Tag Archives: CDC

On Washing Hands

As we enter flu season, I think that the importance of hand-washing can not be overstated for maintaining health. Here is a (somewhat ugly) flyer published by CDC:


You'd think CDC could hire some graphic designers!

Two things that I think many people don't appreciate: (1) washing hands with hot soapy water is better than using alcohol-based sanitizer and (2) you need to wash your hands for a long time to get best results.  A funny story on NPR last spring provides some ideas for timing your hand-washing.  I'm afraid I can't help but sing Bohemian Rhapsody (starting at time stamp 3:06 for 20 secs) while washing my hands ever since hearing this story...

Trailing Off of the Epidemic Curve?

The latest CDC report on the ongoing Salmonella serotype Saintpaul suggests that we may indeed be nearing the end.  Here is the epidemic curve as of 28 July:

28 July Salmonella Epidemic Curve

While there is certainly still the possibility of more cases appearing that have not yet been reported or another introduction (see previous post), the fact that the epidemic curve has continued to trail off in two successive weeks is good news.

The epidemiological evidence continues to implicate fresh jalapeño chiles grown in México.  As of 28 July, 1307 cases have been reported since 1 April 2008. Nearly every state in the union has reported at least one case from this outbreak, as can be seen on this map:

CDC Map of Salmonella Cases 07/28/08

Again the most likely victims (at least to report illness) are 20-29 year-old adults while the least likely to report illness are 10-19 year-olds and those over 80.  Once again, I suggest that this is consistent with a vehicle consumed along with alcoholic beverages. Salsa.  Though contaminated jalapeños (or other produce) could, of course, make their way into other foods as well. The Saintpaul strain was relatively rare before this outbreak, leading CDC to suggest the following:

The previous rarity of this strain and the distribution of illnesses in all U.S. regions suggest that the implicated food is distributed throughout much of the country. Because many persons with Salmonella illness do not have a stool specimen tested, it is likely that many more illnesses have occurred than those reported. 

Let's hope that this outbreak is really coming to an end.  It would be nice if we could identify the source of the infection.  Foodborne disease is an important public health concern that probably does not receive the attention it should.  A 1999 paper by Mead and colleagues (admittedly now a bit long in the tooth) estimated that foodborne diseases cause approximately 76 million illnesses, 325,000 hospitalizations, and 5,000 deaths in the United States each year.  It is not hard to imagine that in the 10 years since this study the foodborne disease burden has increased in the U.S.  Time for another study, I'd say.

Salmonella Outbreak: Is It Really Tomatoes?

An outbreak of Salmonella serotype Saintpaul has sickened 943 people since April.  Nearly 14% of these cases required hospitalization. It has been hypothesized that tomatoes have been the vehicle for this food-borne infection.  Here in Palo Alto, certain types of tomatoes (e.g., Roma and beefsteak) were taken off store shelves for a while.  The latest report from CDC suggests that tomatoes may not, in fact, be the culprit.  CDC epidemiologists are expanding their investigations to include food items that are "commonly consumed with tomatoes."

Epidemiological evidence indicates that while people of just about any age can contract the infection (age range of cases is <1-99 years), the most likely age group to contract the infection are 20-29 year-olds.  The least likely age classes are 10-19 year-olds and people over 80.  What food do young adults commonly eat with raw tomatoes that is less commonly eaten by the young or very old?  I'd say salad greens but if that were the case, I'd expect a sex bias in infections.  50% of the infections are women and my informed guess (based on my experience with largely middle-class college students) is that 20-29 year-old women eat more salad than 20-29 year-old men.  

So what is it if it's not tomatoes?  Something having to do with consumption of alcohol? Some salsa ingredient like jalapeños or scallions? (note: another thing consumed in bars)