Bring Out Your Dead (AKA: Blame the humans)

The Black Plague ravaged Europe starting in the 1300s, with some estimates of 60% of the population being killed. It’s a great history lesson. The only problem? It isn’t history. The plague is still around and still in the US. The plague is also spread by rats and the fleas that love them. Or is it?

Quick background. Yes, the bubonic plague decimated Europe, the Middle East, and Africa. While it started in the 1300’s it was still a big issue through the 1600's. It’s a bacterium (Yersinia pestis – such an apt name) that is vectored by fleas and rats. (Hold that thought, we are coming back to it.) As travel increased, it spread along the Silk Road. More people were crammed together in cities, making it able to spread quickly. Due to poor sanitation, very close living conditions, a lack of effective medical care, and inadequate personal hygiene, people didn’t stand much of a chance. It’s also spread person to person. Because of that, we will never see the plague in the US or any other developed country.

Or will we?

The plague is still around in the US. The CDC reports an average of seven cases per year. The prairie dogs in the southwest are a reservoir, and it’s a short (flea) hop to get to people. That’s probably why Arizona, California, Colorado, and New Mexico have the highest number of cases. The last published data is from 2023 and shows two cases, neither of which was fatal.

Jump forward to just a couple weeks ago – a person in Arizona was diagnosed and died from the plague. In this case, “a person had an interaction with a dead animal infected with the disease." I swear I saw another case earlier this year, but I can’t find it now so if anyone knows, post it in the comments.

I said I’d come back to this: rats have gotten all the blame. Some recent research is disputing that. I’d explain it, but the researchers did a great job:

"Models predicted different patterns of disease-induced death; for example, if the disease spread mainly through direct person-to-person transmission, we would expect a sharp, short-lived spike in deaths. Conversely, if rat fleas were mainly spreading plague by biting humans, we would expect a reduced number of deaths sustained over a longer time period. When comparing the results of their mathematical models to the mortality data recorded from nine different Second Pandemic outbreaks, the authors found that their human parasite model fit best. In other words, their findings suggest that human fleas and lice, not rats or their fleas, were primarily responsible for spreading plague during the Black Death.

This doesn’t mean the rodents are completely off the hook. They were certainly part of it, and we need to continue implementing good rodent control programs for the plague and the many other diseases rodents can directly and indirectly spread. We are seeing a big push by states, cities, and towns to ban rodenticides. That means more rodents. California has done this, and guess what? They are having more rodent problems. I’m not going to get into the wildlife issues or anything else on this subject. It’s fair to say that the more rodents (geographically close to those prairie dogs) there are in a highly populated state, the greater the chance for disease transmission.

As we head into autumn and temperatures drop from the surface of the sun to more manageable heat, more people will be outdoors and potentially interacting with rodents. Those fleas (as well as ticks, mosquitoes, and other biting creatures) will happily snack on a human if one is available.

While we certainly have better medical care than in the 14^th century, it’s not a great idea to go looking for trouble. The bubonic plague has a 30-60% mortality rate. If you don’t die, you are still going to suffer from inflamed lymph nodes: the “bubo” which is the pus-filled wounds you’ve probably seen in pictures. You will also be stricken with fever, chills, and headache. Then, there’s shortness of breath and a really nasty cough. If it gets to septicemic, you can add in abdominal pain, and “possibly bleeding onto the skin and other organs. That can turn the skin black and it dies.

Moral of this story: rodent control is a public health issue. People also need to take personal responsibility and wear a CDC approved repellent. Rodent control programs reduce rodent populations and reduce the risk of rodents being near structures. I doubt we will ever see the severity and mortality that the 14^th century had, but it will still be a very nasty pandemic that will be debilitating on many levels.

We can help you update your rodent control programs to make them more effective and preventative.

Contact us.

Lagniappe – good news, there is a vaccine in the works.

Urban Pest Consulting