Epidemiological Update for
Dengue, Chikungunya and Zika in 2024.

Figure 2. Distribution of cases of dengue, chikungunya, and Zika by epidemiological week (EW), Region of The Americas, 2024. Source:Data entered into the Health Information Platform for The Americas (PLISA, PAHO / WHO)
by the Ministries and Institutes of Health of the countries and territories of the Region. Available at: https://www.paho.org/plisa

Dengue

Between EW 1 and 52 of 2024, a total of 13,063,434 cases of dengue were reported in the Region of the Americas, with a cumulative incidence of 1,295.42 cases per 100,000 population. The year 2024 yielded the highest number of dengue cases since the Pan American Health Organization started collecting dengue case data in 1980. The year 2024 started with intense dengue transmission earlier in the year, peaking in EW 12. The rate of growth of the curve in Figure 3 for 2023 was 493%, from EW 1 until peak on EW 15, while the rate of growth for the curve in 2024 was 512%, from EW 1 until peak on EW 12.

As of EW 52 of 2024, the highest number of dengue cases in the Region have been reported by the following countries: Brazil with 10,266,017 cases (78.6%), Argentina with 581,559 cases (4.5%), Mexico with 558,846 cases (4.3%), Colombia with 320,982 cases (2.5%), and Paraguay with 295,785 cases (2.3%). Distribution of incidence of dengue by subregion is presented in Figure 4. Note that the case counts for the ten countries in the Region account for 12,023,189 total cases or 92.0% of the total cases of dengue.

In 2024, of the total of cases reported in the Region, 6,997,321 (53.6%) were laboratory-confirmed and 23,177 (0.2%) were classified as severe dengue (Figure 5). The highest number of severe dengue cases were reported by the following countries: Brazil with 8,570 cases (37.0%), Mexico with 4,214 cases (18.2%), Colombia with 2,989 cases (12.9%), Honduras with 2,250 cases (9.7%), and Argentina with 1,604 cases (6.9%).

Figure 5 describes the proportion of severe dengue cases among all cases of dengue reported. 16 countries have reported higher proportion of severe cases than the regional mean of 0.18. Of note, the countries reporting the greatest proportion of severe cases among total dengue cases in 2024 were Cuba, (1.02%), Honduras, (1.27%), United States, (1.95%), Guyana, (2.67%), Suriname, (3.16%), Puerto Rico, (4.35%) .

Figure 6 below includes the pattern of dengue cases in the Americas since 2010. Also included in Figure 6 is the Regional, 10-year trend of the proportion of severe cases among all dengue cases and the proportion of dengue deaths among all dengue cases (case fatality rate, or CFR). Additionally, during the same period, a total of 8,431 deaths were reported in the Region (CFR: 0.065%).

In Figure 7 below, we can see a scatterplot of two variables used to monitor the severity of dengue seasons—the Dengue Case Fatality Rate (CFR or the proportion of how many cases of dengue die from the virus among all cases of the virus) and the proportion of severe cases among all dengue cases. This scatterplot attempts to visually demonstrate how these two variables are correlated. In this scatter plot we would expect to see a positive correlation. That means that as countries observe more severe cases, we would expect a greater proportion of these cases die.

All four dengue virus serotypes (DENV 1, DENV 2, DENV 3, DENV 4) were present in the Americas Region in 2024. Brasil , Colombia , Costa Rica , El Salvador , Guatemala , Honduras , México , Nicaragua , Panamá , Puerto Rico reported the detection of all four serotypes in 2024. Dengue serotype circulation by country is detailed in Figure 8.

Chikungunya

Between EW 1 and EW 52 of 2024, a total of 431417 chikungunya cases were reported in 17 of the 52 countries and territories in the Region of the Americas, of which 232586 were confirmed (53.9 %). The regional cumulative incidence for chikungunya in 2024 was of 43.46 cases per 100,000 population. The rate of growth of the curve for 2023 was 181%, from EW 1 until peak on EW 12 , while the rate of growth for the curve in 2024 was 296% , from EW 1 until peak on EW 9. 245 deaths were reported associated with chikungunya infection.

As of EW 52 of 2024, the highest number of chikungunya cases in the Region have been reported by Brazil, with 425,773 cases, which represents (98.7 %) of total regional cases. Paraguay follows in case counts with 3,134 cases (0.7 %), followed by Argentina with 1,388 cases (0.3 %), Bolivia with 505 cases (0.1 %), and United States with 196 cases (0.0%). During the same period, 245 deaths attributed to chikungunya infection were reported. The countries with the highest incidence are incluided in Figure 10.

Zika

Between EW 1 and EW 52 of 2024, a total of 44,490 of Zika have been reported in the Region of the Americas in 16 out of 52 countries and territories. Of all reported cases, 2,117 were lab-confirmed (4.8%). The 44,490 represents a cumulative incidence 4.53 cases per 100,000 population. Only 0 Zika-related death was reported for the year. Since its first detection in Brazil in March of 2014, local transmission of Zika has been confirmed in all countries and territories in the Americas, except for continental Chile, Uruguay, and Canada (Figure 11).

The highest numbers of Zika cases in the Region were reported in the following countries: Brazil with 43,234 cases ( 97.2 %), Argentina with 564 cases ( 1.3 %), Bolivia with 267 cases ( 0.6 %), Colombia with 117 cases ( 0.3 %), and El Salvador with 92 cases ( 0.2 %) of cases in the Region. The five countries with the highest cumulative incidence are included in Figure 12

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Note: As information is updated, PLISA automatically updates data, including retroactively. Therefore, data for any given time period may change as countries update their data.