Crimean Congo Haemorrhagic Fever

There is no Disease Outbreak data at this time

Factsheet

Key Facts

The Crimean-Congo haemorrhagic fever (CCHF) virus causes severe viral haemorrhagic fever outbreaks.
CCHF outbreaks have a case fatality rate of up to 40%.
The virus is primarily transmitted to people from ticks and livestock animals. Human-to-human transmission can occur resulting from close contact with the blood, secretions, organs or other bodily fluids of infected persons.
CCHF is endemic in Africa, the Balkans, the Middle East and Asia, in countries south of the 50th parallel north.
There is no vaccine available for either people or animals.

Crimean-Congo haemorrhagic fever (CCHF) is a widespread disease caused by a tick-borne virus (Nairovirus) of the Bunyaviridae family. The CCHF virus causes severe viral haemorrhagic fever outbreaks, with a case fatality rate of 10–40%.

CCHF is endemic in Africa, the Balkans, the Middle East and Asian countries south of the 50th parallel north – the geographical limit of the principal tick vector.

Crimean-Congo haemorrhagic fever (CCHF) belongs to the Bunyaviridae virus family. CCHF spreads to humans either by tick bites, or through contact with affected animal tissues immediately after slaughter. Person-to-person transmission of CCHF has occurred in health care settings after exposure to blood and secretions of infected patients.

The incubation period for CCHF following a tick bite is usually 1 to 3 days or 5 to 6 days following contact with blood or tissues. The onset of symptoms among CCHF patients is sudden with fever, myalgia and other signs and symptoms. The reported case fatality ratio for CCHF is between 3% and 30%.

General supportive therapy is the mainstay of patient management in CCHF. Intensive monitoring to guide volume and blood component replacement is required. The antiviral drug, ribavirin, has been used in the treatment of established CCHF infection. Both oral and intravenous formulations are effective.

Among the ways to reduce infection in people is by raising awareness of the risk factors and educating people about the measures they can take to reduce exposure to the virus.

Key facts

Controlling CCHF in animals and ticks

It is difficult to prevent or control CCHF infection in animals and ticks as the tick-animal-tick cycle usually goes unnoticed and the infection in domestic animals is usually not apparent. Furthermore, the tick vectors are numerous and widespread, so tick control with acaricides (chemicals intended to kill ticks) is only a realistic option for well-managed livestock production facilities.

For example, following an outbreak at an ostrich abattoir in South Africa (noted above), measures were taken to ensure that ostriches remained tick free for 14 days in a quarantine station before slaughter. This decreased the risk for the animal to be infected during its slaughtering and prevented human infection for those in contact with the livestock.

There are no vaccines available for use in animals.

Reducing the risk of infection in people

Although an inactivated, mouse brain-derived vaccine against CCHF has been developed and used on a small scale in eastern Europe, there is currently no safe and effective vaccine widely available for human use.

In the absence of a vaccine, the only way to reduce infection in people is by raising awareness of the risk factors and educating people about the measures they can take to reduce exposure to the virus.

Public health advice should focus on several aspects.

Reducing the risk of tick-to-human transmission:
- wear protective clothing (long sleeves, long trousers);
- wear light coloured clothing to allow easy detection of ticks on the clothes;
- use approved acaricides (chemicals intended to kill ticks) on clothing;
- use approved repellent on the skin and clothing;
- regularly examine clothing and skin for ticks; if found, remove them safely;
- seek to eliminate or control tick infestations on animals or in stables and barns; and
- avoid areas where ticks are abundant and seasons when they are most active.
Reducing the risk of animal-to-human transmission:
- wear gloves and other protective clothing while handling animals or their tissues in endemic areas, notably during slaughtering, butchering and culling procedures in slaughterhouses or at home;
- quarantine animals before they enter slaughterhouses or routinely treat animals with pesticides two weeks prior to slaughter.
Reducing the risk of human-to-human transmission in the community:
- avoid close physical contact with CCHF-infected people;
- wear gloves and protective equipment when taking care of ill people;
- wash hands regularly after caring for or visiting ill people.

Controlling infection in health-care settings

Health-care workers caring for patients with suspected or confirmed CCHF, or handling specimens from them, should implement standard infection control precautions. These include basic hand hygiene, use of personal protective equipment, safe injection practices and safe burial practices.

As a precautionary measure, health-care workers caring for patients immediately outside the CCHF outbreak area should also implement standard infection control precautions.

Samples taken from people with suspected CCHF should be handled by trained staff working in suitably equipped laboratories.

Recommendations for infection control while providing care to patients with suspected or confirmed Crimean-Congo haemorrhagic fever should follow those developed by WHO for Ebola and Marburg haemorrhagic fever.