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Essentials of Diagnosis
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Incubation period is 7–10 days
Sudden onset of high fever, chills, severe myalgias and arthralgias, headache, and retro-orbital pain
Severe dengue is defined by the presence of plasma leakage, hemorrhage, or organ involvement
Signs of hemorrhage such as ecchymoses, gastrointestinal bleeding, and epistaxis appear later in the disease
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General Considerations
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Four distinct serotypes can cause infection; infection with one serotype does not confer immunity to the others
Dengue is transmitted primarily from human to human by the bite of the Aedes mosquito
Healthcare-associated transmission (needlestick or mucocutaneous exposure) and vertical transmission occur rarely
The World Health Organization (WHO) reports that dengue is endemic in more than 100 countries, mostly in tropical and subtropical regions, with about 70% of cases occurring in Asia
Dengue has been a nationally notifiable condition in the United States (US) since 2010; although it is endemic in northern Mexico, US outbreaks are uncommon
As of October 5, 2022, 616 dengue cases were reported in the United States and 209 in US territories (primarily Puerto Rico)
Case numbers have increased over the last two decades; this surge of cases is associated with climatic factors, travel, and urbanization
When the virus is introduced into susceptible populations, usually by viremic travelers, epidemic attack rates range from 50% to 70%
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Most infected patients are asymptomatic
Only 20% develop symptoms ranging from mild disease (dengue fever) to severe hemorrhagic fever to fatal shock (dengue shock syndrome)
Incubation period is usually 7–10 days
After the incubation period, febrile phase begins abruptly with
Nonspecific symptoms
High fever
Chills
Facial flushing
Malaise
Retro-orbital eye pain
Generalized body pain
Arthralgia
Some patients might have maculopapular rash, sore throat, and conjunctival injection
Not all patients have all symptoms or fever
Mild hemorrhagic manifestations can be seen
Most of the patients will recover and fever is usually cleared by day 8
A subset of patients may progress to severe dengue, which is defined by the presence of plasma leakage, hemorrhage, or organ involvement
Patients with suboptimally controlled type 2 diabetes are at high risk
Pleural effusion and ascites can develop
Plasma leakage may be indicated by
Hematocrit drop
Increasing liver size
Persistent vomiting
Severe abdominal pain
Signs of hemorrhage such as ecchymoses, gastrointestinal bleeding, and epistaxis appear
Severe organ involvement may develop such as hepatitis, encephalitis, and myocarditis
Shock develops when a critical volume of plasma is lost through leakage; the following should raise concern for shock:
Decrease in the level of consciousness
Hypothermia
Hypoperfusion resulting in metabolic acidosis
Progressive organ impairment
Disseminated intravascular coagulation leading to severe hemorrhage
Acute kidney injury in dengue largely occurs with shock syndrome and has a high mortality