Insecticide combo used in Miami effective against Zika mosquitoes, larvae
A double dose of insecticides that are designed to kill both adult mosquitoes and their larvae have delivered an effective “one-two punch” that has stopped the first Zika virus outbreak in the Wynwood section of Miami, Florida in the US, said health officials.
The trendy Miami neighborhood became the first in the continental US to experience a local outbreak of the Zika virus which causes severe birth defects in infants of infected pregnant women.
But the US Centers for Disease Control and Prevention (CDC) has recently declared Wynwood a Zika-free area, saying that there have been no cases of the Zika virus infection in the neighborhood in the past 45 days. However, Florida is still fighting a second outbreak in Miami Beach.
It took several weeks for health officials to get the first outbreak under control. They said that the transmission of the virus seemed to stop after they conduct aerial spraying of insecticides. According to Dr. Tom Frieden, CDC director, aerial spraying has been the most effective tool in controlling mosquitoes on the ground.
To end the outbreak, they conducted aerial applications of naled, a chemical that has been long used in the US to kill adult mosquitoes, in addition to ground sprays that dispersed Bacillus thuringiensis israelensis (Bti), which is a species of bacteria that can kill developing insect larvae in water.
The specific combination of the two was also found to be a significant factor in stopping the spread of the disease. “In the areas that only used naled, mosquito populations rebounded,” Frieden said. “So the one-two punch is important.”
The Aedesaegypti mosquito that carries Zika is especially hard to kill. Frieden likes to call it the “cockroach of mosquitoes” because it’s so difficult to control. It lives in and around houses and can breed in tiny amounts of water.
Aedes spreads not only Zika, but dengue, yellow fever and chikungunya viruses.
People who are worried about the health impacts of the method should not be worried. According to CDC and state health department officials, the naled spray that was used is not dangerous to people when sprayed in ultra-low doses.
In a joint report, they said that less than an ounce of naled was used per acre for the aerial applications, which might explain the absence of observed negative health effects during and after the spraying. Other studies have tested people after naled has been sprayed and find little evidence of it in their bodies.
