Herd Immunity: Spotting MRSA and Other Superbugs Should Be As Easy As Mapping Cows

In Montana, my home state, there are more cows than people - and not by a small margin. At 2.6 million head of cattle and 998,000 people, that's nearly three head of cattle per person.

State and federal agricultural agencies can tell you with precision about the location and status of these animals. They know about their health and their potential for generating economic wealth. They create maps that show precisely how many cows there are in every county in the United States.

And yet no state or federal health agency can provide you a similar level of detail about a different animal that poses a serious health threat to people: methicillin resistant Staphylococcus aureus (MRSA).

To highlight the absurdity of this situation, two academics at the patient advocacy organization Health Watch USA juxtaposed the mapping of cattle with the lack of mapping of MRSA for a brilliant bit of dark comedy: A tale of two cows: Why we have a cow map and not a healthcare acquired infection map. In it, they show how definitional disputes and other minutiae have blocked effective monitoring and data collection. Here's just one piece of what they wrote. (When you see "cow," think "MRSA.")

One state counted two cow herds that year; a true landmark for cow counting! Other states reported no cow herds whatsoever. It was later found that many cows were not counted that first year due to a low number of farmhands, as scores were fired because of financial cutbacks. In addition, no one was verifying if the counting was being done properly. Of course, farms with less than 25 acres weren't required to count cows, as their cow population was deemed negligible.

The satire is rooted in truth. One state actually did report just two MRSA outbreaks for an entire year. Saman and Kavanagh write:

The reporting burden has also been used as an excuse not to report. This has caused some states such as Kentucky to only require the reporting of outbreaks (herds in the above example). Kentucky uses the Centers for Disease Control and Prevention definition of an outbreak, which is a frequency of infection above a baseline. However, the definition of a baseline is left up to the facility. Preliminary data from the Kentucky State Department of Public Health revealed only two reports of infection outbreaks by all Kentucky hospitals during 2011. This data validates how grossly under-reported this epidemic really is.

And another map on Health Watch USA's site shows the huge differences between states in reporting requirements. Washington, where I live now, requires reporting of infections to the state, and the state makes that data public. But Montana has no reporting requirements. It bears repeating: why should people in Montana know more about their cows than their healthcare-acquired infections?

I asked Kavanagh whether the ultimate goal should be a detailed map that shows the number of infections at each healthcare facility. Kavanagh wrote me:

The piece does not call for facility specific data only to get data to outline how severe the problem is that we are dealing with. This will allow community and healthcare action. Patients may be more motivated to make sure their rooms are clean and to have all visitors wash their hands. The same is true from restaurants, etc. This is a not only a hospital or healthcare system wide problem, but it has progressed to a problem affecting the whole community. I feel facility specific data should be made available in both risk-adjusted (when able) and non-risk adjusted forms. After all, how do you risk adjust zero, one or two central line-associated bloodstream infections? The op-ed stops just short of calling for this. The health departments and government should definitely have facility specific data, but there are significant political roadblocks in making this public. There is no reason why aggregate data is not available to be released.

In future posts, I'll write more about ways to improve the mapping of healthcare-associated infections.

Do you have a thought about how best to track MRSA and other infections to improve patient safety? Share it in the comments below, send it to askantidote@gmail.com or ping me on Twitter @wheisel.