US to Use Genetically Modified Mosquitoes to Fight Dengue Fever

Aedes aegypti mosquitoes are seen at the Laboratory of Entomology and Ecology of the Dengue Branch of the US Centers for Disease Control and Prevention in San Juan, March 6, 2016. (REUTERS/Alvin Baez)
Aedes aegypti mosquitoes are seen at the Laboratory of Entomology and Ecology of the Dengue Branch of the US Centers for Disease Control and Prevention in San Juan, March 6, 2016. (REUTERS/Alvin Baez)
TT

US to Use Genetically Modified Mosquitoes to Fight Dengue Fever

Aedes aegypti mosquitoes are seen at the Laboratory of Entomology and Ecology of the Dengue Branch of the US Centers for Disease Control and Prevention in San Juan, March 6, 2016. (REUTERS/Alvin Baez)
Aedes aegypti mosquitoes are seen at the Laboratory of Entomology and Ecology of the Dengue Branch of the US Centers for Disease Control and Prevention in San Juan, March 6, 2016. (REUTERS/Alvin Baez)

After a decade of discussions, officials in Florida have voted to allow the first test in the United States of free-flying, genetically modified mosquitoes that kill any female offspring, as a way to fight the pests and the diseases they spread.

The decision came after about two hours of contentious testimony in a virtual public hearing on August 18. Many speakers railed against uncertainties in releasing genetically engineered organisms. In the end, though, worries about mosquito-borne diseases proved more compelling.

On the day of the vote, dengue fever cases in the Florida Keys islands totaled 47 so far in 2020, the first surge in almost a decade.

The same mosquitoes known for yellow fever (Aedes aegypti) also spread dengue as well as Zika and Chikungunya. The species is especially hard to control among about 45 kinds of mosquitoes that whine around the Keys.

According to a report by the Science News website, the genetically modified mosquitoes plan will kick off in January, 2021. Florida workers will set out boxes of eggs of specially bred male yellow fever mosquitoes. The eggs will grow into normal-looking males, and like other male mosquitoes, they drink flower nectar, not blood.

Then planners hope that during tests, these Oxitec foreigners will charm female mosquitoes into mating. A bit of saboteur genetics from the males will kill any female offspring resulting from the mating, and over time that should shrink the swarms. Sons that inherit their dad's no-daughter genes will go on to shrink the next generation even further.

By now, Oxitec has supplied some billion saboteur male mosquitoes for release elsewhere around the world, especially in Brazil, where Zika can flare up and dengue is common.

The company believes that its successful trials in other regions around the world are a sufficient response to the objections surrounding its project. No potential harms on humans or environment have been observed in the locations where genetically modified mosquitoes were launched.



Latest Tests Show Seine Water Quality Was Substandard When Paris Mayor Took a Dip

 Boats carrying members of delegations sail along the Seine during the opening ceremony of the Paris 2024 Olympic Games on July 26, 2024. (AFP)
Boats carrying members of delegations sail along the Seine during the opening ceremony of the Paris 2024 Olympic Games on July 26, 2024. (AFP)
TT

Latest Tests Show Seine Water Quality Was Substandard When Paris Mayor Took a Dip

 Boats carrying members of delegations sail along the Seine during the opening ceremony of the Paris 2024 Olympic Games on July 26, 2024. (AFP)
Boats carrying members of delegations sail along the Seine during the opening ceremony of the Paris 2024 Olympic Games on July 26, 2024. (AFP)

Tests results released Friday showed the water quality in the River Seine was slightly below the standards needed to authorize swimming — just as the Paris Olympics start.

Heavy rain during the opening ceremony revived concerns over whether the long-polluted waterway will be clean enough to host swimming competitions, since water quality is deeply linked with the weather in the French capital.

Paris Mayor Anne Hidalgo took a highly publicized dip last week in a bid to ease fears. The Seine will be used for marathon swimming and triathlon.

Daily water quality tests measure levels of fecal bacteria known as E. coli.

Tests by monitoring group Eau de Paris show that at the Bras Marie, E. coli levels were then above the safe limit of 900 colony-forming units per 100 milliliters determined by European rules on June 17, when the mayor took a dip.

The site reached a value of 985 on the day the mayor swam with Paris 2024 chief Tony Estanguet and the top government official for the Paris region, Marc Guillaume, joined her, along with swimmers from local swimming clubs.

At two other measuring points further downstream, the results were below the threshold.

The statement by Paris City Hall and the prefecture of the Paris region noted that water quality last week was in line with European rules six days out of seven on the site which is to host the Olympic swimming competitions.

It noted that "the flow of the Seine is highly unstable due to regular rainfall episodes and remains more than twice the usual flow in summer," explaining fluctuating test results.

Swimming in the Seine has been banned for over a century. Since 2015, organizers have invested $1.5 billion to prepare the Seine for the Olympics and to ensure Parisians have a cleaner river after the Games. The plan included constructing a giant underground water storage basin in central Paris, renovating sewer infrastructure, and upgrading wastewater treatment plants.