The “One Health” Concept: Predicting New Pandemics

Why monitoring the health of wild animals is essential, and how can cats cause an epidemic among humans

faq | July 2, 2024

The “One Health” Concept: Predicting New Pandemics

This article is a part of the “One Health” project in collaboration with the biopharmaceutical company MSD Animal Health.

Can We Prevent Future Pandemics? Many experts believe that it is unlikely. Following the COVID-19 pandemic, a group of authors analyzed pandemics over the last hundred years and concluded that there is a high probability of another pandemic occurring within 30-50 years. Epidemiologists have long predicted a pandemic, though they expected it to be a new strain of influenza, and preparations were made accordingly. International health regulations were largely drafted after the SARS-CoV-1 outbreak, and preparations were focused on a new pandemic influenza strain with significant human casualties.

Unfortunately, humanity has a concise memory. When the influenza pandemic began in 2009, countries activated the mechanisms developed to counteract pandemics — implementing mask and glove regimes, using thermal imagers, and stockpiling flu medications. However, that virus had some relationship to a virus that had caused a pandemic in the late 1950s, and older people had partial cross-immunity: since influenza primarily kills the elderly, the lethality of this form of pandemic influenza was lower. The catastrophe did not happen, and people began to forget that there should be stockpiles of drugs and protective equipment in case of a pandemic.

The “One Health” Concept

Today, specialists emphasize the need for sentinel epidemiological surveillance, where teams of experts—epidemiologists, veterinary epidemiologists, and veterinarians—constantly monitor areas where humans interact with wildlife. In veterinary medicine, animal health is monitored; for instance, specialists watch for mass die-offs of wild animals. Observing some areas, such as rainforests, can be challenging, so remote satellite data monitoring is being discussed. In the mid-2000s, the UK proposed methods of remote monitoring of wildlife under the Foresight project. Furthermore, health authorities worldwide must monitor the health of domestic animals and observe disease outbreaks among them, with a growing emphasis on collaboration with public health structures.

The UN is currently discussing the “One Health” concept. Historically, human health monitoring has been separate from animal and environmental monitoring. The UN proposes establishing interactions between relevant structures, agreeing on international standards, and regularly exchanging information between countries. Today, the Convention on Biological Diversity allows countries to withhold information, such as the genetic structure of animals unique to a country, often to protect tourism or biodiversity. As a result, some countries refuse to share information about new pathogens. However, there are positive examples of cooperation: Chinese researchers sequenced SARS-CoV-2 and immediately shared the genetic sequence in public databases, enabling vaccine manufacturers to use the data to develop new vaccines quickly.

Many public figures praise how quickly humanity developed vaccines. However, they forget that this was primarily a result of the SARS-CoV-1 outbreak: it was then established that coronaviruses cause atypical pneumonia, their genetic sequence was decoded, and vaccine development mechanisms against SARS-CoV-1 were initiated. When SARS-CoV-2 appeared, and its structure was sequenced, vaccine developers already knew what to do. However, we are still determining what will happen if the pathogen comes from a different group of viruses, emphasizing the need for monitoring and standardized information exchange. International cooperation in fighting zoonoses originally started with the Food and Agriculture Organization of the United Nations, the World Organisation for Animal Health, and the World Health Organization. Later, the United Nations Environment Programme joined them and released a 2020 report on developing “One Health” approaches.

Preventing Future Epidemics

The first preventive measure to prevent future pandemics is monitoring. Additionally, it is necessary to eliminate sources of potential transmission. International documents recommend community-led interventions—engaging citizens in sanitation efforts to combat orally-fecally transmitted infections. It is not enough to supply toilets; people must learn to use them. Cultural practices where people do not use toilets can be a source of such diseases.

Another problem not directly related to zoonoses but discussed in the context of animal health is antimicrobial resistance. Pathogens resistant to antibiotics used in animals are emerging, making it inappropriate to treat animals with antibiotics meant for humans. Thus, special antibiotics are needed for animal use.

Another preventive measure is the immunization of animals: dogs against rabies, ungulates (intermediate hosts), or dogs (final hosts) against echinococcosis. Human immunizations against rotavirus and cholera are also necessary. Control of vector and intermediate host populations, such as through deratization, is essential. Finally, informational and educational campaigns are crucial. People must be educated that domestic cats can harbour unknown diseases, and if they are let outdoors, pathogens from wild animals or birds can jump to the cat and then to humans.