Congo fever FAQs
What is Crimean-Congo haemorrhagic fever?
Crimean-Congo haemorrhagic fever (CCHF) is a serious viral disease caused by a virus of the Nairovirus group, which infects a number of domestic and wild animals.
Animals become infected with CCHF from the bite of infected ticks.
This disease was first identified in 1944 in the Crimea and given the name Crimean haemorrhagic fever. In 1969 it was discovered that the organism causing Crimean haemorrhagic fever was the same as that which caused an illness in the Congo in 1956. The connection with the two place names resulted in the current name for the disease and the virus.
The disease is endemic in many countries in Africa, Europe and Asia.
Although it is rare for humans to catch CCHF, the disease is very serious and carries a high death rate.
How do people get CCHF?
Humans acquire the virus through direct contact with blood or other infected tissues from livestock such as cattle, sheep and goats. The virus can be passed on in this way for about a week after an animal has become infected.
Humans may also be infected from a tick bite.
Transmission from person to person is possible if they are exposed to blood as a result of an injury with a contaminated sharp object or infected blood on broken skin. Healthcare workers are therefore at risk of infection.
What are the symptoms of CCHF?
The incubation period of CCHF varies between one and 13 days.
The incubation period is normally one to three days for those acquiring infection through a tick bite and five to six days for those infected from blood or tissue.
The illness begins suddenly with fever, muscle aches, dizziness, neck pain and stiffness, backache, headache, sore eyes and sensitivity to light (photophobia).
Over the next few days the patient may experience:
In severe cases patients may experience failure of the liver, kidney and lungs and become comatose.
Death occurs in approximately 30% of patients.
How is CCHF diagnosed?
The virus may be traced through blood or tissue specimens or from antibodies detected in serum.
Diagnosis requires highly specialised and safe laboratory facilities.
How is CCHF treated?
A patient with CCHF will need treatment in hospital.
They will require blood transfusion, balancing fluids and electrolytes, blood pressure control and help with breathing.
There is evidence that CCHF responds to treatment with the antiviral drug ribavirin.
How can CCHF be prevented?
There is no safe and effective vaccine against CCHF available for human use.
Those living in or visiting endemic areas should try to avoid visiting tick-infested areas when they are active, use insect repellents and carefully check clothing and skin for ticks.
Workers who have close contact with livestock or other animals in endemic areas should protect themselves by using tick repellents on their skin and clothing, and wearing gloves or other protective clothing.