The City of Miami Beach is slated to be sprayed again with a powerful insecticide despite the continuing controversy over whether its use is warranted in the fight to eliminate Zika.

On Friday, Tom Frieden, director of the U.S. Centers for Disease Control and Prevention (CDC) credited the use of the insecticide, naled, with helping rid the Miami neighborhood of Wynwood of the mosquito-borne virus.

Despite intense ground-based mosquito elimination efforts, the disease was still spreading until Florida officials instituted the aerial spraying of naled to kill adult mosquitoes, along with the ground use of Bti, which kills larva, said Frieden. 

“It was this combination that successfully stopped Zika transmission in Wynwood,” he added.

“When faced with the potentially devastating outcomes of microcephaly or other serious brain defects that Zika can cause during pregnancy, we must use the best available tools to prevent infection."

But the success of Wynwood has not dampened the concern of some Miami Beach residents who worry about the health effects of the insecticide. Also on Friday, a  University biologist released a study on mosquito counts which, he says, casts doubt on the effectiveness of the spraying. 

Both Wynwood and Miami Beach are located in Miami-Dade County, which is the only area in the U.S. where homegrown Zika has been found, the CDC says.

On Monday, the federal agency lifted its Zika travel advisory for Wynwood, but it still remains in Miami Beach. Still, the CDC says that, in general, pregnant women should remain cautious about traveling to the county.

The CDC says Zika causes microcephaly, a particularly dangerous birth defect that can cause brain damage and other neurological problems in newborns. The virus is also linked to Guillain-Barre syndrome, a neurological disorder in adults.

Saturday's spraying  will be the fourth round in Miami Beach, and possibly the last, since no additional flights have been scheduled. The spraying was originally scheduled for Sunday, but was moved forward a day to avoid a Sunday triathlon.

Although there are thousands of Zika cases in the U.S., the CDC is very concerned that homegrown Zika, which is transmitted by local mosquitoes, could lead to widespread outbreaks in the U.S.

According to figures released Friday, the Florida State Department of Health says that the number of homegrown Zika cases in Miami Beach continues to climb, with three more cases confirmed. This brings to 95 the number of homegrown Zika cases in the state.

There was also one new travel-related case in Hillsborough County.  As of this date, a total of 878 Zika cases have been logged in Florida, which includes 90 involving pregnant women.

In the report released by the CDC, officials noted that homegrown Zika had been raging in Latin America, as well as in Puerto Rico, but had not been found in the U.S. until a cluster of cases was discovered in Wynwood, a trendy area of Miami, at the end of July.

The CDC report only covers Wynwood, and does not delve into the subsequent Miami Beach outbreak.

When homegrown Zika was discovered there, federal health officials originally said that spraying would be ineffective due to the city’s proximity to the ocean.  

But as the number of homegrown Zika cases grew, they instituted the spraying operation earlier this month.

According to Florida International University biologist Philip K. Stoddard, the spraying is unlikely to stop Zika’s spread. Stoddard tells Newsmax Health that he used mosquito count figures he obtained from Miami-Dade County. He said the figures show that, while use of naled and Bti drove Wynwood counts down, they’ve had no such effect in Miami Beach.
 

“In Wynwood, they were able to knock the mosquito population down to 10 percent a couple of times but the weren’t able to hold it there. In Miami Beach, from the data I’m seeing, they haven’t been able to knock it down. So they can continue spraying but it won’t hold the mosquito count down until the weather gets cold and dry,” said Stoddard.

More spraying bothers  Stoddard because he’s concerned about the health effects of naled, which is a powerful neurotoxin. 

According to Frieden, the insecticide “is safe and “when used properly, aerial spraying with naled for mosquito control doesn’t pose a risk to people or the environment.” Also, there was no uptick in in hospital emergency department visits during the spraying period, the CDC report notes.

Stoddard disagrees.

“Such exposure doesn’t usually put them in the ER but it can cause them to feel very badly, and can cost them the ability to work at their jobs for months, so its not a trivial concern,” he said.

The Zika virus can make anyone sick for up to a week with the following flu-like symptoms:

• Fever.
• Rash.
• Joint pain.
• Red eyes.

There is no vaccine or treatment for the virus, making prevention essential. Health experts recommend taking the following precautions:

• Wear long-sleeved shirts and pants outdoors.
• Eliminate standing water where mosquitoes breed.
• Use repellents to keep mosquitoes away.
• Use air conditioning and window screens if possible.
• Call your health care provider if you are at risk of infection.

Consumer Reports released new rankings of mosquito repellents that offer the best protection against Aedes Aegypti mosquitoes, the type that carry the Zika virus. They tested products containing deet, plantlike ingredients lemon eucalyptus and picaridin. The most effective products:

• Sawyer Fisherman's Formula Picaridin.
• Natrapel 8 Hour, with 20 percent picaridin.
• Off! Deepwoods VIII, w/25 percent deet.
• Repel Lemon Eucalyptus.

The magazine also recommended skipping products made with natural plant oils, such as California Baby Natural Bug Blend (a blend of citronella, lemongrass oil, cedar oil, and other ingredients) and EcoSmart Organic, (which includes geraniol, rosemary oil, cinnamon oil, and lemongrass oil).

Women who are pregnant or breast feeding can safely use deet, picaridin, lemon eucalyptus, and IR3535, according to the EPA.

Other tips for using insect repellents safely and effectively:

1. Apply repellents sparingly, and only to exposed skin or clothing.
2. Don’t apply repellents over cuts, wounds, irritated skin, or after shaving.
3. When applying to your face, spray first on your hands, then rub in, avoiding your eyes and mouth.
4. Don’t let young children apply repellents themselves
5. Don’t use near food, and wash hands after application and before eating.
6. At the end of the day, wash treated skin with soap and water, and wash treated clothing in a separate wash before wearing again.