Brazil is experiencing an outbreak of dengue fever, a sometimes fatal mosquito-borne disease, which public health experts say portends a future surge in cases in the Americas, including Puerto Rico. There is.
Brazil’s Health Ministry says more than 4.2 million infections are expected this year, surpassing the 4.1 million infections recorded last year by the Pan American Health Organization for all 42 countries in the region. I’m warning you.
Brazil was set for a major dengue fever outbreak – the number of cases usually rises and falls on a cycle of about four years – but experts say a number of factors, including El Niño and climate change, will greatly amplify the problem this year. point out that
Brazil’s Health Minister Nicia said, “Record heat in Brazil and above-average rainfall since the beginning of the summer and since last year are creating breeding grounds for mosquitoes, even in areas where there have been very few infections.” Stated. Trindade said.
Dengue cases have already surged in Argentina, Uruguay and Paraguay in recent months during the southern hemisphere summer, and the virus will move across the continent seasonally.
Dr. Albert Coe, a Brazilian dengue expert and professor of public health at Yale University, said, “When we see a wave in one country, we typically see waves in other countries. It’s about whether they are interconnected.”
who warned Dengue fever is rapidly becoming an urgent global health problem, with record numbers of cases last year and outbreaks in places where dengue has historically not been reported, such as France.
In the United States, Dr. Gabriela Pas-Bailey, director of the dengue division in the Centers for Disease Control and Prevention’s vector-borne disease division, said dengue transmission rates are expected to rise. A number of cases have occurred in Puerto Rico this year, and the mainland United States, particularly Florida, Texas, Arizona, and Southern California, are expected to see a similar rise in cases.
Dengue fever is spread by the Aedes aegypti mosquito, A type of mosquito that is becoming established in new regions, including warm and humid regions of the United States. In a place that has not been seen until the last few years..
With the widespread use of air conditioners and window screens, the number of infections in the United States is expected to remain relatively low this year, in the hundreds rather than millions. However, Dr Paz Bailey warned: Consistently increasing. ”
Last year, Florida reported a record high of 168 domestically infected people, and California reported similar cases for the first time.
Three-quarters of people infected with dengue have no symptoms at all, and most of those who do have only mild flu-like symptoms. However, some dengue infections are severe, causing headaches, vomiting, high fever, and joint pain, giving the disease the nickname “breakbone fever.” Severe cases of dengue fever can leave you debilitated for several weeks.
And about 5 percent of people who get the disease progress to so-called severe dengue fever, in which plasma, the protein-rich liquid component of blood, leaks from blood vessels.Some patients go into shock, which can lead to organ failure.
For severe dengue fever, the mortality rate is 2 to 5 percent for people whose symptoms are treated with blood transfusions or intravenous fluids. However, if left untreated, the mortality rate is 15 percent.
In Brazil, state governments have set up emergency centers to test and treat people for dengue fever. The city of Rio de Janeiro declared a public health emergency over dengue fever on Monday, days before the start of the annual Carnival, which draws tens of thousands of people to outdoor parties day and night.
Health Minister Trindade said a large number of cases have been reported in Brazil’s southernmost states, which are typically much cooler than Rio and the central and northern states. People in those areas have little immunity to disease from previous exposure.
There are four different serotypes of dengue fever, which are like relatives of the virus. Past infection with one serotype of dengue fever provides only short-term protection against infection with another serotype, and people who have been infected with one serotype of dengue fever in the past are more susceptible to infection with another serotype. Increased risk of developing severe dengue fever.
“Right now, we have a serotype circulating in Brazil that hasn’t been prevalent in Brazil for 20 years,” said Dr. Ernesto Marquez, an associate professor of infectious diseases and microbiology at the University of Pittsburgh.
Brazil has launched an emergency campaign to immunize children in areas with the highest rates or risk of dengue infection using a two-dose vaccine called Qdenga, made by Japan’s Takeda Pharmaceutical Company. Brazil will purchase 5.2 million doses for delivery this year and another 9 million for delivery in 2025, and the company will donate an additional 1.3 million doses, making the majority of the world’s supply of cudenga virtually It will be locked. A company spokesperson said Takeda is working on plans to increase supply, with a focus on supplying countries with high prevalence.
But it’s still enough to cover less than 10 percent of Brazil’s population in two years. The only good news about dengue fever in Brazil so far is the publication of clinical trial results for a new vaccine tested by the Butantan Institute, a public health research center in São Paulo. The vaccine requires only one dose, and clinical trials found that 80% of recipients were protected from developing dengue virus infection. The research center plans to request approval from the Brazilian government for the vaccine, and has equipment to produce the vaccine, with the aim of starting vaccinations in 2025.
Vaccination is of little use when it comes to this outbreak, and public health officials have few other ways to slow it.
“Pesticide resistance really limits what we can do in terms of controlling mosquito populations, and insecticide resistance is widespread,” said Dr. Paz Bailey of the CDC. I know what to do. ”
Medical centers in Brazil are setting up additional beds for patients with severe dengue fever in the hope of preventing health system disruptions and preventing deaths from dengue fever during the coronavirus pandemic.
“The old paradigm that dengue affects children most doesn’t apply in Brazil. We have to think about the elderly, who are very vulnerable,” Dr Koh said. He said it will be important to get the message across to both clinicians and the public to get tested for dengue at the first sign of symptoms, both in children and the elderly.
“My educated guess is that this is going to be a bad year,” Dr. Marquez said. That would be very, very bad. ”
Lis Morriconi I contributed a report from Rio de Janeiro.
