Epidemiology

'Crimean haemorrhagic fever' was first described between 1944 and 1945 when about 200 Soviet military personnel were infected while helping peasants in Crimea during World War II.[1][4]​ In the early 1950s, scientists in the Congo described 'Congo haemorrhagic fever', and more than a decade later the name Crimean-Congo haemorrhagic fever (CCHF) was coined.[5]

During the second half of the 20th century, CCHF outbreaks occurred in Asia, Africa, and Southeast Europe.[2] Since 2000, new outbreaks have been documented in various countries including Pakistan, Iran, Iraq, Oman, Sudan, Senegal, Albania, Kosovo, Bulgaria, Turkey, Greece, Kenya, Mauritania, Kazakhstan, Tajikistan, India,​ Spain,​ Uganda, and Afghanistan (where an increase in cases was reported in 2018 and 2019).[3][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]​​​[25]​ 

A case of CCHF was confirmed in the UK in March 2022. The woman had recently travelled to Central Asia. Prior to this, two cases of CCHF had been imported into the UK (in 2012 and 2014).[26]

Iraq is a CCHF-endemic country with case reports dating back to 1979.[27]​​ According to WHO, Iraq has experienced an increase in cases since 2021, and in 2022, an outbreak alert was issued due to the growing number of cases.[27]​ In the first half of 2022, Iraq reported 212 cases of CCHF, with 37 deaths.[27]​ The number of cases reported in the first five months of 2022 is much higher than that reported in 2021 when 33 confirmed cases were recorded. From January to August 2023, Iraq reported 511 CCHF cases with a total case fatality rate of 12.7 from 18 provinces.[28]​ Eid-al-Adha, an important religious event in Iraq, involves sacrifices of livestock, potentially promoting CCHF outbreaks.[29]

Most cases occur in adults exposed to ticks during the course of their work (agriculture and/or husbandry). Consequentially, sex distribution varies between countries depending on the involvement of women in agricultural work. For example, farmers made up almost 90% of cases in the Turkey outbreak that ended in 2007, with a 1:1 male-to-female ratio.[30]​​[31]​ Healthcare workers are the second-most affected group.​[31]

WHO: geographic distribution of Crimean-Congo haemorrhagic fever Opens in new window

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