A New Era of Infectious Diseases - What we should know about what we don't know

Outbreaks of emerging and novel infectious diseases are a significant threat to both human health and the economy - a tough lesson learned from the COVID-19 pandemic.

Many factors such as climate change, demographic shifts, increased urbanization, population growth, and increasing global travel and migration are contributing to rising rates of bacterial and viral diseases.

While malaria, tuberculosis, and HIV still circulate widely, other infections, such as smallpox, have been eradicated, and polio and measles have been eliminated in multiple countries. Yet it has been predicted that by 2050, infectious diseases will be the number one killer globally, surpassing heart disease.¹ These changes in mortality rates are clearly of importance to life insurers, hence understanding why and how these changes occur can help insurers plan for future risk and pricing.

Understanding Zoonosis

Contact between humans and animals can lead to zoonosis, the transfer of disease from animals to humans, which is currently responsible for most new and emerging infectious diseases.³ Emerging diseases are infections that have spread above levels normally expected or are likely to spread in the future. These infections can be completely new, new to a specific region, or reappear in areas where they were previously contained or eliminated.⁴ In order for zoonoses to take place, there must be:

• A pathogen that persists in an animal reservoir host
• Cross-species spillover through direct or indirect transmission or vector-borne pathways

Since 2003, all but one, the poliovirus in 2014, of the public health emergencies of international concern (PHEICs) declared by the World Health Organization (WHO) have been zoonotic diseases. For a disease outbreak to be declared a PHEIC, it must be an extraordinary event with the potential of presenting a public health danger to countries around the world and requiring an internationally coordinated response.

Recent zoonotic diseases included H1N1 influenza (2009), West African Ebola virus disease (EVD) (2013-2016), Democratic Republic of Congo EVD (2018-2020), Zika virus disease (2015-2016), COVID-19 (2020-present), and monkeypox virus (2022-present).^{5, 6}

Factors Impacting Infectious Disease Outbreaks

Population growth, international travel and migration, consumption of wild animal meat, contact with animal vectors via habitat encroachment, and global warming have influenced zoonotic disease outbreaks such as West Nile virus (WNV) and SARS-CoV-2. Outbreaks occur when the number of cases of a disease rise above what would normally be expected in a defined area or season. Zoonoses account for 65% of infectious diseases globally and have caused 56% of all outbreaks. The number of outbreaks appears to be increasing with time, but improvements in prevention, early diagnosis, and treatment are becoming more effective at reducing infections globally.⁷

Global warming has allowed tick and mosquito populations to adapt to different seasons and invade new regions as average temperatures increase, leading to infectious disease outbreaks in non-endemic regions of the world.

A report from the U.S. Centers for Disease Control and Prevention (CDC) showed that the number of diseases from mosquitos, ticks, and fleas such as WNV, Zika virus, malaria, and Lyme disease increased three-fold from 2004 to 2016.¹ Increased urbanization is adding to the spread of dengue, Zika virus, and Chikungunya virus, which are transmitted by mosquitoes that have adapted to urban environments. Incidence of cholera caused by the Vibrio cholerae bacteria and valley fever caused by the inhalation of Coccidioides fungal spores are also expected to increase due to global warming.⁸

New, Emerging, and Re-emerging Diseases in 2022

There is clearly an ongoing need to monitor and address infectious disease outbreaks to protect against future pandemics. The COVID-19 pandemic is a constant reminder of the disastrous effects of a zoonotic disease on mortality and morbidity rates. Keeping abreast of new, emerging, and re-emerging infectious diseases is particularly important for insurers so they can accurately underwrite these new risks and price accordingly.

Consider these examples:

• In March 2022, a case of circulating vaccine-derived polio virus (cVDPV) was reported in Israel, the first case since 1988.⁹ Since then, cVDPV has been detected in waste-water samples in London and New York, where one person tested positive for polio – the first U.S. case since 2013. The virus identified in these areas is derived from an oral polio vaccine (OPV), most likely resulting from someone recently receiving an OPV and shedding the weakened vaccine virus in their stools.¹⁰
• Monkeypox, endemic in parts of West and Central Africa, was declared a PHEIC by the WHO in July 2022 due to the rapidly rising number of infections in multiple countries around the globe. The U.S. subsequently declared it as a public health emergency in August 2022.⁵ Cases have nearly trebled since the beginning of August (23,620 cases) and there are now over 63,000 reported cases, including 20 deaths. ¹¹
• Langya virus (LayV) is a new zoonotic virus belonging to the family of henipaviruses, which includes the Hendra virus, first identified in Australia in 1994, and the Nipah virus, first identified in Malaysia in 1999. Discovered in China in 2018, there have been 35 reported infections of LayV but no reported deaths to date. Research suggests that the virus does not transmit from person to person, lessening the chance of viral outbreaks. However, as has been seen with SARS-CoV-2, viruses can mutate very quickly, making the monitoring of newly identified viruses imperative in controlling the spread of infectious disease.¹²

Disease Risk Management

What can be done to reduce the risk of disease outbreaks and future pandemics? New data analytic techniques using artificial intelligence and machine learning, mobile phone data tracing patterns of population mobility, vaccination programs, and serology surveys that help to track pathogen exposure through detection of antibodies in the bloodstream have proven useful in disease risk management. Genomic surveillance systems can help track the spread of new variants, and diagnostic screening campaigns and early treatment of zoonotic diseases are also helping to prevent new outbreaks and epidemics.⁸

International organizations such as the WHO are also addressing the risk of emerging and re-emerging diseases. In 2021, the Hub for Pandemic and Epidemic Intelligence was set up to help countries around the world detect, monitor, and manage new health threats, and to provide access to data and insights to achieve effective pandemic and epidemic risk management. The U.K. similarly aims to identify and manage outbreaks of new and emerging diseases through its Health Security Agency’s Emerging Infections and Zoonoses (EIZ) team, which classifies incidents into ”notable incidents of public health significance” and ”other incidents of interest”.⁹

Summary

Demographic changes, growth in world travel and migration, increased contact with animal vectors via habitat encroachment and wildlife trade, and global warming are all contributing to increased incidence of new and emerging infectious diseases. As zoonosis accounts for the majority of these, it is likely that any future pandemic will result from a zoonotic disease. Vaccinations, as well as early disease detection, containment, and monitoring patterns of infection, are paramount. Planning for future risk of infectious disease outbreaks is critically important to protect life insurers against extreme fluctuations in their business, and against sudden increases in claims volume and cost.