Dengue cases in Argentina have risen by 61%, according to the national health ministry’s most recent epidemiological bulletin.

Most cases — nearly 95% — of this mosquito-borne disease were registered in the hot, humid northeast provinces of Chaco, Corrientes, Formosa and Misiones, but it is also spreading in Buenos Aires.

In the last two weeks of December and the first two of January, 16,141 dengue cases were registered. That was up by 61% from the 10,056 cases in the previous week’s National Epidemiology Bulletin, which covered the final three weeks of December and the first week of January.

The vast majority of patients, including those in Buenos Aires City, caught the disease in their local area, rather than while traveling.

Dengue cases tend to increase as the weather gets warmer, creating ideal conditions for mosquito larvae to grow. The case count rose by 65% in the week between November 19 and 25, then more than doubled (+113%) between December 10 and 16, as Argentina’s summer got under way.

Dengue, also known as break-bone fever because of the intense muscular pain that some sufferers experience, is a viral infection transmitted to humans through the bite of infected mosquitoes. It is typically found in tropical and sub-tropical climates worldwide, mostly in urban and semi-urban areas, according to the World Health Organization (WHO).

In 2023, the worst dengue outbreak on record killed dozens of people and sickened tens of thousands in Argentina. The wave came during a five-month heatwave, and public health experts have said that climate change and extreme temperatures are making the problem worse. Argentine medical regulator ANMAT approved a Japanese vaccine for dengue in April 2023.

Most people who get dengue don’t have symptoms. However, those who do can experience high fever, headache, body aches, nausea and rash. Recovery usually takes 1–2 weeks.

The disease can be so severe that patients are hospitalized and in some cases, it can be fatal. People who get dengue for the second time are at greater risk of the severe form of the disease, according to the WHO website.

There is no specific treatment for dengue aside from pain medicine. WHO recommends lowering the risk of getting dengue by avoiding mosquito bites, especially during the day.