Crimean-Congo hemorrhagic fever in Europe: current situation calls for preparedness

Abstract

During the last decade Crimean-Congo hemorrhagic fever (CCHF) emerged and/or re-emerged in several Balkan countries, Turkey, southwestern regions of the Russian Federation, and the Ukraine, with considerable high fatality rates. Reasons for re-emergence of CCHF include climate and anthropogenic factors such as changes in land use, agricultural practices or hunting activities, movement of livestock that may influence host-tick-virus dynamics. In order to be able to design prevention and control measures targeted at the disease, mapping of endemic areas and risk assessment for CCHF in Europe should be completed. Furthermore, areas at risk for further CCHF expansion should be identified and human, vector and animal surveillance be strengthened.

Risk of Crimean Congo haemorrhagic fever virus (CCHFV) introduction and spread in CCHF-free countries in southern and Western Europe: A semi-quantitative risk assessment

“…The disease presents a high fatality rate in humans (approximately 30%) [ 5 ], and significant difficulties in treatment, prevention, and control [ 6 ]. Clinical symptoms include fever, myalgia, nausea, vomiting, diarrhoea, hepatomegaly with abdominal pain, and agitation.…”

“…For all these reasons, CCHF has been identified as a priority disease for the EU [ 6 ]. Several experts have expressed their concerns on the spread of the virus outside its current geographic range through the introduction of infected ticks by migratory birds, wild mammals or the international livestock trade [ 21 , 22 ].…”

Prevalence of tick-borne viruses inIxodes ricinusassessed by high-throughput real-time PCR

“…Recently, fatal autochthonous human cases have been observed in Spain, but this virus is usually transmitted by Hyalomma spp. ticks (Maltezou et al, 2010, Al-Abri et al, 2017, Negredo et al, 2017. Nevertheless, new Nairovirus sequences have been detected in ticks, e.g.…”

“…Environmental changes, human travel and animal transportation have led to the emergence and/or the geographical expansion of several tick-borne pathogens (TBPs) worldwide including viruses (Dantas-Torres et al, 2012, Lindgren et al, 2012, Jore et al, 2014, Vayssier-Taussat et al, 2015. Several TBVs have already emerged in new territories, such as TBEV, LIV, powassan virus (POWV), deer tick virus, and Crimean-Congo hemorrhagic fever virus (CCHFV) (Hinten et al, 2008, Mansfield et al, 2009, Maltezou et al, 2010, while novel arthropod-borne viruses are constantly being discovered (Yu et al, 2011, Yun et al, 2014, Kosoy et al, 2015. These trends highlight the importance of monitoring the distribution and prevalence of TBVs in European tick populations.…”

What is a vector?

“…Many parasites and pathogens responsible for some of the most important diseases in humans, agriculture and nature are routinely described as 'vectorborne'. These include emerging parasites and pathogens such as dengue virus throughout the tropical world [1], West Nile virus in North America [2] and Europe [3], Crimean-Congo haemorrhagic fever virus in Turkey [4], hantavirus in Europe [5], bluetongue virus in Europe [6], zika virus in South America [7], Lyme borreliosis in Europe [8] and chikungunya virus in the Caribbean [9]. Almost 20% of human deaths are caused by infectious diseases that are described as vector-borne, chiefly malaria, yellow fever, leishmaniosis, trypanosomiasis, Chagas' disease and Japanese encephalitis [10], and such diseases are predicted to present a growing threat in the near future [11].…”