The increase in the incidence and geographic distribution of diseases such as chikungunya and dengue, transmitted by the aedes aegypti, represents an important public health problem in the region of the Americas. The alert was made by the World Health Organization (WHO).
Dengue is responsible for the largest number of cases on the continent, with epidemics occurring every three to five years. Although dengue and chikungunya are endemic in most countries in Central America, South America and the Caribbean, in the current summer season, increased transmission and expansion of chikungunya cases have been observed beyond historical transmission areas.
According to WHO, 2023 shows intense dengue transmission. In addition, higher transmission rates are expected in the coming months in the southern hemisphere, due to climatic conditions favorable to the proliferation of mosquitoes.
There were 2.8 million cases of dengue reported in the Americas in 2022, which represents a more than two-fold increase when compared to the 1.2 million cases reported in 2021. The same increasing trend was observed for chikungunya, with a high incidence of brain inflammation (meningoencephalitis) possibly associated with chikungunya.
At the regional level, WHO assesses the risk as high due to the widespread presence of mosquito vectors, the ongoing risk of serious illness and even death, and the expansion outside historical transmission areas where the entire population, including risk groups and healthcare professionals, health, may not be aware of the clinical manifestations of the disease, including severe conditions.
Epidemiological panorama in Brazil
An international study details the spread of the chikungunya virus (CHIKV) since its introduction in the country ten years ago. The research, which has the participation of the University of São Paulo (USP), analyzes 253,545 cases confirmed in the laboratory between 2013 and 2022.
The data suggest that the disease was heterogeneously distributed across the Brazilian territory, with the most affected cities showing some protection against new outbreaks, while municipalities less exposed to previous waves remained more susceptible. The results were published in the scientific journal The Lancet Microbe.
“CHIKV is a major threat to global public health, and the virus is transmitted primarily between humans by mosquitoes of the species aedes aegypti It is Aedes albopictus, the same vectors of dengue and Zika. During the last 20 years, more than 10 million cases of chikungunya have been reported in more than 125 countries and territories”, says virologist William Marciel de Souza, from the University of Texas Medical Branch, United States, first author of the article in a press release. .
The disease is characterized by symptoms such as a sudden onset of high fever and severe joint pain. Despite the similarities in symptoms, the main difference between dengue and chikungunya is joint pain, much more intense in chikungunya, affecting mainly feet and hands, usually in the ankles and wrists.
The diagnosis must be made by a doctor and can be confirmed by specific laboratory tests, which can be performed by the Unified Health System (SUS). As the disease is transmitted by mosquitoes, the prevention measure includes the elimination of breeding sites in houses and neighborhoods, which basically consist of places where stagnant water accumulates (see below ).
“Chikungunya is a febrile illness typically characterized by acute and chronic human signs and symptoms, usually with severe arthralgia [dor nas articulações], often chronic and disabling, but also including some neurological complications and death. There are currently no licensed vaccines or antiviral medications available to prevent or treat the infection,” explains the researcher.
Source: CNN Brasil