Why are nosocomial (hospital acquired) infections so infamously difficult to prevent and cure? Obviously, part of the problem is the infectious bugs themselves – MRSA resides in the skin and nostrils, while E. coli is carried in the digestive system, making both of these culprits difficult to keep out of the hospital. It’s been well documented that hospital workers are often lax with handwashing protocols, and there’s even some doubt about the thoroughness of environmental cleaning. However, a recent eight-year study is introducing a new wrinkle in the problem: the weather.
Data from 132 different hospitals is showing a link between the rate of infections and the temperature; as things heat up outside, the rate of nosocomial infections starts rising along with the mercury. So what does this mean? First off, it’s a wake up for health care officials; during warmer weather, they should be especially careful and on the lookout. But it’s also important news for the rest of us; if global climate change leads to warmer temperatures, it could very well increase the overall chances of infection and illness.
In the study, a privately maintained database of more than 200,000 bloodstream cultures from between January of 1999 and September 2006 were used to plot the incidence of infection against the weather. Weather information was gathered from the US National Climate Data Center, and included measurements of mean temperature, dew point and total precipitation. It also accounted for the variations in hospital admissions that are to be expected in different seasons. What they found was that between winter and summer, the Gram-negative bacteria (some of the worst pathogen offenders) showed increases that ranged from slight to extreme. The incidence of E. coli infections rose by 12.2%. Pseudomonas showed a 28.1% increase, while Klebsiella rose 28.6%.
However, Acinetobacter infections, which are known to be very antibiotic resistant, rose 51.8 percent. Those same Gram-negative pathogens showed a rise in infection rate for every 10-degrees Fahrenheit rise in temperature. The size of the increase varied by pathogen, and was independent of season, humidity or precipitation. The next question is, why would this happen? Hospitals in the US are climate controlled, so the interior temperature rarely changes. That means the most likely answer is the increase of pathogen growth outside the hospital in the warmer weather, leading to an increased chance of the bacteria being transferred to inside the hospital. This leads us to an obvious conclusion: hospitals and health care facilities must increase their vigilance in warmer months.
Cleaning and hand washing, while always important, should be doubled. The not so obvious conclusion is this – What happens if the earth is faced with a permanent temperature increase? Unlike earlier studies that were season-specific, this most recent study correlated the rise in infection with any rise in temperature, regardless of the season. So it’s a natural conclusion that if temperatures rise year round, these deadly nosocomial infections will also rise in frequency. Alarmingly, there is also evidence to suggest that not only do these Gram-negative pathogens increase their numbers when it’s warmer; they also become stronger and harder to eradicate. If the Earth’s average temperatures are going up, regardless of the reason, then we can expect to see more of these deadly hospital infections.
Jenny works as a research scientist for legionella testing specialists Dakro Environmental. She does her best to keep up to date with the wide world of infections and diseases, so ultimately she can help protect against them.
