Earlier in our post about Dengue we discussed Dengue Syndrome/Dengue/ Dengue Fever. In this post, we will talk about prevention from Dengue.
Dengue can’t spread without the help of the Aedes Mosquito. They depend upon the mosquito for their survival and transmission. Cutting the problem at the root of the cause will bring out very effective changes in the spread of the dengue virus and help in prevention form dengue.
A) Environmental Management
When it comes to Dengue or any other Mosquito-borne diseases elimination of their breeding place can play a major role in the prevention from dengue infection and its further spread.
Aedes mosquito which is the vector for Dengue breeds in water which has been stagnant for a few days (clean as well as dirty). Eg: domestic containers, flower pot plates/trays, ornamental containers, toilet bowls, closed perimeter drains and gully traps, AC vents, water coolers, Aquariums etc.
Elimination of these types of breeding place near your household can help in decreasing the Aedes mosquito population which decreases the spread of Dengue, protecting yourself and your family.
Although the chemical method is a widely used method for control of mosquito, it should be used in complementary with Environmental management except in emergencies.
Adulticides, Larvicides are used as a method of chemical treatment.
In the case of Aedes, mosquito larvicides may be impractical to apply in hard to access areas such as leaf axils and tree hole. Applying insecticides indoors in pots, containers, vessels also seems to be impractical as it may cause more harm than benefit
Larvicides which are used in water storage container should be of low toxicity and should not alter the taste, colour, odour and any chemical nature of the water.
Drinking water containers should not be contaminated with larvicides as it may cause more harm than benefits.
In this chemical control method, we target directly the adult mosquito. By using this method we directly kill the mosquito or prevent them from entering our surrounding.
Space spray and Residual treatment are adulticides methods.
a) Residual Treatment
Mostly the mosquito resides in buildings, rooms. By residual spraying, we expose the vectors to the chemical which generally reduce their lifespans and kill them.
The insecticide used for residual treatment is used among the four available classes of WHOPES-approved insecticides (i.e. organochlorine (DDT); organophosphates (primiphos-methyl); carbamates (bendiocarb); and pyrethroids (alphacypermethrin, deltamethrin, and lambdacyhalthrin).
Since 1990, DDT is no longer used in Nepal the only insecticides that have been used are the pyrethroids, presently alpha-cypermethrin.
b) Space Sprays
Space spraying is recommended for control only in emergency situations to suppress an ongoing epidemic or to prevent an incipient one. The objective of space spraying is the massive, rapid destruction of the adult vector population.WHO
Space spraying is generally used to control an epidemic and if used effectively before a greater outbreak occurs it can be combined with other long term effective methods for reduction and control of the disease spread.
In this method, we introduce the organisms to the environment that prey upon the vectors or compete with the vectors for survival reducing the target species.
Lrvivorous fish are used as one method for mosquito control on nearby water bodies. But in case of Dengue the vector breed in confined, stored, stagnant water bodies. These water bodies are not suitable for fish to live and grow on.
Commonly, guppies adapt well to these types of confined water bodies and have been most commonly used.
Various Predatory copepods (small crustaceans) are also used in water bodies for control for Dengue Vectors. Some countries, these methods have been very successful and have completely removed Dengue.
2. Individual protection
Individual protection means to protect yourself and people around you from a mosquito bite. Protecting yourself is a very easy task and can prevent you a lot of trouble if done correctly.
Environmental Management is also a type of Individual protection
Clothing that minimizes your skin exposure during dusk and dawn when Aedes mosquitoes are most active might give you some protection from the bites of dengue vectors and is encouraged particularly during outbreaks.
Use of Mosquito nets will help you prevent mosquito bites when asleep. Also, the use of insecticides treated mosquito nets give high-level protection from mosquito bites.
Use of Mosquito repellents on skin or clothing to repel the dengue vectors but should always be used properly according to the label of the repellent.
Use of mosquito sprays (aerosol), mosquito coils, insecticides vaporisers etc will help in preventing mosquito bites.
Door screening, Window screening will reduce the mosquito bites and will prevent dengue and other mosquito-borne diseases.
Prevention from Dengue involves use of various insecticides and all insecticides are toxic to some level. Proper safety protocols for use of these insecticides should be known should be handled with care and far from the reach of children.