For most US physicians who are seeing a patient with fever, dengue does not usually come to mind – unless the patient has a history of travelling to an endemic area. However, if SARS-CoV-2 has taught us anything, it is that we live in a global community. When it comes to viruses, “what happens in Vegas stays in Vegas” is not true. What happens in another country can rapidly become what happens in the US, and vice versa!
Dengue is one of these viral infections that is becoming increasingly common in the US. This week, Pediatrics is early releasing a State-of-the-Art Review, entitled “Dengue: A Growing Problem with New Interventions,” by Dr. Joshua Wong and colleagues from the Centers for Disease Control and Prevention (CDC), Johns Hopkins University, and Wake Forest University (10.1542/peds.2021-055522).
The authors provide a quick review of what you learned in medical school parasitology. Dengue is the disease caused by one of 4 dengue viruses, generally transmitted by the bite of an infected female Aedes mosquito. As immunity is serotype-specific, it requires infection with all 4 dengue serotypes. The second infection (meaning a second bite that carries the dengue virus) is the worst, because disease is due to antibody-dependent enhancement, which is characterized by plasma leakage which, when severe, results in shock, coagulopathy, and/or end-organ damage. The incidence of symptomatic dengue cases and hospitalizations is highest in children and adolescents.
While we have generally considered dengue to be a disease that is largely confined to tropical and subtropical areas, the authors point out that climate change has expanded the geographic range of the Aedes mosquito.
There is much to digest from this excellent review, including data about epidemiology, pathophysiology, presentation and evaluation, diagnosis, and vector control measures.
One of the newest advances is a licensed dengue vaccine (Dengvaxia), which is now available in the US. It is a live, attenuated tetravalent (targeting all 4 serotypes) vaccine and is given in a 3-dose schedule, 6 months apart. It has 80% efficacy, and serious side effects are rare (<1%). Importantly, the vaccine can be given only to children with laboratory-confirmed evidence of past dengue infection. If the vaccine is given to someone who has not had dengue infection, it can act as a primary infection, thus placing the recipient at risk for severe disease if they contract wild-type dengue.
If you have patients who live in/have lived in/are going to areas where dengue is endemic, you will want to provide them with information about dengue, prevention measures, and the dengue vaccine. Healthy Children and the CDC have provided an article specifically for parents on this topic, so you can provide this LINK to your families.