In one house out of 100 in Belo Horizonte there are larvae of the Aedes aegypti mosquito, which transmits dengue, which represents 0.9% of the total. The number may seem low, but it also indicates that 83% of mosquito outbreaks are in homes, i.e. they can be avoided with prevention and disinfestation measures in the so-called breeding sites, those places that accumulate stagnant water.
According to the standard of the Ministry of Health, the recommended Aedes aegypti larvae infestation rate to minimize the risk of an epidemic is up to 1%, which puts the indicator of Belo Horizonte (0.9%) low risk. Nevertheless, four of the nine regional offices in the capital have reached a medium risk level for the proliferation of mosquito larvae.
The information comes from the City of BH’s 2022 Quick Survey of Indexes for Aedes aegypti (LIRAa) released this Monday (26). For the investigation, the agents of the Municipal Health Department visited 45,000 buildings in the capital.
The Venda Nova region has the highest incidence of mosquitoes, reaching a rate of 1.7% of households with the presence of Aedes larvae, which represents an average risk. Followed by the regions of Pampulha, East and Northwest, still at medium risk, which respectively indicate 1.2%, 1.1% and 1.1% incidence of mosquito larvae in homes.
The Western Region has the lowest incidence, with larval infestations identified in 0.4% of homes in the area. The Nord, Barreiro and Noroeste regions have almost reached an average risk, being 0.7%, 0.7% and 0.8% respectively. When the index exceeds 1% of households with an incidence of dengue mosquito larvae, the risk is considered medium.
The survey also examined the most registered reproductive sites in homes in the capital. The dishes with plants dominate the ranking, in 26.5% of the cases; followed by debris (19.2%); domestic containers (10.2%); barrels/kegs (7.5%); and tires (6.3%).
According to the Undersecretary of Health Promotion and Surveillance in Belo Horizonte, Fabiano Pimenta, the survey result calls for direction in actions to combat dengue, zika and chikungunya in regions with the most infestations. “With LIRAa we will intensify some action in points of attention, for example where the predominant breeding site was made up of rubble, we will amplify the clean-up efforts. As for vegetable dishes, the Agents for the fight against endemic diseases, who already transmit this guide, will give greater prominence during the inspections of the properties”.
City Hall informed that the municipality takes all the measures recommended by the Ministry of Health, which are the responsibility of the public government, to reduce the occurrence of cases of dengue, chikungunya and zika. In 2022, approximately 4 million inspections were carried out by the Agents that fight endemic diseases, identifying the risks of water accumulation, providing guidance on how to eliminate these breeding sites and, when necessary, applying biolarvicides.
Check the shares according to a note from the BH Town Hall
“Throughout the year, the municipality of Belo Horizonte maintains surveillance and fight against diseases transmitted by Aedes aegypti. The endemic combat agents travel through the properties reinforcing the guidelines on the risks of water accumulation and which can become potential mosquito breeding sites, as well as providing guidance on how to eliminate these breeding sites and, if necessary, apply biolarvicides.
The City Department of Health also maintains the application of ultra-low volume (UBV) insecticide to combat adult mosquitoes in areas with suspected cases of local transmission and due to an environmental assessment by zoonoses control teams. In 2022, interventions using UBV were carried out in around 23,000 properties. The product is intended to eliminate the mosquito in its adult stage, in which the virus can be transmitted. The application is carried out with special equipment and the work is preferably carried out in the morning or in the late afternoon.
The monitoring of the outbreaks is also carried out using drones, whose images have facilitated the identification of possible outbreaks in places that are difficult to access for the teams of Agents for the Fight against Endemic Diseases. Drones are also being used to apply larvicide directly to risk locations when these are difficult for the Zoonosis team to access. So far, 143 overflights have been carried out with the identification of almost 17,000 probable potential outbreaks in the nine regional areas of the municipality.
There is also the expansion of the Wolbachia method and the continuity of the progressive release of mosquitoes in all regions of the municipality. The method is complementary to other dengue, zika and chikungunya control and prevention actions carried out throughout the year by the municipality of Belo Horizonte. Wolbachia is an intracellular microorganism and cannot be transmitted to humans or animals. Mosquitoes carrying the microorganism have a reduced ability to transmit arboviruses, thus reducing the risk of disease and yellow fever. It should be noted that this method does not involve any genetic modification of the Aedes aegypti vector.”
