20 August 2009

Crimean Congo haemorrhagic fever: Turkey

Turkey

Between 1 January 2009 and 14 August 2009, 1,181 cases and 54 deaths due to Congo Crimean haemorrhagic fever (CCHF) have been confirmed [1]. This is similar to the number of cases (1,220) and deaths (56) reported during the same period in 2008 [1].

CCHF is an emerging disease in Turkey; the first clinical cases were reported in 2002 [2,3].  The number of confirmed cases reported each year has increased between 2002 and 2008 [3]. The area of Turkey most affected is the rural agricultural region of middle and eastern Anatolia [4]. Most cases occur between April and September of each year, corresponding to the tick season [3].

Global epidemiology

CCHF is endemic in many countries in Africa, Asia, the Middle East and Eastern Europe and is an emerging disease in the Balkans [4]. In addition to the cases in Turkey in 2009, there have been recent unconfirmed media reports of CCHF from Kosovo, Kazakhstan and Russia, and a confirmed report of a cluster of cases in Tajikistan [5].

Crimean Congo haemorrhagic fever 

CCHF is caused by a virus of the Bunyaviridae family. It is primarily a zoonosis with natural hosts including hares, birds, cattle, sheep, pigs and goats. The disease is transmitted to humans either by the bite of an infected tick (usually ixodid ticks of the Hyalomma genus) or through direct contact with blood or other tissue from infected livestock. Healthcare workers are at risk from the blood or tissues of an infected person [3]. The majority of cases of CCHF occur amongst those working in agriculture and animal husbandry.

The incubation period of CCHF after a tick bite is between one and three days. It is longer (five to six days) after contact with blood or tissue from infected animals. Initial symptoms are fever, myalgia, headache and dizziness; some patients will have nausea and diarrhoea. As the disease progresses, haemorrhagic manifestations develop. In severe illness the mortality rate is approximately 30%, with a wide range. The fatality rate in the Turkish cases has been about 5% [3]. Treatment is supportive, and the anti-viral, ribavirin is experimental therapy [6].

                         

Advice for travelers

The risk of CCHF to tourist travelers is very low.  However, travellers to affected areas are advised to take measures to minimise their exposure to ticks. These include:

• Wear clothing with long sleeves and long trousers (tucked into socks), which can be treated with insecticide sprays such as permethrin.
• Apply insect repellent (DEET) to exposed skin.
• Check the body for ticks regularly. Larval ticks are tiny and difficult to see. Adult ticks, once they have fed and become engorged, may be the size of a coffee bean. Common areas for ticks to attach are at the hair-line, behind the ears, elbows, backs of knees, groin and armpits.
• Remove ticks as soon as possible by using a pair of tweezers or tick remover. The tweezers should be placed as close as possible to the skin and then the tick pulled slowly, ensuring the mouth parts are removed. Care needs to be taken not to squeeze the stomach contents into the site of the bite.

 

Animal handlers should take precautions to avoid exposure to blood and tissues of livestock and healthcare workers should observe appropriate infection control measures.

There is no vaccine to prevent CCHF.

Outbreaks of CCHF are listed in the NaTHNaC Outbreak Surveillance Database.

References

 1. Turkish Ministry of Health. Health Services General Directorate. Crimean Congo Fever Homepage – Press release 14 August 2009 (in Turkish). [Accessed 19 August 2009]. Available at http://www.saglik.gov.tr/KKKA/BelgeGoster.aspx?F6E

10F8892433CFF404F9755767D76FFD487E0AB7DA

A4988

2. Karti SS, Odabasi Z, Korten V, et al. Crimean-Congo hemorrhagic fever in Turkey. Emerg Infect Dis. 10:1379-84, 2004. Available at: http://www.cdc.gov/ncidod/EID/vol10no8/03-0928.htm

3. Yilmaz GR, Buzgon T, Irmak H et al. The epidemiology of Crimean-Congo haemorrhagic fever in Turkey 2002-2007. Int J Infect Dis. 13:380-6, 2009.

4. World Health Organization Regional Office for Europe. Epidemiology of Crimean–Congo haemorrhagic fever virus: Turkey, Russian Federation, Bulgaria, Greece, Albania, Kosovo. 11 August 2008. [Accessed 19 August 2009]. Available at:  http://www.euro.who.int/communicablediseases/outbreaks/2008

0806_1

5. World Health Organization Regional Office for Europe. Crimean-Congo haemorrhagic fever in Tajikistan. 13 August 2009. [Accessed 19 August 2009] Available at: http://www.euro.who.int/communicablediseases/outbreaks/2009

0813_2

6. Ergonul O. Treatment of Crimean-Congo haemorrhagic fever. Antiviral Res. 78:125-31, 2008.

Links

NaTHNaC Health Information Sheet: Insect bite avoidance

World Health Organization Crimean-Congo haemorrhagic fever factsheet

Health Protection Agency: Crimean Congo haemorrhagic fever homepage

Health Protection Agency. Historical cases and outbreaks of CCHF