Why Dengue and Chikungunya Remain Problems in South America Even in Winter

In full wintercontinue to report in South America cases of people diagnosed dengue And Chikungunyaviral infections transmitted by mosquito bites.

According to protocol Pan American Health Organization (PAHO)For the first time, the region has surpassed 10 million dengue cases, the worst epidemic in history since the infection re-emerged in the 1990s.

Thus, from the beginning of the year to last week, 10,165,294 cases have been registered in the Southern Cone and Andean Zone. However, last year only 3.8 million cases were registered in these subregions. In 2024, the most affected countries will be Brazil, Argentina, Paraguay And Peruand more than 5,100 dengue deaths were recorded.

The virus is also circulating heat Chikungunya and in South America, there have been more than 346,000 confirmed cases. The disease has killed more than 136 people in Brazil this year. “Since May, cases have decreased due to the drop in temperatures in Brazil. This is because mosquitoes’ reproductive capacity decreases in winter,” he said. Information Mauricio Lacerda Nogueirateacher and researcher Faculty of Medicine of São José do Rio Preto (FAMERP) and a FAPESP-supported researcher in Brazil.

V Argentina, dengue epidemic It is also in decline. But until 2023, local circulation of the virus slowed in winter. This did not happen last year, with cases reported in the northeast. This year, the circulation continued into June.

According to the latest epidemiological bulletin Ministry of Health of the Nation Argentina has recorded 10 cases Chaco And Currents in June. In the area of ​​the city. Center21 confirmed cases have been reported in 5 provinces, including the province of Buenos Aires.

Over the past 4 weeks in the area of ​​the city. Northwest 61 cases have been confirmed. Of this total, 47 cases were in the province TucumanOn the other hand, in the Cuyo region and the province of La Pampa, no cases were recorded in June.

“Yes. In June, in Argentina, especially in the province of Tucuman, which is part of the northwest region, there was a transmission of dengue virus, as well as some isolated cases in the northeast and center. But the incidence curve tends to stop transmission, as in the seasons up to 2023,” he said. Information Dr. Thomas Orduna, former head of the Tropical Medicine and Travel Medicine Service in F.J. Muñiz Infectious Diseases Hospital and member of the scientific committee Healthy World Foundation.

There are several factors that have contributed to the spread of dengue and chikungunya, which are transmitted by mosquitoes. Aedes aegyptiin months with lower temperatures.

As explained Information Jose Luis San Martin, Regional Advisor for Arboviral Diseases OPS, “In the southern hemisphere, the season of highest transmission is usually in the first half of the year, which coincides with the hot and rainy season. June and July are traditionally cooler, which does not favor the spread of mosquito vectors.”

However, “Climate change, which leads to increased rainfall and higher temperatures, is one of the main reasons for the rise in dengue cases. These factors contribute to the reproduction and spread of mosquitoes, as well as the spread of the disease to new territories,” he explained.

With climate change and the spread of vectors, the number of cases is increasing, and the season during which these insects are present each year is also lengthening. “This extends the annual broadcast season,” he said.

In addition, factors that contributed to the increase in dengue cases this year include the rapid expansion of unplanned cities, population growth, and poor water supply and sanitation. These changes have created conditions conducive to the spread of mosquitoes in discarded items and containers that collect water.

The transmission of dengue and chikungunya fever poses challenges for the future of the region. Is there anything that can be done to reduce new cases and deaths from these infections?

For the expert Susana Lloverasex-president Latin American Society of Travel Medicine and the section leader Medical zoopathology infectious diseases hospital Francisco Javier Muñiz City of Buenos Aires, “the main task is to control breeding sites and avoid accumulation of garbage and potential reservoirs of larvae.” From government officials to the general public must be involved.

Moreover, Lloveras emphasized in a dialogue with Information– “It is important that the health care system is prepared for a future epidemic and that medical teams are trained to promptly diagnose and treat affected people.”

In the city Hotelsprovinces MissionsIn northeastern Argentina, urban mosquito surveillance teams have begun visiting homes, accompanied by provincial police cadets.

“The technicians are accompanied by trainees, and this allows people to identify mosquito breeding sites in water containers in their homes with greater confidence,” he said. Information Fabricio TejerinaDirector of Surveillance and Vector Control Posadas.

The severity of the epidemic in South America has also attracted the attention of experts from other regions. A specialist journal recently Annals of Medicine and Surgery Researchers from India and Nepal stressed in an editorial that the dengue situation “is a stark reminder of the ongoing fight against infectious diseases and the need to remain vigilant, prepared and cooperative across borders.”

They noted that “by taking advantage of the collective experience and resources of countries in the region, improving surveillance and response systems, and prioritizing public health measures, the impact of dengue can be mitigated and we can move towards a future in which outbreaks of such fevers can be reduced to the scale of the past.”

To avoid the presence of mosquitoes in winter, it is reported Informationdoctor Maria Sol De Mayofrom the Mosquito Research Group of the Faculty of Exact and Natural Sciences of the University of Buenos Aires recommends:

• Use a brush to clean the sides of containers where water may accumulate.
• Pour boiling water into hard to reach places
• Throw away unused containers.

To prevent water from accumulating in containers, it is recommended:

• Store unused containers upside down.
• Attempting to puncture tires or throw them away
• Clean out your gutters to prevent water from pooling.