What are the other Names for this Condition? (Also known as/Synonyms)

• CCHF (Crimean-Congo Hemorrhagic Fever)
• Crimean-Congo Haemorrhagic Fever
• Tick-borne Hemorrhagic Fever

What is Crimean-Congo Hemorrhagic Fever? (Definition/Background Information)

• Crimean-Congo Hemorrhagic Fever (CCHF) is a deadly viral illness that presents with fever and severe bleeding manifestations. It is widespread in south-eastern Europe, the Middle East, Africa, and Asia. Globalization and climate change have increased the risk of infection transmission to areas where it was not identified earlier
• The illness is caused by the Crimean-Congo Hemorrhagic Fever virus (or CCHFV), an RNA virus that spreads to humans and animals primarily through the bites of hard ticks. The tick picks up the virus in the blood when it bites an infected animal, and then transmits it to other animals or humans via bites; thus, acting as a vector for the infection. The animals carry the virus asymptomatically and do not develop any clinical illness
• Humans get infected through the bites of infected ticks, direct physical contact with blood, body fluids, or tissues of other infected humans and animals. Infections also occur from contact with the (infected) dead body or used linens and clothes of those who died of Crimean-Congo Hemorrhagic Fever
• The signs and symptoms appear between 1-13 days after exposure to the virus. The illness consists of the pre-hemorrhagic stage (prodromal phase), followed by the hemorrhagic stage. The prodromal phase presents with flu-like, non-specific signs and symptoms. The hemorrhagic stage develops after 3 to 5 days of symptom onset and is characterized by various bleeding manifestations
• The presentation of Crimean-Congo Hemorrhagic Fever is generally non-specific and the infection frequently misdiagnosed, leading to delays in seeking medical attention. A definitive diagnosis is best made with molecular techniques, such as polymerase chain reaction, to detect the genetic material of the virus
• There are no effective antiviral drugs available for Crimean-Congo Hemorrhagic Fever. Therefore, typically symptomatic treatment is provided. Also, presently there are no approved vaccines available for its prevention
• Nevertheless, Crimean-Congo Hemorrhagic Fever can be an extremely severe disease leading to early fatalities from a lack of specific treatment. If medical attention and treatment are not received soon after the appearance of initial symptoms, severe life-threatening complications can develop. The death rates in such cases are approximately 40%

Who gets Crimean-Congo Hemorrhagic Fever? (Age and Sex Distribution)

• Crimean-Congo Hemorrhagic Fever can affect individuals of any age group and both male and female genders
• It is seen most commonly in the spring and summer when adult ticks are seeking the blood meals needed for their maturation
• The condition is globally widespread in parts of south-eastern Europe, Middle East, Africa, and Asia. Until now, it has not been reported in North America, South America, and Australia

What are the Risk Factors for Crimean-Congo Hemorrhagic Fever? (Predisposing Factors)

The possible risk factors for Crimean-Congo Hemorrhagic Fever include:

• Occupations involving contact with animals, e.g., farmers, hunters, animal herders, livestock workers, and slaughterhouse workers
• Contact with livestock in endemic regions
• Drinking raw milk and eating raw or inadequately cooked meat
• Providing care for individuals with the disease - healthcare workers and family members are at an increased risk
• Procedures that can spray particles of the infected person’s body fluids, such as during chest compressions, cardiopulmonary resuscitation (CPR), intubation, mechanical ventilation, and endoscopies
• Blood transfusion or transplant organ received from an asymptomatic carrier or an infected individual

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one's chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Crimean-Congo Hemorrhagic Fever? (Etiology)

Crimean-Congo Hemorrhagic Fever (CCHF) is caused by the Crimean-Congo Hemorrhagic Fever virus (CCHFV), a virus belonging to the genus Orthonairovirus of the Nairoviridae family of viruses. This is an RNA virus, which means that it has ribonucleic acid (RNA) as its genetic material.

• CCHFV is a tick-borne virus transmitted through the bites of hard ticks. The tick picks up the virus in the blood when it bites an infected animal and then injects them into the blood of another animal or human it bites; thus, acting as the vector for the infection.
• Humans get the disease from infected ticks, animals, as well as from other infected humans
• The possible ways through which the CCHF virus is transmitted to humans include:
  • Bites from infected ticks
  • Contact with blood, tissues, or body fluids of infected animals
  • Contact with blood, tissues, or body fluids of infected humans through
    • Direct body contact
    • Blood transfusion
    • Organ transplant 
    • Breeched skin (e.g., needlestick) or mucous membranes (splash to eyes, nose, or mouth)
  • Contact with a dead body or used linens and clothes of a person who died of CCHF

What are the Signs and Symptoms of Crimean-Congo Hemorrhagic Fever?

Crimean-Congo Hemorrhagic Fever (CCHF) is clinically similar to other viral hemorrhagic fevers. Early supportive therapy can aid in the full recovery of the individual, but the condition can be severe and life-threatening if not treated promptly.

The clinical illness develops suddenly between 1 to 13 days after exposure to the virus. It begins with the prodromal phase (pre-hemorrhagic stage) which presents with non-specific flu-like signs and symptoms:

• Fever
• Chills
• Fatigue, malaise, and weakness
• Headache
• Pain behind the eyes
• Muscle and joint pains
• Low-back pain
• Decrease appetite
• Nausea/vomiting
• Abdominal pain
• Diarrhea
• Cough and sore throat
• Dizziness
• Irritability and mood swings

After 3 to 5 days of symptom onset, the hemorrhagic stage develops, which is characterized by various bleeding manifestations. These may include:

• Bleeding in the skin causing petechial rash
• Conjunctival petechiae due to bleeding in eyes
• Bleeding from gums and nose
• Blood in vomitus, cough, urine, or stools
• Bleeding from sites of vein puncture
• Fluid in lungs
• Low blood pressure
• Liver damage
• Massive internal bleeding, and hypovolemic shock
• Neurological signs such as tremors, muscle spasms, seizures, delirium, and coma

If medical attention and treatment (basically supportive) are not received soon after the appearance of initial symptoms, the condition can be life-threatening.

How is Crimean-Congo Hemorrhagic Fever Diagnosed?

The signs and symptoms of Crimean-Congo Hemorrhagic Fever are non-specific. Therefore, to make the diagnosis, it is important to have a high index of suspicion and collect information about the following:

• Clinical data including signs and symptoms, physical examination, and course of the illness including changes in blood chemistry
• History of travel to endemic regions
• History of contact with individuals with similar symptoms
• History of contact with animals infested with ticks
• History of tick bite

Clinical diagnosis alone is difficult, and the following tests are used to confirm the diagnosis:

• Polymerase chain reaction (PCR) to help detect the genetic material of the virus
• Enzyme-linked immunosorbent assay (ELISA)
  • Helps detect the antibodies
  • Not appropriate during the early phase of the disease, as antibody responses are often absent or delayed in serious CCHF cases
• Virus isolation in cell culture: Specific but requires highly sophisticated laboratories with advanced biosafety mechanisms
• Immunohistochemical staining: Detects viral antigen in formalin-fixed tissues

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Crimean-Congo Hemorrhagic Fever?

As Crimean-Congo Hemorrhagic Fever symptoms worsen, life-threatening complications may occur, such as:

• Multiple organ failure
• Severe bleeding
• Hypovolemic shock

Not much is known about the long-term complications of the disease. The condition can result in fatalities from severe complications and inadequate treatment.

How is Crimean-Congo Hemorrhagic Fever Treated?

Currently, there are no antiviral treatments approved for individuals with Crimean-Congo Hemorrhagic Fever. Only supportive therapy is provided to individuals to help them cope with the disease and its symptoms. These include:

• Fever control
• Pain relief
• Fluid and electrolytes maintenance
• Oxygen and blood pressure maintenance
• Transfusions for bleeding disorders

How can Crimean-Congo Hemorrhagic Fever be Prevented?

There is no approved vaccine currently available, although research is ongoing to develop vaccines to prevent Crimean-Congo Hemorrhagic Fever (CCHF). The following measures can help prevent infection with Crimean-Congo Hemorrhagic Fever virus:

• Thoroughly check oneself for ticks after working with animals and immediately remove them
• Use insect repellents on exposed skin and clothing
• Avoid contact with body fluids (e.g., blood, saliva, vomitus, respiratory secretions, semen, urine, stool, sweat, etc.) of affected individuals
• Immediately wash hands with soap and water in case of contact
• Avoid direct contact with dead bodies and used linens and clothes of individuals who have died of CCHF
• Follow all infection-control procedures in healthcare and other settings; use protective clothing, masks, and gloves
• Ensure proper sterilization of medical equipment and proper disposal of contaminated products, needles, etc.
• Be careful while handling patient samples, especially during research
• Spray animals infested with ticks using a recommended acaricide to kill the ticks
• Avoid contact with blood and body fluids of livestock; use gloves and protective clothing
• Boil milk and cook meat properly before consuming

What is the Prognosis of Crimean-Congo Hemorrhagic Fever? (Outcomes/Resolutions)

Crimean-Congo Hemorrhagic Fever is an extremely severe disease that can lead to early deaths.

• If medical attention and treatment are not received soon after the appearance of initial symptoms, the individual can develop severe complications, followed by death in approximately 40% of cases
• In others, recovery is slow and usually starts after 9 to 10 days of illness. The long-term effects of the disease have not been studied well enough

Additional and Relevant Useful Information for Crimean-Congo Hemorrhagic Fever:

The first outbreak of Crimean-Congo Hemorrhagic Fever was recognized in 1944 in the Crimean Peninsula and the illness was named Crimean Hemorrhagic Fever (CHF). In 1969, it was recognized that the agent that caused CHF was the same as the one that caused an illness in the Belgian Congo (present Democratic Republic of the Congo, DRC) in 1956. This led to the name Crimean-Congo Hemorrhagic Fever.