Our health depends not only on the quality of care in clinics and hospitals, but also on food safety, animal health, and the quality of the air and water that sustain us. Often taken for granted or overlooked, these factors are closely interconnected and affect our everyday lives.

One Health Day, observed every year on 3 November, reminds us that protecting human well-being requires us to look beyond humanity to the wider world we share.

The idea behind One Health is simple: the health of humans, animals, plants and the environment is interdependent. Putting this into practice requires different sectors to come together, working across disciplines to prevent disease and tackle health threats.

For Singapore and its neighbours, these connections are far from theoretical.

During the Nipah virus outbreak in Malaysia and Singapore in 1998–1999, infected pigs transmitted the virus to people in close contact with them. The outbreak showed how animal diseases can become human health crises, and underscored the need for close collaboration between healthcare, animal health surveillance and food systems to protect human health.

Antibiotic resistance is another warning. Antibiotics fight bacterial infections and underpin the safety of many modern medical procedures. But when bacteria develop resistance, these medicines become much less effective.

How antibiotics are used in humans and animals, and how waste is managed, can influence the emergence and spread of resistant bacteria. Hospitals cannot solve this problem alone. Preserving the effectiveness of these life-saving medicines requires coordinated action across healthcare, veterinary care, food production and environmental management. Singapore has adopted a One Health approach to tackling antimicrobial resistance, bringing agencies responsible for these different areas into close collaboration.

Environmental conditions also directly affect our health. Regional haze reminds us that the air we breathe is affected by activities in surrounding areas and across borders. Protecting health therefore requires collaboration beyond the healthcare system.

The outbreak of COVID-19 in 2019 exposed how quickly health threats can upend the global order. It also underscored the urgency of studying how pathogens cross the species barrier between animals and humans. In fact, One Health mechanisms play a crucial role well before a crisis fully unfolds.

Unusual symptoms in patients, unexplained disease outbreaks among farmed animals or abnormal changes in the environment may appear to be isolated events. Yet they often provide pieces of the picture of a potential crisis. If these observations remain within individual agencies, important warning signs may be missed. Only by sharing information and interpreting it together can the relevant authorities connect the dots, identify emerging risks early and take preventive action.

This requires practical arrangements: secure channels for sharing information, laboratories able to compare test results, and clear responsibilities for investigating warning signals. It also requires trust among the people, institutions and countries involved.

Internationally, the World Health Organisation, the UN Food and Agriculture Organisation, the UN Environment Programme and the World Organisation for Animal Health have been working together towards this goal. Their collaboration reflects a simple fact: agencies may have different responsibilities, but health threats cross those boundaries.

Building a system that connects human, animal and environmental health is a core task for governments and the relevant institutions. Researchers and professionals should also actively pursue interdisciplinary research, while countries urgently need to build strong, reliable partnerships.

Beyond policy, individuals also have an essential part to play. In our daily lives, we can take antibiotics strictly as prescribed, practise food safety and good hygiene, be responsible pet owners and follow safety guidelines when interacting with wildlife. We can also support environmental protection efforts and safeguard the ecosystems that sustain us.

For Singapore, regional cooperation is especially important. Our connections with other countries through travel, trade and food supplies mean that our well-being is closely tied to that of our neighbours. Working across borders to identify and reduce health risks ultimately benefits everyone.

One Health Day is an opportunity to put this approach into everyday practice: sharing information earlier, using medicines more responsibly, producing food more safely and taking greater care of the environment that sustains us.

After all, much of the work that protects human health begins long before anyone enters a hospital.

Leo Yee Sin is co-founder of the Asia Pacific One Health Initiative at Temasek Life Sciences Laboratory and a senior adviser at the National Centre for Infectious Diseases and the Saw Swee Hock School of Public Health at the National University of Singapore.

Zhang Xianyi is co-founder of the Asia Pacific One Health Initiative at Temasek Life Sciences Laboratory.