Introduction
Leishmania tropica (Kinetoplastida: Trypanosomatidae) is the
major cause of Anthroponotic Cutaneous Leishmaniasis (ACL) in the Middle
East and some areas of North Africa (Pratlong et al., 2009) andPhlebotomus sergenti Parrot, 1917 (Diptera: Psychodidae) is its
main vector (Guilvard et al., 1991; Schnur et al., 2004).
For a long time, P. sergenti was considered the sole vector ofL. tropica (Al-Zahrani et al., 1988; Guilvard et
al., 1991) however, the vectorial capacity of P. arabicus has
been demonstrated in a focus in northern Israel (Svobodová et
al., 2006), and P. similis is considered a probable vector on
the island of Crete (Ntais et al., 2014). In Morocco, P.
sergenti exhibits a wide ecological plasticity although it is believed
to have a marked preference for semi-arid habitats (Boussaa et
al., 2009), therefore, increased vector surveillance is essential to
prevent and control CL outbreaks. In emerging ACL Moroccan foci,
P. sergenti density varies from 4 to 16 specimens/m2(Ramaoui et al., 2008) with 12.8% to 76.7% of relative
abundance (Boussaa et al., 2009).
The World Health Organization included Morocco as one of the 12
high-burden countries for CL (WHO, 2016). There are three endemicLeishmania species in Morocco: L. major, L. tropica, (both
dermotropic) and L. infantum (mainly viscerotropic).
Leishmania tropica has the widest geographic distribution (Ministry of
Health, Morocco, 2016; Mouttaki et al., 2014) and until 1989, ACL
had been mainly reported in hypoendemic rural foci scattered around the
sub-arid area of central Morocco. Later, ACL emerged in several
northern, central and southern provinces of the country, initially as
new outbreaks and then establishing endemic foci that highlighted the
expansion of this Leishmania species (Ajaoud et al.,2013). The first CL case in Settat province (central Morocco) was
detected in El Borouj locality in 2006, preceding an epidemic outbreak
and then establishing as an endemic area (Amarir et al., 2015;
Gijón-Robles et al., 2018). Currently, El Borouj is the only
active CL focus in the province of Settat (Ministry of Health, Morocco,
2016).
The identification of factors that determine the ACL emergence and
expansion is required to develop better interventions for this largely
neglected disease. We showed that differences in the exposure to theL. tropica vector, reflected by differences in P. sergentidensity in the households, was the only factor associated with CL cases
in El Borouj focus (Gijón-Robles et al. in 2018).
On the other hand, the presence of four mitochondrial (mt) lineages
within P. sergenti has been previously reported (Yahia et al.
2004; Barón et al. 2008; Merino-Espinosa et al., 2016) and three
of them are present in Morocco. Phenotypic differences of biomedical
importance may exist between these mitochondrial lineages, thus
population genetics could help to assess the threat of the geographical
expansion of ACL. Therefore, our aim was to analyse the density and
genetic characteristics of P. sergenti populations in two
Moroccan localities, one endemic and another free of ACL.
Material and methods