Measuring standards of global health is the cornerstone of protecting both humans and animals alike.
Over the past two years, the Covid-19 pandemic has taught health officials and experts two crucial things in that regard.
The first, as continued daily reports of new cases and deaths show, is that managing health threats first requires measuring them. The second is that human health can only be protected in conjunction with animal health under a One Health approach, whether that means preventing zoonotic diseases from passing to people from wild animals like bats or keeping livestock healthy to produce enough meat, milk and eggs.
The lessons of the pandemic point to a need for greater investment and research into the tools and data that will allow health authorities to protect human health by acting sooner on animal health and diseases.
At present, many health decisions are based on mortality figures but in both humans and animals, they only tell part of the story.
When England changed how it counted deaths from coronavirus, for example, this led to the official death toll falling by more than 5,000, while global mortality has been estimated at as many as 22 million excess deaths compared to the official tally of 5.5 millions. Similarly, countries have recorded the spread of Covid-19 in different ways, making it challenging to track the global incidence of the virus and identify hotspots.
The same difficulties arise when agriculture and public health departments look at livestock. The definition of mortality as a measure of animal health can change with every study, preventing meaningful comparisons across years and countries.
For researchers tracking long-term animal health challenges, mortality rates are not always an accurate metric to assess the state of animal health in a country and monitor changes over the years. Mortality can fluctuate enormously, impacted by unpredictable climatic events such as feed or water shortages, or infectious disease outbreaks.
Alternative measures to assess mortality in animals, such as mortality in young animals or the number of offspring surviving beyond a year, can give a more accurate indication of overall livestock health.
Mortality up to six months, for example, is a much more accurate measure because most livestock deaths tend to occur in the first weeks of life, so this metric provides a more consistent way to identify new or unexpected threats to survival and life expectancy.
At the same time, disease outbreaks, which cause sporadic spikes in mortality, should be counted separately as “excess deaths”, and should not influence longer term mortality figures. This will enable authorities to differentiate between a one-off outbreak and an ongoing health trend.
But to develop these metrics and a methodology that allows countries and authorities to measure health more consistently, more investment and research is needed.
In particular, funding for animal health research should support the collection and sharing of high-quality data, which underpins a functioning animal health system.
As reinforced by Covid-19, animal and human health are inextricably linked, and there are more than 200 known zoonotic or cross-species diseases that affect both people and animals, responsible for an estimated billion cases of illness and millions of deaths every year.
And beyond their direct impact on human health, livestock also contribute to the livelihoods of 1.3 billion people worldwide. More effort to protect animal health can contribute to food security and safety, and keep families afloat in difficult times, contributing to their long-term health and wellbeing.
Monitoring and protecting livestock will be a crucial step towards preventing the next pandemic and better protecting people, particularly in low-income countries where animal health is a matter of life and death.
Now that the pandemic has removed all doubt as to the importance of animal health in relation to our own, the world needs ambitious and accurate data collection to inform evidence-based decision-making that prevents future health emergencies.
Only in this way can the world fight this pandemic, avoid future ones, and protect the livelihoods of millions of people in developing countries, which are now more precarious than ever.