Measurements the health public to prevent the spread COVID-19 It had unexpected consequences for Latin america Southeast Asia in 2020: HIV infections dengue fever It is avoided in hundreds of thousands of people, according to a study published in the scientific journal The Lancet this month.
The research provides clues to new strategies to combat this serious tropical disease that affects more people each year.
The study found a sharp decline in infections as of April 2020 in many areas where dengue is transmitted by mosquitoes; It is estimated that there were 720,000 dengue cases worldwide in the first year of the epidemic, due to movement restrictions.
“We’ve found really unexpected benefits from Covid restrictions that will help us fight dengue better in the future,” said Dr Oliver Brady, an epidemiologist at the London School of Hygiene and Tropical Medicine and lead author of the study.
More than 5 million people contracted dengue fever — also known as “break-bone fever” because of the severe joint and muscle pain it causes — in 2019.
Brady said that at the start of the pandemic, he and other infectious disease researchers feared a catastrophe as resources were diverted to Covid-19 and other disease control measures such as mosquito sprayThey were interrupted.
The huge drop in dengue cases came as a happy surprise and made them curious to find out the possible cause behind it. They eliminated other potential factors, including environmental changes and decreased underreporting of dengue fever by public health agencies. That, he said, left only the severe disruption of people’s displacement as a plausible explanation.
School closures, in particular, appear to have played a major role in reducing dengue cases. The main carrier of dengue and mosquitoes Aedes aegypti, Feed during the day. Most dengue control programs focus on homes — spraying to kill mosquitoes and monitoring standing water where they can breed — assuming that this is where transmission occurs.
“But if the home is really a place of danger and mosquitos are biting in the house, you would expect stay-at-home orders to increase the risk, but we haven’t seen that in many countries,” he said. .
The researchers are not suggesting that stay-at-home orders should continue, but the exceptional circumstance allowed for an unexpected outcome. Brady said his findings suggest that bites occur in the school or workplace, which means mosquito control should focus in public places.
Dengue may also have decreased during stay-at-home orders because when people became infected, they did not go to places where new mosquitoes could bite them and then pass the virus on to other people.
Dengue findings may be related to other mosquito-borne viruses, including Zika And the ChikungunyaStudy suggests. But Brady cautioned that the dengue data for 2021, due soon, and for the post-pandemic period, may bring bad news: infection rates may return to pre-Covid levels or worse if vectors for control programs are halted, while immunity levels may It may have decreased because fewer people were said to have been exposed.
Translated by Luis Roberto M. Gonsalves