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Extreme measures to control ZIKV - Jamaica part of pilot project to use genetically modified mosquitoes

Published:Thursday | May 5, 2016 | 5:44 PMAnastasia Cunningham
An Aedes aegypti mosquito is shown on human skin.
A man uses a machine to spray mosquitoes as part of the vector spraying in the Newlands community of Portmore earlier this year. Fogging only kills about 30 per cent of Aedes aegypti mosquitoes.

The extreme difficulty in controlling the disease-carrying Aedes aegypti mosquito population has forced countries around the world to employ creative means in the ongoing fight against the vector. One such method is the sterile insect technique: using genetically modified mosquitoes as a control method. Jamaica is now one of several countries that will participate in a pilot project to look at using this control measure.

According to Sherine Huntley-Jones, medical entomologist in the Ministry of Health, the initiative is being led by the International Atomic Energy Agency, which will be looking to include the sterile insect technique as part of the overall integrated vector management programme for the Latin America and the Caribbean. The first meeting is scheduled to be held in Mexico in July, to discuss the full implementation of the project.

"The sterile insect technique is not new, and, in fact, has been used for a number of years as a biological control of insects of medical or agricultural importance, as well as part of integrated vector-management programmes," she told The Gleaner.

However, Huntley-Jones pointed out that if Jamaica decides to use the genetically modified mosquitoes as a vector-control method, it would be some time before it would be employed as there would be several factors to examine, including the cost.

The domestic Aedes aegypti mosquito, responsible for the Zika virus (ZIKV), chikungunya, dengue, and yellow fever epidemics, is proving to be quite a challenge, based on its behaviour patterns.

With more than 36 countries across the Americas and the Caribbean now fighting a ZIKV outbreak, health agencies across the world have been taking an aggressive approach to stemming the spread.

Yesterday, authorities in The Cayman Islands announced that its Mosquito Research and Control Unit (MRCU) would be partnering with the United Kingdom-based biotechnology company Oxitec for the use of genetically modified mosquitoes as a new control measure.

Cayman now becomes the second country in the world to employ this mosquito-control measure. Genetically modified mosquitoes have been used in Brazil.

Oxitec's pioneering technology produces a genetically engineered non-biting male mosquito that breeds with the disease-transmitting Aedes aegypti females. This, in turn, means that offspring inherit a gene that causes them to die before reaching adulthood, ensuring that they do not reproduce.

The company said this was an environmentally friendly approach to curtailing the breed as no insecticides are necessary.

The World Health Organisation (WHO) declared ZIKV a global public health emergency, posing greater risk to infants, pregnant women, the elderly, and persons with pre-existing medical conditions, this, after its proven link to the birth defect microcephaly, as well as the autoimmune diseases Guillain-Barre Syndrome and acute disseminated encephalomyelitis.

In March, the WHO recommended that countries employ the Oxitec mosquito-control solution as part of the global response to the Zika crisis.

Yesterday, Cayman's Premier Alden McLaughlin announced that although the country has no confirmed ZIKV cases, it was no stranger to mosquito-borne diseases and had decided to take the pre-emptive measure.

"We have had an ongoing relationship with Oxitec since 2010 as MRCU has been at the forefront of mosquito-control research. Trials successfully reduced the Aedes aegypti by 96 per cent in an area of the island where the study was taking place, so we are happy to have now signed an agreement with Oxitec for a new project, which we envisage being the first step in a multiphase roll-out across Grand Cayman," the premier said.