Dengue: Americas could record worst outbreak in history, warns PAHO

With more than 3.5 million cases of dengue recorded in the first three months of the year, the American continent could record, in 2024, the worst outbreak of the disease in history. The accumulated number is three times greater than the total number of cases registered in the same period last year. The alert was made this Thursday (28) by the Pan American Health Organization (PAHO).

Brazil, Argentina and Paraguay, according to the entity, account for more than 90% of cases and more than 80% of deaths from dengue in the Americas. Opas data show that Brazil appears in first place in rankingwith 2,966,339 cases and 758 deaths, followed by Paraguay, with 191,923 cases and 50 deaths, and Argentina, with 134,202 cases and 96 deaths.

In a press conference, the director general of PAHO, Jarbas Barbosa, classified the situation on the continent as worrying. He recalled that even countries such as Barbados, Costa Rica and Guatemala, where dengue outbreaks usually occur in the second half of the year, are already reporting an increase in cases of the disease. Puerto Rico, for example, declared a dengue emergency at the beginning of the week.

Jarbas highlighted that, in 2024, the four dengue serotypes circulate throughout the Americas and that, when two or more serotypes circulate, the risk of serious cases increases considerably. To date, data from PAHO indicate that at least 21 countries on the continent have reported the circulation of more than one serotype, including Brazil.

For the director general of PAHO, environmental causes play a “fundamental role” in the epidemiological scenario identified in the Americas. Jarbas cited, as an example, high temperatures, heat waves and intense droughts that lead the population to store water inappropriately, as well as floods that contribute to the increase in the circulation of the mosquito vector.

Asked whether it would be a case of declaring a public health emergency of international interest, as happened with the Zika virus in 2016, Jarbas explained that these are very different scenarios. In 2016, according to him, the emergency was declared due to a strong relationship between the Zika virus and cases of microcephaly in babies whose mothers were infected.

“The WHO [Organização Mundial da Saúde], rightly, declared the emergency until we could have an assessment of what was happening”, he said. “In dengue, the only new thing is the increase in transmission, but there is no change in the clinical expression of the disease or in the symptoms”, he added.

“Dengue is an important challenge. When we have an epidemic, circulation is so strong that almost everyone has contact with that serotype. Then we spend a period of three or four years until we have another outbreak. It seems that the disease has disappeared, gone away”, concluded Jarbas, highlighting the need for permanent programs in the Americas to identify new outbreaks early.