A. Bouratbine

Cutaneous Leishmaniasis in North Africa: a review

In North African countries, cutaneous leishmaniasis transmission has been increasing since the 1980s, with a significant increase in the incidence of cases and a spread of the geographical distribution. The disease currently represents a major public health problem with a productivity gap and an impediment for development, which results in dramatic socioeconomic and psycho-sanitary impacts. The incidence is more than thousands of cases every year in Algeria, Libya, Morocco, and Tunisia. In Egypt, only a few dozen cases per year are reported, mainly in the Sinai Peninsula. Three Leishmania species, associated with distinct eco-epidemiological and clinical patterns, are involved, namely Leishmania infantum, L. major, and L. tropica. However, L. major is by far the most frequent in Algeria, Libya, and Tunisia, with more than 90% of the registered cases. It is mainly encountered in rural areas under semi-arid, arid and Saharan climates. Leishmania tropica is more prevalent in Morocco, reaching 30–40% of isolates in some districts. Much data is still missing concerning the risk factors of the infection and the lesion development, as well as vector and reservoir ecology and behavior. The knowledge of such parameters, following multidisciplinary and integrated approaches, is crucial for better management and control of the disease, that also faces a lack of resources and efficient control measures.

Natural Infection of North African Gundi (Ctenodactylus gundi) by Leishmania tropica in the Focus of Cutaneous Leishmaniasis, Southeast Tunisia

North African gundis (Ctenodactylus gundi) were trapped in the Leishmania (L.) tropica focus of cutaneous leishmaniasis, situated in southeast Tunisia and evaluated for Leishmania infection by real-time kinetoplast DNA polymerase chain reaction (PCR). Species identification was performed by internal transcribed spacer one (ITS1)-PCR-restriction fragment length polymorphism (RFLP) and high-resolution melting (HRM) analysis of the 7SL RNA gene. Real-time PCR on blood was positive in 6 of 13 (46.2%) tested gundis. Leishmania tropica was identified in five infected gundis and Leishmania major in one specimen. Alignments of the ITS-1 DNA sequences and 7S-HRM curves analysis indicated that similar genotypes were present in humans, a sandfly, and gundis from the same region suggesting a potential role of this rodent as reservoir host of L. tropica in southeast Tunisia.

Actualités épidémiologiques de la leishmaniose viscérale en Tunisie

OBJECTIVEnVisceral leishmaniasis is an important health problem in Tunisia. The aim of this study was to update the epidemiological and clinical features of the disease.nnnDESIGNnWe performed a retrospective systematic sampling of epidemiological and clinical data collected from the medical records of 1,096 cases of visceral leishmaniasis diagnosed between 1996 and 2006 all over the country.nnnRESULTSnThe mean annual incidence of cases was 99.6 cases/year. The mean annual incidence rate was 1.04 cases/100,000 inhabitants, showing an important increase compared to former studies. As expected, children under 5 years (866 cases) were the most affected with a mean annual incidence rate of 9.6 cases/100,000 (p<0.001). The geographical distribution of cases revealed the spreading of the disease from the Northern parts of the country to the Central and even to Southern ones. Rural cases (65.3%) were significantly more numerous than urban ones (34.7%), p<0.001. The sex ratio was 1.03. The diagnostic delay (average of 54 days) was considerably shortened during the study period compared to previous reports, and explains the decrease of the lethality rate (2.9%).nnnCONCLUSIONSnVisceral leishmaniasis has been present in central Tunisia since the early 1990 s. Its incidence and the distribution area have increased. This evolution is probably linked to the development of irrigation and agriculture favorable to the multiplication of vector sandflies and dogs reservoirs of Leishmania infantum.

Données épidémiologiques sur la leishmaniose viscérale infantile en Tunisie en 1993

Summary In order to list all cases of human visceral leishmaiasisdiagnosed in Tunisia during 1993, a retrospective study, based on the epidemiological record of the ministry of health and investigations in the most important hospitals on the north, was performed. 153 cases were reported essentially in children of 1 to 3 years of age (64%). The cases were distributed mainly in the north and the center of Tunisia. This study confirmed the increase of the incidence of visceral leishmaniasis and its geographical extention to the center of the country these last years.

Phlebotomus (Paraphlebotomus) riouxi: a synonym of Phlebotomus chabaudi without any proven vectorial role in Tunisia and Algeria.

Phlebotomus (Paraphlebotomus) riouxi Depaquit, Léger & Killick‐Kendrick (Diptera: Psychodidae) was described as a typological species based on a few morphological characters distinguishing it from Phlebotomus (Paraphlebotomus) chabaudi Croset, Abonnenc & Rioux. The naming of P.u2009riouxi coincided with its incrimination as a rural vector of Leishmania tropica Wright (junior synonym: Leishmania killicki Rioux, Lanotte & Pratlong) in Tataouine governorate, an arid region of southern Tunisia. The current report finds insufficient evidence to incriminate either phlebotomine sandfly as a vector of L.u2009tropica in North Africa. Phlebotomus riouxi was found not to have the characteristics of a phylogenetic or biological species, and therefore it is synonymized with P.u2009chabaudi. Both taxa were recorded together for the first time in Tunisia, in Tataouine, where three of 12 males showed intermediate morphology and both sexes of each taxon were not characterized by specific lineages of the nuclear gene elongation factor‐1α or the mitochondrial gene cytochrome b, for which a long 3′ terminal fragment is recommended for phlebotomine phylogenetics. This case study indicates that the eco‐epidemiology of leishmaniasis should focus more on identifying key components of vectorial transmission that are susceptible to interventions for disease control, rather than on defining sibling species of vectors.

Fréquent d'isolement des oocystes de Cryptosporidium dans les selles diarrhéiques d'enfants tunisiens

Summary Tunisian children were screened for Cryptosporidium oocysts using the classical Ziehl Nielsen modified technique. 112 stool specimens from immunocompetent patients and 20 stool specimens from patients with congenital immunodeficiency were examined. 9 out of the 112 (8%) immunocompetent children and 3 out of the 20 (15%) immunodeficient ones (p=0.26), were carriers. This study demonstrated the high rate of intestinal Cryptosporidium carriage in both immunocompetent and immunodeficient children, in Tunisia. A case control study including investigation of other pathogens (viruses, bacteria) is necessary to better estimate pathogenicity of Cryptosporidium species .

Larval habitats characterization and species composition of Anopheles mosquitoes in Tunisia, with particular attention to Anopheles maculipennis complex.

In Tunisia, malaria transmission has been interrupted since 1980. However, the growing number of imported cases and the persistence of putative vectors stress the need for additional studies to assess the risk of malaria resurgence in the country. In this context, our aim was to update entomological data concerning Anopheles mosquitoes in Tunisia. From May to October of 2012, mosquito larval specimens were captured in 60 breeding sites throughout the country and identified at the species level using morphological keys. Environmental parameters of the larval habitats were recorded. Specimens belonging to the An. maculipennis complex were further identified to sibling species by the ribosomal deoxyribonucleic acid (rDNA)-internal transcribed spacer 2 (ITS2) polymerase chain reaction (PCR) technique. In total, 647 Anopheles larvae were collected from 25 habitats. Four species, including An. labranchiae, An. multicolor, An. sergentii, and An. algeriensis, were morphologically identified. rDNA-ITS2 PCR confirmed that An. labranchiae is the sole member of the An. maculipennis complex in Tunisia. An. labranchiae was collected throughout northern and central Tunisia, and it was highly associated with rural habitat, clear water, and sunlight areas. Larvae of An. multicolor and An. sergentii existed separately or together and were collected in southern Tunisia in similar types of breeding places.

Identification of soluble and membrane antigenic markers of acquired toxoplasmosis by immunoblot

The overall performance of quantitative assays in the detection of anti‐Toxoplasma IgG is satisfactory, but discrepancies between assays are not uncommon especially when IgG concentrations are close to the limit of detection of the tests. The purpose of our study was to identify soluble and membrane antigens extracted from Toxoplasma gondii tachyzoites by immunoblot to select the most relevant antigenic bands to be used for qualitative serodiagnosis of acquired toxoplasmosis. We selected five relevant bands (98, 36, 33, 32 and 21 kDa) with soluble antigens and four relevant bands (42, 35, 32 and 30 kDa) with membrane antigens which gave high sensitivity and/or specificity in immunodiagnosis. The association on the same blot of at least three of the five relevant bands in the soluble antigen immunoblot showed the highest sensitivity/specificity (97·4%/99·0%, respectively). Our results indicate that immunoblot using soluble tachyzoite extract with simultaneous detection of at least three of the five bands (98, 36, 33, 32 and 21 kDa) represents a valuable test for serodiagnosis of acquired toxoplasmosis and should be further evaluated as a confirmatory test for sera which give discrepant results in quantitative assays.