The weather outside is frightful (at least up hear in Canada!) – it’s getting colder, the weatherman now warns us about “flurries” instead of “showers”, there’s frost on the cars in the morning, and we’ve all had to start putting on those extra bulky layers before leaving the house in the morning. There’s lots of grumbling about the oncoming winter weather. Let’s take a look at the silver lining though – people who live at more northern latitudes often don’t appreciate what a few months of cold weather does for us!
Insects in particular, including mosquitoes, ticks and others that transmit various diseases, are almost entirely inactive outdoors when it’s cold outside. Many insect species can’t even survive Canadian winter weather, which is why they are only concerns in more southern climates. For example, the brown dog tick (Rhipicephalus sanguineus), which can transmit many diseases including canine babesiosis, anaplasmosis, and Rocky Mountain Spotted Fever (RMSF, which can also be transmitted to people), doesn’t exist in Canada except on dogs that have travelled to the south. The cold weather also helps keep heartworm in check through mosquito control – the prevalence if heartworm in North America decreases dramatically the farther north you go. Bacterial pathogens are often good at surviving in the cold, but many are killed by freezing, and even if they can survive, it is almost impossible for bacteria to grow and multiply in the cold. Winter provides a reasonable knock-down effect for a lot of pathogens and parasites that often thrive in the outdoor environment during the summer months.
Of course, microbes and insects can still survive in the same environments where we do over most of the winter – indoors, where it’s nice and warm. So it’s still important to do things like wash your hands after handling your pet and before you handle food. And, as always, come spring we’ll have to be prepared for the return of all those worms and germs as we venture back to our favourite warm-weather outdoor activities.
In the meantime, grumble though we may, try not to give old man winter too hard a time – a few months of freezing temperatures isn’t all bad afterall.