In an idea drawn from science fiction and the imagination of entomologists, health activists plan to send an armada of mosquitoes deliberately infected with bacteria into areas where Zika-carrying mosquitoes are transmitting the dangerous virus.
In fairly short order, they hope, the “good” mosquitoes will overrun the Zika-infected mosquitoes by interbreeding with them, passing along the naturally occurring bacteria that suppresses their ability to transmit dangerous viruses. The bacteria, Wolbachia, occurs naturally in the insect world, but not among the species of mosquito that carries Zika. Wolbachia is not harmful to humans.
The $18 million effort is being financed partly by the Bill and Melinda Gates Foundation of Seattle, partly by the U.K.’s Wellcome Trust and by government agencies.
The success of the program should become evident relatively quickly.
“We’ll know within a year, if these mosquitoes we’ve released, if they’re becoming common amongst the population,” Bill Gates told the Associated Press. “Then we’ll see simply by the number of people who get sick from either Zika or dengue. If those numbers come down quite substantially in these cities but not in other cities, that’ll be the proof of this over a decade-long quest to use this intervention.”
Turning insects against themselves
The idea of deploying small biological allies in a fight against hostile invaders is a familiar one, raised prominently in H.G. Wells’ “War of the Worlds,” for instance.
Wells’ 1897 novel described the way naturally occurring organisms halted the menace of invading Martians, but Zika is an equally confounding foe.
The virus, which is carried by mosquitoes, can briefly sicken adults, but cause severe birth defects in unborn children whose mothers are bitten by mosquitoes who carry it. While early outbreaks occurred in Brazil and elsewhere, mosquitoes carrying the virus now have been found in Florida. Zika cases have been found throughout the United States.
Guarding against Zika infection
No vaccine against Zika exists. The U.S. Centers for Disease Control and Prevention offers some tips to people who are at risk for infection.
The agency advises:
- Try to prevent mosquito bites by using EPA-approved insect repellent and by covering exposed skin.
- Avoid traveling to areas with Zika outbreaks if you are pregnant or trying to become pregnant. Consult the CDC’s list and maps of affected areas.
- Be aware that Zika can be transmitted by sexual contact.
- If you show Zika symptoms, such as a fever, rash or red eyes, consult your health care provider to see if you should be tested for the virus.
If you think you may have been exposed to the Zika virus, discuss next steps with your health care provider. You can find a Providence provider here.
See our other posts about Zika Virus
- Zika is typically mild in children
- Zika virus may damage brains of adults
- Women can give Zika to men
- Two new studies: Zika virus can affect adults
- The Zika virus and pregnancy: What you need to know
To learn more
You can read a description of the mosquito project, “Trials of Wolbachia-carrying mosquitoes scaled up in South America,” at the Wellcome Trust web site. The trial was widely reported by news sites following a press conference and wire service interview with Bill Gates.
Projects of the Bill and Melinda Gates Foundation, including several efforts to understand and eradicate Zika, are described on its web site.
The CDC provides extensive information about the spread of Zika and the effort to combat it at its web site. A list of Zika symptoms, which usually are mild, is here.