Mosquitoes carrying Dengue develop resistance to insecticides

A team of researchers at the Mosquito Research Unit in The Ministry of Health are confirming the aedes egypti mosquito that carries the deadly dengue disease is developing a resistance to the insecticides uses in Vector Borne Disease Control mosquito fogging. The synthetic pyrethroid is very similar to the insecticides used in most domestic insect spray cans that are found on supermarket shelves. The ‘fog’ is created by blasting the mixture of insecticide and water into very fine droplets through the fogging machine. The amount of insecticide in the fog is very small, and is dispersed at quantities that can only kill something as small as a mosquito, so at the concentrations used there will be no adverse health effects on people who are occasionally exposed to the fog. The Ministry of Health have been conducting increased ‘mosquito fogging’ operations in Jamaica over the last month. These operations have been in response to the increased numbers of dengue cases that have been recorded, mainly in Portmore. Precautionary fogging is also being applied at schools in the sunshine city.

Why is mosquito fogging necessary?

The aim of the mosquito fogging operations is to kill, or ‘knock-down’, any adult added egypti mosquitoes that may be carrying the dengue virus. The mosquitoes become infected with the virus after biting and taking blood from someone who is sick with dengue. To try and prevent the infected mosquito from biting another person and passing on the disease, the MOH is applying the mosquito fog in areas where a lot of dengue cases have been reported to try to kill as many adult mosquitoes infected with dengue as possible.

“This is now becoming increasingly difficult” relayed one researcher as the 30 minutes span after being fogged, that usually results in a 98-100% knock down of mosquitoes, is now achieving a 90% knock down. However, after 45 minutes the initial 100% knock down is experienced; so even though the mosquitoes are taking a longer time to die, fogging is still effective. The research is an ongoing effort to continuously develop more effective ways of control the dengue disease.

The ‘mosquito fogger’ is a very large and noisy machine that is transported in the back of a truck. The vehicle has a warning light and is driven slowly around the streets where high dengue numbers have been recorded, blowing the fog into the yards for a distance of up to 90 metres away. It is useful for residents to leave all doors and windows in their house open at the time of fogging, as this will allow the fog to enter the house and kill any mosquitoes inside. Mosquito fogging operations are usually carried out between 5.30-7.30am, or 4.30-6.30pm, as this is the time when the outdoor dengue vector is most active and is looking to bite.

While the fogging operations will have some success in killing adult mosquitoes in the areas that are treated, the residents of Jamaica are warned that this activity alone is not enough to protect everyone or prevent all dengue infections. To reduce and control dengue outbreaks a number of actions need to be taken not only by public authorities but also by residents. These include:making sure there are no dengue mosquitoes breeding in your yard, such as in tyres, drums, buckets and any water storage containers.
that you also protect your family from mosquito bites inside and outside the house during the day and in the early morning and early evening. The best methods of personal protection are to apply insect repellent and/or to wear long sleeves and long pants.

making sure there are no dengue mosquitoes breeding in your yard, such as in tyres, drums, buckets and any water storage containers.
that you also protect your family from mosquito bites inside and outside the house during the day and in the early morning and early evening. The best methods of personal protection are to apply insect repellent and/or to wear long sleeves and long pants.

The MOH plans to continue with the mosquito fogging operations until dengue case numbers have dropped substantially.

Remember:

  • Mosquito fogging operations are being conducted at locations in Portmore where dengue case numbers are increasing.
  • The insecticide in the fog is not harmful to human at the low concentrations used.
  • Fogging operations are conducted in the early morning or late afternoon.
  • Residents are advised not to be concerned about the fog, and are also requested to leave their doors and windows open when the fogging machine is in their area, so that the fog can kill mosquitoes inside the house.
  • Residents are also advised that they need to continue to prevent dengue mosquitoes breeding in their yard and to protect themselves and their family from mosquitoes bites during the day and in the early morning and early evening.


Published by choosenaturesguide

NaturesGuide will be your number one guide to naturality, connecting humans with nature. Our website will show you how you can begin to engage in more simpler lifestyle practices and essentially putting health and wellness at the forefront of everyone's life through proper dieting, exercising and leisuring (fun sessions).