On Monday, authorities leaders in Puerto Rico declared a dengue epidemic after a spike in circumstances of the mosquito-borne illness hit the island.From the beginning of the yr by way of March 10, there have been 549 circumstances, together with 341 hospitalizations and 29 extreme circumstances, in accordance with the newest knowledge present by the Puerto Rico Division of Well being. Circumstances are concentrated in cities together with San Juan, Bayamon, Guaynabo and Carolina.Between 2010 and 2020, greater than 30,000 dengue circumstances have been reported from 4 U.S. territories, with Puerto Rico reporting essentially the most. In 2012, Puerto Rico reported 199 deaths, which was the final time the commonwealth declared a dengue epidemic.Dengue fever poses a major public well being menace in lots of elements of the world, notably in areas with excessive mosquito populations and restricted entry to well being care.The Facilities for Illness Management and Prevention mentioned it’s working with the Puerto Rico Division of Well being and the Puerto Rico Vector Management Unit on surveillance of the virus and on coaching well being suppliers. The CDC can also be concerned with cleanup campaigns, utilizing pesticides the place applicable, and in schooling efforts.The Puerto Rico Division of Well being mentioned it’s working to boost surveillance, laboratory, vector management and outreach interventions.“We work on a community-based technique strategy. … These interventions can [include]: academic supplies, subject visits to determine environmental well being dangers, coordination with municipalities to remove potential mosquitoes breeding websites and purposes of larvicides or adulticides,” Melissa Marzán, chief epidemiologist officer of the Puerto Rico Division of Well being, mentioned in an e-mail.What’s dengue fever, and the way is it unfold?Dengue could cause excessive fever, extreme headache, joint and muscle ache, rash and, in extreme circumstances, dying.The virus that causes dengue infect 100 million to 400 million individuals worldwide every year, in accordance with the World Well being Group.It’s transmitted to people mostly by the Aedes aegypti mosquito. Dengue is brought on by 4 associated viral serotypes, that are variations or strains of a virus. As a result of the variations can have an effect on the immune response to the virus, an infection with one serotype doesn’t present immunity in opposition to others. So individuals can undergo from dengue repeatedly, with the chance of extreme problems rising with every subsequent an infection.In accordance with the CDC, about 1 in 4 individuals who get contaminated with dengue develop signs, and 1 in 20 individuals who get sick from the virus undergo extreme sickness.Infants, older adults and people who are pregnant or immunocompromised have a higher danger of growing extreme signs.The place is it mostly discovered?Dengue is commonest in tropical and subtropical climates — prevalent in nations with heat climates the place the Aedes aegypti mosquito thrives. Areas in Southeast Asia, the Western Pacific, the Americas, Africa and the Jap Mediterranean are notably affected by dengue fever outbreaks. International locations similar to Brazil, India, the Philippines, Indonesia and Thailand have reported excessive numbers of dengue circumstances in recent times.Albert Ko, an infectious-disease doctor and epidemiologist on the Yale College of Public Well being, mentioned the continuing spike in Puerto Rico is uncommon as a result of transmission of the virus in drier months is usually low.“The truth that it’s taking place now’s actually type of a heads up, a warning signal for us. … We’re having introductions of the virus by individuals touring, and we’re seeing these outbreaks in Puerto Rico which are out of the season, that are actually uncommon,” Ko mentioned.Earlier this month, The Washington Submit reported a surge in circumstances in Brazil, inflicting many states within the South American nation to declare a state of emergency.Public well being consultants say these surges are prone to turn into extra widespread due to local weather change and since illnesses as soon as believed to be contained to particular areas are spreading due to elevated journey, facilitating simpler transmission of illness worldwide.“A superb instance is what we skilled throughout Zika, additionally transmitted by the identical mosquito when infections in vacationers unfold the virus rapidly throughout the Americas,” Ko mentioned.There aren’t any antiviral medicines to deal with dengue. As an alternative, remedy entails supportive care similar to ibuprofen, acetaminophen and different nonsteroidal anti-inflammatory medicine.“It might have a waxing and waning course, however you’re normally speaking about a few weeks total the place it’s worse within the first week or so, and we begin to see some restoration over time,” mentioned Jack C. O’Horo, an infectious-disease doctor on the Mayo Clinic.Two vaccines can be found for dengue. One is Dengvaxia, developed by Sanofi. The opposite is Dengue Tetravalent Vaccine, developed by Takeda Prescription drugs. Each pictures present safety in opposition to all 4 dengue virus serotypes.Dengvaxia is the one Meals and Drug Administration authorized vaccine for kids 9 to 16 years outdated. However one hurdle is that kids will need to have proof of a previous an infection — as proven by a blood check — earlier than getting the shot.Ko mentioned that for individuals who have by no means been uncovered to dengue and get the vaccine, it has been proven that they’ve a better danger of growing extreme dengue in the event that they turn into contaminated. He mentioned the reason being as a result of there’s “incomplete safety in opposition to the 4 serotypes (some greater than others) so the issue is when breakthrough infections happen, there’s an elevated danger of extreme outcomes similar to hospitalizations in those that weren’t uncovered beforehand to dengue.”The opposite vaccine, Qdenga, manufactured by a Japanese pharmaceutical firm, Takeda, is authorized within the European Union, United Kingdom, Brazil, Argentina, Indonesia and Thailand. In July 2023, the corporate withdrew its utility for FDA approval citing “points of information assortment, which can’t be addressed” within the designated evaluate timeline.