[Contribution of Real-Time PCR in the Diagnosis of Cutaneous Leishmaniasis: Experience of the Pasteur Institute of Tunis]

The aim of this study was to assess the performance of real-time PCR (qPCR) in the diagnosis of cutaneous leishmaniasis (CL). Culture, direct microscopic examination (DE) and qPCR were performed on dermal exudate samples collected from 235 confirmed CL cases. The qPCR was found to be more sensitive than other diagnostic techniques and was able to correct the diagnosis in 49 patients (20.9%) with negative dermal smears. Median parasitic load (PL) of the 49 dermal exudates with negative DE was lower than that of positive ones in microscopy. This suggests that PL likely impact the sensitivity of microscopy. On the other hand, qPCR was performed on DNA extracts of scraped products collected from the 23 out of 49 archived negative Giemsa-stained slides and showed 11 positive. Parasitic loads in the latter smears were lower than those in corresponding exudates. The results highlight qPCR relevance for the diagnosis of CL and recommend its use directly on dermal exudates collected from CL lesions.

[Epidemiology of Cutaneous Leishmaniasis in West Africa: a Systematic Review]

Cutaneous leishmaniasis (CL) has been described in West Africa (WA) since the beginning of the 20th century. The incidence of cases has markedly increased during the last decades in several countries of the region. Despite that, data remain scarce and fragmentary. The current incidence and geographic distribution of the disease as well as the involved vectors and reservoirs remain poorly documented. The objective of this review was to collect and analyze available data about CL in WA in order to improve the management of cases and the control of the disease transmission. A systematic literature review was performed using the Pubmed, Google Scholar and Hinari databases. Publications focusing on epidemiological aspects of CL, involved parasite species, sand flies and potential reservoir hosts were searched without any restrictions. Unpublished studies were extracted from Google. Manuscripts without full text or summary available were excluded as well as those whose summaries did not contain any usable data. One hundred and fifteen studies were recorded. Among them, 93 filled selection criteria. CL has been reported in 10 West African countries with outbreaks described in five countries. Burkina Faso, where the average incidence of the disease is around 928 cases per year, and Ghana seem to be the most affected. Cases have been confirmed in the majority of studies by microscopy sometimes associated with culture or histology. The exposure rate to Leishmania infection based on leishmanin skin test was relatively high with an overall average of 30.2%. Leishmania major was the only species identified with a predominance of MON-74 (62%) and MON-26 (30.6%) zymodemes. Phlebotomus duboscqi is retained as the vector whereas Sergentomyia darlingi and Sergentomyia ingrami were found naturally infected. Rodents including Arvicanthis niloticus, Gerbilliscus gambiana and Mastomys spp. are reported as the main reservoir hosts. Additional studies are needed to better characterize CL in WA in order to optimize the management of cases and to organize the control of the disease transmission.

[Epidemiology of Cutaneous Leishmaniasis in Algeria through Molecular Characterization]

Three distinct noso-epidemiological cutaneous leishmaniasis (LC) entities coexist in Algeria: the so-called sporadic form of the North (LCN), the zoonotic form (LCZ) and the chronic form (LCC). The precise identification of the parasitic species involved in each of the forms makes it possible to specify the geographical distribution of each of the forms raised, to distinguish their clinical aspects, to guide the therapeutic behaviors and to adapt the control programs. Ninety-seven (97) human strains from 97 cases of LC were subjected to molecular characterization by PCR-ITS1 followed by sequencing of this inter-gene space. Our results confirm the endemicity of the three forms. The LCN, caused by L. infantum (17 isolates/97 i.e. 17.52%) is limited to the North of the country mainly (16 isolates/17). Its geographical distribution is superimposable to that of visceral leishmaniasis with an extension more and more reported in previously unaffected areas, such as the regions of Tlemcen and Oran in the West, Setif, Annaba and Collo in the East. The LCZ, due to L. major (70 strains/97 i.e. 72.16%), remains the dominant form in the arid and semi-arid zones (47 strains/70) with a progression towards the North (20/70 strains). Indeed, long confined to the Sahara, it shows a geographical extension outside its historic homes of Biskra and Abadla. This form is progressing dangerously towards the highlands and the steppe regions of the country. The most interesting fact was the identification of L. tropica for the first time in North-Central and North-West Algeria in Algerian patients who had never left the national territory. Out of the 10 strains of L. tropica identified, 8 belonged to patients of Syrian origin and 2 to Algerian patients. L. tropica was reported for the first time in 2008 in 6 patients living in Constantine (North-East Algeria) and in 2017, still in the North-East of the country, in Annaba. The observation of L. tropica in the North and Northeast center of the country, where L. infantum and L. major coexist, suggests changes in the epidemiology of cutaneous leishmaniasis in Algeria, which highlights the interest of more investigations to better understand the transmission cycle of the different entities.

[Pediatric cutaneous leishmaniasis in Morocco: Clinical and epidemiological features]

INTRODUCTION

Cutaneous leishmaniasis (CL) is a parasitic disease caused by a flagellate protozoa of the genus Leishmania and is a public health problem throughout the world. In Morocco, CL may be sporadic or endemic depending on the species of Leishmania and the region involved. Casablanca is a non-endemic city but many children with CL come from elsewhere in the country. The aim of our study is to describe the clinical and epidemiological particularities of CL diagnosed in children at the Casablanca University Hospital.

MATERIALS AND METHODS

A cross-sectional study was conducted between 2010 and 2016. All patients with one or more skin lesions suggestive of CL underwent parasitological and molecular investigation. Epidemiological and clinical data from patients with positive genotyping were collected and analyzed. A comparative study was made of epidemiological and clinical variables between children and adults and between different species found in children.

RESULTS

One hundred and six cases of CL were diagnosed, of which 40 in children (37.7%): 29 due to L. tropica (72.5%), 7 due to L. major (17.5%), and 4 due to L. infantum (10%). CL caused by L. tropica was significantly associated with children (P=0.009) and was distinguished by the predominance of the nodular form (P=0.04) and a facial location (P=0.007). Compared to adults, childhood CL lesions were characterized by their small size (P=0.001) and facial location (P=0.003). Children were treated mainly with pentavalent antimonials, with good safety and clinical response.

CONCLUSION

In our series, CL due to L. tropica was predominant in children, reflecting the epidemic nature and wide geographical distribution of this species in Morocco. CL due to L. tropica was significantly associated with facial location and nodular form in children.

[Cutaneous leishmaniasis of the vermilion border of the upper lip extending to the oral mucosa]

BACKGROUND

Cutaneous leishmaniasis is endemic in Morocco. Mucosal involvement is rare. We report a case in Morocco of cutaneous leishmaniasis of the vermilion border of the upper lip extending to the oral mucosa due to Leishmania tropica.

PATIENTS AND METHODS

A 15-year-old girl was seen with 2 ulcerated lesions, present for 4 months, situated on the left cheek and vermilion border and extending to the oral mucosa. The diagnosis of leishmaniasis was confirmed by direct examination revealing high numbers of Leishmania amastigotes. Culture of the offending organism in NNN medium and isoenzymatic characterization resulted in identification of L. tropica. Treatment with meglumine antimoniate (Glucantime) was ineffective. The outcome was good after treatment with fluconazole.

CONCLUSION

In Morocco, cutaneous leishmaniasis with mucosal involvement is rare, and usually develops as a complication of cutaneous leishmaniasis via direct extension.

[Cutaneous leishmaniasis]

Cutaneous leishmaniasis is a parasitic infection caused by a flagellated parasite belonging to the genus Leishmania. In most cases, it is a zoonotic disease transmitted via a bite by bloodsucking sand-flies of the genus Phlebotomus. The disease reservoirs consist of wild or semi-domesticated animals, generally rodents or dogs. The disease itself is distributed extensively worldwide in the Americas, Asia, Europe and Africa. Epidemiology is affected by environmental, migratory and climatic factors. Identification of the different types of leishmaniasis is based chiefly on the biochemical characteristics (isoenzymes) on which their classification is based. The offending parasites are dimorphic intracellular organisms within the phagosome of the host's immune cells, and a single-cell flagellated protozoan with a kinetoplast contained in the gut of the vector and in culture. Three major clinical forms are seen: cutaneous leishmaniasis, mucosal leishmaniasis and visceral leishmaniasis. The clinical presentation depends on factors associated with the virulence of the parasite, with individual immune response and with the site of lesions. Although each type of leishmaniasis may have its own specific cutaneous signs and endemic regions, the most common presentations are crusted, ulcerated nodules and plaques. The natural history of leishmaniasis must also be considered when formulating therapeutic strategies. Cutaneous leishmaniasis resolves spontaneously within between one month and six years. While numerous therapeutic options have been considered in recent decades, very few have shown proven efficacy and safety. Antimony compounds administered either directly to the lesion or parenterally remain the standard treatment and their toxicity calls for vigilance and monitoring of therapy.

[When to ask for a skin biopsy in a patient with leg ulcer? Retrospective study of 143 consecutive biopsies]

OBJECTIVE

A vascular cause is found in around 85% of leg ulcer patients, but non-vascular causes are also observed. Their diagnosis is based on a set of clinical arguments and skin biopsy with histological analysis. The aim of this study was to analyze the results of these biopsies and to find common criteria for ulcers whose skin biopsies had led to the diagnosis of a non-vascular ulcer.

MATERIAL AND METHOD

A retrospective study was carried out on the analysis of 143 skin biopsies of leg ulcers. The reasons for the biopsy were mainly atypical clinical signs and/or the lack of improvement in care after 6 months, as advocated by the French health authorities.

RESULTS

The skin biopsies led to a diagnosis of non-vascular ulcer in 4.9% of cases (7/143), including skin cancer (n=5, 3.5%), cutaneous leishmaniasis (n=1, 0.7%) and Pyoderma gangrenosum (n=1, 0.7%). The univariate statistical analysis revealed that an elevated rim and abnormal excessive granulation tissue were significantly more frequently found in these ulcers. All patients with a positive skin biopsy had associated vascular involvement.

CONCLUSION

This study found a 5% rate of non-vascular causes of ulcers, mainly skin cancer. Elevated rims and abnormal excessive granulation tissue were the unusual features most commonly found in these ulcers. All patients whose skin biopsy revealed a non-vascular cause had associated vascular involvement. This information confirms the need to perform a skin biopsy, even in the presence of a vascular disease.

[Cutaneous leishmaniasis due to Leishmania infantum associated with HIV]

BACKGROUND

In Senegal, reported cases of cutaneous leishmaniasis are often due to Leishmania major. Immunosuppression related to HIV infection contributes to the emergence of leishmaniasis in humans and to cutaneous localization of viscerotropic species. We report the first observed case in Senegal of opportunistic cutaneous leishmaniasis due to Leishmania infantum associated with HIV.

PATIENTS AND METHODS

A 5-year-old boy presented crusted ulcerative lesions of the scalp and left forearm, together with axillary and cervical lymphadenopathy present for two months. Direct parasitological examination of the scalp and arm lesions, coupled with liquid aspiration of lymph nodes and bone marrow, enabled identification of amastigote forms of Leishmania. Polymerase chain reaction performed on skin, lymph node and bone marrow biopsy samples allowed identification of L. infantum. The child was positive for HIV1. Treatment of HIV infection and leishmaniasis resulted in clinical improvement.

DISCUSSION

Co-infection with cutaneous leishmaniasis due to L. infantum and HIV is a complex combination in terms of the related therapeutic issues. The clinical and laboratory outcomes depend on restoration of immunity and on the efficacy, safety and availability of anti-leishmaniasis drugs.

[Ankle and foot ulcerations in a diabetic patient revealing cutaneous leishmaniasis]

INTRODUCTION

Cutaneous leishmaniasis is a parasitic disease that typically manifests as a typical crusted ulcer called the oriental sore. Its localization on the lower limbs can be mistaken for a leg ulcer.

CASE REPORT

An 81-year-old male, native of Algeria, with type 2 diabetes, arterial hypertension and arteriopathy developed a chronic ulceration of the right ankle and foot compatible with the diagnosis of infectious diabetic foot. Non-improvement with antibiotics, local treatment and rest, and the absence of any hemodynamic arteriopathy led to skin biopsies. Polymerase chain reaction performed on biopsy samples for parasitological investigations yielded the diagnosis of cutaneous leishmaniasis due to Leishmania major. Complete healing was obtained with topical care alone, the patient having declined an etiological treatment.

DISCUSSION

Cutaneous leishmaniasis is one of the rare infectious etiologies of chronic leg ulcers. Several therapeutic options, including abstention, can be proposed.