Crimean Congo Hemorrhagic Fever, abbreviated as CCHF, was first described in 1944 in Crimea (Ukraine) and in 1956 in Congo (Zaire) on the African continent. Crimean Congo hemorrhagic fever (CCHF) is a viral disease of the arbovirus group of the Bunyaviridae family that is common between humans and animals and begins suddenly.
Virus durability:
The virus has low resistance to heat and is destroyed at 56°C for 30 minutes and remains in the blood for 10 days at 40°C. The virus is not resistant to disinfectants, especially acidic compounds, so it is destroyed in the acidic environment created in meat after the carcass is frozen.
Ways of transmission of Crimean Congo fever:
The virus is transmitted by hard ticks of the genus Hyaloma that live on the body of cattle. This virus causes numerous epidemics through direct contact with the blood and body secretions of the patient and the carcasses of infected animals. It can also be transmitted through the consumption of contaminated meat through illegal slaughtering of livestock and breathing in contact with infected livestock. In fact, the reservoir of this disease is hard hyaluronan ticks, and this arthropod is able to transmit the virus to the next generation through its eggs.
Symptoms of Crimean-Congo fever:
Symptoms of Crimean-Congo hemorrhagic fever include fever, headache, muscle pain, vomiting, lethargy, bleeding and death if treatment is delayed.
Disease vectors:
Crimean-Congo fever is transmitted through the ear or by crushing a tick on the skin with a hole or an open wound.
Vertebrates: dogs, rodents, hedgehogs, livestock
Birds: Indirect vector because it causes the tick to transmit to others (animals-humans).
Insects: By feeding on blood contaminated with CCHF
Epidemiology:
This disease is observed in most parts of Africa, Eastern Europe, the Middle East (especially Iran and Iraq), Pakistan and India. Crimean-Congo fever has recently become widespread in Iran and at least 222 suspected cases of the disease have been reported between 1999 and the beginning of 2002. In these cases, 81 people have been confirmed to have the disease with positive IgM and ELISA tests.
Stages of the disease:
- The incubation period of the disease is 1-3 days and a maximum of 9-13 days. (In livestock, 3-12 days and in humans, 3-9 days).
- Pre hemorrhagic stage: This stage lasts 1 to 7 days and includes fever, weakness, severe headache, chills, severe pain in the back, waist and legs, confusion and bruising, anorexia, nausea and vomiting unrelated to eating, diarrhea and abdominal pain, etc., which of course may only be seen in the individual.
- Hemorrhagic stage: The disease usually begins on day 3 to 5 and lasts 1 to 10 days. Bleeding in the mucous membranes and petechiae in the skin, hematomas and other bleeding phenomena such as melena, hematuria, nosebleeds and gums are seen. It should be noted that sometimes bleeding is not visible to the patient’s caregivers, which is one of the signs of delayed diagnosis.
Diagnosis of the disease:
Diagnosis of the disease is possible based on clinical symptoms, serology or virus culture, blood PCR to find the virus causing the disease, and for its treatment, in addition to supportive measures to correct DIC shock, specific medication can be used.
A suspected case of the disease has sudden fever, headache, muscle pain, bleeding, along with an epidemiological finding in the two weeks before the onset of symptoms, and a probable case is when the suspect has a platelet count less than 150,000/mL or a 50% decrease in platelet count within 3 days, leukopenia, or leukocytosis.
Prevention methods:
1-Keeping meat and offal of livestock in a cold store or refrigerator for at least 24 hours after slaughter
2-Avoiding consumption of raw or undercooked liver and meat of livestock (the most important cause of mortality)
3-Buying livestock from places that are approved by veterinary medicine
4-Slaughtering livestock in slaughterhouses
5-Personal protection when contacting livestock
6-Not separating the tick with your hands from the surface of the animal or human body (in this case, applying oil to the back of the tick is effective to stop its breathing and gradually release the skin).
Work from the Scientific and Technical Unit of Tak Nam Pendar Aria Company, August 2021
