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‘Critical gaps’ in understanding climate change fuel tropical disease spread

A girl, holding a child, walks to a mobile health clinic in a flood-affected village in Pakistan. Water-logging has led to an increase in spread of malaria in the region. (file)
© UNICEF/Shehzad Noorani
A girl, holding a child, walks to a mobile health clinic in a flood-affected village in Pakistan. Water-logging has led to an increase in spread of malaria in the region. (file)

‘Critical gaps’ in understanding climate change fuel tropical disease spread

Health

A comprehensive review by the UN health agency has revealed critical gaps in understanding the full impact of climate change on malaria, dengue, trachoma and other tropical diseases.

The World Health Organization (WHO) study, conducted in partnership with Reaching the Last Mile (RLM), a global health initiative to eliminate neglected tropical diseases (NTDs), found that rising temperatures and changing weather patterns are altering the spread of vector-borne diseases, posing significant health risks.

As the geographical spread of disease vectors like mosquitoes expand, the risk of introducing or reintroducing these diseases to new areas increases. This shift is likely to have the most severe impact on communities already disproportionately affected.

The study analysed peer-reviewed papers from January 2010 to October 2023, crunching data on national disease burdens, healthcare access and climate vulnerability scores.

The majority of data sets used focused on malaria, dengue, and chikungunya, while other NTDs were significantly underrepresented.

Lack of evidence

Only 34 per cent of studies reviewed (174 studies) addressed mitigation and a mere five per cent (24 studies) looked at adaptation, underscoring the dire lack of evidence available to help malaria and NTDs.

Ibrahima Socé Fall, Director of the Global NTD Programme at WHO, emphasized the need for more comprehensive, collaborative and standardized modelling to predict and mitigate effects of climate change on health.

This important and timely review reveals alarming trends and is a call to urgent action. Malaria transmission is likely to shift both polewards and to higher altitude, while the mosquito vector responsible for transmission of dengue and chikungunya is predicted to continue to expand its range,” she said.

“If we are to protect and build upon the hard-won victories of the past two decades, the time to mobilize is now.”

Neglected tropical diseases

Neglected tropical diseases (NTDs) are a diverse group of conditions caused by a variety of pathogens, including viruses, bacteria, parasites, fungi and toxins.

These include Chagas disease, dengue, chikungunya, leprosy, rabies, soil-transmitted helminthiases, snakebite, trachoma and yaws. It is estimated that they affect more than one billion people, according to WHO.