The Crimean-Congo hemorrhagic fever virus (CCHFV) belongs to the order Bunyavirales, family Nairoviridae, genus Orthonairovirus. Ticks, particularly those of the genus Hyalomma, are both reservoir and vector for CCHFV. CCHFV is found throughout the Mediterranean region, southern and eastern Europe, Africa, central Asia, northwestern China, the Indian subcontinent, and the Middle East. The distribution of the pathogen in Europe is closely linked to that of the vector tick Hyalomma marginatum.
Numerous wild and domestic animals such as cattle, goats, sheep and rabbits serve as amplification or intermediate hosts, although infections in these animals are usually asymptomatic. Transmission to humans occurs through tick bites or contact with infectious blood or body fluids from infected animals or humans. Livestock keepers, livestock breeders, slaughterhouse employees, and hospital personnel in endemic areas are thus particularly affected by infections. Crimean-Congo hemorrhagic fever (CCHF) is characterized by symptoms such as headache, high fever, back and joint pain, stomach pain and vomiting. In advanced stages, severe bruising, profuse nosebleeds, and generalized bleeding develop. This so-called hemorrhagic diathesis usually begins on the fourth day and lasts for up to two weeks. The mortality rate in hospitalized patients ranges from 9% to 50%. According to the German “Biostoffverordnung” (regulation on biological substances), CCHFV is assigned to risk group 4.
Laboratory diagnostics for human cases should be performed at the Bernhard-Nocht-Institute for Tropical Medicine (consiliary laboratory) or at the FLI (National Reference Laboratory for CCHFV infections in animals) for suspected infections in animals. Virus detection in humans and animals is performed from blood and other clinical material during the acute phase of infection by RT-qPCR, virus isolation and propagation in cell culture, or by inoculation into newborn mice. In addition to RT-qPCR, serological detection of CCHFV-specific antibodies using (in-house) ELISA methods is possible in the National Reference Laboratory for CCHFV infections in animals. After commissioning of the BSL4 high containment laboratory, further methods such as the virus neutralization test will be established and used in the future for the analysis of suspect samples.