MODE OF TRANSMISSION

• bite of an infective tick

• contact with blood or secretions/excretions of an infected person or animal

• virus has also spread by aerosolization

DISTRIBUTION

• Eastern Europe, central and western Asia, Middle East, Sub-Saharan and southern Africa

INCUBATION PERIOD AND COMMUNICABILITY

• 3 to 6 days

• blood of an infected person has high concentration of virus for 8 to 10 days

TREATMENT

• supportive

• ribavirin may be helpful

PREVENTION AND CONTROL

• strict isolation of infected patients

• avoidance of contact with ticks and infected persons and animals

• in the Commonwealth of Independent States, a killed vaccine is used in high-risk populations, with uncertain efficacy

FACTORS FACILITATING EMERGENCE

• lack of effective tick control

• lack of effective animal quarantine

• sudden onset of fever, headache, joint and muscle pain

• nausea, vomiting, abdominal pain, and rash may be present

• fever typically lasts 3 to 7 days; convalescence may be prolonged

• initial phase of DHF/DSS may be similar to the above, but is followed by hemorrhagic phenomena, bleeding from multiple sites, and vascular collapse