Re-Emergence of Visceral and Cutaneous Leishmaniasis in the Greek Island of Crete

Abstract

Leishmaniases are vector-borne diseases transmitted by phlebotomine sand flies. Three species of Leishmania are found in the Mediterranean basin: Leishmania infantum, the most common species responsible for both visceral (VL) and cutaneous leishmaniasis (CL); Leishmania major, found in North Africa and Middle East causing CL; Leishmania tropica with a limited presence in Europe, causing CL. During the last 25 years, Crete has become an endemic zone for L. infantum with a high number of infected dogs and an increasing number of human cases every year; in the last 4 years, the incidence has reached an average of seven VL patients per year in a population of 600,000. At the same time, CL has re-emerged in Crete due to L. tropica, with an average of three CL cases per year in the last 4 years. Isolates were typed as L. infantum MON-1 and MON-98 and L. tropica MON-300, a zymodeme not reported before. Both VL and CL have spread to the whole of the island during the last 25 years, primarily in semi-urban and urban areas with altitudes of 0-50 m. The prevailing Phlebotomus species were Phlebotomus neglectus (proven vector of L. infantum) and Phlebotomus similis (suspected vector of L. tropica).

Epidemiology of human leishmaniasis in Greece, 1981-2011

“…In a survey conducted in the island of Crete, covering the period from 1986 to 2010, all isolated strains (n=16) from visceral leishmaniasis patients were of L. infantum type, while isolated strains from cutaneous leishmaniasis patients (n=5) were of L. infantum (n=3) and L. tropica type (n=2) [5].…”

“…Greece is considered to be an endemic country for both forms of the disease, with visceral leishmaniasis being the predominant form, endemic in nearly all geographical areas of the country and cutaneous leishmaniasis occurring sporadically [4,5]. L. infantum is the responsible species for the clinical manifestations of visceral leishmaniasis (and some cases of cutaneous leishmaniasis), while the vector species that transfer this type of parasite are Phlebotomus neglectus, P. tobbi and P. perfiliewi [6][7][8][9].…”

“…Anthroponotic cutaneous leishmaniasis is also present in Greece, caused by L. tropica, which is transmitted by P. sergenti [6]. Sporadic cases caused by L. tropica have been diagnosed both in the Greek mainland and in Greek islands [5,10,11].…”

Data collection to characterise the impact of canine leishmaniosis and modelling of the role of animals in spreading Leishmania infantum within the European Union

“…There is evidence that P. papatasi and P. sergenti are specific vectors for L. major and L. tropica respectively (Dostalova and Volf, 2012) and not involved in the transmission of L. infantum. P. similis is also a suspected vector of L. tropica, although the role of this species has yet to be proven (Christodoulou et al, 2012, Ozbel et al, 2011. Figure 32a.…”

Geographical Distribution of MDR1 Expression in Leishmania Isolates, from Greece and Cyprus, Measured by the Rhodamine-123 Efflux Potential of the Isolates, Using Flow Cytometry

“…[1][2][3] Two species of Leishmania (Kinetoplastida: Trypanosomatidae) are the causative agents of the disease, Leishmania infantum (zymodemes MON-1 and MON-98) responsible for visceral (VL) and canine leishmaniasis (CanL) and Leishmania tropica (MON-300, MON-58, and MON-57) responsible for cutaneous leishmaniasis (CL). 1,4 The Republic of Cyprus, on the other hand, presents an unusual situation in which two distinct leishmaniasis transmission cycles run in parallel: in dogs with L. infantum (MON-1 and MON-98) and in humans with the newly introduced Leishmania donovani (MON-37).…”