This year, the dengue vaccine will only be administered to children and adolescents, in specific cities, as planned by the Ministry of Health. While the vaccine does not arrive and the forecast is for a rise in cases, the population must adopt protective measures against the virus. main vector of the disease, the mosquito Aedes aegypti.
Avoiding the accumulation of standing water, using mosquito repellent and wearing clothes with sleeves are three basic protection strategies against the dengue mosquito, but there are ways to enhance risk reduction by better understanding the insect’s behavior, as pointed out by Flávio Cesar Viani, professor of biomedicine at Cruzeiro do Sul University, for the Canaltech.
1. Know the mosquito’s habits
Mosquitoes have nocturnal habits, such as Culex quinquefasciatusbut in the case of Aedes aegypti, these insects are mostly diurnal. So, the chance of being bitten is greater at dawn and dusk than at night.
“However, as it is opportunistic and very adapted to living close to humans, attacks can also occur at night”, explains biomedical scientist Viani. In a preventive manner, protective measures must always occur in risk areas, regardless of the period.
2. Be careful with risk areas
“Normally, areas close to rivers are not at risk for dengue transmission, but rather areas with population clusters”, says the specialist.
After all, the Aedes aegypti tends to live close to humans, in and around houses. As part of its reproductive cycle, it needs small pools of water — still, clean and free of organic matter — to lay its eggs.
“In areas of natural vegetation and waterways, other mosquitoes responsible for transmitting other diseases predominate”, reinforces Viana. This does not mean that they are risk-free, as other arboviruses can be fatal.
3. Avoid dengue breeding sites
In risk areas, people must always pay attention to environmental control, that is, to eliminate breeding sites and places with stagnant water. These are the cases of vases, water tanks, drains or even tires in the backyard.
If it is not possible to remove pooled water in a location, it is recommended to add bleach to prevent the dengue mosquito from using that space to proliferate.
4. Choose the right repellent
As an individual protection strategy, it is best to use repellents against the dengue mosquito, reapplied from time to time. When purchasing, you need to check whether the product is registered with the National Health Surveillance Agency (Anvisa) — this can be seen on the product label.
“For Anvisa to approve a repellent, the company must prove its effectiveness and safety through laboratory tests recommended by the WHO”, comments Viana on the importance of validation.
Today, the synthetic active substances registered with Anvisa are: DEET, Icaridin and IR3535. Furthermore, there are other products whose active substance is plant extract or plant oil of the genus Cymbopogonthe well-known citronella.
When to reapply the repellent?
“The time for action [do repelente] varies according to each principle, DEET-based products have an average action time of between 30 and 90 minutes, and must be reapplied after this period, the same happens with those based on IR3535”, advises the biomedical practitioner. In the case of repellents with Icaridin, the action time can be up to 120 minutes.
5. Use citronella sparingly
In search of natural solutions, there are those who directly use citronella oil as a natural repellent against the dengue mosquito. However, these products are not registered with Anvisa and there is no way to guarantee their effectiveness.
“Even though citronella has a repellent and even disinfectant effect on eggs and larvae, a product that can be safely applied to the skin and has a proven repellent action must pass all the tests and approvals required by the national health authority”, points out Viana.
6. Wait for the dengue vaccine
If this year the forecast is that the dengue vaccine will be administered to a limited number of people, the expectation is that more doses of Qdenga will arrive in Brazil in the coming years, expanding vaccination coverage.
In parallel, it is possible that another vaccine may soon contribute to national vaccination campaigns: the Butantan-DV vaccine, developed by the Butantan Institute. The estimated efficacy is 79.6%, which is comparable to the protective effect of Qdenga.
Alert on: dengue cases spike in several states
Trending on Canaltech:
+The best content in your email for free. Choose your favorite Terra Newsletter. Click here!