The Zika virus is no longer a Brazilian problem. The World Health Organisation (WHO) has declared it a public health emergency  and Singapore has now joined Miami as an area of particular concern . At the end of July, the UK was aware of 53 infected patients  and, although pregnant women are the group at significant risk, it is extremely infectious and there is recent evidence to suggest that it can be transmitted through tears .
In Miami-Dade, the pest control bill looks set to hit $10m  as the county continues its attempts to eradicate the mosquitoes. Aerial spraying of the controversial insecticide, naled, planned for the morning of 9th September, looked set to go ahead over Miami Beach even though farmers in South Carolina admitted that anti-Zika spraying with naled was responsible for the death of 2.5 million bees. The toxin is banned in the European Union and the US Center for Disease Control and Prevention advises using a larvicide such as Bacillus thuringiensis israelensis (Bti) instead but naled is effective and the final decision rests with the Commissioner of Miami Beach.
British firm Oxitec may have the solution to the Zika virus
Oxford University spin-out Oxitec has another answer. Over the past decade, it has developed a genetically-engineered male mosquito of the Zika-carrying Aedes aegypti strain. These ‘friendly’ mosquitoes are sent into the wild to mate with the far more dangerous females that transmit the disease by biting. The offspring inherit a self-limiting gene from the father that causes them to die before they reach adulthood. This solution does not work in isolation and must be combined with public awareness programmes designed to eliminate breeding habitats but it has been used in affected areas of Brazil, Panama and the Cayman Islands where it is thought to have suppressed the wild population by more than 90% in the past year .
In the USA, though the Food and Drug Administration (FDA) approved a clinical trial of Oxitec’s genetically-modified mosquito last month, it is proving hard to obtain local support for the release of the insects, even in Zika strongholds such as the Florida Keys . Two surveys have produced contradictory results regarding the preference of the local residents so a vote is scheduled for 8 November. Until then, their local commissioner will decide whether larvicide or insecticide is the treatment of choice.
 World Health Organisation. Emergencies: Zika virus. www.who.int
 CNN. Singapore’s Zika cases send warning signal to Asia. http://edition.cnn.com
 Guardian. Fifty-three cases of Zika virus confirmed in UK, says health agency. www.theguardian.com
 Independent. Zika virus patients could be spreading the disease through their tears, scientists say. www.independent.co.uk
 University of South Florida. Miami-Dade County Faces A $10 Million Tab For Mosquito Control. www.usf.edu
 Oxitec. Independent Surveys Reveal Public Support for Genetically Engineered Mosquitoes. www.oxitec.com
 The New American. Floridians Oppose FDA-approved Genetically Modified Mosquitoes. www.thenewamerican.com