Usefulness of PCR in the diagnosis of cutaneous leishmaniasis in Tunisia

Abstract

We assessed the efficiency of a PCR method in establishing the diagnosis of cutaneous leishmaniasis (CL) in Tunisian patients. Four hundred and thirty specimens collected passively from patients with cutaneous ulcers suggestive of leishmaniasis attending health centres for diagnosis were included in the study. Dermal scrapings were analysed both by parasitological (examination of Giemsa-stained smears and in vitro cultivation) methods and by a genus-specific PCR detecting a fragment of the 18S rRNA gene. Microscopy revealed amastigotes in 245 samples (57.0%) and in vitro cultivation gave positive results in 88 cases (20.5%), whereas PCR detected Leishmania in 301 samples (70%). The sensitivities inferred from our results were 99.3%, 80.8% and 29% for PCR, microscopic examination and in vitro cultivation, respectively. The different forms of CL in this country are caused by three species of Leishmania and are treated with the same protocol. Of 303 well-documented cases in our study, 99% were probably caused by Leishmania major and 1% by Leishmania infantum. The lack of species-specific diagnosis is not known to affect treatment or prognosis in Tunisia. These data support the incorporation of PCR into diagnostic strategies for CL, particularly in Tunisia.

Use of PCR, IFAT andin vitroculture in the detection ofLeishmania infantuminfection in dogs and evaluation of the prevalence of canine leishmaniasis in a low endemic area in Tunisia

“…Leishmania strains were isolated from three symptomatic dogs (4.5 %) by in vitro culture. Since there is no gold standard for the biological detection of CanL in the presence of a hypersensitive method such as PCR (Lachaud et al, 2002;Chargui et al, 2005), the sensitivity of each technique was defined using the total number of samples positive with at least one method (Table II). Thus, the sensitivities of PCR, IFAT, and in vitro cultivation would be 100 %, 50 % and 18.75 %, respectively.…”

“…Several molecular methods had been developed for the detection of Leishmania (Van Eys et al, 1992;Ashford et al, 1995;Spanakos et al, 2002). Though PCR was already used in the diagnosis of human leishmaniasis in Tunisia (Chargui et al, 2005), this is the first study to investigate the prevalence of CanL with molecular methods compared to serological and parasitological ones. (Dedet et al, 1973).…”

Retrospective Analysis of Leishmaniasis in Central Tunisia: An Update on Emerging Epidemiological Trends

“…An additional advantage of the molecular techniques is their rapidity in that culture of isolates is no more needed. On the other hand, they are much adapted for both diagnostic (PCR, Multiplex PCR, Real time-PCR) and epidemiological (PCR-RFLP, Multiplex PCR, RAPD) purposes (Aoun et al, 2008;Bel Hadj et al, 2002;Ben Said et al, 2006;Chargui et al, 2005;Guerbouj et al, 2007;Guizani et al, 1994aGuizani et al, , 1994bGuizani et al, 2002;Hanafi et al, 2001;Saadi et al, in preparation). In addition, molecular techniques are specific and highly sensitive, allowing identification of parasite species hard to isolate or to maintain in vitro in culture or too scarce to be detected or cultured.…”

“…In addition, specimens from patients with lesions highly evocative of CL but found negative in parasitological examination were addressed for PCR to the laboratory of parasitology of the Faculty of Pharmacy, Monastir, where a molecular biology unit has just been set up. PCR was performed according to Chargui et al, 2005. …”

Identification of Cutaneous Leishmaniasis Agents in Four Geographical Regions of Khuzestan Province Using Nested PCR

“…Different species may have the criteria for the treatment phase (6). The main biological samples used for diagnosis and identification of CL species by PCR are dermal scrapings or biopsies (7,8).…”