What You Need to Know About Crimean-Congo Hemorrhagic Fever (CCHF)
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What is Crimean-Congo Hemorrhagic Fever (CCHF) and How Does It Spread?
CCHF is a zoonotic hemorrhagic fever caused by the tick-borne Nairovirus of the order Bunyavirales (formerly the Bunyaviridae family), which also includes Hantavirus and Rift Valley Fever. CCHF is endemic in most of Africa, South-Eastern Europe, the Middle East, Asia, and the Balkans and accounts for 10,000-15,000 infections each year. The virus can be found in about 30 different tick species but is primarily transmitted by the Hyalomma tick, which is both a reservoir and vector. CCHF has the largest geographic range among tick-borne viruses infecting humans.
Infections in humans primarily occur from either a tick bite or from exposure to infected blood or body fluids of wild or domestic animals such as goats, cattle, sheep, ostriches, and other birds and mammals. Cases commonly occur in people with occupational exposures to livestock. Crushing an infected tick with bare hands may also transmit the disease. Human-to-human transmission occurs through contact with infected blood or body fluids or through contact with contaminated medical equipment or re-use of needles. Learn more about transmission (CDC, https://www.cdc.gov/vhf/crimean-congo/transmission/index.html, Accessed 10/19/2023).
The incubation period is dependent on the mode of transmission. If transmitted via tick bite, incubation is usually 1-3 days with a maximum of 9 days. If transmission is via contact with infected blood or body fluids from animals or humans, incubation is usually 5-6 days with a maximum of 13 days.
CCHF Outbreaks 2023
While CCHF has been detected in numerous countries where it is endemic this year, the following countries have reported unusually high case numbers* since January 2023.
- Iraq: 545 confirmed cases, 70 deaths
- Afghanistan: 950 confirmed cases, 96 deaths
- Iran: 60 confirmed cases, 3 deaths
- India: 1 confirmed case, 1 death
*As of October 17, 2023
Signs and Symptoms of CCHF Infection
Symptom onset for CCHF is usually sudden and includes headache, high fever, sore throat, myalgias, dizziness, neck pain and stiffness, back pain, joint pain, stomach pain, nausea, vomiting, and diarrhea. Other common symptoms include flushed face, reddened eyes—sometimes with photophobia, red throat, and petechiae (red spots) on the palate. More severe symptoms include jaundice and changes in mood, confusion, and sensory perception. After 2-4 days, confusion/agitation may be replaced by sleepiness, depression, and physical and mental fatigue. Abdominal pain may localize to the right upper quadrant with palpable hepatomegaly.
As CCHF symptoms progress, large areas of bruising, nosebleeds, and bleeding at injection sites may be seen in varying degrees of severity. Tachycardia and lymphadenopathy may also be present. These symptoms usually occur on or around day 4-5 of illness and may progress to rapid renal deterioration, liver failure and respiratory failure.
Case fatality rates for CCHF are approximately 30 percent. In general, patients who recover usually show improvement on days 8-9. Recovery is slow and complications after recovery have not been well studied.
Clinical Care for Patients Infected with CCHF
Treatment for CCHF remains predominately supportive with fluid balance and electrolyte support, supplemental oxygenation and hemodynamic support including treatment of secondary infections. Ribavirin has shown effectiveness in vitro and has been utilized for treatment of patients with reported benefit.
Currently there are no vaccines approved for human use available for CCHF though several vaccine candidates are in development.
Testing and Lab Considerations for CCHF
Laboratory tests that may be used to diagnose CCHF include antigen-capture enzyme-linked immunosorbent assays (ELISA), real-time reverse transcription polymerase chain reaction (RT-PCR) tests, viral isolation and culture, serum naturalization, and detection of antibody by ELISA. Laboratory diagnosis of a patient with CCHF can be made during the early phases of illness by using the combination of detected viral antigen (ELISA antigen capture), and viral RNA sequencing (RT-PCR) from blood or by tissues collected from a fatal case. Immunohistochemical staining can show evidence of viral antigen in formalin-fixed tissues. In the later phases of the disease or among those surviving the infection, antibodies can be found in blood, but antigen, viral RNA, and virus are no longer present.
Clinical specimens suspected of containing CCHF are considered Category A when shipping. Appropriate training, as well as shipping containers and documentation are required. It is important to work with your local health departments to identify testing locations as well as appropriate specimen types.
Clinical specimens suspected of containing CCHF virus should be handled with enhanced precautions. Laboratory risk assessments should be completed to determine what tests can be carried out with minimal risk. Specimen collection, handling, and processing should be done while using appropriate personal protective equipment (PPE) and engineering controls (e.g., biosafety cabinet).
Recommended PPE
- If clinically stable without vomiting (suspect CCHF): gown, gloves, respirator, eye protection
- If clinically unstable (suspect CCHF) or confirmed CCHF: same as Ebola “wet” precautions:
- Impermeable gown or coverall
- PAPR or N95 respirator
- Eye protection
- Examination gloves with extended gloves
- Boot covers (or shoe covers in combination with coverall with integrated socks)
- Apron
Place the patient in an Airborne Infection Isolation Room (AIIR), when available.
| Suspect Case without vomiting or cough | Suspect Case with vomiting/diarrhea/cough |
| Gown | Impervious gown or coverall |
| Gloves – single or double glove | Extended cuff gloves – 2 pair |
| Respirator – PAPR or N95 (or equivalent) | Respirator – PAPR or N95 (or equivalent) |
| Eye protection | Eye protection |
| Shoe or boot covers | |
| Apron |
Infection Control Measures for CCHF Infection
Because CCHF virus can spread from person-to-person, current recommendations are to place the patient in AIIR when available and to use contact, droplet/airborne isolation, and eye protection to prevent hospital-acquired infections and safeguard staff.
Additional Resources for Health Care Personnel
Crimean-Congo Hemorrhagic Fever (CCHF) | CDC
Crimean-Congo Hemorrhagic Fever (CCHF) | WHO
NETEC’s Viral Hemorrhagic Fever’s and PPE Matrix
About the Authors
Karie Brouillard, BS, ASCP, is the special pathogens laboratory coordinator at Providence Sacred Heart Medical Center & Children’s Hospital in Spokane, Washington. Prior to her role in the Special Pathogens Unit, Karie worked in the Microbiology department and as a point of care specialist in the Lab Regulatory and Safety department. Before joining the team at Sacred Heart, Karie was the bioterrorism coordinator for Eastern Washington and Northern Idaho of the Laboratory Response Network (LRN). She conducted trainings for sentinel laboratories and first responders on recognizing the agents of bioterrorism.
Gavin Harris, MD, is an Assistant Professor of Medicine at Emory University School of Medicine, holding appointments in both the Division of Pulmonary, Allergy and Critical Care Medicine and the Division of Infectious Diseases. He has been on faculty at Emory since 2020 and his professional expertise lies in the areas of disaster preparedness, medical countermeasures, and the treatment of special pathogens. Gavin is the medical director for the Emory University Serious Communicable Diseases Program Project ECHO and SitRep, the Critical Care Co-Liaison for Emory’s Serious Communicable Diseases Unit (SCDU), and a rostered physician for the SCDU. Additionally, Gavin is an alumni fellow of the Johns Hopkins University Bloomberg School of Public Health’s Center for Health Security Emerging Leaders in Biosecurity Initiative (ELBI), and a biothreats subject matter expert with the Southern Regional Disaster Response System (SRDRS). At NETEC, he is a member of the Adult Care work group.
Brooke Henriksen, BSN, RN, CCRN, is the Training and Education Coordinator for the Special Pathogens Program in Region 10 at Providence Sacred Heart Medical Center and Children’s Hospital (PSHMC&CH) in Spokane, Washington. She is a co-chair for the NETEC PPE work group. Brooke is also a member of the NETEC Infection Prevention and Control (IPC) work group and the Biocontainment Unit (BCU) work group.
Vicki Herrera, MS, is a research coordinator at University of Nebraska Medical Center/Nebraska Medicine. She is the training and education lead for the Nebraska Biocontainment Unit Laboratory. In addition, she is also an Alternate Responsible Official for the biosafety level 3 (BSL-3) lab located on the UNMC campus. At NETEC, Vicki leads the Lab workgroup responsible for developing educational resources and offering support for laboratories handling special pathogens.
Angela Hewlett, MD, MS, is a professor of internal medicine and infectious diseases at the University of Nebraska Medical Center and the University of Nebraska College of Public Health and is the George W. Orr and Linda Orr Chair in Health Security. She serves as Medical Director of the Nebraska Biocontainment Unit. Her clinical interests include the management of complicated bone and joint infections, and she is the director of the Orthopedic Infectious Diseases Service. At NETEC, Angela is a member of the BCU and Adult Care work groups.
Caroline Croyle Persson, CIC, MPH, MPA, is the Program Director for the Mountain Plains Regional Disaster Health Response System and biocontainment unit at Denver Health. Her work focuses on healthcare emergency management, coordination and collaboration, and capacity building to enhance healthcare preparedness and response efforts. Prior to her current role, Caroline worked in infection prevention and control with a focus on influenza, emergency management, high risk pathogens, program and policy management, hand hygiene, and regulatory compliance. She has worked on various public health projects prior to arriving at Denver Health spanning malaria prevention, community health worker sustainment, emergency management, and HIV/AIDs mobile health application acceptance. At NETEC, Caroline is the co-chair of the Infection Prevention and Control (IPC) work group and the Biocontainment Unit (BCU) work group, and a member of the Regional Outreach work group.
Patricia Tennill, RN, BSN, is an Associate Director of Nursing in Staff Development and the nursing lead for the NYC Health + Hospitals / Bellevue Special Pathogens Program. Patricia has been involved with the Special Pathogens Program since 2014 as a nurse leader responsible for coordinating and overseeing all nursing operations on the Special Pathogens Unit, including the development of protocols concerning the movement and care of patients with special pathogens and the subsequent hands-on training for all staff involved in the Special Pathogens Program. At NETEC, Trish is the co-chair of the Infection Prevention and Control (IPC) work group and a member of the the Biocontainment Unit (BCU), Personal Protective Equipment (PPE), and Regional Outreach work groups.