Dengue Ceará maintains dengue cases below average – 02/21/2024 – Health

With more than 650,000 probable cases of dengue reported by the Ministry of Health, Brazil is on alert for the outbreak of the disease, driven especially by notifications in the Federal District, São Paulo, Rio de Janeiro and Minas Gerais. Ceará is going against this reality: according to data from the State Health Department, the notification of cases practically fell by half this year compared to last year.

The state recorded 2,047 probable cases of dengue this year, while last year there were 3,234 cases in the same period. To date, 266 cases have been confirmed. Last year, there were 575 in January and February.

According to experts and managers, the state’s historical coexistence with the disease, the fact that it has a smaller portion of the population susceptible to the serotypes in circulation in the country and the late start of the rainy season are some reasons that explain the low incidence of the disease at the beginning of this year. year.

“Ceará is going against the grain because it has been in the hands for a long time”, says the Executive Secretary for Health Surveillance at the Ceará Health Department, Antonio Lima Neto, known as Tanta. The state has experienced at least seven dengue epidemics in the last 40 years and, according to the manager, has a kind of “immunological barrier” against some serotypes of the disease.

Dengue infection is caused by four serotypes that circulate in the Americas: DENV-1, DENV-2, DENV-3 and DENV-4. The types currently in greatest circulation in Brazil are 1 and 2, the same ones that were already circulating in the municipalities of Ceará in recent years. As Ceará and other states in the Northeast have a history of epidemics, Tanta believes that the portion of the population susceptible to contracting the disease would be lower than in states in the Southeast and South, which began to face the disease more recently, with a higher associated prevalence. climate emergency and excessive rainfall.

The situation in Ceará seems more comfortable than in other parts of the country, but expert managers agree that we cannot let our guard down against mosquitoes. This is because another factor that may explain the low incidence in the state is the later start of the rainy season, when there is usually more water accumulation and, consequently, greater proliferation of the Aedes Aegypti. The peak of dengue fever in Ceará is usually between April and May.

“The rainy season started later. We may see, from now on, an increase in arboviruses, such as dengue, chikungunya and zika”, ponders Magda Almeida, professor at the Department of Community Health at the Federal University of Ceará , although I recognize that the low incidence in the first months is encouraging.

Tanta recognizes that the risk of an increase in cases cannot be ruled out, but claims it is unlikely. He explains that the secretariat creates a control diagram, with moving average data from the historical series of dengue cases. From there, an upper limit is statistically calculated. “When you are below average, it means you are in a period of low transmission, which is what is happening now,” he details.

According to him, although the disease peaks usually in April, in years of outbreaks the first months already indicated an increase. Be that as it may, the manager himself admits that the situation could change if, for example, DENV-3 or DENV-4 return to Ceará. Although it is rare to experience two epidemics in consecutive years, the state experienced this in 2011 and 2012 with the replacement of DENV-1 with DENV-4. “If you don’t have a serotype alternation, the population that is susceptible [no Ceará] It’s much lower than in some states,” he says.

Lessons from epidemics

The lessons learned from epidemics in recent decades, according to experts, also contribute to controlling the incidence and, especially, preventing deaths. One of them is clinical management: informing the population so that they know how to identify the warning signs of the severity of the disease (such as nausea, dizziness, vomiting and abdominal pain) and organizing the health system to respond to them in a timely manner. crucial.

“If I treat this person at this stage, with saline solution, I save 99% of cases”, explains the infectious disease doctor and coordinator of the Tropical Medicine Center at the Federal University of Ceará, Ivo Castelo Branco.

Another lesson, according to Secretary Tanta, is to learn not to underestimate the disease’s capacity for an epidemic explosion and to act to stop transmission when an increase in mosquito infestation rates is noted (the LIRA, carried out by sampling from visits households), before the data reflects cases of the disease.

Having an active and attentive surveillance team and an informed population to eliminate mosquito outbreaks at home is another important lesson. “We’ve had a culture of individual accountability for some time now,” says Magda Almeida. The outbreaks, in fact, change from region to region, and the mosquito may be proliferating in the trash, in plastic bottles, but also in open water tanks.