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Jamaica no stranger to havoc of mosquito disease

Published:Friday | May 6, 2016 | 5:00 AMAnastasia Cunningham

Although Jamaica currently only has eight confirmed cases of the Zika virus (ZIKV), the country is no stranger to the mayhem of the disease-carrying Aedes aegypti mosquito as both dengue fever and chikungunya have wreaked havoc on the population.

Outside of its islandwide 'Mosquito Search and Destroy' operation, where communities are included in an aggressive approach to destroying the breeding sites of this domestic mosquito, Jamaica is also looking at more effective control methods, including the sterile insect technique, using genetically modified mosquitoes.

Sherine Huntley-Jones, medical entomologist at the Ministry of Health, shared that although Jamaica actually has 68 species of mosquitoes, only one type feeds mainly on human blood and transmits diseases: the Aedes aegypti. It also breeds in domestic environments such as homes, communities, schools, business places, and anywhere people congregate.

The female Aedes aegypti, easily recognised by the contrasting black and white rings on its legs and the lyre-shaped pattern of silver markings on the upper surface of the thorax, is the main culprit.

Fogging kills 30 per cent

Huntley-Jones said this mosquito feeds on human blood and produces on average 100 to 200 eggs per batch, which hatch in seven to 15 days. Laid eggs can survive for very long periods in a dry state, often for more than a year. The lifespan of the adult mosquito is two weeks to a month.

With data showing that fogging only controls approximately 30 per cent of the Aedes aegypti population (mainly because the breed is always hiding inside homes), public education has consistently been targeted at householders to eliminate mosquito breeding sites in and around homes, the community, and other areas where people congregate.

"The sterile insect technique would really just be a part of the overall programme to control the vector. A large component in controlling this breed of mosquito is based on community participation and persons taking action to rid their environment of the breeding sites," said Huntley-Jones.

"So the difficulty in controlling the Aedes aegypti will always be the fact that persons are not taking the necessary action to control the breeding in and around their environment." Because of this inability to manage the Aedes aegypti, she said, other control methods were being looked at.

"If people would take the necessary action and change their behaviour as it relates to controlling this vector, there would be no need for the sterile insect technique."

Last week, agencies in the United States (US) met to examine the best solutions to control the Aedes aegypti, even as they, too, face a ZIKV outbreak.

Aerial spraying won't "get to the mosquito that's sitting on the wall of your bedroom," noted David Dyjack, executive director of the US National Environmental Health Association.

Officials in the Florida Keys are now working with the Food and Drug Administration to launch a trial using genetically engineered male mosquitoes, whose larvae die before adulthood.

anastasia.cunningham@gleanerjm.com