Dengue outbreaks are spreading across the globe thanks to a “perfect storm” of climate change, rapid urbanisation and intercontinental travel, experts have warned.

So far this year 1.6 million cases of the mosquito-borne fever have been reported in South America, with 80 per cent of these in Brazil.

The Nicaraguan government has also issued an alert after 55,000 cases were reported in the last seven months, and Honduras is facing its worst outbreak for 50 years.

Numerous countries in southeast Asia have also identified a surge in the number of cases. The Philippines declared a national epidemic this week after 146,000 infections and 622 deaths were recorded so far this year, while one hospital in Bangladesh logged 1,300 infections in just 24 hours in July.

In the 1970s the flu-like virus – colloquially known as break bone fever because of the severe pain it causes – was endemic in just nine countries.

But now severe dengue has taken hold in more than 100 countries, with roughly half of the world’s population now at risk, and is estimated to affect around 100 million people every year.