What is the mortality rate for dengue fever?

Mortality Rate of Dengue Fever

The mortality rate for dengue fever is generally low at less than 0.5% with appropriate clinical management in hospitalized patients, though it can be higher in cases of severe dengue, with reported mortality rates of 1-5% for dengue hemorrhagic fever and dengue shock syndrome. 1, 2

General Mortality Statistics

• Dengue fever takes a mild course in more than 90% of cases, with severe dengue being relatively rare 2
• In 2013, an estimated 58 million symptomatic infections and 13,000 deaths occurred worldwide 1
• In U.S. territories during 2010-2020, the case-fatality rate was approximately 0.2% (68 deaths among 30,903 reported cases) 3
• In a 2004 study from Singapore, the case-fatality rate for dengue hemorrhagic fever was 5.4% 4

Risk Factors for Increased Mortality

• Patient-related factors:

  • Presence of comorbidities increases mortality risk by up to 11 times, particularly with renal disease, infectious diseases, pulmonary disease, and diabetes 5
  • Age may be a factor, with approximately half of reported cases occurring among persons aged <20 years in U.S. territories 3

• Disease-related factors:

  • Development of dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS) significantly increases mortality risk 1, 6
  • Rapidly progressive clinical deterioration, typically around day 4 of fever 4
  • Development of complications such as adult respiratory distress syndrome, disseminated intravascular coagulopathy, and multi-organ failure 4

• Laboratory predictors of mortality:

  • Lethargy (OR 3.84), bleeding (OR 8.88), increased pulse rate (OR 1.04), decreased serum bicarbonate (OR 0.79), and increased serum lactate (OR 1.27) are significant predictors of death 7
  • A prediction model incorporating serum bicarbonate and ALT levels has shown good accuracy in predicting mortality 7

Special Populations

• Pregnant women:
  • Higher risk of developing dengue shock syndrome (15% of pregnant women compared to 5% of non-pregnant population) 1
  • Increased maternal morbidity and mortality compared to non-pregnant women 1
  • Risk of perinatal complications including stillbirth and neonatal mortality 1

Prevention of Mortality

• Early recognition and appropriate clinical management can reduce the case-fatality rate among hospitalized patients to less than 0.5% 1
• Daily monitoring of complete blood count to track platelet counts and hematocrit levels is essential 6
• Adequate fluid management is critical, with careful fluid resuscitation for patients showing signs of shock 6
• Avoidance of aspirin and NSAIDs due to increased bleeding risk 6
• For significant bleeding, blood transfusion may be necessary, and for persistent tissue hypoperfusion despite adequate fluid resuscitation, vasopressors may be required 6

Common Pitfalls in Managing Dengue Mortality

• Delayed recognition of warning signs of severe dengue (persistent vomiting, abdominal pain, lethargy, restlessness, mucosal bleeding, rising hematocrit with falling platelet count) 6
• Delayed fluid resuscitation in patients showing signs of shock 6
• Use of aspirin or NSAIDs, which can increase bleeding risk 6
• Failure to recognize the triphasic course of dengue (febrile phase, critical phase, recovery phase) 2

Understanding these mortality statistics and risk factors can help clinicians better identify high-risk patients and implement appropriate interventions to reduce mortality from dengue fever.