Better Assessing and Managing Risk to Fight Infectious Diseases

As Bill Gates said in 2016 “If anything kills over 10 million people over the next few decades, it’s most likely to be a highly infectious virus rather than a war. Not missiles, but microbes.”

Not only does coronavirus show us how much that could be true today, already with hundreds of thousands of deaths worldwide, but we have many other threats that we are just not prepared to defend against and in this article, we’ll look specifically at the risk of these viral threats in context and suggest an urgent risk-centric path forward that we should take very seriously and perhaps push to the very top of our agenda for future change.

Risk managers of all kinds and in almost all situations like to use a simple four-quadrant grid or matrix with 2 axes — one for the likelihood of a risk emerging and one for the consequences or impact of that risk. This creates a ‘risk-threat’ chart such as the one below for infectious diseases.

The scary thing about this particular chart is that these are only 32 of the pathogens that cause human suffering in the world (and a rough estimate of the deaths they lead to in a given year). Not only could I have added more, but there are pathogens not yet even seen that could occur in the future! Some of these are perhaps old viruses that are trapped under ice in the earth (and could be released by global warming at some point), while others are new mutations within species and between species, that have yet to emerge. In any case, these 32 can be plotted in all 4 quadrants to begin to classify the different risks we should be managing.

It should be noted that even the pathogens in the bottom left of this chart, which are largely controlled today, can resurge to become a huge problem (along with others here) as vaccines run out/lose their controlling effect or antimicrobial or antibiotic defenses are weakened or diminished. My point is that we need a strategy to tackle all of these as a massive priority to protect human and animal health and avoid the impact we have already seen from Covid19.

Of course, most of these quadrant classifications, other than top right, are somewhat relatively arbitrarily assigned, as situations can change quickly as an individual pathogen may (due to massive overcrowding or poor sanitary conditions or poor/no nutrient intake, for example) suddenly mean that a given disease becomes more likely to spread and become more serious as a threat to life as both an illness and ultimately to life itself. We’ll look at this in more detail but first, let’s look at how the mortality rates for infectious diseases are calculated.

Infectious diseases and their mortality rate

Just to be clear, the mortality rate due to any infectious disease is a mathematical function of the following three factors:

· The Rate of transmission of the pathogen

· The Probability that the pathogen will actually cause disease in the individual

· The Probability that the disease will lead to death (case-fatality ratio or CFR for short)

If any one of the above increases, mortality will also increase. We must, therefore, appreciate how certain crisis conditions (e.g. displacement, flooding, food insecurity) can affect the above three factors and allow us to construct charts like the one below produced by W.H.O.

The Key Risk Factors when managing infectious disease risk

Using the 2 risk axes on the first chart I showed above or the Likelihood/chances of emerging’ and ‘Consequences or Impact’, I believe we can identify 8 separate risk factors that we should be thinking about. Of course, when it comes to the potential for emergence and transmission impact, there are clear differences, from country to country in the world, in what might help to accelerate the spread of an infectious disease and cause harm. This is particularly the case when it comes to the relative economic wealth of nations. However, the following 8 factors apply universally, to a greater or lesser extent, so let’s look at each in a little more detail.

· The risk of Overcrowding

o This simply involves a high population density, which leads to the greater opportunity for contact between infectious and susceptible people. Hence, once an epidemic begins, it spreads faster.

o From a purely epidemiological perspective, providing sufficient residential space and avoiding very large groups of people are high impact public health interventions. We have seen this played out all over the US to ‘flatten the curve’ and, in particular, in New York city where US population density is greatest. In the modern world, of course, airplane travel with its recirculated air is a specific risk that many of us face.

· The risk of Insufficient nutrient intake

o Not surprisingly this involves a less than optimal diet and insufficient nutrition, which can lead to lower overall levels of immunity and even scope for higher transmission in groups.

o Lower immunity usually means lower vaccine efficacy, and simply put, higher susceptibility = greater transmission.

· The risk of Poor water, sanitation and hygiene conditions

o Most infectious diseases can be heavily controlled by careful handwashing and good sanitation and hygiene on all surfaces, which can cut the rates of transmission significantly-hence all the education to encourage people to do this as often as necessary.

o It is obviously critical that clean running water needs to be available, ideally in hot and cold temperatures to make this good hygiene possible.

· The risk of Inadequate shelter

o Although this applies much more in poorer nations or with homeless and other vulnerable populations, inadequate shelter usually means insufficient protection, especially to natural elements such as cold or heat and even precipitation, for example.

o Exposure to the elements can lead to hypothermia, dehydration, and other problems, meaning that people become weaker and even more vulnerable and thereby more susceptible to catching the disease.

· The risk of Insufficient vaccination coverage

o In order to protect an entire community to avert an outbreak or quickly control it if it does, we must reach the ‘herd immunity’ threshold coverage.

o We need mass vaccination capability to meet the needs of a given population, but, in practice, this may mean no vaccine yet (in which case we have to use other interventions such as physical distancing) or having enough in stock and deployable as quickly as this is needed. Many countries (including large western world ones such as the US, UK and Italy) simply do not carry enough stockpiles to cover its primary healthcare workers, lets alone others!

· The risk of High exposure to and/or proliferation of disease vectors

o Different diseases spread in a variety of ways and we, therefore, all need to be aware of how this happens. In simple terms, disease spread occurs either directly or indirectly. Direct person-to-person contact usually happens by fluid (touch, fluid exchange or sweat/droplets)-the example here is most STDs.

o Indirect transmission usually happens in airborne/breathable form, from contaminated objects (like doorknobs), from contaminated food and water (often arising from undercooked meats), and from animal to person contact (bites or scratches from dogs or mosquitos, for example). Another transmission form is animal reservoirs which allow a disease in animals to transfer to humans on occasions (called zoonosis). Anthrax from sheep or rabies from dogs or plague from rodents, are all examples here.

· The risk of Individual Susceptibility

o We’ve seen from the current coronavirus situation that the disease has a much greater impact when individuals are older (and perhaps their immune system is less able to cope than younger people) and when they have major prevailing health problems.

o Major health problems in many infectious disease situations include (but are not limited to) Obesity/Diabetes, Heart/Chest/Respiratory problems and having multiple chronic conditions.

· The risk of Lack of and/or delay in treatment

o Once again, we’ve seen from the current coronavirus situation that we cannot leave vulnerable affected people without quick testing and treatment and we need the equipment to help when the infection has a serious effect (e.g. ICU beds and ventilators, not to mention all the necessary PPE to protect people).

o There are two key parameters to consider here in managing this risk: Coverage and Effectiveness of treatment.

Summary and conclusion

There are many infectious diseases in the world with different levels of potential impact on and threat to human life. Some of these are under relatively effective control (mainly with good water supply and sanitation, control of carrying organisms (like mosquito spraying) and effective and available vaccines. However, many others are not well controlled in many parts of the world for many reasons and if many of these diseases emerge, they can quickly overwhelm defenses and quickly create panic and economic crises. To add to this, we have many strains of existing pathogens that we have yet to see (and for which we have no vaccines) and new diseases that have yet to emerge, which have as much or even more potential to be a threat to life as any of those on the chart at the top of this article. For this reason, if fighting coronavirus has taught us anything across the world, it is that we need a much more planful and coordinated effort to manage these threats going forward and this needs to be done at the top of government and with all governments working together well, including committing serious money to conduct more and wider research and committed to quickly deployable resources when outbreaks occur.

One way to start doing this greater planning is to agree at the outset the major risk parameters and then start to manage this on a national and international basis before we experience the inevitable new disease outbreaks we will undoubtedly see in our increasingly crowded and travel-hungry world. This will clearly take a considerable amount of investment and goodwill at governmental level, but given that we can spend trillions ‘reactively’ in a crisis, it will be a much smaller ‘proactive’ investment and help to reduce future costs, both human and financial, considerably. The ‘Bill and Melinda Gates Foundation’ is clearly already working to do this. Perhaps we should encourage every Government to join them in their efforts.

Jon Warner is CEO of Silver Moonshots-www.SilverMoonshots.org, a research and mentoring organization for enterprises interested in the 50+ older adult markets. He is a Psychologist and Adjunct Professor of Entrepreneurship at the University of Redlands in California.