References:
- Global Infectious Diseases and Epidemiology Online Network: Infectious Diseases of the Philippines, 2013 eBook Edition, ISBN 978-1-61755-582-4, by Stephen Berger. Accessed here.
| Agent | VIRUS - RNA. Flaviviridae, Flavivirus: Dengue virus |
| Reservoir | Human Mosquito Monkey (in Malaysia and Africa) |
| Vector | Mosquito - Stegomyia (Aedes) aegypti, S. albopictus, S. polynesiensis, S. scutellaris |
| Vehicle | Blood (rare) |
| Incubation Period | 5 to 8 days (as early or late as 2 to 15 days) |
| Diagnostic Tests | Viral isolation (blood) Serology Nucleic acid amplification Biosafety level 2 |
| Typical Adult Therapy | Supportive; IV fluids to maintain blood pressure and reverse hemoconcentration |
| Typical Pediatric Therapy | As for adult |
| Clinical Hints | Headache, myalgia, arthralgia, relative bradycardia, leukopenia and macular rash; dengue hemorrhagic (DHF) = dengue + thrombocytopenia and hemoconcentration; dengue shock = DHF + hypotension. |
| Synonyms | Bouquet fever, Break-bone fever, Dandy fever, Date fever, Dengue Fieber, Duengero, Giraffe fever, Petechial fever, Polka fever. |
CDC Case Definition
For surveillance purposes, the U.S. Centers for Disease Control (CDC) case definition of dengue fever consists of “acute febrile illness characterized by frontal headache, retro-ocular pain, muscle and joint pain, and rash.”
- The initial fever rises rapidly and lasts for two to seven days.
- Occasionally “saddleback” fever pattern is evident, with a drop after a few days and rebound within 24 hours.
- Relative bradycardia is common.
- Conjunctival injection and pharyngeal inflammation may occur as well as lymphadenopathy.
- Rash occurs in up to 50 percent of patients, either early in the illness with flushing or mottling, or between the 2nd to the 6th day as a scarlatiniform or maculopapular rash that usually spreads centrifugally.
- The later rash usually lasts for two to three days.
- Diffuse erythema and late desquamation of hands and feet may be confused with toxic shock syndrome.
- As fever drops, petechiae may be seen.
- Additional manifestations of dengue may include post-dengue depression, acalculous cholecystitis, uveitis, retinitis and psychological depression.
Dengue Fever
Clinical description
- An acute febrile illness of 2-7 days duration with 2 or more of the following: headache, retro-orbital pain, myalgia, arthralgia (as many as 41% of cases 1 , rash, hemorrhagic manifestations, leucopenia.
Laboratory criteria for diagnosis involves one or more of the following:
- Isolation of the dengue virus from serum, plasma, leukocytes, or autopsy samples
- Demonstration of a fourfold or greater change in reciprocal IgG or IgM antibody titers to one or more dengue virus antigens in paired serum samples
- Demonstration of dengue virus antigen in autopsy tissue by immunohistochemistry or immunofluorescence or in serum samples by EIA
- Detection of viral genomic sequences in autopsy tissue, serum or CSF samples by polymerase chain reaction (PCR)
Case classification
- Suspected: A case compatible with the clinical description.
- Probable: A case compatible with the clinical description with one or more of the following:
- Supportive serology (reciprocal hemagglutination-inhibition antibody titer >1280, comparable IgG EIA titer or positive IgM antibody test in late acute or convalescent-phase serum specimen).
- Occurrence at same location and time as other confirmed cases of dengue fever.
- Confirmed: A case compatible with the clinical description, laboratory confirmed.
Dengue Hemorrhagic Fever
A probable or confirmed case of dengue and hemorrhagic tendencies evidenced by one or more of the following:
- Positive tourniquet test
- Petechiae, ecchymoses or purpura
- Bleeding: mucosa, gastrointestinal tract, injection sites or other
- Hematemesis or melena
- And thrombocytopenia (100 000 cells or less per mm3)
- And evidence of plasma leakage due to increased vascular permeability, manifested by one or more of the following:
- 20% rise in average hematocrit for age and sex
- 20% drop in hematocrit following volume replacement treatment compared to baseline
- signs of plasma leakage (pleural effusion, ascites, hypoproteinemia)
Dengue Shock Syndrome
All the above criteria, plus evidence of circulatory failure manifested by rapid and weak pulse, and narrow pulse pressure (≤20 mm Hg) or hypotension for age, cold, clammy skin and altered mental status.