be provided adequate human resources to conduct frequent and timely review of epidemiological information and PulseNet data to rapidly identify disease clusters and follow up without delays.

CDC Updates Case Count in the Peanut Butter-Associated Salmonella Outbreak

By Bala Swaminathan, 11 February, 2009, No Comment

CDC’s update of February 9 indicates that the case count is now 600 with illnesses connected with the outbreak being reported in 44 states. The onset date of the most recent illness associated with the outbreak was January 23.

Also, CDC has informed me that the PulseNet pattern JPXX01.0459 is indeed a new pattern that was first submitted to the PulseNet National Database in September 2008. (I had previously guessed that it was an old pattern.  Apparently, some of the old pattern numbers assigned by the National PulseNet Database Team are being recycled.)

CDC’s Recent Salmonella Report Raises Questions

By Bala Swaminathan, 6 February, 2009, No Comment

On January 29, CDC published a very comprehensive report, which details the various facets of the investigation into the peanut butter outbreak. The latest figures show 550 cases of infections in 43 states; the most recent case developed illness on January 17.

I wish CDC had provided a timeline of the outbreak investigation as they did in the spinach-associated E. coli O157:H7 outbreak in 2006. To that end, I tried to construct a timeline of events from the data provided in the MMWR report. I invite informed readers to bring any mistakes and omissions in the chronology to my attention in the comments section.

Click on image for a larger version.

Click on image for a larger version.

After reading the report, I came up with a list of the following questions and concerns:

  1. The PulseNet network appears to have detected the outbreak at an early stage: when the case count was 13 and it appeared to be a 12-state cluster on November 10. It is interesting that all patients in the disease cluster had been infected with a previously not seen strain of Salmonella Typhimurium that had a unique DNA “fingerprint.” This is much more meaningful than a cluster of 13 case patients infected with a frequently encountered strain of S. Typhimurium.
  2. On November 24, PulseNet reported a second cluster of 27 patients who had been infected with a strain of S. Typhimurium that was closely related to the strain from the first cluster.
  3. By November 25, the number of cases in the first cluster had increased to 35. This is when the CDC OutbreakNet team began an epidemiological investigation with its partners in state and local health departments. My question: Were any patient interviews conducted between November 10 and 25? Were any food exposure questionnaires administered to the cases in the cluster between November 10 and November 25?  Could the lapse of time have contributed to problems with accurate recall of food exposures?
  4. By December 2, the cases in the second cluster had increased from 27 to 41. Additional laboratory characterization of the salmonella isolates from the first and second clusters and epidemiological data from the two clusters indicated that they were part of the same outbreak.
  5. I am struck by the time it took (six to eight weeks, November 10 to December 28, when King Nut came under suspicion, and January 12, when the company’s involvement was confirmed) to identify the source of the outbreak. I wonder if it was because the peanut butter was distributed in bulk packages to institutions such as nursing homes and schools and was NOT sold in retail outlets. Also, it is likely that the epidemiological investigations were confounded because the contaminated peanut butter was used as an ingredient in many different food products that were sold through retail outlets under several different brand names. In any case, it is apparent that the early warning signal provided by the PulseNet network did not prevent a large buildup of cases associated with the outbreak.
  6. This is the third peanut butter-associated outbreak of Salmonella infections that has been recognized and investigated. These include the Australian outbreak of 1996 and the U.S. outbreak of 2006. Interestingly, the serotypes of Salmonella associated with all three outbreaks (Salmonella Mbandaka in 1996, Salmonella Tennessee in 2006 and Salmonella Typhimurium currently) have been isolated from the product implicated in today’s epidemic (more than 2,700 serotypes of Salmonella are known. Typhimuirum is a very commonly encountered serotype; Tennessee and Mbandaka are infrequently isolated). In fact, the exact same strain of S. Tennessee that caused the 2006-2007 outbreak was isolated from a product implicated in the current one.
  7. The low numeric value of DNA “fingerprint” pattern JPXX01.0459 that was isolated from the ill humans and from the implicated product in Connecticut, Michigan and other states indicates that this pattern previously existed in the PulseNet database (pattern numbers are assigned sequentially by CDC PulseNet Database Team in the order in which they are deposited in the database). Since the MMWR report did not elaborate on the significance of JPXX01.0459, I am assuming that this was probably a sporadic case isolate without much clinical/epidemiological information.

Click image for larger version (on CDC site).

Table of salmonella strains associated with outbreak. Click image for larger version (on CDC site).

We will learn a lot more about the outbreak and the investigation of it in the next weeks and months. The finding of multiple, closely related Salmonella Typhimurium strains in ill persons and the implicated product suggests that the parent strain of Salmonella Typhimurium may have been resident in the peanut butter processing facility for some time. If that was the case, why did it not cause illnesses before? What triggered this outbreak? What is the significance of the finding of the salmonella strain from the 2006-2007 outbreak in King Nut peanut butter? Is there a connection between the two outbreaks? I am sure CDC is in hot pursuit of answers to these questions.