Are Dwindling Frog Numbers Behind Rise in Dengue and Chikungunya?

How an ecological imbalance is leading to an epidemic.

The frog could be the key to solving our mosquito woes. (Photo: iStock)

The croaks of frogs were always a constant soundtrack to the rains. Now, Delhi’s monsoons are silent and frogs have disappeared. Of the 17 species that were found in Indian cities in 2006, more than 90% have now disappeared from city limits. This has created an ecological imbalance, threatening these 250-million-year-old species and showing us just how poor the quality of our environment is.

Why should you care?

Because frogs eat mosquitoes. The imbalance caused by dwindling frog numbers could be adding to our mosquito woes. While frog populations have been going down, the number of Dengue and Chikungunya cases have been going up.

Delhi had 120 cases of Chikungunya in 2010. This year, we already have 1724 cases – a 14-fold increase. And the number is still rising.

Hospital beds in Delhi are filling up as Dengue and Chikungunya cases keep rising. (Photo: NDTV)

Frogs are extremely important indicators not just of climate change, but also pollutants in the environment.

Sathyabhama Das Biju

But rapid development has been devastating for India’s city-dwelling frogs.

Frog skin is permeable, so toxins in the soil and water like chemical pesticides and fertilisers seep in through their skin and kill them. Their habitat has been carelessly destroyed in cities. Delhi lost almost half its water bodies just between 2007 and 2010 – from 793 down to just 400 wetlands.

Drastic steps will have to be taken to bring frogs back to urban spaces.

Several lakes in Delhi are filled in for developmental construction. (Photo: Debaadityo Sinha)

Clearly, fumigation and repellents alone cannot solve the problem of mosquitoes. We need to address the root cause. Restoring this ecological balance could not only save several species but also several lives lost to mosquito-borne diseases.