Just Finished Reading: Deadly Companions – How Microbes Shaped Our History by Dorothy H Crawford (FP: 2007/2018) [215pp] 

Viruses, bacteria and parasites have been around far longer than humans. But interestingly it’s only comparatively recently that we have been exposed to those microbes responsible for the great epidemic diseases that fill our history books. For most of human history the vast majority of people lived in hunter-gatherer bands of around 50-150 people. In that kind of environment there was little ‘purchase’ that any virus (for example) could take hold of. With only a few tens of possible targets to infect the early human diseases where either shrugged off, killed or debilitated their hosts enough that the group could no longer sustain them or recovered from the agent and acquired a level of immunity to further infection. Within a very short time the infectious agent had nowhere left to move to – and died out. It was only at the very dawn of human history, when people began settling in larger static communities that all of the diseases we know and, at least some of us, have coped with took hold. From that date to very recent human history humanity has had to cope with (or more often suffer through) epidemic, plague and pandemic events ever since. This, in a nutshell, is the story told in this excellent short book. 

With the advent of modern medicine and especially techniques like inoculation and vaccination, it’s sometimes easy to forget just how dangerous, deadly and frightening disease was. Before the wide acceptance of Germ Theory people had no clear idea of why people got sick and died. Even once the vector of the disease was understood it still took a long time to devise ways to combat it – especially the deadliest epidemics that swept through Europe in the Middle Ages like the infamous Black Death in the 14th century that killed over 30% of the population with deaths exceeding 60% in places. Such events could not help to be both catastrophic and life changing on an historic scale. [Side note: It’s interesting to see that the reasons for the end of the widespread plague outbreaks have yet to be definitively accounted for. They simply stopped without any apparent reason and certainly not because of human action.] Thankfully, most of the old scourges that literally plagued mankind have been eliminated – at least in countries with access to safe drinking water and with a health community of a sufficient level to tackle them. Instead, we have a growing issue with anti-biotic resistance and the distinct possibility of new diseases (or old diseases in new packages) introduced into the human population as the result of climate change, habitat destruction and a transport system seemingly designed to spread pathogens in the most effective way possible – as we saw very recently with the COVID-19 outbreak we’ve just lived through.  

I’m never one to shy away from a topic that’s exploding (or has recently exploded) on the News and I’m a firm believer that it’s far better to know stuff and be informed than to be ‘safely’ ignorant. This is very much a general introduction to human pathogens and how we’ve dealt with them over the millennia and is a very useful background read for anyone new to or refreshing their knowledge of epidemiological history. Recommended.