Dengue alert: 7 Brazilian cities at orange or red

Seven of the 131 Brazilian cities that RaisLife tracks are in the orange or red dengue alert level for epidemiological week 39 of 2026, which ran from Sept. 27 to Oct. 3. The two red alerts, the highest level on the scale, are in Aparecida de Goiânia (Goiás state) and Campina Grande (Paraíba state). Orange alerts are in São Paulo, Campinas, Rio de Janeiro, Belo Horizonte and Caucaia (Ceará state). The levels are calculated by InfoDengue, a system run by Fiocruz, a Brazilian public health research institute, and the Fundação Getulio Vargas (FGV), a university and think tank. The remaining cities are in the green (118) or yellow (6).

How the tracking works

RaisLife monitors the capital and the four largest cities of each Brazilian state (in the Federal District, only Brasília), a criterion set by the portal itself. Each city's alert level comes from InfoDengue, which combines reported cases with climate data. An epidemiological week runs from Sunday to Saturday, and week 39 of 2026 began on Sept. 27. The data in this report was read on Thursday (Oct. 15).

According to InfoDengue's glossary, yellow means conditions favorable to transmission and at least one case. Orange means rising incidence, with the reproduction number (Rt) above 1 for at least two weeks but still within historical levels. Red means high incidence by the city's own standards, above 90% of the threshold calculated with the moving epidemic method (MEM).

One note of caution: figures for the most recent weeks are estimates, because case notifications arrive late and the numbers are often revised in the following weeks. In Belo Horizonte, for example, InfoDengue had 58 notified cases for week 39 so far and gives a range of 395 to 1.470 cases for the full total.

The two red alerts

Aparecida de Goiânia, in the metropolitan area of Goiás' capital, was the only tracked city to jump from green to red from one week to the next, and it has the highest incidence of the 131. InfoDengue estimates 899 cases in week 39 (179.5 per 100.000 residents), up from 663 in week 38, when the city was still in the green. Under RaisLife's trend rule, the last two weeks combined (1.562 estimated cases) are just over double the previous two weeks (771), which classifies the movement as rising. Neighboring Goiânia remains in the green, with 462 estimated cases and a stable trend.

In Campina Grande, red is nothing new: InfoDengue data show the city at that level for the last six weeks, with 109 estimated cases in week 39 (26.1 per 100.000 residents) and very similar numbers from one week to the next. The trend is stable. Because red is measured against each city's own history, a city can be at that level with fewer cases per 100.000 residents than another that is in the green, such as Goiânia, with 32.7.

Five cities in the orange, four with rising cases

Belo Horizonte has 726 estimated cases (30.3 per 100.000 residents), and the last two weeks combined, at 1.272 cases, are about 55% higher than the previous two (823). In Rio de Janeiro there are 336 estimated cases, or 5.1 per 100.000 residents; the last two weeks combined (635) exceed the previous two (415) by about 53%. Campinas, in São Paulo state, has 193 estimated cases, and its recent total (393) is about 37% higher than the earlier one (287). Caucaia, in the Fortaleza metropolitan area, also shows a rising trend. São Paulo, the city with the most estimated cases among those tracked, 1.152 in week 39 (9.4 per 100.000 residents), is in the orange with a stable trend.

In the yellow are Recife, Jaboatão dos Guararapes (Pernambuco state), Contagem (Minas Gerais state), São Luís, Salvador and Rorainópolis (Roraima state). The trend is a RaisLife measure, not an InfoDengue one: it compares the estimated cases of the last two weeks with the two before, and flags a rise when the number grows by 25% or more and a fall when it shrinks by 20% or more. Where case counts are low, week-to-week changes say little, so the trend should be read with care.

What Brazil's Ministry of Health advises

According to Brazil's Ministry of Health, dengue follows a seasonal pattern, with cases and epidemic risk rising mainly between October of one year and May of the next. The ministry advises anyone with a sudden fever of 39 °C to 40 °C (102°F to 104°F), together with at least two of the following signs, to seek health care immediately: headache, extreme tiredness, muscle or joint pain, and pain behind the eyes. Because symptoms vary from person to person, RaisLife adds a reminder: when in doubt, seek medical care.

The ministry also points to the period when the fever subsides, between the third and seventh day of illness, when warning signs can appear: severe abdominal pain, frequent vomiting, dizziness or a feeling of fainting, difficulty breathing, bleeding from the nose, gums or stool, fatigue and irritability. It recommends against self-medicating and says anyone with bleeding or any warning sign should go to an emergency service right away. At home, under medical guidance, the ministry recommends rest, plenty of fluids and a return visit for clinical reassessment. Pregnant women, infants, children up to age 2, people over 65 and those with chronic conditions such as diabetes and hypertension face a higher risk of complications, according to the agency.

For prevention, the ministry highlights controlling the Aedes aegypti mosquito as the main method: remove containers that collect water from the home, seal water tanks and storage containers, clear gutters, flat roofs and drains, and use window screens. It also mentions repellent in areas where the disease is transmitted. The dengue vaccine was added to Brazil's public health system, the Sistema Único de Saúde (SUS), on Dec. 21, 2023, but as a complement: even with it, controlling the mosquito remains the main form of prevention. Anyone who wants to know whether they can be vaccinated should check with their local health clinic or their municipal health department.

An alert level describes the situation in a city; it does not say whether any individual is ill. The full dashboard, with the situation in each tracked state and municipality, is at raislife.com/dengue. There are also state pages, such as Goiás, Paraíba and Minas Gerais.

Sources

• InfoDengue (Fiocruz and Fundação Getulio Vargas): alert levels, estimated cases and incidence by epidemiological week
• InfoDengue glossary: meaning of the alert levels
• Ministry of Health: dengue: symptoms, warning signs and prevention
• RaisLife dengue dashboard: copy of the data and the trend calculated by the portal

Text by Rai, RaisLife's virtual reporter (artificial intelligence), with automated editorial review. Data: raislife.com/dengue.