John Metcalfe was CityLab’s Bay Area bureau chief, covering climate change and the science of cities.
Bacterial infections are killing more people in some parts of country, but not others.
Dying from sepsis is not an exit most would choose. Virulent microbes marching through the body trigger an immune response, which causes a massive inflammation that can be marked with fever, confusion, "absent bowel sounds" and organ failure – a third to half of patients with severe sepsis perish from it, essentially due to the body poisoning itself.
Unfortunately, Americans are likely to hear more and not less about sepsis, because the condition seems to be on the upswing here. Reasons for that range from an older population that's more at risk to the rise of drug-resistant bacteria. It's unnerving to think that something that killed about 35,500 people in 2011 and costs the U.S. healthcare system billions of dollars annually could get worse because of our failure to prevent it.
But the sepsis puzzle just got a slight bit clearer, thanks to new research from the University of Pennsylvania. A medical team has conducted a detailed survey of American sepsis mortality, identifying several "hotspots" with abnormally high reports of deaths. They also located a "coolspot" in the western part of the country where sepsis rates appear to be below average. Take a look at where bacteria are making life miserable in this map of severe-sepsis deaths in 2010:
It would appear that the eastern half of the U.S. is disproportionately suffering. The inequality looks more pronounced in this second map, which shows counties with high rates of severe-sepsis deaths in 2010:
Sepsis incubators appear in the Mid-Atlantic, the Midwest and the South, and there seems to be less of it in the Southwest and Rocky Mountain states. These disparities are not what the research team initially expected to uncover, says David Gaieski, an assistant professor of emergency medicine at UPenn's Perelman School of Medicine.
"We thought we'd find it to be sort of homogenous across the entire country. The variation we found was striking," he says. "There is definitely something going on there. The question is, What is it?"
Gaieski thinks there could be multiple answers. Assuming the map gives an accurate picture of the sepsis scene, the hotspots might be due to older populations, ethnic differences, the quality of care or variations in the microbes themselves – whether they're resistant to antibiotics or not in that location, for instance.
In the Mid-Atlantic, the nasty bacterial infections could be influenced by the advanced age of the population, the urban density and the proximity of people to "medical centers that do lots of transplant care or oncology work," says Gaieski, although that's only a theory at this point.
Brilliant bacterial blooms in certain areas could also indicate a lack of bureaucratic harmony. People who enter hospitals get coded according to their afflictions. Whereas a person might receive a code for sepsis at one hospital, at another he or she may be branded with "low blood pressure," a symptom of the disease. "We need a uniform coding or reporting system," says Gaieski.
The university's step toward mapping the geography of infection could one day lead to a "paradigm shift" in treating disease, Gaieski says. That could come in the form of more trauma centers specifically geared to handle patients with severe infections. It might also mean earlier recognition of sepsis, perhaps through standardized point-of-care screening, and improved forms of resuscitation.
"Some of those things are not done in 100 percent of hospitals," Gaieski says. "We need to get the stuff that's known to work at all hospitals. We'd get way better outcomes, right off the bat."
Images courtesy of Penn Medicine