25 July 2006

 

Crimean Congo haemorrhagic fever in Turkey and the Russian Federation

 

Turkey

Between 1 January and 17 July 2006 a total of 150 cases of Crimean-Congo haemorrhagic fever (CCHF) have been laboratory confirmed in Turkey and 15 of these cases have died [1,2].  Twenty-two Turkish provinces have been affected, with most cases occurring in the Kelkit Valley, north-east Turkey. No cases have been reported from the Mediterranean tourist resorts.

In the past three years the reported cases (and deaths) of CCHF were as follows

2003 - 150 (6); 2004 - 249 (13); 2005 - 266 (13). The figure observed for 2006 is therefore suggestive of increased disease activity.

The Ministry of Health in Turkey, in close collaboration with the Ministry of Environment and the Ministry of Agriculture and Rural Affairs, have taken several steps: implemented control measures, established enhanced surveillance, put into place case management guidelines that include a treatment protocol with ribavirin, and implemented a public awareness campaign.

Russian Federation

According to media reports, there has been an increase in the cases of CCHF in the Southern Federal District of the Russian Federation [3]. Forty seven cases from Rostov region have so far been confirmed as CCHF, including five deaths. Sixteen cases were reported during the corresponding period of 2005.

The increase in CCHF cases has been associated with increased tick density in the district.

Crimean-Congo haemorrhagic fever

The causative agent of CCHF is a virus belonging to the Nairovirus genus of the Bunyaviridae family. CCHF is primarily a zoonosis with natural hosts including hares, birds, cattle, sheep, pigs and goats. The virus is endemic in many countries in Africa, eastern Europe, Asia, and the Middle East. The disease can be transmitted to humans either by the bite of an infected tick (usually ticks of the Hyalomma genus) or through direct contact with blood or other tissue from infected livestock. The majority of cases of CCHF occur amongst agricultural workers, slaughterhouse workers, and veterinarians.

Following a bite from an infected tick the incubation period of CCHF is between one to three days, with a maximum of nine days. The incubation period is longer (5 to 6 days) after contact with blood or tissue from infected animals. Initial symptoms include rapid onset of 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%. Early initiation of supportive treatment is essential to improve the outcome. Ribavirin has been used for treatment of CCHF [4].

Advice for travellers

  

Travellers to areas affected by CCHF are advised to take measures to minimise their exposure to ticks. These include:

Wearing long sleeved clothing and long trousers. Trousers should be tucked into socks when walking in tick infested areas.

• Applying insect repellent to exposed skin.
• Using a permethrin based insecticide on clothing.
• Inspecting for ticks and removing them immediately with tweezers or tick removers.

 

Animal handlers should take precautions to avoid exposure to blood and tissues.

Travellers who return from an affected area who become unwell following a tick bite should seek prompt medical attention.  

 

References

1. European Centre for Disease Control and Prevention. Crimean-Congo hemorrhagic fever - information for travellers to north-eastern Turkey. 20 July 2006 [cited 25 July 2006] http://www.ecdc.eu.int/

2. World Health Organization Regional Office for Europe. Crimean-Congo hemorrhagic fever (CCHF) activity in Turkey. 6 July 2006. [cited 25 July 2006] http://www.euro.who.int/surveillance/outbreaks/20060706_2

3. ProMED-mail. Crimean-Congo hemorrhagic fever - Russia (Southern Federal District) (03). ProMED-mail 2006; 19 Jul: 20060719.1985. [cited 25 July 2006] http://www.promedmail.org/pls/promed/f?p=2400:

1001:3446304863249391991::NO::F2400_P1001_BACK_PAGE

,F2400_P1001_PUB_MAIL_ID:1010,33633

4. Mardani M, Jahromi MK, Naieni KH, Zeinali M. The efficacy of oral ribavirin in the treatment of Crimean-Congo hemorrhagic fever in Iran. Clin Infect Dis 2003;36:1613-8.

 

Links to further information

European Network for Diagnostics of ‘Imported’ Viral Diseases (ENIVD) Crimean-Congo Haemorrhagic Fever fact sheet http://www.enivd.de/VHFDISEASES/fs_vhfdiseases.htm

NaTHNaC Insect bite avoidance information sheet http://www.NaTHNaC.org/pro/factsheets/iba.htm

Ergönül Ö. Crimean-Congo haemorrhagic fever. Lancet Inf Dis. 2006;6:203-14