03 September 2007

 Chikungunya virus infection in Italy, Ravenna District

On 30 August 2007 the Ministry of Health of Italy reported an outbreak of Chikungunya virus (CHIKV) infection in the District of Ravenna, Region Emilia-Romagna [1]. The first case was reported on 4 July 2007 and as of 30 August, there have been 135 cases with the peak of the outbreak occurring between 17 and 19 August. All but four of the cases have occurred in two small villages divided by the River Savio and near the town of Cervia. Eleven cases have been hospitalised and there has been one death in an elderly patient with other chronic medical conditions. Twenty-seven of the cases have been confirmed as CHIKV infection by antibody testing or PCR. It is believed that the index case was a visitor from India. This is the first time indigenous transmission of CHIKV has been detected in Italy.

Efforts to control the outbreak have included enhanced surveillance for illness following a standard case definition, increased public awareness and vector control through disinsection of public sites and homes. The daytime biting Aedes albopictus is the most likely vector. The European Centre for Disease Control and Prevention is assessing the risk for spread to other European countries and is coordinating a response of increased awareness, and vector surveillance within European Union member states.

 Advice for Travellers

Chikungunya virus is a mosquito transmitted viral infection and is endemic to large parts of Africa, the Middle East, India and south-east Asia. A large epidemic of CHIKV infection occurred in the islands of the Indian Ocean in 2005 and 2006 [2], and cases have been ongoing in India [3].

Initial symptoms of CHIKV infection include a sudden onset of severe arthralgias and myalgias, accompanied by fever, headache and conjunctivitis. Joint involvement is usually symmetrical, affects the extremities and can result in swelling, pain, redness and limitation of movement. A maculopapular rash involving primarily the trunk can occur concurrently with defervescence. Illness usually resolves over three to five days. Most patients recover fully over a period of a few weeks, although 5 - 10% of patients will experience chronic joint pain, stiffness and swelling that can persist.

There is no vaccine available to protect against CHIKV. Travellers to affected areas are advised to take insect bite precautions, particularly during daylight hours when Aedes mosquitoes are active.

The mosquito vector for CHIKV infection does not exist in the UK. However, health professionals who see returned travellers with a compatible illness should consider the diagnosis of CHIKV infection as imported cases are well-documented in the UK [4, 5].

 References

1. Ministero della Salute, Italy. Casi di indezione virale in provincia di Ravenna: il punto della situazione. On-line resource, accessed 3 September 2007. Available at: http://www.ministerosalute.it/

2. NaTHNaC. Chikungunya virus – update. Clinical Update, 21 July 2006 On-line resource, accessed 3 September 2007. Available at: http://www.nathnac.org/pro/clinical_updates/chik_210706.htm

3. International and Tropical Department, Health Surveillance Institute (DIT-InVS), France. India: Chikungunya and dengue. Bulletin Hebdomadarie International No. 98, 2–8 Aug 2007. On-line resource, accessed 3 September 2007. Available at: http://www.invs.sante.fr/international/bhi/bhi_090807.pdf

4. NaTHNaC. Imported chikungunya virus in the United Kingdom, 2006. Clinical Update 12 April 2007. On-line resource, accessed 3 September 2007. Available at: http://www.nathnac.org/pro/clinical_updates/chik_uk 120407.htm

5. Health Protection Agency. Imported chikungunya virus in the United Kingdom, 2006. Health Protection Report. 1(15) 13 April 2007. On-line resource, accessed 3 September 2007, Available at: http://www.hpa.org.uk/hpr/archives/2007/hpr1507.pdf

 Links

Health Protection Agency. Chikungunya. On-line resource. Available at: http://www.hpa.org.uk/infections/topics_az/Chikungunya/ default.htm

United States Centre for Disease Control and Prevention. Chikungunya Virus Fact Sheet: http://www.cdc.gov/ncidod/dvbid/Chikungunya/chickvfact.htm

European Centre for Disease Control and Prevention: http://www.ecdc.eu.int/index.html