Crimean–Congo hemorrhagic fever

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Crimean–Congo hemorrhagic fever
Virus classification
Group: Group V ((-)ssRNA)
Order: Unassigned
Family: Bunyaviridae
Genus: Nairovirus
Crimean-Congo hemorrhagic fever
Classification and external resources

Isolated male patient diagnosed with Crimean-Congo hemorrhagic fever
ICD-10 A98.0
ICD-9 065.0
DiseasesDB 31969
MedlinePlus article
eMedicine 830594/



Signs and symptoms[edit]



The virus is a member of the genus Nairovirus, family Bunyaviridae. The genome is circular, ambisense RNA in three parts - Small (S), Middle (M) and Large (L). The L segment is 11-14.4 kilobases in length while the M and S segements are 4.4-6.3 and 1.7-2.1 kilobases long respectively. The L segment encodes the RNA polymerase; the M segment encodes the envelope proteins (Gc and Gn); and the S segment encodes the nucleocapsid protein. The envelope protein is initially translated as a glycoprotein precursor which is then cleaved into two smaller proteins.

The virons are 80-120 nanometers (nm) in diameter and are pleomorphic. There are no host ribosomes within the viron. Each viron contains three copies of the genome. The envelope is single layered and is formed from a lipid bilayer 5 nm thick. It has no protrusions. The envelope proteins form small projections ~5-10 nm long. The nucleocapsids are filamentous and circular with a length of 200-3000 nm.


This virus appears to have evolved 3100–3500 years ago.[1] The mutation rates for the three parts of the genome were estimated to be: 1.09 x 10−4, 1.52 x 10−4 and 0.58 x 10−4 substitutions/site/year for the S, M, and L segments respectively.


Hyalomma tick

The virus has been isolated from at least 31 different species of ticks from the genera Haemaphysalis and Hyalomma.[2] Sporadic infection of people is usually caused by Hyalomma tick bite. Clusters of illness typically appear after people treat, butcher or eat infected livestock, particularly ruminants and ostriches. Outbreaks have occurred in clinical facilities where health workers have been exposed to infected blood and fomites. The causative organism is found in Asia, Eastern Europe, the Middle East, a belt across central Africa and South Africa and Madagascar (see map [3]) The main environmental reservoir for the virus is small mammals (particularly European Hare, Middle-African hedgehogs and multimammate rats). Ticks carry the virus to domestic animal stock. Sheep, goats and cattle develop high titers of virus in blood, but tend not to fall ill. Birds are generally resistant with the exception of ostriches.

Tick species that have been identified as infected with this virus include Argas reflexus, Hyalomma anatolicum, Hyalomma detritum, Hyalomma marginatum marginatum and Rhipicephalus sanguineus.Both working with humans and animals infected from Congo-Crimean Hemorrhagic fever usually transmit the virus to other humans.


The cell surface protein nucleolin has been identified as a putative receptor for this virus.[4]







In 2011, a Turkish research team led by Erciyes University has succeed to develop the first non-toxic preventive CCHF-vaccine in lab trials. The vaccine is pending approval by the FDA.[5]


Treatment is primarily symptomatic and supportive, as there is no established specific treatment. Ribavirin is effective in vitro[6] and has been used during outbreaks,[7] but there is no trial evidence to support its use.





On May 27, 2010 Hospitals reported 70 cases of CCHF in Kosovo's Kosovo Polje, with 4 deaths reported so far. The Authorities are not able to deal with the disease because of the lack of advanced medication.


In January 2011, the disease has been reported in Gujarat, India, with 4 reported deaths, which consisted of the patient along with the doctor and the nurse who treated the patient.[9]




A case reported in the 12th century of a hemorrhagic disease from what is now Tajikistan may have been the first known case of Crimean–Congo hemorrhagic fever. Soviet scientists first identified the disease they called Crimean hemorrhagic fever in 1944 and established its viral etiology by passage of the virus through human "volunteers" (fatality rate unreported), but were unable to isolate the agent at that time.[12] In June 1967, Soviet virologist Mikhail Chumakov registered an isolate from a fatal case that occurred in Samarkand (on the ancient Silk Road in Central Asia, not the Crimea) in the Catalogue of Arthropod-borne Viruses.[13] Four months earlier, virologists Jack Woodall, D Simpson and others had published initial reports[14][15] on a virus they called the Congo virus, first isolated in 1956 by physician Ghislaine Courtois, head of the Provincial Medical Laboratory, Stanleyville, Belgian Congo. Strain V3010, isolated by Courtois, was sent to the Rockefeller Foundation Virus Laboratory (RFVL) in New York City and found to be identical to another strain from Uganda, but to no other named virus at that time. Chumakov later sent his strain to the RFVL, where it was found to be identical to the Congo virus.[16] The International Committee on Taxonomy of Viruses proposed the name Congo-Crimean hemorrhagic fever virus, but the Soviets insisted on Crimean–Congo hemorrhagic fever virus. Against all principles of scientific nomenclature based on priority of publication, it was adopted as the official name in 1973 in possibly the first instance of a virus losing its name to politics and the Cold War.[citation needed] However, since then Congo-Crimean or just Congo virus has been used in many reports, which would be missed in searches of medical databases using the official name. These reports include records of the occurrence of the virus or antibodies to the virus from Greece, Portugal, South Africa, Madagascar (the first isolation from there), the Maghreb, Dubai, Saudi Arabia, Kuwait and Iraq.[17][18][19]


  1. ^ Carroll SA, Bird BH, Rollin PE, Nichol ST (2010) Ancient common ancestry of Crimean-Congo hemorrhagic fever virus. Mol Phylogenet Evol 55(3):1103-1110
  3. ^ Map
  4. ^ Xiao, X.; Feng, Y.; Zhu, Z.; Dimitrov, D. S. (2011). "Identification of a putative Crimean-Congo hemorrhagic fever virus entry factor". Biochem. Biophys. Res. Commun. 411 (2): 253–258. doi:10.1016/j.bbrc.2011.06.109. PMID 21723257. 
  5. ^
  6. ^ Watts DM, Ussery MA, Nash D, Peters CJ. (1989). "Inhibition of Crimean-Congo hemorrhagic fever viral infectivity yields in vitro by ribavirin". Am J Trop Med Hyg. 41 (5): 581–5. PMID 2510529. 
  7. ^ Ergönül Ö, Celikbas A, Dokuzoguz B, et al. (2004). "The chacteristics of Crimean-Congo hemorrhagic fever in a recent outbreak in Turkey and the impact of oral ribavirin therapy". Clin Infect Dis 39 (2): 285–9. doi:10.1086/422000. PMID 15307042. 
  8. ^
  9. ^ originated from sanand /739292/
  10. ^
  11. ^
  12. ^ Chumakov, 1947 INCOMPLETE

External links[edit]