Every year on World Zoonoses Day (6 July), we are reminded that some of humanity’s deadliest diseases have not originated in humans, but in animals. Yet the lesson goes much deeper than the transmission of microbes across species. It is about how humanity’s changing relationship with nature is reshaping the future of infectious diseases.
Having spent over four decades treating, researching and responding to infectious diseases— from HIV/AIDS to Ebola, Mpox, Zika, Covid-19 and avian influenza—I have learnt one enduring lesson: viruses are inevitable; pandemics are not. Human actions determine whether a local spill over remains a contained outbreak or becomes a global catastrophe. The world often treats each emerging infection as an isolated crisis. It is not.
HIV, Ebola, SARS, COVID-19, Mpox, Nipah, Zika, hantavirus and H5N1 are different chapters of the same story. They remind us that the boundaries separating humans, animals and the environment are becoming increasingly blurred.
We Are Creating The Perfect Conditions
Population growth, deforestation, destruction of wildlife habitats, illegal wildlife trade, intensive farming, climate change and unprecedented international travel have dramatically increased opportunities for pathogens to jump from animals to humans. Nature has always harboured viruses, not thousands millions of them. What has changed is our behaviour.
Every intrusion into forests, every disruption of fragile ecosystems and every increase in close human-animal interphase creates new opportunities for viral spill overs.
This is precisely why the One World – One Health approach; which recognises that human, animal and environmental health are inseparable, is no longer an academic concept. It is an urgent global necessity.
HIV Taught Us The First Great Lesson:
Among all zoonotic diseases, HIV remains perhaps the most consequential. What probably began as a cross-species transmission evolved into one of the greatest public health challenges in modern history, claiming millions of lives while simultaneously transforming medicine, public health, scientific collaboration and global solidarity?
The HIV response taught us lessons that remain relevant today:
- Early surveillance saves lives.
- Science must guide policy.
- Communities must become partners, not passive recipients.
- Global cooperation is indispensable.
- Stigma is as dangerous as the pathogen itself.
These lessons continue to apply to every emerging zoonotic disease.
H5N1 Reminds Us To Remain Vigilant, Not Fearful
Recent concerns surrounding H5N1 avian influenza have understandably attracted public attention. Human infections can be severe and the reported case fatality rate among confirmed cases has been high. Fortunately, sustained human-to-human transmission remains exceedingly rare, preventing H5N1 from becoming a pandemic so far. That should not lead either to complacency or panic.
Instead, it should reinforce the importance of continuous surveillance of animal outbreaks, genomic sequencing, rapid sharing of scientific information, investment in vaccines and therapeutics, and strengthening public health systems. These measures are far more valuable than reacting after a crisis has already unfolded.
Preparedness Is Not Panic
One of the greatest mistakes during emerging outbreaks is confusing preparedness with fear. Pandemic preparedness should become a permanent component of national emergency preparedness. Surveillance, laboratory capacity, trained workforce, genomic monitoring, research, vaccine platforms and international collaboration cannot be activated overnight; they require sustained investment long before the next outbreak occurs.
Equally important is responsible communication. Public health messaging must be evidence based, transparent and proportionate. Sensational headlines and speculative predictions may attract attention, but they also erode trust, generate unnecessary anxiety and distract from genuine preparedness. Scientific caution should always prevail over sensationalism.
India’s Opportunity
India possesses one of the world’s largest public health systems, an expanding biotechnology sector and internationally respected scientific institutions.
This is the moment to strengthen:
- One Health surveillance integrating human, animal and environmental health.
- Real-time genomic surveillance.
- Early warning systems supported by artificial intelligence and digital epidemiology.
- Laboratory networks extending into rural India.
- Vaccine and therapeutic research.
- Transparent risk communication.
India has already demonstrated global leadership during the HIV epidemic and COVID-19through the Vaccine-Maitri. It can do so again in preparing the world for future zoonotic threats.
The Future Is Still In Our Hands
The next pandemic may emerge from influenza, a coronavirus, a paramyxovirus or from an entirely unknown pathogen. We cannot predict its name, its place of origin or its timing. But we can predict one thing with certainty.
If we continue to damage ecosystems, ignore scientific evidence and neglect preparedness, new zoonotic diseases will continue to emerge.
On this World Zoonoses Day, our focus should therefore not be on fear of the next virus but on strengthening the systems that prevent local outbreaks from becoming global disasters.
Viruses will continue to evolve. Whether they become epidemics or remain isolated outbreaks depends less on the pathogen than on our preparedness. The greatest tribute we can pay to those lost to HIV, Ebola, COVID-19 and countless other infections is to ensure that the next spill over is detected early, contained rapidly and communicated honestly. The future of global health lies not in predicting the next pandemic, but in preventing it.
Dr. Ishwar Gilada is an infectious disease physician with over 45 years of experience in HIV/AIDS and emerging infections. He is Secretary General, People’s Health Organisation (India), President Emeritus, AIDS Society of India, and a Governing Council Member and Asia-Pacific regional Chair of the International AIDS Society.