Crimean-Congo Haemorrhagic Fever

Primary reference(s)

WHO, 2025. Crimean-Congo haemorrhagic fever. World Health Organization (WHO). Accessed 26 May 2025.

Annotations

Key relevant UN convention / multilateral treaty

International Health Regulations (2005), 3rd ed. (WHO, 2016).

United Nations. 2023. UN Recommendations on the Transport of Dangerous Goods - UN Model Regulations. Available from: https://unece.org/transport/dangerous-goods/un-model-regulations-rev-23

Drivers

The CCHF virus is transmitted to people either by tick bites or through contact with infected animal blood or tissues during and immediately after slaughter. The majority of cases have occurred in people involved in the livestock industry, such as agricultural workers, slaughterhouse workers and veterinarians (Ergönül, 2006).

Human-to-human transmission can occur resulting from close contact with the blood, secretions, organs or other bodily fluids of infected persons. Hospital-acquired infections can also occur due to improper sterilization of medical equipment, reuse of needles and contamination of medical supplies. In the absence of a vaccine, the only way to reduce Crimean-Congo haemorrhagic fever infection in people is by raising awareness of the risk factors and educating people about the measures for reducing exposure (WHO, 2025).

Impacts

Onset of symptoms is sudden and can include fever, muscle ache, dizziness, neck pain, backache, headache, sore eyes and photophobia (sensitivity to light). There may be nausea, vomiting, diarrhoea, abdominal pain and sore throat early on, followed by sharp mood swings and confusion. After 2–4 days the agitation may be replaced by sleepiness, depression and lassitude, and the abdominal pain may localize to the upper right quadrant, with detectable hepatomegaly (liver enlargement) (WHO, 2024a).  

Other clinical signs include tachycardia (fast heart rate), lymphadenopathy (enlarged lymph nodes), and a petechial rash (a rash caused by bleeding into the skin) on internal mucosal surfaces, such as in the mouth and throat, and on the skin. The petechiae may give way to larger rashes called ecchymoses, and other haemorrhagic phenomena. There is usually evidence of hepatitis, and severely ill patients may experience rapid kidney deterioration, sudden liver failure or pulmonary failure after the fifth day of illness (WHO, 2024a).

Multi-hazard context

CCHF has been observed where conflicts are on-going and in areas where humans are in close contact with wild animals carrying the virus (Ergönül, 2006). Changes in climatic conditions have been suggested to be one of the factors that has facilitated reproduction of the tick population, and consequently the increased incidence of tick-borne infectious diseases (Ergönül, 2006).

Risk Management

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. There are no vaccines available for use in animals (WHO, 2024a). 

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 (WHO, 2025). Public health advice should focus on several aspects such as reducing the risk of tick-to-human transmission: wearing protective clothing (long sleeves, long trousers); wearing light coloured clothing to allow easy detection of ticks on the clothes; using approved acaricides (chemicals intended to kill ticks) on clothing; using approved repellent on the skin and clothing; regularly examining clothing and skin for ticks; if found, remove them safely; seeking to eliminate or control tick infestations on animals or in stables and barns; and avoiding areas where ticks are abundant and seasons when they are most active (WHO, 2025). 

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 (WHO, 2025). 

WHO is working with partners to support CCHF surveillance, diagnostic capacity and outbreak response activities in Europe, the Middle East, Asia and Africa (WHO, 2023).

Monitoring

WHO supports countries to conduct all-hazards strategic risk assessment in the contexts of health emergencies and disasters, which results in the development of a country risk profile. Empowered with the country risk profile, inclusive of a seasonal risk calendar, countries can anticipate potential emergencies before they occur to trigger early alerts and inform early actions (WHO, 2021).

WHO's Early Warning, Alert and Response System (EWARS) has been designed to improve disease outbreak detection in emergency settings, such as in countries in conflict or following a disaster from natural hazards. It is a simple and cost-effective way to rapidly set up a disease surveillance system. EWARS is deployed during an emergency as an adjunct to the national disease surveillance system. WHO works with Ministries of Health and health sector partners to train local health workers to use the system. After the emergency, EWARS should re-integrate back into the national system (WHO, 2023).

The section and the table below offer an overview of monitoring for Crimean-Congo haemorrhagic fever. This information can be used for forecasting within a national early warning system (EWS). Since EWS capacities and processes differ across countries, the most current and specific information regarding EWS should be obtained from the appropriate national or regional agency/authority responsible for disaster management.