Since the beginning of 2023, dengue outbreaks of significant magnitude have been recorded in the WHO Region of the Americas, with close to three million suspected and confirmed cases of dengue reported so far this year, surpassing the 2.8 million cases of dengue registered for the entire year of 2022. Of the total number of dengue cases reported until 1 July 2023 (2 997 097 cases), 45% were laboratory confirmed, and 0.13% were classified as severe dengue. The highest number of dengue cases to date in 2023 are in Brazil, Peru, and Bolivia. Additionally, 1302 deaths were reported in the Region with a Case Fatality Rate (CFR) of 0.04%, in the same period.
As part of the implementation of the Integrated Management Strategy for the Prevention and Control of Arboviral Diseases (IMS-Arbovirus), WHO is actively working with the Member States to strengthen healthcare and surveillance capacity.
WHO has assessed the risk of dengue as high at the regional level due to the wide spread distribution of the Aedes spp. mosquitoes (especially Aedes aegypti), the continued risk of severe disease and death, and the expansion out of historical areas of transmission, where all the population, including risk groups and healthcare workers, may not be aware of warning signs.
WHO does not recommend any travel and/or trade restrictions for countries in the Americas experiencing the current dengue epidemics based on the currently available information.
Description of the situation
Dengue is the arbovirus that causes the highest number of cases in the Region of the Americas, with epidemics occurring cyclically every 3 to 5 years. During the first half of 2023, dengue outbreaks of significant magnitude were recorded in South America. Between epidemiological week (EW) 1 and EW 26 of 2023 (week ending on 01 July), a total of 2 997 097 cases of dengue were reported in the Region of the Americas, including 1302 deaths with a CFR of 0.04%, with a cumulative incidence rate of 305 cases per 100 000 population. Of the total number of dengue cases until EW 26 of 2023, 1 348 234 (45%) were laboratory confirmed, and 3907 (0.13%) were classified as severe dengue.1 The highest number of dengue cases was observed in Brazil, with 2 376 522 cases, followed by Peru with 188 326 cases, and Bolivia with 133 779 cases.
The highest cumulative incidence rates were observed in the following subregions: the Southern Cone2 with 862 cases per 100 000 inhabitants, the Andean Subregion3 with 268 cases per 100 000 inhabitants, and the Central American Isthmus and Mexico4 with 59 cases per 100 000 inhabitants.
The highest number of severe dengue cases was observed in the following countries: Brazil with 1249 cases, Peru with 701 cases, Colombia with 683 cases, Bolivia with 591 cases and Mexico with 141 cases.
All four dengue virus serotypes (DENV1, DENV2, DENV3, and DENV4) are present in the Region of the Americas. In 2023, up to EW 26 (ending on 1 July), simultaneous circulation of all four serotypes has been detected in Brazil, Colombia, Costa Rica, Guatemala, Honduras, Mexico, and Venezuela; while in Argentina, Panama, Peru, and Puerto Rico, DENV1, DENV2 and DENV3 serotypes circulate, and in Nicaragua the serotypes DENV1, DENV3 and DENV4.
In 2022, 2 811 433 dengue cases were reported in the Region of the Americas, the third highest year on record, only surpassed by 2016 and 2019. In 2019, the highest number of historical dengue cases was registered, with more than 3.1 million cases for the Region of the Americas, including 28 203 severe cases and 1823 deaths.
Between 12 June to 1 July 2023, some countries in the Southern Cone and the Andean subregion have been showing a decrease in the number of cases due to multiple factors, including, the implementation of control measures, and the change in temperature and climate, mainly in the Southern Cone. There is also a delay in the notification of data from some countries in Central America and the Caribbean. These have resulted in a decline in cases and the downward trend observed in the epidemiological curve below.
