Tracking down the source of infection outbreaks is tough (see Chapter 2 in Germ Proof Your Kids – The Complete Guide to Protecting (without Overprotecting) Your Family from Infectons (ASM Press, Washington, D.C., 2008). The disease detectives from your state and local health departments, as well as from the Centers for Disease Control and Prevention (CDC) do extensive interviews of infected individuals in an outbreak, and compare their exposures to uninfected individuals. As with the recent national Salmonella outbreak, sometimes the clues that emerge are mixed or muddied. Whereas 5 weeks ago tomatoes seemed to be the most likely culprit (see Dr. Rotbart’s GERMBlog entry from June 8, 2008), now attention is focused on peppers (jalapeno and serrano varieties). This doesn’t yet absolve tomatoes in the earlier cases, but the farms producing them back in April and May are no longer in production and there are still cases of Salmonella occurring, albeit at a slower rate. So…the investigations go on. One unifying hypothesis might be that salsa containing both tomatoes and peppers is at the root of some of the cases – but not yet tested or proven.
This is not a case of crying wolf (or crying tomatoes, as the case may be), nor a case of a botched investigation. Rather, it’s evidence that tracking germ routes and germ roots is challenging and often time-consuming (see Chapter 2 in Germ Proof Your Kids – The Complete Guide to Protecting (without Overprotecting) Your Family from Infectons).