Beware Sandflies While in Europe!

Special Feature

By Stan Deresinski, MD, FACP, Clinical Professor of Medicine, Stanford, Associate Chief of Infectious Diseases, Santa Clara Valley Medical Center, is Editor for Infectious Disease Alert.

Source: Depaquit J, et al. Arthropod-borne viruses transmitted by Phlebotomine sandflies in Europe: a review. Euro Surv. 2010; 15(10):pii=19507. http://www.eurosurveillance.org/ViewArticle.aspx?Articled=19507

Synopsis: Sandfly bites may transmit several viral infections in Europe, including some that result in the development of meningoencephalitis.

Leishmaniasis, transmitted by sandflies of the genus Phlebotomus, is well-established in the Mediterranean region of Europe, and visceral leishmaniasis has become a particular danger to AIDS patients in that area.1 Depaquit et al have now examined the current status of viral infections that are transmitted by sandflies in Europe and assessed the prospects for their further spread, as well as the potential for introduction of new viral pathogens into the region.

Sicilian and Naples viruses are bunyaviruses transmitted by Phelobotomus pattasi. Sandfly fever, due to these two related viruses, caused outbreaks of febrile illness in troops during the invasion of Italy in 1943 and 1944, and Major Albert Sabin et al identified the etiologic agent.2 They each cause a self-limited febrile illness, with frequent retro-orbital pain and myalgia. Within Europe, these viruses have been directly, or indirectly, identified in Cyprus and the former Yugoslavia, as well as in Italy. The virus is also present in north Africa, the horn of Africa, the Middle East, and some central Asian republics.

Toscana is a bunyavirus transmitted by Phlebotomus perniciousus. It is highly prevalent in central Italy, as its name implies, where the seroprevalence is 22%, but it has also been recognized to be of importance in Portugal, southern France, and Spain. Seroprevalence studies have also detected evidence of infection with this virus in Turkey. The Toscana virus is neurotropic and is a major cause of meningitis and meningoencephalitis from May to October in Italy. Toscana was also identified as the cause of bacterial culture-negative meningitis in six patients (three adults and three children among 308; 5.6%) studied in a metropolitan area of northern Portugal.3 Toscana virus also produces a non-specific febrile illness, as well as asymptomatic infections.

Depaquit et al suggest that other viruses transmitted by sandflies that have the potential to emerge in Europe include Chandipura vurus, a vesiculovirus and, thus, related to vesicular stomatitis virus. Chandipura virus is a cause of epidemic illness, including encephalitis, in India.4

While these infections are of obvious importance to Europeans, they also must be considered as possible causes of febrile illness, including meningoencephalitis in travelers to this region. While undoubtedly vastly underdiagnosed, infections caused by sandfly-associated viral pathogens have been reported in tourists and others. Between 1986 and 1989, 36 Swedish tourists acquired infection with Sicilian virus and one acquired Naples virus infection while visiting Cyprus. Many cases of travel-acquired Toscana virus infection, including meningoencephalitis, have been reported in the literature.

Reference

  1. Ready PD. Leishmainiasis emergence in Europe. Euro Surv 2010; 15 (10), 11 March 2010. http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19505
  2. Sabin A, Philip CB, Paul JR. Phelobotomus (pappataci or sandfly fever): A disease of military importance. Summary of existing knowledge and preliminary report of original investigations. JAMA. 1944;125:603-606.
  3. Santos L, et al. Toscana virus meningitis in Portugal, 2002-2005. Euro Surveill. 2007;12:E3-E4.
  4. Tandale BV, et al. Chandipura virus: A major cause of acute encephalitis in children in North Telangana, Andhra Pradesh, India. J Med Virol. 2008;80:118-124.