climate change and desease

Protecting ecosystems, fostering collaboration and embracing the ‘One Health’ is the best defences

IPCC report 2023

In its latest report released this March, the Intergovernmental Panel on Climate Change (IPCC) delivers a stark warning: climate change heightens the global risk of infectious diseases. 

The close relationship between climate and disease is being demonstrated every year

1 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 and animal reservoirs that host the parasite.

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

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. 

2022 published in Nature Climate Change 

warns that humans now face a broader spectrum of infectious agents than ever before. 

Over half of all-known infectious diseases threatening humans worsen with changing climate patterns. 

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

Reason

1 While ecosystems shape local climates, climate change is transforming ecosystems. 

2 This dynamic introduces invasive species and extends the range of existing life forms. 

3 Both these results shown in ecosystems that are complex and confound ecologists and epidemiologists to predict outbreaks. 

4 Human-induced climate change is unleashing an unprecedented health vulnerability crisis. 

India, in particular has summers and erratic monsoons causing water scarcity across the Gangetic plains and Kerala. 

These climatic shifts shows in 

🌺severe health crises,

🌺 including a dengue epidemic in Dhaka (Bangladesh) and Kolkata 

🌺and the Nipah outbreak in Kerala. 

Surveillance and reporting

Changed disease scenarios require 

🌺a revision of strategies

🌺 to detect and deal with them. 

Over the past two decades, India has improved its reporting of outbreaks

1  The Integrated Disease Surveillance Programme (IDSP) was rolled out in a few States in 2007.

 From reporting 553 outbreaks in 2008, it last reported 1,714 in 2017.

2  It was phased out in favour of a new, a web-enabled, near-real-time electronic information system called Integrated Health Information Platform (IHIP)

IHIP was launched in seven States in 2018

. It added 20 additional disease conditions over IDSP’s 13 and could present disaggregated data to its users.

 Tragically, the programme, which would have enabled real-time tracking of emerging disease outbreaks, has not delivered on expectations.

The current design of surveillance is not adequate for the emerging disease scenario

 Mitigating the spread of climate change-induced diseases requires

🌺 safeguarding ecosystems,

🌺 curbing greenhouse gas emissions, 

🌺and implementing active pathogen surveillance. 

A unified approach, termed One Health 

which integrates monitoring human, animal, plant, and environmental health, recognises 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.

India must launch One Health and infectious disease control programmes by building greater synergies between the Centre and States and their varied specialised agencies. 

robust surveillance systems

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

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

3  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.

‘Disease x’ and beyond

1 Globally, there is an obsession with the enigmatic “disease X,” but it is the familiar annual cycles of known agents such as 

🌺influenza, 

🌺measles,

 🌺Japanese encephalitis,

🌺 dengue, 

🌺diarrhoea 

among others that will continue to test the public health system. 

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.