Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne viral disease carried by Hyalomma ticks and transmitted to humans via tick bites or contact with infected animal blood. The virus is endemic in Africa, the Middle East, Asia, and the Balkans. It causes severe hemorrhagic fever in humans with flu-like symptoms initially, which can develop into vomiting blood, black stools, liver swelling, and shock. The disease has a high fatality rate of around 30% and is diagnosed through blood tests and tissue sampling. There is no vaccine available though supportive care and ribavirin treatment may help recovery. Prevention involves avoiding tick bites and reducing contact with potentially infected

1. Congo-Fever
A rising threat

2. Introduction
• Crimean–Congo hemorrhagic fever (CCHF) is a
widespread tick-borne viral disease that is endemic in Africa,
the Balkans, the Middle East and Asia.
• The virus is a member of the Bunyaviridae family of RNA
viruses.
• It is a zoonotic disease carried by several domestic and wild
animals.

3. Epidemiology
 Primary Host : It is a zoonotic disease carried by several
domestic and wild animals.
 Transmission : By Hyalomma tick
 Human : Infected by Tick bite

4. Epidemiology
• Crimean–Congo hemorrhagic fever occurs most frequently
among agricultural workers following the bite of an infected
tick
• Crimean hemorrhagic fever, first isolated in Crimea in 1945.
• Identical Congo fever was first isolated in Congo in 1956.
That’s why name given as Crimean-Congo fever.

5. Epidemiology
• First Case in Gujarat : In
January 2011, the disease
was reported in Sanand,
Gujarat, India, with 4
reported deaths, which
consisted of the patient
along with the doctor and
the nurse who treated the
patient.

6. We have to discuss about…..
• Agent
• Vector
• Host

7. (Arbovirus –> Bunyavirus –> Nairovirus)

8. Congo-Fever
 Group :Group V (negative ssRNA)
 Order :Unassigned
 Family :Bunyaviridae
 Genus :Nairovirus
 Species :Crimean-Congo hemorrhagic fever virus

9. Arbovirus
Arbovirus
Togaviridae Flaviviridae Bunyaviridae
Bunyavirus Phlebovirus Nairovirus
Crimean-congo
fever
Hantavirus
Reoviridae Rhabdoviridae

10. Bunya virus
• Bunyaviridae is a family of negative-stranded, enveloped RNA
viruses. Though generally found in arthropods or rodents
• Bunyaviridae are vector-borne viruses. transmission occurs
via an arthropod vector (mosquitos, tick, or sandfly).
 exception : Hantaviruses
 Hantaviruses are transmitted through contact with
deer mice feces.

12. Hard Tick
• Ixodid (hard) ticks, especially those of the genus – Hyalomma,
are both a reservoir and a vector for the CCHF virus.
• Numerous wild and domestic animals, such as cattle, goats,
sheep and hares, serve as amplifying hosts for the virus.

13. Transmission
• Transmission to humans occurs through contact with infected
ticks or animal blood.
• CCHF can be transmitted from one infected human to another
by contact with infectious blood or body fluids.
• Documented spread of CCHF has also occurred in hospitals
due to improper sterilization of medical equipment, reuse of
injection needles, and contamination of medical supplies.

15. In host, it causes : Congo Fever

16. Clinical Features
 Incubation period - 1–3 day.
 Following a tick bite (5–6 days after exposure to infected blood
or tissues), flu-like symptoms appear, which may resolve after
one week.
 In up to 75% of cases, however, signs of hemorrhage appear
within 3–5 days of the onset of illness.
 Throat petechiae, then soon nosebleeds, and vomiting, and
black stools.

17. Clinical Features
 Liver : swollen and painful.
 DIC
 acute kidney failure and shock,
 sometimes acute respiratory
distress syndrome.
 Patients usually begin to show
signs of recovery after 9–10
days from when the symptoms
appear, however 30% of the
cases result in death on the
second week of the illness.

19. Diagnosis
• Antigen-capture enzyme-linked immunosorbent assay (ELISA),
• real time polymerase chain reaction (RT-PCR),
• virus isolation attempts, and
• detection of antibody by ELISA (IgG and IgM).

20. Diagnosis
• Laboratory diagnosis of a patient with a clinical history
compatible with CCHF can be made during the acute phase of
the disease by using the combination of detection of the viral
antigen (ELISA antigen capture), viral RNA sequence (RT-
PCR) in the blood or in tissues collected from a fatal case and
virus isolation.
• Immunohistochemical staining can also show evidence of viral
antigen in formalin-fixed tissues.

21. Treatment
• Treatment is primarily symptomatic and supportive, as there
is no established specific treatment.
• Supportive Therapy :
1. fluid balance and correction of electrolyte
abnormalities,
2. oxygenation and hemodynamic support, and
3. appropriate treatment of secondary infections.
• Ribavirin is effective in vitro and has been used during
outbreaks, but there is no trial evidence to support its use.

22. Prevention
• Mouse-brain derived vaccine : The only available and
probably somewhat efficacious CCHF vaccine is an inactivated
antigen preparation currently used in Bulgaria.
• In 2011, a Turkish research team led by Erciyes University has
successfully developed the first non-toxic preventive vaccine,
which passed clinical trials. The vaccine is pending approval
by the FDA.

23. Bibliography
• http://www.cdc.gov/vhf/crimean-congo
• Ananthnarayan and Paniker’s Textbook of Microbiology
• https://en.wikipedia.org/wiki/Crimean%E2%80%93Congo_hemorrh
agic_fever