Dengue surveillance across the Americas recorded 1,813,577 suspected cases by epidemiological week 39 of 2026, according to an update published on 23 October.
The cumulative figure was accompanied by an incidence of 278 cases per 100,000 population. It was 55% lower than the total reported at the equivalent point in 2025 and 62% below the average for the previous five years.
The comparison describes the regional position through week 39, rather than a count for that week alone. The bulletin does not assign a cause for the overall fall. Its figures are preliminary surveillance data and may change as countries submit notifications or make adjustments.
What was reported in week 39
Twenty-one countries and territories reported 28,008 new suspected cases during epidemiological week 39. Of those, 8,196 were laboratory-confirmed, while 76 were classified as severe dengue. The update recorded 10 deaths for the week and put the case-fatality rate at 0.036%.
For the year to that point, 565,945 of the 1,813,577 suspected cases had been laboratory-confirmed, or 31.2%. The regional total also included 3,834 cases classified as severe dengue and 614 recorded deaths. The stated case-fatality rate for weeks one to 39 was 0.034%.
Those distinctions matter when reading the headline total. A suspected case is part of the surveillance count, whereas laboratory confirmation is reported separately. The bulletin therefore does not present the 1.81 million figure as a total of confirmed diagnoses.
Different patterns across the region
The latest week did not show the same pattern in every sub-region. Central America and Mexico registered 3,323 new suspected cases. The bulletin described the sub-region as 34% lower than the same point in 2025 and 62% below the five-year average. It also identified increases against the preceding four epidemiological weeks in El Salvador, at 13%, and Honduras, at 12%.
The Caribbean recorded 81 new suspected cases in week 39. Its reported position was 64% below the equivalent point in 2025 and 69% below the five-year average.
In the Andean sub-region, 9,680 new suspected cases were registered. This was the one sub-region where the comparison with the same point in 2025 moved upward, by 11%, although the figure remained 10% below the five-year average. The report noted increases against the previous four weeks in Peru, at 41%, and Bolivia, at 25%.
The Southern Cone registered 14,924 new suspected cases, the largest of the four sub-regional weekly totals. Its position was 61% below the same point last year and 66% below the five-year average. Paraguay was identified as having a 23% increase against the preceding four weeks.
How the figures should be read
Dengue is a mosquito-borne viral infection, and illness can range from mild symptoms to severe disease. The regional update records trends reported through public-health surveillance; it is not a clinical account of individual patients or an explanation of why transmission differs between places.
Twenty countries reported circulation of dengue virus serotypes during 2026. Panama, Brazil, Venezuela, Mexico and Colombia reported all four serotypes. The report does not draw a causal link between those findings and the changes in weekly case numbers.
Data for the regional total are supplied by health ministries and institutes in the countries and territories concerned. With notifications and classifications still capable of revision, the latest figures offer a current regional snapshot rather than a final year-end account.
