Jamie Funnell contributed to the writing of this post
Rewind to 1900 and infectious diseases were the second biggest cause of death in England and Wales. By 1960, deaths from infectious diseases were all but eradicated.
However the recent rise in antimicrobial resistance (AMR) – effectively the resistance of viral and bacterial disease to drugs – poses a serious threat to modern medicine; David Cameron even suggested it could send medicine 'back into the dark ages'1.
Source: ONS data
This statement may appear overly dramatic; however, the rise in AMR threatens to render current treatments ineffective and even potentially dangerous. The risk of infection following major surgery, organ transplantation and chemotherapy – treatments which already put considerable strain on the immune system – could increase significantly; it has been estimated that up to 40% of patients having total hip replacements would suffer a post-operation infection with a 30% fatality rate2. The possible threat has seen AMR included on the UK’s National Risk Register of Civil Emergencies alongside terror attacks and natural disasters.
Antibiotics are commonly prescribed for many infectious diseases and resistance to these drugs threatens to render these diseases more potent. Increasing patient pressure and so-called 'soft-touch' doctors have seen antibiotics over-prescribed – often for conditions such as the common cold when they will have no effect at all - to such an extent that there have been recent calls for GPs to be punished over the issue3. Considering the rapid improvement in mortality from infectious diseases since the 1900s as shown in the chart, one could be forgiven for overreacting to this threat. Antibiotics were not commercially available until the late 1940's and by this point much of the improvement in mortality driven by infectious diseases had already been realised; primarily through improvements in hygiene and better social conditions.
"Antibiotics are commonly prescribed for many infectious diseases and resistance to these drugs threatens to render these diseases more potent"
AMR can arise naturally from random mutations in disease-causing microorganisms, but it is accelerated by the prolific use of antibiotics and antivirals. While the impact on current treatments poses a serious threat, the emergence of a disease that is immune to all known drugs, ushering in a pandemic akin to the 1918 influenza outbreak illustrated by the spike in respiratory diseases in the chart, has the potential to be far more devastating in the short-term; modelling suggests there could be up to 750,000 excess deaths caused by such a pandemic4. The damning self-commissioned report5 into the World Health Organisation’s ability to handle such a pandemic referencing the recent Ebola crisis further adds to this worry.
For actuaries, it may have another, less recognised impact on mortality improvements. We have shown in our recent research6 that there is considerable annual volatility in crude mortality improvements due to short-term factors especially influenza. The treatment for influenza most often involves a course of antiviral drugs and research into the 2009 H1N1 pandemic suggests a 65% mortality reduction with early treatment7; if these treatments were undermined by AMR we could see an increase in the severity of this variation, although the level of this impact in comparison to that from vaccine effectiveness, vaccine uptake and cold weather is difficult to quantify.
Quantifying the impact of the various risks associated with AMR is difficult, both due to the complexity and lack of data on the subject, but it clearly has the potential to have a significant impact on mortality improvements going forward.
2 Smith, R and Coast, J. The true cost of antimicrobial resistance. BMJ. 2013; 346: 1493