Dengue: 6 Brazilian cities on orange or red alert

Six of the 131 Brazilian cities that RaisLife tracks are on orange or red alert for dengue in epidemiological week 43 of 2026, which ran from Oct. 25 to 31. The two red alerts, the highest level on the scale, are Aparecida de Goiânia, in Goiás state, and Campina Grande, in Paraíba state. Aparecida de Goiânia has been red since the previous week and saw a sharp rise in estimated cases; Campina Grande has stayed red. Four cities are on orange: Belo Horizonte, Campinas (São Paulo state), Florianópolis and Vilhena (Rondônia state). The levels are calculated by InfoDengue, a system run by Fiocruz, Brazil's public-health research institute, and the Getulio Vargas Foundation (FGV), a Brazilian university and think tank. Of the other cities, 114 are green and 11 are yellow.

How the tracking works

RaisLife monitors the capital and the four largest cities of each Brazilian state (in the Federal District, only Brasília). That selection criterion is RaisLife's own. Each city's alert level comes from InfoDengue, which combines reported cases with climate data. According to the system's glossary, yellow means weather favorable to transmission and at least one case. Orange means rising incidence, with the effective reproduction number (Rt) above 1 for at least two weeks but still within historical levels. Red means incidence that is high by the city's own standards, above 90% of the threshold set by the moving epidemics method (MEM). The data were read on Nov. 5.

Case counts for the most recent weeks are estimates, because case reports arrive with a delay and the figures are revised in the following weeks. For that reason, the numbers and levels cited here for earlier weeks come from InfoDengue's revised series. In Aparecida de Goiânia the estimated range is wide: InfoDengue had 31 reported cases for week 43 at the time of reading and puts the likely total anywhere from 239 to 8.874 cases.

Aparecida de Goiânia sees a sharp estimated rise; Campina Grande stays red

Aparecida de Goiânia, in the Goiânia metropolitan area, has the highest case estimate of any city tracked. InfoDengue estimates 1.417 cases in week 43, or 283 per 100.000 residents, up from 897 in week 42, according to the revised series, an increase of about 58%. The city was green in week 40, moved to orange in week 41 and to red in week 42. Because the latest weeks are still subject to revision, the size of the increase could change. Under RaisLife's trend rule (explained below), the last two weeks combined (2.314 estimated cases) are more than double the two weeks before (1.031), which counts as a rise. Neighboring Goiânia, the state capital, was orange in week 42 but is back to green, with 586 estimated cases (41.4 per 100.000) and a stable trend.

Campina Grande has been red for at least 12 weeks and has 65 estimated cases in week 43 (15.5 per 100.000 residents). The last two weeks combined (113) are about 19% below the previous two (139), a change that still falls within the stable range. Because red is measured against each city's own history, a city can be red with lower incidence than a green city such as Goiânia (41.4 per 100.000).

Vilhena, Belo Horizonte and Campinas on the rise

Vilhena, in Rondônia state, had been red for the previous four weeks and has now dropped to orange. The estimate, however, went up: 303 cases in week 43, or 316.9 per 100.000 residents, the highest incidence among the 131 cities tracked, compared with 235 in week 42. The recent total (538) is about 37% above the earlier one (393), which makes the trend a rise by RaisLife's criterion. InfoDengue sets the level from each city's history, so a change in color does not always follow the weekly change in cases. In the system's glossary, orange signals rising incidence, and moving down from red does not mean there are fewer cases.

Belo Horizonte, the capital of Minas Gerais state, has been orange since week 42, with 502 estimated cases in week 43 (21 per 100.000). The last two weeks combined (956) are about 38% above the two before (692). Campinas went back to orange after two weeks in green, with 238 estimated cases (20.3 per 100.000); its recent total (480) is about 28% above the earlier one (374). Florianópolis has been orange for a second week in a row, with 54 estimated cases (9.4 per 100.000) and a stable trend: its recent total (134) is about 9% higher than the earlier one (123).

São Paulo, which had been orange for the previous four weeks, turned green. It still has the second-highest estimate of the cities tracked, 1.132 cases in week 43 (9.3 per 100.000 residents), and the last two weeks combined (2.489) are about 6% below the earlier total (2.651), which points to stability.

Yellow cities, trends and the rest of the country

Eleven cities are on yellow: Recife, Jaboatão dos Guararapes and Paulista (all in Pernambuco state), Salvador, São Luís, Aracaju, São Cristóvão (Sergipe state), Contagem, Juiz de Fora and Uberlândia (all in Minas Gerais state) and Rorainópolis (Roraima state). São Cristóvão and Rorainópolis moved into this level this week. São Luís, which had been red for at least ten weeks, through week 41, is yellow for a second week and trending down, as is Uberlândia.

By RaisLife's criterion, eight cities show a rising trend. Besides Aparecida de Goiânia, Vilhena, Belo Horizonte and Campinas, they are Guarulhos (São Paulo state), Várzea Grande (Mato Grosso state), Caucaia (Ceará state) and Cruzeiro do Sul (Acre state); the last four are all still green. Seven cities are trending down, 40 are stable, and in 76, there are too few cases to establish a trend. The trend is a RaisLife measure, not an InfoDengue one. It compares the sum of estimated cases in the last two weeks with the sum for the two weeks before, and counts a rise when the figure goes up by 25% or more and a decline when it falls by 20% or more. With fewer than 100 estimated cases across the four weeks, the portal does not classify a trend. Where cases are few, the change says little and should be read with caution.

What the Ministry of Health advises

According to Brazil's Ministry of Health, dengue follows a seasonal pattern, with cases and the risk of epidemics rising mainly from October of one year through May of the next. The ministry advises anyone with a sudden fever of 39 °C to 40 °C (about 102 °F to 104 °F), along with at least two of the following signs, to seek health care immediately: headache, extreme tiredness (prostration), muscle or joint pain, and pain behind the eyes. Symptoms vary from person to person and the fever does not always reach those levels; when in doubt, seek care.

The ministry also advises extra attention 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 to go to an emergency department (or urgent care) immediately in case of bleeding or any warning sign. Pregnant women, infants, children up to 2 years old, people over 65 and those with chronic conditions such as diabetes and hypertension face a higher risk of complications, according to the agency.

On prevention, the ministry names control of the Aedes aegypti mosquito as the main method: remove containers that collect water from the home, cover or seal water tanks and storage containers, clear gutters, flat roofs and drains, and put screens on windows. The agency also mentions repellent in areas where the disease is spreading. The dengue vaccine was added to Brazil's public health system (SUS) on Dec. 21, 2023, as a complementary measure; even with it, mosquito control remains the main form of prevention. Anyone who wants to know whether they can be vaccinated should ask at a health clinic or the city health department.

An alert level describes the situation in a city. It does not say whether any one person is sick. The full dashboard is at raislife.com/dengue, with pages for individual states, such as Goiás, Minas Gerais and Rondônia.

Sources

• InfoDengue (Fiocruz and the Getulio Vargas Foundation): 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.