Crimean-Congo haemorrhagic fever virus - a challenge for public health

摘要

Crimean-Congo haemorrhagic fever virus (CCHFV) causes a zoonotic disease in many countries of Asia, Africa, the Middle East and south-eastern Europe. Given global trade and the effects of climate change, it may even spread to Central Europe. This fever is transmitted primarily by ticks of the genus Hyalomma. The virus circulates in a life cycle of tick-vertebrate-tick, but can also be transmitted horizontally and vertically within the tick population (Fig. 1). Endemic areas can only become established where suitable tick vector populations are present. Hyalomma ticks infest a wide spectrum of wildlife species, e.g. deer and hares, as well as free-ranging livestock, e.g. goats, cattle and sheep. These animals play a crucial role in the life cycle ofticks, and in the transmission and amplification of the virus. Since infected animals do not develop clinical signs, CCHFV infections have no effect on livestock production. However, human infections often result in a severe disease, Crimean-Congo haemorrhagic fever (Fig. 2). Every year, more than 1,000 human CCHF cases are reported from Albania, Bulgaria, Kosovo and Turkey. In othercountries, infection rates and case numbers are largely unknown. Case fatality rates of 5% (in Turkey) to 80% (in China) have been reported and may depend on the virus strain, the awareness and knowledge of the local population and the effectiveness of public health interventions.