North and South America: Epidemiological Alert - Dengue - 21 November2018

Following a period of low dengue transmission in the Region of the Americas, an increase in cases has been reported in some countries. With the start of high transmission season for dengue in the Southern Hemisphere, the Pan American Health Organization / World Health Organization (PAHO/WHO) recommends Member States implement preparedness and response actions in order to prevent transmission of dengue as well as deaths due to this disease.

Situation summary in the Americas

In the Region of the Americas, between epidemiological week (EW) 1 and EW 44 of 2018, a total of 446,150 cases of dengue were reported (incidence of 45.9 cases per 100,000 population), including 240 deaths. Of the total cases, 171,123 were laboratory-confirmed and 2,164 (0.49%) were classified as severe dengue.

As of EW 44 of 2018, 13 countries in the Americas reported an increase in cases nationally or in parts of the country (compared to the same period in 2017): Antigua and Barbuda,
Argentina, Brazil, Chile, Colombia, El Salvador, Guatemala, Guyana, Honduras, Jamaica,
Mexico, Paraguay, and Venezuela. In Peru, though there was a decrease in the number of cases reported at the national level, an increase was observed (compared to 2017) in the departments of Loreto and Madre de Dios.

In 2018, the number of cases reported to date is similar to the total registered in 2017, and if this trend continues, it could exceed the total reported in that year (Figure 1).

Compared to previous years, the total number of cases reported by the end of 2017 (581,207) was less than that reported in 2016 (2,178,929) and the lowest in the past ten years. However, the proportion of cases of severe dengue reported in 2017 was higher than the two previous years.

The four dengue virus serotypes (DENV 1, DENV 2, DENV 3, and DENV 4) are circulating simultaneously in some countries of the Region, which increases the risk of severe dengue, and therefore, could cause an additional burden on health services.

If timely interventions are not applied to control the vector, Aedes aegypti, an increase in cases could be expected in 2019—the magnitude of which will depend on the intensity and effectiveness of the control and prevention measures implemented.