Dengue mosquito fight intensifies

Low-flying planes visible

The Mosquito Control and Research Unit will spend less time fumigating arriving air and sea vessels for mosquitoes in the next 12 month.

Instead, it will focus more resources on reducing existing mosquito populations, particularly the potential dengue fever carrier, Aedes aegypti.

Ayres Turbo Thrush airplane

Photo Caption: One of the Mosquito Research and Control Units Ayres Turbo Thrush airplanes at the units airport hanger. Photo: Submitted

The Aedes aegypti mosquito – the most common carrier of dengue fever – re-established itself on the island in the aftermath of Hurricane Ivan.

MCRU Director Dr. William Petrie said Hurricane Ivan spawned a 1300 per cent increase in the Aedes aegypti population.

While there is no sign the species is carrying or spreading dengue fever on Grand Cayman, Mr. Petrie said the MCRU would be doing all it could to reduce its numbers.

‘We don’t know if it’s possible to eradicate it again but we will be doing everything to keep the population as small as possible.’

Mr. Petrie said there was little point spraying incoming vessels for the species now that it was already here.

Air and sea vessels arriving at Cayman Brac and Little Cayman – which are free of Aedes aegypti – will continue to be sprayed.

Mr. Petrie said diseases like dengue fever and malaria are more likely to be brought to Grand Cayman by infected humans than by mosquitoes.

‘Contrary to belief, it is humans, not mosquito’s, that bring the diseases in.

‘We have people travelling here regularly from places with known dengue problems.

‘The chances of a mosquito infected with dengue fever surviving the trip here and then biting someone is very low.

‘We’re more worried about a mosquito here biting an infected person.’

Mr. Petrie said Aedes aegypti was most prevalent in George Town and West Bay.

Since 1974 the mosquito has been eliminated from the island 30 times only to re-establish itself again.

As Aedes aegypti only breeds in residential areas, the public has a big role to play, Mr. Petrie said.

Residents should empty all still water deposits around the house to prevent the mosquito laying larvae.

Last week the MCRU began a large scale assault on mosquito populations across Cayman.

The small pellets dissolve when they come into contact with water, releasing a chemical that kills mosquito larvae after they hatch.

The chemical pellets pose no threat to people or pets.

In addition to dropping mosquito killing pellets on breeding sites, MCRU officers are visiting residences to kill existing larvae and prevent further breeding.

MRCU is also carrying out hatch and strand operations in which swamps are artificially flooded, causing larvae to hatch, before the water is drained out to sea.

The hatched eggs are then either consumed by predators or stranded on dry land before completing their development.

To learn more

For more information about the larviciding campaign contact the MRCU at 949-2557.