This summer the Centers for Disease Control and Prevention (CDC) has issued a health advisory as countries in the Americas report 9.7 million cases of dengue, the highest number in any year. The United States and Puerto Rico have reported 2,559 cases of dengue since January. The CDC expects the numbers to continue to rise as the environment warms.

Nurses in every specialty, but especially those who prepare individuals and families for international travel, will want to know about this latest dengue surge. All U.S. nurses will want to know how to triage, manage, and follow-up these patients to prevent local outbreaks and life-threatening complications.

Dengue (“den-gay”) fever is an age-old viral illness rapidly expanding its global impact beyond the tropics. According to the Rockefeller Foundation, “dengue fever is the most rapidly spreading mosquito-borne viral infection in the world.”

Also known as “breakbone fever” because of the painful arthralgias and myalgias associated with the infection, dengue is a common disease in the Americas, Africa, the Middle East, Asia, and the Pacific Islands, where it is a health risk for travelers and locals alike.

Currently 3.9 billion people are at risk in 129 countries, including certain areas of the United States. The WHO estimates that 400 million people are infected yearly, with 500,000 hospitalizations and 40,000 deaths. Within the United States, dengue primarily occurs among travelers and in sporadic outbreaks of locally acquired disease in some U.S. states, as well endemic outbreaks in the U.S. territories of Puerto Rico, American Samoa, and the U.S. Virgin Islands. Since 2023, the CDC has reported dengue cases in 45 states, including Florida, Texas, New York, Hawaii, California, and Arizona.

Dengue cases by jurisdiction of residence in the United States, 2024 (Source: CDC; click to expand image)

What is dengue and how do you contract this illness?

Dengue fever is categorized as an arboviral disease, primarily transmitted by infected Aedes mosquitoes, either A. aegypti or A. albopictus (known as the Asian tiger mosquito). The dengue virus is comprised of four serotypes (DENV 1,2,3,4). Infection with one does not protect against infections with other serotypes. Aedes are aggressive mosquitoes adapted to rural and urban human environments, biting during the day, especially in the hours around dawn and dusk. Infrequent causes of dengue transmission include perinatal transmission, blood transfusion, organ transplant, and needlestick injury.

Who is at risk for dengue fever?

Persons traveling, working, visiting, or migrating from areas endemic for dengue are at risk, as is anyone living in endemic or outbreak areas. Children can be especially vulnerable to mosquito bites and severe infections.

Clinical manifestations and supportive treatment

Approximately one in four dengue infections results in mild to severe disease. In general, dengue fever is a febrile illness which appears three to 14 days (average five to seven days) after an infected mosquito bites an individual. Early infection can present as a mild “flu-like” illness with similar symptoms to those seen with malaria or influenza. Patients can then experience high fever (104), severe headache, severe eye pain, joint and muscle aches, and a diffuse maculo-papular rash.

Most cases of dengue are diagnosed clinically, although the CDC now encourages diagnostic testing with RT-PCR and rapid public health reporting. There is no definitive treatment. Outpatient care consists of hydration and symptomatic relief for pain and fever; aspirin and NSAIDS must be avoided to prevent bleeding. Most patients fully recover within a week; however, a small percentage (1-5%) can go on to experience what is known as severe dengue. Patients with dengue need to be carefully monitored and instructed to report signs of worsening disease or bleeding. Severe dengue requires hospitalization as a life-threatening emergency characterized by symptoms of shock, severe bleeding, respiratory distress, or organ damage.

Dengue fever prevention

There is a dengue vaccine, but it is only recommended by the CDC for “children 9 through 16 years old who have laboratory-confirmed previous dengue virus infection and are living in an area where dengue is endemic”; in addition, its manufacturer has announced it is being discontinued. Clinical trials of potential prophylactic medications are ongoing.

The best way to avoid dengue is to prevent mosquito bites. The CDC recommends what is known as PPM (personal protection measures). The recommendations for PPM are:

  • Avoid outdoor activities at peak times for Aedes activity, around dawn and dusk.
  • Wear protective outdoor clothing pretreated with the insecticide permethrin: long-sleeved shirts, long pants, closed shoes, and hats.
  • Apply a DEET (30 to 30%) or picaridin repellent according to directions to exposed skin. Reapply per manufacturer’s directions.
  • Sleep in rooms with closed windows, intact screens, or permethrin-treated bed nets.
  • Promptly report dengue symptoms to your health provider.

Why is the risk of dengue spreading so rapidly now?

The global incidence of dengue fever has grown dramatically in recent decades. Over the past 50 years the incidence of this infection has increased 30-fold. Researchers identify warming temperatures and serious flooding as major factors that encourage Aedes mosquitos to reproduce more rapidly and spread beyond previous breeding grounds. Other factors include dramatic increases in urbanization, deforestation, and population migration that brings the mosquitoes into new areas.

What can health professionals do?

The CDC has issued recommendations for how health professionals can respond to dengue cases.

  • Keep informed to provide proper triage, management, and follow-up.
  • Follow CDC guidance for testing and reporting.
  • Educate the public and travelers about how to avoid mosquito bites and recognize dengue early signs.

Professional and patient resources for additional learning

CDC Dengue Website: https://www.cdc.gov/dengue/areas-with-risk/index.html

CDC Yellow Book: https://wwwnc.cdc.gov/travel/yellowbook/2024/infections-diseases/dengue

Dengue Fever: A Global Threat Hitting Home: a free, on demand, CE-accredited learning module offered by the American Travel Health Nurses Association: https://athna.clcmoodle.org/login/

By Gail Rosselot MS, MPH, ANP-BC, FAANP, FATHNA, is the
director of Travel Well of Westchester and the Westchester Courses in Travel Health Fundamentals and a founder and past president of the American Travel Health Nurses Association