Crimean-Congo hemorrhagic fever

Definition

A severe, often fatal tick-borne viral disease of humans and livestock caused by Crimean-Congo hemorrhagic fever orthonairovirus (family Nairoviridae, order Bunyavirales). The virus is maintained in nature through a tick-vertebrate cycle involving ixodid ticks, primarily of the genus Hyalomma, and various wild and domestic ungulates. Transmission to humans occurs via tick bite, contact with infected animal blood or tissues, or nosocomial exposure. Clinical presentation ranges from mild febrile illness to acute hemorrhagic syndrome with case fatality rates of 10–40%. The disease spans Africa, the Balkans, the Middle East, and Asia, reflecting the distribution of competent vector species.

Etymology

Named for its independent discovery in Crimea (1944) and Congo (1956), later recognized as the same viral entity.

Example

Hyalomma marginatum, a hard tick widespread in Mediterranean Europe, is the principal vector amplifying Crimean-Congo hemorrhagic fever virus among hares and livestock; human cases in Turkey and Bulgaria typically peak during spring and autumn when questing nymphs and adults are most active.

Synonyms

• CCHF

Related Terms

• tick-borne disease
• Arbovirus
• Nairoviridae
• Hyalomma
• viral hemorrhagic fever
• Zoonosis
• vector competence
• medical entomology

Usage Notes

Abbreviated CCHF in clinical and epidemiological literature. Distinguished from other tick-borne hemorrhagic fevers (e.g., Kyasanur Forest disease) by geographic range and vector association. The causative agent is now classified as Crimean-Congo hemorrhagic fever orthonairovirus following 2019 taxonomic revision; older literature uses 'CCHF virus' or 'CCHFV'. Surveillance and control efforts focus on acaricide use in livestock, personal protection against tick bites, and barrier nursing for suspected cases.