Don’t fear the fog - Health officials vouch for safety and effectiveness of chemical used in ZIKV prevention

Officials in the Ministry of Health yesterday affirmed the safety and effectiveness of the chemicals used in its fogging exercises.

Speaking during a post-Cabinet press briefing on Wednesday, health minister Horace Dalley said fogging activities have been increased across the island in order to reduce the population of the Aedes aegypti mosquito, the vector for the Zika virus.

Fogging is one of the main vector-control mechanism being used by the health ministry as Jamaica remains on high alert for the Zika virus.

Responding to concerns about the effectiveness of the chemicals used to do the fogging, Dr Kevin Harvey, permanent secretary in the Ministry of Health, pointed out that the chemicals would only destroy about half of the mosquito population in a given area.

With regard to the resistance that the mosquitoes may have built up to the chemicals, Harvey said: "There is some resistance to some of the chemicals that we use, but we have several other ones that we can use that the mosquitoes are susceptible to."

He added: "And even with the susceptibility, these mosquitoes rest mainly inside of your house as you can imagine the fogging around your house and community only get to a certain percentage, so it's only about half of the adult mosquitoes that will be brought down by routine fogging."

The ministry utilises three main fogging chemicals: malathion, deltamethrin, and anvil.

Dr Sherine Huntly-Jones, medical entomologist with the health ministry, disclosed that tests have shown that the mosquitoes have built up a resistance to malathion, and as such, the use of that chemical has been discontinued.

RESISTANCE DETECTED

Huntly-Jones further asserted that no resistance had been detected for the deltamethrin and anvil chemicals and that they are effective in reducing the mosquito population.

"As it relates to the chemicals that we use in our vector-control programme, all the chemicals are effective ... even though the teams will be fogging, persons do not normally heed our request to open their windows and doors to allow the fog to drift in ... so the chemicals are effective, but the process of fogging may be affected by the fact that mosquitoes are on the inside, but persons do not necessarily open their windows and doors," she said.

The medical entomologist further pointed out that the chemicals were safe and that there was no need to fear any adverse health impacts.

"The chemicals are safe. The ministry uses the chemicals as per the manufacturer's recommendation, so the chemicals are safe," she said.