International mobility, urbanisation behind spike in dengue cases globally

Public health fellow at the University of Otago, Wellington Dr Mary E. McIntyre said that the dengue fever, transmitted through the Aedes aegypti mosquito, is taking on two distinctive characteristics.

‘Firstly, it is becoming an infection of people who travel, in tourism and trade. It is also becoming an infection of urban poverty where people don’t have proper sanitary conditions and have a lot of water lying around,’ she said in an interview with Astro AWANI.

Rapid human population growth and increased urbanisation have led to poor and inadequate habitat planning which has created conducive breeding grounds for mosquitoes.

According the World Health Organisation, the cases are expected to rise in coming months with more than 2.5 billion people worldwide are at risk of being infected with the virus.

"Tropical countries being the most vulnerable as mosquitoes thrive in warmer climates,’ she added.

In Malaysia, dengue cases have spiked 316 percent from January to February 2014, compared to the same period last year. As of Feb 22, 2014, the Ministry of Health reported 18,047 dengue cases that have claimed 36 lives.

Commenting on the situation in Malaysia, Mary was of the opinion that prolonged flooding and drought could have contributed to the outbreak.

‘It is very likely that dengue can be related to flooding especially when there’s a lot of water lying around. You also get a problem when there is a drought and people start storing water, sometimes in an unsafe manner that leads to mosquitoes breeding in it,’ she said, citing Fiji as an example.

The South Pacific island recorded 3,556 confirmed dengue cases including seven deaths since October last year.

"The dengue outbreak in Fiji is associated with severe flooding that happened recently. The mosquitoes also breed very quickly because it is the warmer time of the year.’

New Zealand, too, has been warned of a possible dengue fever outbreak following the Fiji spate.

‘The situation in New Zealand is different. Most of the dengue cases here involved people who were infected somewhere else, comes home and require hospital treatment.’

"An epidemic will occur when someone who has been identified with dengue fever has not been out from the country for two to three weeks, which covers the incubation period of the virus,’ she said, adding that = the situation is still under control as of now.