**2. Body**

As many other regions of the Mediterranean basin, Tunisia is an endemic focus for both cutaneous and visceral leishmaniases. Each of these two clinical forms has its own epidemiological profile.

#### **2.1. Cutaneous leishmaniases**

Cutaneous leishmaniasis refers to a dermal lesion which appears at the site of the infected sand fly bite. The lesion is usually painless and characterized by a gradual evolution. It firstly appears as a tiny erythema, which then develops into a papule and nodule that can ulcerate within 2 weeks to 6 months. It heals gradually over months or years. Although CL is mild and not life threatening, its disfiguring lesions and scars with altered pigmentation severely affect the social and psychological functioning of the affected individuals causing anxiety, depression, decrease in body satisfaction, and low quality of life [1–3]. The clinical form of CL lesions varies between patients, reflecting different species of parasite, different virulence degree inside the same species or a difference in the immunological status of patients.

The first real documented case of CL in Tunisia date from 1884 in the region of Gafsa, south Tunisia [4, 5]. Indigenous people named it "Habb El Seneh" (sore of a year) or "Bess El Tmeur" (evil of the dates) related to their supposition that the disease is the result of the consumption of dates, sting of palms or the drinking of the water [6]. In 1882, Achard, military physician in Gafsa, gave the infection the name of "Clou de Gafsa" (boil of Gafsa). It was only in 1905 that Nicolle and Cathoire made microbiological analysis of the sore scraping and reported the presence of small oval bodies sized of 4 μm similar to those already described by Wright in 1903 in the oriental sore [7–9]. While Wright proposed the name *Helcosomatropicum* to the reported protozoa, Nicolle as well as other authors named them *Leishmania tropica* [6]. In 1908, Nicolle made the first isolation of the parasite by using the Novy-MacNeal media and inoculated it to the monkey *Macacus sinicus* in order to reproduce the boil of Gafsa [10].

Given that the Gafsa boil was almost observed on the uncovered parts of the body, that the infection was restricted to some cities of Gafsa near water sources, and that patients reported the bite of insects few days before the onset of the lesion, Billet supposed that the infection is transmitted by the bite of the mosquito Pyretophorus chaudoyei [11]. It was only in 1921 that the brothers Sergent proved the transmission of CL by the female sand fly *Phlebotomus papatasi* [12]. Since that date, some studies were conducted on the phlebotomine fauna in some Tunisian regions such Tunis, Zaghouan, Kebili, El Kef, and Makhtar [13–18].

Nevertheless, few were the data available on the incidence of the disease, its geographical distribution and the causative species. Since the 1980s of the last century and by the introduction of both biochemical and molecular tools, many research teams have investigated the epidemiology of CL in many regions of the country focusing on the characterization of the parasite and the identification of both reservoirs and phlebotomine sand fly hosts.

The precise characterization of the parasite circulating in Tunisia started in 1981 using the gold standard method (isoenzymatic analysis) [19]. Since then, many research teams have been involved in the isoenzymatic analysis of *Leishmania* strains. Three taxa were identified to be responsible for the genesis of CL: *Leishmania major, Leishmania infantum*, and *Leishmania killicki*.

#### *2.1.1. Cutaneous leishmaniasis due to Leishmania major*

## *2.1.1.1. History*

to 393,600 and from 1200 to 2000 cases, respectively. In Tunisia (North Africa, South Mediterranean basin), leishmaniases are largely spread causing a serious public health problem. Clinically, both CL and VL are encountered in this region. Nevertheless, the cutaneous form is most prevalent and largely distributed. Visceral leishmaniasis is less prevalent in this region

In Tunisia, leishmaniases are historical. Indeed, the first documented cutaneous case was reported in 1884, while the first VL case was in 1904. Nevertheless, these infectious diseases were stayed neglected for a long period and the epidemiological investigations were scarce. Indeed, an analysis of the published research on leishmaniases in Tunisia over about a century (1884–1980) showed around 20 published items. From the beginning of 1980s of the last century, the number of publications has increased from 5 publications (1981–1985), to 14 publications

The aim of this chapter is to review the history of leishmaniases in Tunisia and to present the new insights into the epidemiological features of this disease. This includes clinical forms,

As many other regions of the Mediterranean basin, Tunisia is an endemic focus for both cutaneous and visceral leishmaniases. Each of these two clinical forms has its own epidemio-

Cutaneous leishmaniasis refers to a dermal lesion which appears at the site of the infected sand fly bite. The lesion is usually painless and characterized by a gradual evolution. It firstly appears as a tiny erythema, which then develops into a papule and nodule that can ulcerate within 2 weeks to 6 months. It heals gradually over months or years. Although CL is mild and not life threatening, its disfiguring lesions and scars with altered pigmentation severely affect the social and psychological functioning of the affected individuals causing anxiety, depression, decrease in body satisfaction, and low quality of life [1–3]. The clinical form of CL lesions varies between patients, reflecting different species of parasite, different virulence degree

The first real documented case of CL in Tunisia date from 1884 in the region of Gafsa, south Tunisia [4, 5]. Indigenous people named it "Habb El Seneh" (sore of a year) or "Bess El Tmeur" (evil of the dates) related to their supposition that the disease is the result of the consumption of dates, sting of palms or the drinking of the water [6]. In 1882, Achard, military physician in Gafsa, gave the infection the name of "Clou de Gafsa" (boil of Gafsa). It was only in 1905 that Nicolle and Cathoire made microbiological analysis of the sore scraping and reported the presence of small oval bodies sized of 4 μm similar to those already described by Wright in 1903 in the oriental sore [7–9]. While Wright proposed the name *Helcosomatropicum* to the

inside the same species or a difference in the immunological status of patients.

(1991–1995), 41 publications (2001–2005), and 85 publications (2011–2015).

with a zoonotic transmission of the causative agent.

118 The Epidemiology and Ecology of Leishmaniasis

transmission cycles, and geographical distribution.

**2. Body**

logical profile.

**2.1. Cutaneous leishmaniases**

Zoonotic cutaneous leishmaniasis (ZCL) due to *L. major* was the first described form of leishmaniasis in Tunisia in 1884 by Deperet and Boinet in the region of Gafsa, southwest Tunisia. Between 1882 and 1893 outbreaks affected different regions of Gafsa and thereby autochthonous cases were recorded each year in this region [6].

In 1908, an extension of the Gafsa boil occurred from the southwest (Gafsa) to the west (Feriana, Kasserine) and southeast (Aioun, Tataouine) regions. Since then, the endemic area did not go beyond Kasserine (Sbeitla) [20]. The Tunisian Centre has been free from ZCL until a major outbreak in 1982 in the Sidi Saad Region (Kairouan) [21, 22]. Then, ZCL has spread to many foci in centre and south of Tunisia [23, 24]. Ruiz Postigo 2010 [25] reported an annual incidence of 2750 new case of ZCL. Nevertheless, the true incidence of this noso-geographical form of CL is underestimated due to multiple factors including the increasing prevalence of the disease, the unrecorded cases, and the expanding areas of endemicity.

#### *2.1.1.2. Clinical forms*

*L. major* is responsible for localized cutaneous lesions. It is always "wet" with a deep ulceration in the center and covered by a crust. It heals slowly leaving ugly scars that severely affect the social and psychological functioning of the affected individuals.

Although *L. major* is the main species responsible for CL in Tunisia, a very limited number of studies have investigated and explored the clinical spectrum of CL caused by this *Leishmania* species. Indeed, the published studies have described the clinical polymorphism of cutaneous leishmaniasis without any isoenzymatic or molecular identification of the causative species. Masmoudi et al. have studied the different clinical aspects of CL in some zoonotic CL foci of the centre and the south of the country. Eleven different clinical forms of ZCL (vegetative, impetiginoid, erysipeloid, necrotic, warty, erythematosquamous, lupoid, sporotrichoid, papulous, eczematoid, and recidivans) were reported but without any identification of the parasite. The ulcerocrusted form was the most predominant form (54.9%) followed by the sporotrichoid and lupoid aspects with 18.6 and 15.7%, respectively [26, 27]. A recent study conducted in 2012 in our laboratory has analyzed the clinical polymorphism of CL due to *L. major* based on the identification of the parasite by PCR sequencing. Thus, 12 clinical forms were noticed. The most common type was the ulcerocrusted form (38.66%) followed by the papulonodular form (16%) and the impetiginous form (13.33%). The ulcerated, mucocutaneous, lupoid, and sporotrichoid forms were less common. The eczematiform, erysipeloid, verrucous, psoriasiform, and pseudotumoral types were represented by a single CL case (1.33%) (unpublished data) (**Figure 1**).

**Figure 1.** Clinical forms of CL lesions caused by *L. major*: (a, b) ulcerocrusted, (c) ulcered, (d) nodular, (e) papulonodular, (f) warty, (g) lupoid, (h) erysipeloid, and (i) vegetative. (Laboratory of Parasitology-Mycology, Faculty of Pharmacy, University of Monastir, Tunisia).

This clinical polymorphism seems to be rather high, which could reflect the complexity of the disease involving several factors related to the parasite (virulence, parasitic load, and the presence of other pathogens), the type and duration of clinical lesion, the geographic location, the disease reservoir, and the host immune status [28, 29].

#### *2.1.1.3. Causative species*

Although *L. major* is the main species responsible for CL in Tunisia, a very limited number of studies have investigated and explored the clinical spectrum of CL caused by this *Leishmania* species. Indeed, the published studies have described the clinical polymorphism of cutaneous leishmaniasis without any isoenzymatic or molecular identification of the causative species. Masmoudi et al. have studied the different clinical aspects of CL in some zoonotic CL foci of the centre and the south of the country. Eleven different clinical forms of ZCL (vegetative, impetiginoid, erysipeloid, necrotic, warty, erythematosquamous, lupoid, sporotrichoid, papulous, eczematoid, and recidivans) were reported but without any identification of the parasite. The ulcerocrusted form was the most predominant form (54.9%) followed by the sporotrichoid and lupoid aspects with 18.6 and 15.7%, respectively [26, 27]. A recent study conducted in 2012 in our laboratory has analyzed the clinical polymorphism of CL due to *L. major* based on the identification of the parasite by PCR sequencing. Thus, 12 clinical forms were noticed. The most common type was the ulcerocrusted form (38.66%) followed by the papulonodular form (16%) and the impetiginous form (13.33%). The ulcerated, mucocutaneous, lupoid, and sporotrichoid forms were less common. The eczematiform, erysipeloid, verrucous, psoriasiform, and pseudotumoral types were represented by a single CL case

**Figure 1.** Clinical forms of CL lesions caused by *L. major*: (a, b) ulcerocrusted, (c) ulcered, (d) nodular, (e) papulonodular, (f) warty, (g) lupoid, (h) erysipeloid, and (i) vegetative. (Laboratory of Parasitology-Mycology, Faculty of Pharmacy,

This clinical polymorphism seems to be rather high, which could reflect the complexity of the disease involving several factors related to the parasite (virulence, parasitic load, and the

(1.33%) (unpublished data) (**Figure 1**).

120 The Epidemiology and Ecology of Leishmaniasis

University of Monastir, Tunisia).

The precise characterization of the parasite circulating in Tunisia foci started only in 1981 [19]. Since then, many research teams have been involved in the isoenzymatic analysis of *Leishmania* strains from ZCL foci. All the strains were identified as *L. major* with the single zymodeme MON-25. This genetic homogeneity gathered with the wide distribution of MON-25 suggests the rapid diffusion of this zymodeme in many Tunisian provinces [23, 24, 30, 31].
