27 Sep-2023-Editorial

WITH CLIMATE CHANGE, TACKLING NEW DISEASE SCENARIOS

Intergovernmental Panel on Climate Change (IPCC) delivers a stark warning: climate change heightens the global risk of infectious diseases.

For instance, the periodicity of mosquito-borne disease outbreaks no longer follows expected patterns.

Dengue manifests in two to three peaks throughout the year. Variability in temperature, precipitation, and humidity disrupt disease transmission cycles. These also alter the distribution of the vectors (carrier) and animal reservoirs that host the parasite.

Heat has been proven to interfere with the genomic structure of pathogens, changing their infectivity and virulence (severity).

Climate change, more infections

Habitat loss forces disease-carrying animals to encroach upon human territory, increasing the risk of human-animal interaction and the transfer of pathogens from wildlife to humans.

Viruses which do not harm animals can be fatal for humans. Nipah virus, which has been causing outbreaks in Kerala for many years now, is a good example.

An analysis of 2022 published in Nature Climate Change warns that humans now face a broader spectrum of infectious agents than ever before.

How does the Transmission occurs?

Diseases often find new transmission routes, including environmental sources, medical tourism, and contaminated food and water from once-reliable sources.

While ecosystems shape local climates, climate change is transforming ecosystems. This dynamic introduces invasive species and extends the range of existing life forms.

How do changing weather patterns affect infections?

India, in particular, has felt the ominous impact, with early summers and erratic monsoons causing water scarcity across the Gangetic plains and Kerala.

These climatic shifts are manifesting in severe health crises, including a dengue epidemic in Dhaka (Bangladesh) and Kolkata and the Nipah outbreak in Kerala. Why should we not be surprised at the recent outbreaks in Kolkata or Kerala or at its un-seasonality?

Disease Control Program

The Government is implementing 3 (three) disease eradication programmes namely, National Vector Borne Diseases Control Programme (NVBDCP), National Leprosy Eradication Programme (NLEP) and National TB Elimination programme (NTEP).

Under the National Vector Borne Diseases Control Programme (NVBDCP), 3 diseases namely Malaria, Filaria & Kala-Azar are under elimination programme.  These diseases are targeted for elimination, and not for eradication.

Eradication of the disease is permanent reduction to zero of the worldwide incidences of infection caused by specific agent as a result of deliberate efforts; and when intervention measures are no longer needed.

Vector Borne Diseases

However, Vector borne diseases (VBDs) are caused by vector and vector is climate sensitive and ecological driven. Vectors are affected by temperature, humidity, rainfall etc, and, therefore, it is not possible to eradicate the VBDs completely from the world.

Surveillance and reporting

Over the past two decades, India has improved its reporting of outbreaks. The Integrated Disease Surveillance Programme (IDSP) was rolled out in a few States in 2007.

It was phased out in favour of a new, Integrated Health Information Platform (IHIP). Tragically, the programme, which would have enabled real-time tracking of emerging disease outbreaks, has not delivered on expectations.

Gaps in our surveillance

The current design of surveillance is not adequate for the emerging disease scenario. Mitigating the spread of climate change-induced diseases requires

1. safeguarding ecosystems,
2. curbing greenhouse gas emissions, and
3. implementing active pathogen surveillance.

Interconnected Programs are needed

A unified approach, termed One Health which integrates monitoring human, animal, plant, and environmental health, recognizes this interconnectedness.

This approach is pivotal in preventing outbreaks, especially those that originate from animals. It encompasses zoonotic diseases, neglected tropical diseases, vector-borne diseases, antimicrobial resistance, and environmental contamination.

Inter Departmental Coordination

Animal husbandry, forest and wildlife, municipal corporations, and public health departments need to converge and set up robust surveillance systems.

More importantly, they will need to build trust and confidence, share data, and devise logical lines of responsibility and work with a coordinating agency.

So far, the Office of the Principal Scientific Adviser to the Prime Minister has been taking this lead but with new World Bank and other large funding in place, this will need greater coordination and management.

Climate Change affects ‘Disease x’ and beyond

Climate change is not limited to infectious diseases. It also exacerbates injuries and deaths from extreme weather events, respiratory and cardiovascular diseases, and mental health issues.

The re-emergence of Nipah in Kerala is a wake-up call, that mere biomedical response to diseases is inadequate. In the face of a changing climate and the growing threat of infectious diseases, protecting ecosystems, fostering collaboration, and embracing the One Health paradigm are our best defences.

The road ahead demands concerted efforts, not just to adapt but also to proactively safeguard our planet and its inhabitants.

Mains Questions

1. Discuss how Climate Change affects our health? Suggest Way Forward. (250 Words) 15 Marks