QCOSTARICA – As has happened with other viral diseases, dengue declined substantially this year, although cases may increase when the rains intensify if the population becomes neglectful.
For the first semester of 2021, the Ministry of Health registered 1,556 cases of dengue.
The figure is 280% lower than that registered for the same time in 2020, when 4,355 cases were reported, reported epidemiologist Melissa Ramírez, of the Health Surveillance Directorate, of the Ministry of Health.
The numbers of Zika and Chikungunya, two other vector-borne diseases, are practically flat with 21 and 15 cases, respectively, in the same period.
“We do not have evidence of what may be happening. These diseases are multifactorial. Dengue has cyclical behaviors. Every five years, an epidemic peak attributed to climate change is expected,” said Ramírez.
The epidemiologist discusses some hypotheses. The main one is related to less mobility of people due to the coronavirus pandemic.
“We think that due to covid, people are at home more, there is less movement in the population due to (vehicle) restrictions, and this may cause the virus to decrease. Even if there is a vector (in this case, a transmitter mosquito), there are fewer carriers of the virus,” she explained.
Another of the situations derived from the pandemic, which would be the second hypothesis to explain this reduction, is the possibility that dengue, Zika or Chikungunya patients visit health services less for fear of catching Covid.
And the third possible cause is that people, being more at home, have a greater concern for maintaining cleanliness, both inside and around their home.
The dengue virus entered the country in 1992. According to the World Health Organization (WHO), the infection causes symptoms similar to those caused by the flu (fever and body pain).
Sometimes it progresses to a life-threatening condition called severe dengue, previously known as hemorrhagic dengue.
The females, mainly of the Aedes aegypti species and, to a lesser extent, of A. albopictus, are the ones that transmit the disease, as with Zika and Chikungunya.
Currently, no outbreak of these diseases is reported in the country, although the cantons of Talamanca (Limón), San Carlos (Alajuela) and Pérez Zeledón (San José) continue to lead the number of patients.
In the region of the Americas, the epidemiologist explained, there is also a significant decrease in the curve after the epidemic outbreaks of 2019, which caused several hundred deaths.
At the gates of the strongest phase of the rainy season, the specialist said it is not yet known what will happen precisely, but it is likely that the cases will increase because the populations of mosquitoes transmitting these diseases increase with the rains.
This explains the importance, always in force, of eliminating mosquito breeding sites in the surroundings of the houses.
So far this year alone, teams have visited more than 363,000 homes across the country and have been responsible for eliminating 596,000 breeding sites.
The little big enemy
The female mosquito Aedes aegypti is responsible for transmitting several viruses at the same time; among them, dengue, chikungunya, and zika. The task in all households is to destroy their breeding sites.