Dengue &Equity &Mosquitoes &Urban &Vector Control Bill Brieger | 27 Apr 2025 04:58 am
Dengue Transmission in the Heliópolis Favela of Sao Paulo, Brazil
Lance Rombro shared his concerns about dengue fever in our discussion forum for the course Urban Health in Developing Countries. He was addressing urban equity issues wherein slum dwellers are disproportionately affected.
Although I have not experienced this urban health equity problem personally, in the past, I closely interrogated and proposed interventions to target the increased rates of dengue transmission in the Heliópolis favela of São Paulo, Brazil. In 2024, Brazil had the most dengue cases (3, 040,736 laboratory confirmed cases and 6,296,795 suspected cases) of any country in the world. Moreover, São Paulo is the sixth most populated city in the world, and the high population density has led to an increased likelihood of infected individuals and a higher prevalence of dengue. Within São Paulo, the highest prevalences of dengue are found in favelas (similar to slums), which are communities with lower socioeconomic status that have worse infrastructure and resilience to combat dengue transmission.
In Heliópolis, it is common for homeowners to have tires, flower pots, and basins lying near the home, which create an ideal breeding ground for the Aedes aegypti mosquito, which is the vector for dengue fever. A. aegypti prefer to breed in still, clean water, which can accumulate in many sources (i.e., water barrels) throughout Heliópolis.
Combatting this issue requires several intervention streams focusing on different aspects, from education to product access and epidemiology. For example, educating the community could involve handing out dengue info-pamphlets at farmers markers or hoisting banners at soccer games, two environments that are heavily frequented by community members. Product access interventions could manifest as town hall events where supplies like mosquito repellent or bed nets are widely distributed to the community. There could also be a focus on insecticide spraying in homes (although this may cause hesitancy in the community) and repair of leaky water barrels that can promote the likelihood of mosquito breeding.
Finally, tracking and recording epidemiological statistics on dengue prevalence and incidence could inform both public health professionals and the community about the current risk of dengue and inform the need for future interventions to further limit dengue exposure and transmission.
The issue of dengue in Heliópolis presents itself in many ways. Community buy-in can realize tangible interventions that could help reduce the risk of dengue in the favela. In many ways, this form of primary prevention is necessary, given that later forms of prevention and treatment may be financially infeasible for members of the favela who have limited economic resources. However, achieving effective strategies also requires stakeholder engagement with community members, government entities (such as the Ministry of Health), and SINAN (the main system for collecting dengue statistics in São Paulo).
Ultimately, with most urban equity concerns, the main ethical issues involve failures to uphold justice and beneficence. However, focusing on this specific population would be an essential opportunity to support, uplift, and build the resilience of a community that consistently faces social and economic marginalization. It is also worth noting that Heliópolis faces a risk from other mosquito-borne diseases like Zika virus, so proposed solutions and interventions could cover a broad spectrum of public health concerns.