How is Crimean-Congo Hemorrhagic Fever Transmitted to Humans?
The primary vectors for CCHF are ixodid (hard) ticks belonging to the Hyalomma genus. The Hyalomma genus of ixodid ticks acts as a vector and a reservoir for the CCHF virus. Main species include H.marginatum, H.rufipes, H.anatolicum, and H.asiaticum .
CCHF cases are most prevalent during the spring and summer when the Hyalomma ticks find the environment most suitable. CCHF-carrying ticks infest many types of animals, including domesticated sheep, cattle, goats, hares, hedgehogs, and more, but these animals mostly remain asymptomatic. This viral hemorrhagic fever is transmitted to humans when they come in contact with the infected ticks themselves or the blood of an infected animal host. Birds are not usually susceptible to CCHF infections, but migratory birds can carry and spread the virus [4, 12].
Human to human transmission occurs through the exchange of body fluids or contact with infected blood. Another way is through healthcare-associated infections (HAI) or nosocomial transmission through contaminated medical equipment.
People most at risk are butchers or those who work with livestock or in slaughterhouses, and healthcare workers . The risk of contracting CCHF from travel is rare, but instances have been reported.
CCHF and Travel
Reports of Crimean-Congo hemorrhagic fever (CCHF) related to travel are rare. The following chronology is abstracted from GIDEON. 
- 1985 – South Africa ex. Democratic Republic of Congo (fatal).
- 1986 – South Africa ex. Tanzania (nonfatal)
- 1997 – An English traveler died of probable CCHF contracted in Zimbabwe.
- 2001 – A German tourist acquired Crimean-Congo hemorrhagic fever in Bulgaria.
- 2004 – A case of imported Crimean-Congo hemorrhagic fever (nonfatal) was reported in a traveler returning to France from Senegal. Infection in a second French national was diagnosed locally in Senegal.
- 2009 – An American soldier died in a hospital in Germany after contracting Crimean-Congo hemorrhagic fever in Afghanistan.
- 2011 – An outbreak (4 cases) in a Pakistan hospital was related to an index patient who had arrived from Afghanistan.
- 2012 – A patient died of Crimean-Congo hemorrhagic fever in Scotland following the acquisition of the disease in Afghanistan.
- 2013 – A woman died of Crimean-Congo hemorrhagic fever in Uganda following contact with her infected husband in South Sudan.
- 2014 – A British traveler acquired Crimean-Congo hemorrhagic fever in Bulgaria.