Climate Change and Infectious Disease

A new study conducted by researchers from the Banaras Hindu University (BHU) shows that climate change is making children vulnerable to infectious diseases. 

• As changing climate is moving the comfort zone for many animals (e.g.-disease-carrying mosquitoes that kill about 1 million people a year), the threat of infectious disease is not rise.
• Climate change is responsible for at-least 1,50,000 deaths per year, a number that is expected to get double by 2030.

Key-findings of the Report

• Driven by human-made activities, climate change may challenge the gains in the public health sector made over the years.
• Globally, it is estimated that children bear most of the burden of disease due to climate change, with the poorest disproportionately affected.
• Maximum temperature and humidity are important drivers leading to infectious disease among children.
• A 1 degree Celsius rise in maximum temperature was associated with an increase in diarrhoea and skin-disease cases by 3.97 per cent and 3.94 per cent.
• Climate parameters like temperature, humidity, rainfall, solar radiation, and wind speed were associated with infectious diseases like gastrointestinal diseases, respiratory diseases, vector-borne diseases, and skin diseases

Why climate change intensifies the spread of infectious disease?

• Rising temperatures and increased precipitation can promote an array of infectious diseases, from vector-borne diseases (eg, malaria, dengue, and leishmaniasis), to enteric infections and diarrhoea (eg, cholera, vibriosis, and rotavirus infection), and to parasitic diseases such as schistosomiasis.
  • Climate-related suitability for dengue transmission in 2018 had globally increased since 1950 by an estimated 8·9%, when considering Aedes aegypti, and by 15·0%, when considering Aedes albopictus.
  • This increase is partly due to the broadened geographical reach of these vectors—eg, several Aedesspp, absent from Europe before 1990, have become established in several European countries.
  • Other vectors, such as Ixodes ricinusticks, carriers of Borrelia burgdorferi (causing Lyme disease) and tick-borne encephalitis virus, have also gradually spread to wider regions in Europe.
  • In the past 10 years, Europe has seen a return of malaria, with sustained local transmission of Plasmodium vivaxinfections in Greece in 2012, increased incidence of pathogenic Vibrio spp infections in the Baltic region, recurring summer outbreaks of West Nile virus in southern and eastern Europe, cases of local transmission of chikungunya in France and Italy, and a report of local transmission of Zika virus in France in 2019.

What role is played by temperature?

• Temperature controls several factors that underlie the time it takes for a virus to be transmittable to humans. These include:
  • how long it takes for a mosquito to ingest a virus during one feeding and then be ready to inject it in a later feeding
  • the length of the mosquito’s life cycle
  • how often mosquitoes bite
• The traits rely on temperature, but they tend to be nonlinear.

As temperatures rise with climate change, mosquito season extends past the summer months in many parts of the world.

Conclusion

Given the increasing temperature and climate change, it is essential to understand and predict the rise and spread of diseases. In the absence of effective measures, health is going to suffer for sure and the global government would not be able to handle this.