more aggressive dengue virus advances in Brazil, says Health MinistryGrows in some states the circulation of serotype 2, the most aggressive of the four existing viruses.
While most cases of dengue in Brazil is still caused by the type 1 disease, grows in some states the circulation of serotype 2, the most aggressive of the four existing viruses. Data from the latest epidemiological bulletin of the Ministry of Health, with statistics 3 January to 28 of May, show that, a total of 2,2 thousand samples positive for dengue analyzed in the laboratory this year, 6,4% already they are of type 2, before 0,7% last year. In the state of Sao Paulo, this type of virus is already responsible for 13,6% of cases of disease, before 0,5% in 2015.
Besides being considered by the most virulent experts of the four dengue serotypes, or type 2 It is also related to another risk in the country. As part of the population has been infected by type 1, the occurrence of a second infection with another strain increases the risk of developing a severe disease, that can lead to death, as haemorrhagic fever.
According to the infectious disease Artur Timerman, President of the Brazilian Society of Dengue and Arboviroses, the greatest risk for a second infection by the disease is related to the immune response of the patient to have contracted the virus since. "As already exist antibodies against dengue type in the body, there is an increased inflammatory reaction, that impairs the body, but can not neutralize the new serotype. The risk of developing a severe form of dengue is 15 a 20 times greater when it is a second infection. "
The large number of Brazilians infected by type 1 the dengue epidemics in recent years is one of the reasons for the increase in cases caused by type 2, second specialists. "As the virus type 1 dengue is circulating for a long time in Brazil, we have many people immune to it. When there is contact with another strain of this population, it increases the number of these types of cases because more people are susceptible to it. And a second dengue infection tends to greater severity ", explains Marcos Boulos, Disease Control coordinator of the State Health Secretariat.
Besides São Paulo, other states recorded circulation type 2 Dengue above the national average. No stop, 33,3% of the samples corresponding to this serotype. No Federal District, this figure is 26,8% and Rondônia, from 13,1%.
according to Boulos, in the state of Sao Paulo, this serotype is present predominantly in the region of Ribeirão Preto, in the interior. In partnership with the Municipal Department of the city's Health, researchers from USP in Ribeirão Preto School of Medicine have made virological surveillance of dengue cases in the city to establish what is the percentage of cases of each serotype.
"What we have seen is that, the end of last year here, there was even an increase in cases of dengue type 2. Depending on the month, they now account for about 25% a 30% cases in town. But I do not think this is restricted to Ribeirão. This increase should be happening in other areas of the state also ", says Benedito Antonio Lopes da Fonseca, College Professor of Infectious Diseases and one of the coordinators of virologic monitoring in the city.
The researcher also said that at least one of the seven deaths from dengue recorded this year in the city took place by an infection caused by type 2 disease. The patient had a chronic disease, condition that increases the risk of complications.
according to Boulos, on the type advancement 2 of dengue in the state, the state Department of Health should strengthen with doctors and other health professionals people care guidelines with suspected disease. "Everyone has to become more aware of dengue worsening signs. We will have to think twice before releasing the patient. "