PulseNet Explains Why It Doesn’t
Jim Prevor’s Perishable Pundit, October 18, 2006
We’ve been exploring the story both here and here that PulseNet, which is the major mechanism for identifying foodborne illness outbreaks — whether caused by terrorism or other reason — closes on the weekend
In the spinach crisis, the key report connecting the dots of people getting sick and their consumption of bagged spinach was sent to PulseNet after 5 pm on Friday, when PulseNet was closed for the weekend. It is possible that people got sick, because that important data sat unlooked at until Monday morning.
Here is the link to the LA Times article that establishes the timeline.
Pundit investigator Mira Slott was able to get a comment from Peter Gerner-smidt M.D., Ph.D., Acting Chief, Enteric Diseases Laboratory Response Branch, Center for Disease Control & Prevention.
Dr. Gerner-smidt gave his take:
The PulseNet laboratory and database at CDC is usually shut down during the weekends because the state laboratories don’t submit data to the database on weekends because they also are closed.
After the outbreak was recognized, PulseNet checked for submissions also during the weekends. The delay that is introduced in the surveillance by the PulseNet labs (at CDC and in the states) not working the weekends does not add much to the total time it takes to recognize an outbreak. It usually takes approximately two weeks from when a patient becomes ill with an O157 infection until the isolate is submitted to the PulseNet database.
Unless all the patients in an outbreak become ill at the same time, it will also take a few days before a sufficient number of isolates with indistinguishable profiles have been submitted to the database to enable the recognition of the outbreak. The first week is gone before the patient sees a doctor and has a stool specimen examined. The second week goes by finishing the diagnostic work in the clinical laboratory, forwarding the isolate to the public health lab, where it is confirmed as an O157 and sub-typed further by PFGE.
It would increase the cost of the PulseNet system considerably if the public health labs and CDC were to work routinely on weekends… funds that are not available.
To which there are a few responses:
- When Wisconsin entered its data into the system, Wisconsin was open, PulseNet was closed. At the very least, if PulseNet wants to conform to the hours of state laboratories, it has to do so from opening time on the East Coast to quitting time on the West Coast. Since these are scientists, doctors and public health professionals, it certainly is reasonable to think they may work until, say, 7:00 PM. So if the criteria is to conform to state lab hours, PulseNet should be open until at least 7:00 PM Pacific Time or 10:00 PM East Coast Time.
- Leaving state lab hours aside, Dr. Gerner-smidt’s rationale for being closed on weekends could apply equally to closing PulseNet on Wednesdays or any other day. Yes, of course, it typically takes more than one day to identify an outbreak, but there is an equal chance of sufficient data arriving at PulseNet at 5:15 PM on a Friday as there is on a Thursday or Wednesday. To not be open to review data that Wisconsin, much less Colorado or California or Hawaii, is sending in is unacceptable. And in this case people may have gotten sick unnecessarily.
- As far as the cost goes, keeping PulseNet open every day until California calls and says they are closing for the night is pretty insignificant as costs go. Strictly on a financial basis, remember that avoiding one death is a reduction of liability in the millions. Not to mention if it should ever be terrorism, obviously we would want to know the first possible second. Funds are never available until they are requested. I am going to bring this to the attention of some of our friends in Congress. We can find money for such an obviously sensible project.
- A whole other question is why in the world the state laboratories are closed on weekends. It seems like decisions on these matters are being thought of like a civil service issue rather than a need issue. Hotels are open on weekends because travelers need lodging every night. The desire of employees not to work weekends is really beside the point. Equally people get just as sick on Saturday as they do on Tuesday, and not processing these matters on the state level on the weekend delays passing the info to PulseNet. This means people are needlessly falling ill and, perhaps, even dying. It is simply unacceptable in this day and age.
There is one bright spot as Dr. Gerner-smidt went on to explain:
PulseNet is not changing its ways because of this outbreak. However, PulseNet is working on speeding up the detection of outbreaks by introducing new more rapid subtyping methods to supplement and perhaps replace PFGE in the future. One of these methods, called MLVA, is currently in the final stages of being validated and will gradually be introduced in the PulseNet laboratories starting now.
That is great, but speeding up the typing doesn’t change the fact that if California, Oregon and Washington each submitted some MLVA subtyping at 2:15 Pacific Time in the afternoon on Friday, nobody would do anything with the data until Monday morning. That is penny wise and pound foolish, and could cause people to suffer needlessly. That simply cannot be allowed to continue. I’m going to start my letter-writing right away.