Dengue infections can range from asymptomatic infection to mild and even severe cases. In mild cases, individuals generally experience a high fever within 4-7 days of infection. A flat, red rash over the entire body often occurs within 2-5 days after the onset of fever and can be followed by a second “measles-like” rash. Infected individuals often experience skin sensitivity and general discomfort.
Additional symptoms may also include nausea, vomiting, fatigue, muscle and joint pain, headache mainly behind the eyes, cough, swollen lymph nodes, nasal congestion, and sore throat.
Persons who develop severe dengue generally experience symptoms that include stomach pain and tenderness, vomiting three or more times in 24 hours, bleeding from the gums or nose, vomiting of blood or blood in the stool or urine, fatigue, difficulty breathing, bleeding under the skin, irritability, or restlessness. These symptoms usually begin 24-48 hours after the fever has subsided.
Severe dengue is more commonly seen in individuals who are infected a second time due to a condition known as antibody-dependent enhancement (ADE). In dengue, antibodies present in the body from the first infection will bind to the infectious dengue virus from the second infection from a different serotype. These antibodies, however, are not capable of neutralizing the virus but instead cause it to become more infectious.
Approximately 25 percent of individuals exposed to dengue will develop symptoms and most people who become sick will recover within one week. Only 5 percent of symptomatic dengue cases will develop severe illness.
Complications of severe dengue infection include heart impairment, severe plasma leakage resulting in shock or fluid accumulation with respiratory compromise, severe organ impairment, severe bleeding, and altered consciousness. Encephalitis (inflammation of the brain), pancreatitis, hepatitis, and myocarditis may also occur, however, these complications are not common.
Pregnant women who developed dengue during their third trimester generally recovered without complications, and few adverse events were reported among infants born to infected mothers. Reported maternal complications during pregnancy included thrombocytopenia requiring platelet transfusion and postpartum hemorrhage. Low birth weight, pre-term birth, and stillbirths have been reported among infants born to dengue infected women.
A study of 15 pregnant women who developed dengue before 24 weeks gestation found there was a higher risk of miscarriage (33.3 percent of all cases), decreased amnionic fluid for gestational age later in pregnancy (66.7 percent), and warning signs of severe dengue (33.3 percent). Of the women who experienced a miscarriage, 80 percent reported a previous history of at least one miscarriage.
Additional maternal complications included placental abruption (1.7 percent), postpartum hemorrhage (12.8 percent), dengue shock syndrome (12.8 percent), and death (10.2 percent). Five babies (55.8 percent) born to mothers infected with dengue before 24 weeks experienced intrauterine growth restriction and one (11.1 percent) was born prematurely.
Severe dengue can lead to death, often due to a rapid decrease in blood pressure that results in shock. Between 2010 and 2021, less than one percent of all travel-associated dengue cases among U.S. travelers resulted in death.
IMPORTANT NOTE: NVIC encourages you to become fully informed about Dengue and the Dengue vaccine by reading all sections in the Table of Contents, which contain many links and resources such as the manufacturer product information inserts, and to speak with one or more trusted health care professionals before making a vaccination decision for yourself or your child. This information is for educational purposes only and is not intended as medical advice.
