Dengue Fever: A Growing Global ConcernDengue Fever: A Growing Global Concern US health officials have issued a warning to medical professionals to be vigilant for cases of dengue fever, as the tropical disease reaches unprecedented global levels. Dengue is transmitted by mosquitoes and has surged worldwide due to climate change. In the Americas alone, dengue cases have already exceeded annual records in just six months. Symptoms and Risks While many infected individuals remain asymptomatic, others experience headaches, fever, and flu-like symptoms. Severe dengue can lead to life-threatening complications such as bleeding, shock, and death. Repeated dengue infections can be particularly perilous. The body’s antibodies from an initial infection may not effectively neutralize subsequent infections, facilitating the virus’s entry into immune cells and replication. Global Impact In 2021, over 6.6 million dengue infections were reported in approximately 80 countries. The first four months of 2022 saw an alarming 7.9 million cases and 4,000 deaths globally. The Americas, including Brazil and Peru, have experienced particularly severe outbreaks. US Cases In the United States, dengue cases are still rarer than in other parts of the world. However, the country has witnessed a three-fold increase in domestically acquired cases this year compared to the same period last year. While the majority of infections are travel-related, local mosquitoes pose a growing threat. Treatment and Vaccines There is currently no widely available treatment for dengue fever. Vaccines have faced challenges, with the only US-recommended vaccine, made by Sanofi, having limited usage due to its restricted indications. Another vaccine, developed by Takeda, is not yet licensed in the US. Prevention Preventing mosquito bites is crucial for minimizing dengue risk. Travelers to endemic areas should use insect repellent, wear long sleeves and pants, and consider sleeping under mosquito nets. Conclusion Dengue fever represents a growing global health concern. Healthcare providers should be aware of the symptoms and consider dengue testing when appropriate. Continued efforts are needed to develop effective treatments and vaccines to mitigate the impact of this devastating disease.
US health officials warned doctors on Tuesday to be alert to cases of dengue as the tropical disease breaks international records.
The virus, which is spread by mosquitoes, is on the rise worldwide, helped by climate change. In just six months, countries in the Americas have already broken calendar year records for dengue cases.
The World Health Organization declared a state of emergency in December and Puerto Rico declared a public health emergency in March.
Dengue is still less common in the continental United States, but in the fifty states so far this year there have been three times more cases than at the same point last year. Most were infections that travelers acquired abroad, and officials note there is no evidence of a current outbreak. But they also warn that local mosquitoes pose a threat.
In its health alert Tuesday, the Centers for Disease Control and Prevention advised doctors to know the symptoms, ask questions about where patients have recently traveled and consider ordering dengue testing if necessary.
Dengue (pronounced DEHN’-gay) is caused by a virus spread by a species of warm-weather mosquito that is expanding its geographic range because of climate change, experts say.
Many infected people do not get sick, but some suffer from headaches, fever and flu-like symptoms. In severe cases, severe bleeding, shock and death can result.
Repeated infections can be particularly dangerous.
There are four types of dengue viruses, known simply as 1, 2, 3 and 4. When a person is first infected, their body builds up antibodies against that type for life. If they become infected with another type of dengue, the antibodies from the first infection may not be able to neutralize the second type – and may even help the virus enter immune cells and multiply.
That’s a concern in Puerto Rico, which has seen widespread exposure to type 1 over the past two decades. Last month, the island reported its first dengue death of the year.
“We are currently seeing an increase in cases due to dengue 2 and dengue 3, for which the population has very little immunity,” says Dr. Gabriela Paz-Bailey, the Puerto Rico-based head of the CDC’s dengue division.
There is no commonly available medication to treat dengue infections.
Vaccines have been tricky. U.S. officials have recommended one vaccine in 2021, made by Sanofi. The three-dose vaccine is designed to protect against all four types of dengue and is only recommended for children ages 9 to 16 who have laboratory evidence of previous dengue infection and who live in an area – such as Puerto Rico – where dengue is common .
Given these limitations and other problems, it is not widely used. By the end of last month, only about 140 children had been vaccinated in Puerto Rico since shots became available there in 2022, and Sanofi Pasteur has told the CDC it will stop making the vaccine.
Another vaccine, made by Tokyo-based pharmaceutical company Takeda, is not currently licensed in the US. Others are in development.
Globally, more than 6.6 million infections were reported by about 80 countries last year. In the first four months of this year, 7.9 million cases and 4,000 deaths were reported, the World Health Organization said. It has been particularly intense in the Americas, including Brazil and Peru.
In the United States, the numbers were much more modest: about 3,000 cases in U.S. states and territories last year. But it was the worst in a decade and local infections were on the rise, thanks to native mosquitoes. Most were in Puerto Rico, but about 180 were in three U.S. states: Florida, Texas and California.
So far this year, there have been nearly 1,500 locally acquired cases in the U.S., almost all of them in Puerto Rico.
Most cases in the continental US remain people who became infected during international travel.
It’s “a traveler’s nightmare” and a growing international concern, said Dr. Lulu Bravo, who studies tropical diseases in children at the University of the Philippines in Manila and who worked with Takeda on its vaccine.
“If you have an outbreak in a country, tourists may not want to come,” Bravo said.
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