A colleague recently let me know about an article in the journal Infection Ecology and Epidemiology entitled “Human wound infectious caused by Nesseria animaloris and Neisseria zoodegmatis, former CDC Group EF-4a and EF-4b" (Heydecke et al 2013).
These are new bugs to me…
The article outlines an effort to characterize these bacteria from people with wound infections, most from dog bites. Thirteen bacterial isolates were studied – 11 were determined to be N. animaloris and 2 the related bacterium N. zoodegmatis. The authors concluded that localized infections occur most often, but severe complications can sometimes develop and that recovery is often slow (probably because of suboptimal treatment).
The true role of these bacteria in disease is unclear, since they might be missed by diagnostic labs or misinterpreted as being contaminants (and therefore not tested further or reported). These bugs tend to be resistant to quite a few antibiotics, so identifying them promptly is important to get the right treatment started.
There’s never a dull moment in infectious diseases. We’re constantly hearing about new pathogens. Sometimes, it’s because people just rename bugs about which we already know a lot. Sometimes, it’s because we realize that what we thought was one bacterial species is actually more than one. Sometimes, it’s because we realize that something we’ve dismissed as innocuous is truly a potential problem (so we start paying attention to it). Finally, sometimes truly new microorganisms are identified. With bacteria, the latter usually happens when someone first figures out how to identify an organism that’s been around for a while, but true emergence of new microorganisms can occur.
Anyway, whenever a new bug is found, it’s important to figure out how relevant it is. In this case, in the end, we’re still left with the main point being that the mouths of our domestic pets are cesspools of bacterial badness. Most often, our skin and immune system are able to prevent this from being a problem. However, when bites occur (or in other situations, such as licking wounds or when people have compromised immune systems), the potential for disease increases. Yet, it doesn’t really matter what the bug is – the key prevention points are the same:
- Reduce the risk of bites by good animal training, good animal handling and common sense.
- Promptly and thoroughly wash any bite wounds.
- If you have a compromised immune system, make sure you talk to your physician about any risks of pet contact and what to do in the event of a bite.
This report doesn’t mean that dogs are any higher risk to people than they were before. It just means we have a new name for a risk that’s been present for a while.