Crimean-Congo hemorrhagic fever
Disease Name :
Crimean-Congo hemorrhagic fever
Species Affected:
Bovine, Ovine, Caprine and Avian e.g. Ostrich.
About the Disease:
Crimean Congo hemorrhagic fever is an acute widespread emerging tick-borne viral disease, a
zoonosis caused by virus. Wide range of livestock animals especially cattle, sheep, goats and
even birds such as Ostrich etc. are the carrier or amplifying host of the causal organism. The
disease is also known as Congo Fever. This disease is a particular threat to farmers and other
agricultural workers, veterinarians, laboratory workers and hospital personnel. The disease can
be responsible for severe outbreak in human but it is not pathogenic for livestock animals. The
virus circulates in nature in a tick vertebrate-tick cycle, mainly among cattle, sheep, goats and
hares. This disease is an OIE Reportable Disease as in the Multiple Species Disease
Category. The disease is one of the emerging public health problems with high fatality that has
risen in incidence during the recent past few years.
Animals Affected:
Cattle, Sheep and Goat are mostly affected.
Cause:
Crimean-Congo hemorrhagic fever is caused by arbovirus Crimean-Congo hemorrhagic
fever virus. This RNA virus is a member of the genus Nairovirus in the family Bunyaviridae.
The Hyalomma species of tick are the most important vector for this disease. The disease is
transmitted via the bite of an infective tick, particularly Hyalomma spp, Boophilus,
Dermacentor and Ixodes may also transmit the virus locally. Infection can also occur via skin
lesions when crushing an infected tick.
Source of infection:
The sources of infection are the infected livestock animals and birds and ticks are the
transmitting vector of the disease.
Symptoms:
Infected animals usually do not show any visible symptoms as the causal organisms are being
amplified without much tissue reaction, however, the infected animals often show vireamia and
malaise from where ticks suck blood containing virus and responsible for further transmission
by biting. The followings are visible symptoms in man;
1. High fever
2. Malaise
3. Severe headache
4. Back pain and joint pain
5. Gastrointestinal symptoms
6. Vomiting
7. Melaena
8. Petechiae (red spots) on the palate
9. Epistaxis
10. Jaundice
11. Haematuria
Control and Management:
1. Control of ticks in farm animals and farm premises using of acaricides in an endemic area.
2. Wearing gloves and other protective clothing is recommended.
3. Avoid contact with the blood and body fluids of livestock who shows symptoms of
infection.
Vaccines:
No safe vaccine is currently available.
Meteorological Occurrence:
The dry climates and arid type vegetation favors the occurrence of the Hyalomma ticks.
However rise in temperature and decrease in rainfall factors also enhances the occurrence of
disease. Its geographical distribution is worldwide. However, changes in climatic conditions
could also expand the range of its tick vectors, and increase the incidence of disease.
Prepared by:
Dr. Peter N
JRF, NADRS, Manipur.
Disease Investigatory Laboratory
Directorate of Veterinary, & A.H. Services,
Manipur