Crimean-Congo Haemorrhagic Fever Disease
CCHF is viral illness that occurs in Africa, the Balkans, the Middle East and Asia, in countries south of the 50° parallel north. • The principal reservoir and vector of CCHF are ticks of the genus Hyalomma, although other tick genera can be infected with CCHF virus. • The CCHF virus is transmitted to humans mainly by tick bites or through contact with infected animal blood or tissues during and immediately after slaughter. • 88% of people infected will have subclinical symptoms. One in eight people will develop a severe disease.
Clinical features of CCHF disease
• The incubation period ranges from 2-14 days. • 70% of CCHF cases have a history of tick bite. • It is estimated that 88% of infections are subclinical. • Case fatality ratio can reach 15% among patients hospitalized with severe presentation. • Most common symptoms include: • Abrupt onset fever, chills, shudders, myalgia, headaches, sicknesses and vomits, abdominal pain, arthralgia; • After a few days: bleeding from mucous membranes, hematomas, ecchymosis, melena, hematuria, nose bleeding, vaginal bleeding, bradycardia, thrombocytopenia, leukopenia.
Crimean-Congo Haemorrhagic Fever diagnosis
Symptoms are non-specific; clinical diagnosis may be difficult. • Differential diagnosis includes other viral haemorrhagic fevers, malaria, typhoid fever, shigellosis, and other viral and bacterial diseases. • Patient history is essential and should include: exposure to ticks; or exposure to wild animals and livestock; and/or area/village endemic for CCHF; and/or contact with CCHF cases.
Laboratory diagnosis of CCHF
Definitive diagnosis requires testing: • reverse transcriptase polymerase chain reaction (RT-PCR) assay; • IgG and IgM antibodies enzyme-linked immunosorbent assay (ELISA); antigen detection tests; • virus isolation by cell culture. Handling and processing specimen requires suitably equipped laboratories under maximum biological containment conditions and staff collecting samples should be trained
Crimean-Congo Haemorrhagic Fever Treatment
Early aggressive intensive care support: monitor fluid, electrolyte balance, renal function, blood pressure, and oxygenation, and careful rehydration • Support of coagulation system with blood component therapy. • Supportive drug therapy including : painkillers, antiemetic for vomiting, anxiolytic for agitation, +/-antibiotics and/or antimalarial drugs. • Antiviral drug ribavirin can be given early in course of the disease.
Reducing risk of Ticks-to-human transmission
Protect yourself from tick bites 1. Avoid tick-infested areas. 2. Wear light colored clothing for easy finding of ticks on clothes. 3. Wear protective clothing (long sleeves, long pants). 4. Tuck your pant legs into your socks so that ticks cannot crawl up inside of your pant legs. 5. Use chemical repellent with DEET (on skin) and acaricides (tick killer) on boots and clothing. • Perform daily tick checks : regularly examine clothes and skin in search of ticks and remove them.
CCHF prevention: Safely remove ticks
• Use fine-tipped tweezers (or a thread) . • Grab the tick as close as possible to the skin. • DO NOT twist or jerk the tick. • Gently pull straight up until all parts of the ticks are removed. • Wash hands with soap and water. Apply antiseptic on tick bite or clean with soap and water. • NEVER crush a tick with your fingers.
Reducing human-to-human transmission
Avoid contact with infected CCHF patients and deceased. • Wash hands regularly with soap and water. • Encourage early treatment in CCHF Treatment Center. • Use gloves and mask and practice hand-hygiene when caring for suspected CCHF patient at home. Seek health advice
•Dr Pierre Formenty