Cutaneous leishmaniasis in Tunisia: results of the iso-enzymatic characterization of 71 strains

Three clinico-epidemiological forms of cutaneous leishmaniasis (CL) exist in Tunisia: zoonotic cutaneous leishmaniasis (ZCL; epidemic in the centre and the south-west); sporadic cutaneous leishmaniasis (SCL; found in the north); and chronic cutaneous leishmaniasis (CCL; originally described from Tataouine, in the south-east). As few isolates of Leishmania from Tunisian cases of CL have been typed, isolates were collected, using NNN medium, from 71 such cases. Most (59) of the cases investigated came from the north of the country, including 16 from Sidi Bourouis, where there was an epidemic outbreak of SCL in early 2001; the other 12 cases were natives of the centre or south of the country. The 71 strains were then characterized, at the Centre National de Référence des Leishmania, in Montpellier, France, by iso-enzyme analysis. This revealed four zymodemes: two of L. infantum and one each of L. major and L. killicki. The MON-1 zymodeme of L. infantum, which is more usually associated with visceral leishmaniasis, was recovered from seven of the cases, including six natives of Sidi Bourouis. The MON-24 zymodeme of this species, which appears to be responsible for the SCL, was isolated from 48 cases, all of whom lived in the north of the country. Another 15 cases (nine from the centre, four from the north, and two from the south-east of the country) were found to be harbouring L. major MON-25, the zymodeme usually causing ZCL. Only a single isolate of L. killicki was made; this was of the MON-8 zymodeme responsible for the CCL, and came from a native of Gafsa, in the south-west. Six of the cases investigated (five infected with L. infantum MON-24 and one with L. major MON-25) showed involvement of their nasal and labial mucosae. These results increase the number of strains typed from Tunisian cases of CL more than four-fold, and should help to elucidate the geographical distribution and epidemiology of the various forms of the disease.

Surveillance of leishmaniases in France, 1999 to 2012

Leishmaniasis is endemic in the south of France, where autochthonous disease is caused by Leishmania infantum, and affects both humans and dogs. The prevalence of canine leishmaniasis is between 3 and 66% depending on the region and the methods used. Human leishmaniases are also imported into France, mainly from French Guiana and North Africa. The surveillance of autochthonous and imported human leishmaniases is based on passive notification to the National Reference Centre for Leishmaniases (NRCL) created in 1998. Between 1999 and 2012, 317 autochthonous and 1,154 imported cases were notified to the NRCL. The average number of autochthonous cases notified per year was 22.6, mainly cases of visceral leishmaniasis (84.5%). All cases were infected in the south of France. Leishmaniasis incidence is 0.22 per 100,000 inhabitants in the endemic area. Imported cases were more frequent (annual mean of 82.4 cases) and consisted predominantly in cutaneous leishmaniasis (CL) cases (91%), essentially L. major CL imported from Maghreb and Sub-Saharan Africa, and L. guyanensis CL from French Guiana. This national notification system allowed a better understanding of the incidence and distribution of the disease; it is also useful to assess the temporal-spatial evolution of the disease in France, which appears relatively stable.

Surveillance of leishmaniases in France, 1999 to 2012

Leishmaniasis is endemic in the south of France, where autochthonous disease is caused by Leishmania infantum, and affects both humans and dogs. The prevalence of canine leishmaniasis is between 3 and 66% depending on the region and the methods used. Human leishmaniases are also imported into France, mainly from French Guiana and North Africa. The surveillance of autochthonous and imported human leishmaniases is based on passive notification to the National Reference Centre for Leishmaniases (NRCL) created in 1998. Between 1999 and 2012, 317 autochthonous and 1,154 imported cases were notified to the NRCL. The average number of autochthonous cases notified per year was 22.6, mainly cases of visceral leishmaniasis (84.5%). All cases were infected in the south of France. Leishmaniasis incidence is 0.22 per 100,000 inhabitants in the endemic area. Imported cases were more frequent (annual mean of 82.4 cases) and consisted predominantly in cutaneous leishmaniasis (CL) cases (91%), essentially L. major CL imported from Maghreb and Sub-Saharan Africa, and L. guyanensis CL from French Guiana. This national notification system allowed a better understanding of the incidence and distribution of the disease; it is also useful to assess the temporal-spatial evolution of the disease in France, which appears relatively stable.

[Conjonctival human myiasis by Oestrus ovis in Northern Africa]

Following the publication of a paper on Conjonctival human myiasis by Oestrus ovis in southern Tunisia by Anane and Ben Hssine (Bull Soc Pathol Exot (2010) 103(5):299-304), the author reminds that the discovery of this disease was made in Algeria, in 1907 by Edmond and Etienne Sergent.

[Georges Moustardier, physician of the Colonial Health Service and Overseas Pasteur Institutes and university professor]

The purpose of this article is to provide a step-by-step description of Georges Moustardier's career. After completing studies at the Ecole Principale du Service de Santé de la Marine et des Colonies in Bordeaux, and at the Ecole d'Application du Service de Santé des Troupes Coloniales in Marseille, he was deployed to Indochina where he served as physician first at the Poulo Condor penitentiary from (1929 to 1930) and then in Cambodia from (1931 to 32). In 1933, he returned to Paris where he followed lectures on Microbiology at the Institut Pasteur, in Paris. He was then assigned to the Institut Pasteur in Madagascar from 1931 to 1932. From 1939 to 1944, he was Head of the General Hospital in Brazzaville, Congo and Director of the Medical School in French Equatorial Africa. He retired from the army in 1946. From 1949 to 1972, he held an academic position as Professor of Bacteriology at the Bordeaux School of Medicine.

Canine Leishmania infantum enzymatic polymorphism: a review including 1023 strains of the Mediterranean area, with special reference to Algeria

This bibliographic review reports the isoenzyme polymorphism of 1023 Leishmania infantum strains isolated from dogs that have been characterized by multilocus enzyme electrophoresis in the Leishmania Reference Centre of Montpellier, or in other laboratories, to which this typification technique has already been transferred. Between 1981 and 2010, a total of 12 zymodemes were identified around the Mediterranean basin: MON-1, MON-24, MON-34, MON-72, MON-77, MON-80, MON-98, MON-105, MON-108, MON-199, MON-199 var NP1130 and MON-281, of which 6 were present in Algeria. The zymodeme MON-1 was predominant (86.5% of the strains). The dog was confirmed as the main reservoir of L. infantum MON-1, while the reservoir of the other zymodemes has not yet been identified. The enzymatic polymorphism is relatively high in Algeria and in Spain in contrast to other Mediterranean countries. The reasons for this polymorphism are discussed.

Increase in the prevalence of canine leishmaniasis in urban Algiers (Algeria) following the 2003 earthquake

Between 2005 and 2008, a serological survey for leishmanial infection was conducted among dogs from urban and peri-urban Algiers, with the focus on the new, densely populated areas that were built after the 2003 earthquake. Serum samples were collected from 1810 animals and tested for the presence of leishmanial antibodies by IFAT, ELISA and western blotting. The overall seroprevalence recorded was 25.1%. Of the seropositive dogs, 58.8% showed no clinical signs of the disease, 25.8% had a few, minor signs and the remaining 15.4% showed more severe illness. The major clinical signs of infection were weight loss, skin lesions and lymphadenopathy. Although seropositive dogs were found in all of the boroughs (daïras) of Algiers, seroprevalences were highest in the western part of the city (i.e. in the boroughs of Bouzaréah, Chéraga and Zéralda), ranging from 23.0% to 44.5%. Statistical analysis showed a relationship between seropositivity for leishmanial infection and the dog's age and lifestyle (i.e. whether the dog lived outside and/or in areas with dense vegetation). Only two zymodemes were identified amongst the 50 isolates investigated: MON-1 (88%) and MON-281 (12%). The latter zymodeme has not been previously found in Algeria, sandflies or dogs.

The Sergent brothers and the antimalarial campaigns in Algeria (1902-1948)

Edmond and Etienne Sergent, "the Sergent brothers", were both born in Algeria. They both studied medicine at the Algiers Medical School and then followed the Course of Microbiology of Emile Roux at the Institut Pasteur in Paris (1899-1900). From 1900, they were put in charge of a permanent mission aimed at antimalarial control in Algeria, which was supervised by the Institut Pasteur. The first campaign was carried out during the summer of 1902 at a station of the East Algerian Railway Company. The success of this mission lead to the creation of the Antimalaric Department of Algeria in 1904, which was directed by Etienne Sergent for the duration his life. This antimalarial programme was progressively extended to many other locations. The programme was optimized between 1927 and 1947, in the experimental field study of the Ouled Mendil Marsh, where global environmental measures and drainage lead to settlement of farms, the families of which did not suffered from malaria. At a time when neither insecticides nor synthetic antimalarial drug existed, antimalarial control measures that were developed tended to target human reservoirs and the mosquito vectors. The extension of the programme across the Algerian territory lead to a decrease of both malaria endemicity and extension of affected areas.

[Cutaneous leishmaniasis caused by Leishmania infantum MON-24 in Tunisia: extension of the focus to the center of the country]

Three clinico-epidemiological forms of cutaneous leishmaniasis (CL) were described in Tunisia: the zoonotic CL (ZCL) epidemic which occurred in the centre of the country caused by Leishmania major MON-25, the chronic CL (CCL) In the south-east of the country caused by Leishmania killicki MON-8 and the sporadic CL In the North (SCL) caused by Leishmania infantum MON-24. The latter form, described in 1991, prevails in northern Tunisia with approximately thirty cases per year. Its vector, unknown for a long time could be according to the last publications, Phlebotomus perfiliewi or Phlebotomus langeroni; however, its reservoir remains unknown until now. The systematic isoenzymatic characterization permits to identify a great number of strains improving then knowledge on the eco-epidemiology of the disease. Indeed, changes were noted in the geographical distribution of these clinical forms: extension of the ZCL to the North and South, extension of the CCL to North and the SCL to the centre. We report in this note the first mention of L. infantum MON-24 in the two provinces of the centre of Tunisia: Kairouan and Sidi Bouzid, confirming the extension of the SCL to the Centre.

[Cutaneous leishmaniases in French Guiana]

Cutaneous leishmaniases are endemic over the entire territory of French Guiana. At least 5 distinct Leishmania species coexist in the sylvatic ecotopes of this French territory. The present paper checks the advances in the ecological research field during the past 5 years. The current epidemiological situation and trends are detailed successively Links between the recrudescence of leishmaniases and gold-mining are highlighted. The potential adaptation of the pathogenic complexes to the newly anthropized habitats is also described.

First detection and genetic typing of Leishmania infantum MON-24 in a dog from the Moroccan Mediterranean coast: genetic diversity of MON-24

As in the countries edging the Mediterranean basin, Leishmania infantum zymodeme MON-1 is the main causative agent of visceral leishmaniasis in Morocco, where visceral leishmaniasis is most active in the North-Eastern slopes of the Rif mountains. The dog was confirmed to be the main reservoir of L. infantum MON-1, while the reservoir of L. infantum MON-24 causative agent of both infantile visceral leishmaniasis and cutaneous leishmaniasis has not yet been identified. Here we report the first detection of this last zymodeme in a dog in Morocco. The isolated strain was first identified by the use of genotyping markers and confirmed by isoenzyme analysis. Phylogenetic analysis with the use of concatenated sequences from 26 Leishmania donovani complex strains revealed strong geographical correlation with the MON-24 strain from Morocco clustering with other East African strains whereas two other MON-24 strains clustered with L. infantum strains. Interestingly, the two distinct populations of MON-24 identified with the use of genotyping markers cannot be distinguished by multilocus enzyme electrophoresis.

[Edmond Sergent's discoveries on the vectorial transmission of agents of human and animal infectious diseases]

Edmond SERGENT has been head of the Institut Pasteur in Algeria from 1910 to 1963. During these years, he carried out an impressive scientific production and studied a lot of agents responsible for human, animal and plant diseases. In the field of vectorial transmission of infectious diseases, he made two essential discoveries: the transmission of cosmopolitan relapsing fever by human body louse in 1908, a year before Charles NICOLLE discovered the transmission of the classical exanthematic typhus by the same insect, and the transmission of cutaneous leishmaniasis by the phlebotomine sandfly. Moreover he made other discoveries in similar fields, such as the transmission of dromedary trypanosomiasis by Tabanids and later by stomoxys calcitrans, or the transmission of the pigeon Haemoproteus by Lynchia maura. Finally he described the transmission of Theileria dispar (now T. annulata) by the tick Hyalomma mauritanicum (1928).

Leishmaniasis in Portugal: enzyme polymorphism of Leishmania infantum based on the identification of 213 strains

This study reports isoenzyme polymorphism of Leishmania strains isolated in different regions of Portugal between 1982 and 2005. A total of 213 strains were obtained from cases of visceral and cutaneous leishmaniasis isolated from immunocompetent patients (adults and children) and immunocompromised adults, as well as from dogs and sandflies. Four zymodemes were identified: MON-1, MON-24, MON-29 and MON-80. Zymodeme MON-1 was identified in 96.7% of the strains, predominating in both immunocompetent and immunocompromised human patients, and it was the only zymodeme isolated from dogs. Isoenzyme diversity in HIV-infected patients was higher than in the immunocompetent group, in which all the strains from visceral leishmaniasis were MON-1. The domestic dog was confirmed as the reservoir host of zoonotic leishmaniasis in Portugal and Phlebotomus perniciosus and Phlebotomus ariasi as vectors. The overall low enzyme polymorphism observed in the Portuguese foci contrasts with the neighbouring foci in Spain.

Stages in the identification of phlebotomine sandflies as vectors of leishmaniases and other tropical diseases

The first time the term phlebotomine sandfly was used, was by an Italian naturalist, Philippo Bonanni, in 1691. The first description though was made by another Italian naturalist, Scopoli, under the name Bibio papatasi. The name of the genus, Phlebotomus, was not given until 1840 by Rondani and Berté. The first description of an American phlebotomine sandfly was made by Coquillett, in 1907. The discovery of the three first sandflies in Brazil is the work of Lutz and Neiva, in 1912. From this date till 1921, 11 new species were described in this country and since then their number is still increasing and has reached 229 at this time. The history of the identification of phlebotomine sandflies as vectors, in Brazil like elsewhere in South America, is as complex as the one of the leishmaniases themselves, to which it is closely linked. The knowledge of cutaneous leishmaniasis in Brazil goes back to 1909, when Gaspar Vianna proposed to name the parasites that were found Leishmania braziliensis (1911). Following the observation of the Sergent brothers on the role of Phlebotomus papatasi in the transmission of cutaneous leishmaniasis in Algeria (1921), it became obvious that phlebotomine sandflies should be incriminated as vectors of cutaneous leishmaniasis in the Americas and that proof should be sought of their role. This is what various Brazilian scientists have done, like Aragão in 1922, Pessôa and Pestana in 1940. In the 1950s evidence was produced that the different forms of leishmaniasis that infest the American continent were caused by distinct species of the parasite. Subsequently, successful searches for the specific vectors were carried out. A by-product of the epidemiological studies of leishmaniases has been the discovery of the transmission of other parasites of the Trypanosomatid families (Crithidia, Endotrypanum, Trypanosoma). More recently, since the 1960s, a large number of viruses amongst which Rhabdoviridae, Bunyaviridae and Reoviridae, have been isolated from phlebotomine sandflies. Between 1961 and 1995, 69 serotypes of different arboviruses were obtained from different zones of Brazilian Amazonia.

Anthroponotic cutaneous leishmaniasis in Tunisia: Presence of Leishmania killicki outside its original focus of Tataouine

The first three documented cases of anthroponotic cutaneous leishmaniasis due to Leishmania killicki are reported from locations outside the original focus of Tataouine in southeast Tunisia. Three strains were isolated from three patients from Gafsa, Sidi Bouzid and Seliana indicating an extension of this parasite's range towards the centre and the north of Tunisia.

Comparative study of cutaneous leishmaniasis in human immunodeficiency virus (HIV)-infected patients and non-HIV-infected patients in French Guiana

BACKGROUND

Few data are available on cutaneous leishmaniasis caused by dermotropic species in human immunodeficiency virus (HIV)-infected patients.

OBJECTIVES

To describe nine cases of cutaneous leishmaniasis in HIV+ patients and to compare their clinical features and their response to treatment with those of HIV- patients with the forms of leishmaniasis commonly found in French Guiana.

METHODS

A case-control study was carried out between July 1994 and December 2000 in French Guiana. We compared the following variables in nine HIV-infected patients with leishmaniasis and 27 matched controls: clinical type of leishmaniasis, number of lesions, presence of lymphangitis and adenopathy, the rate of recovery after treatment, and recurrence or reinfection.

RESULTS

Eight of the HIV-infected patients had localized cutaneous leishmaniasis and one had mucocutaneous leishmaniasis. All of the controls had localized cutaneous leishmaniasis. Leishmania guyanensis was the only species isolated from HIV-infected subjects. HIV-Leishmania coinfected patients had a higher rate of recurrence or reinfection (P < 0.02) and a lower rate of recovery after one treatment cycle with pentamidine (P < 0.02) than did HIV- subjects. The CD4+ lymphocyte counts exceeded 200 mm(-3) in all HIV+ patients at the time of the diagnosis with leishmaniasis.

CONCLUSIONS

In French Guiana, cutaneous leishmaniasis in moderately immunosuppressed HIV-infected subjects (> 200 CD4+ T cells mm(-3)) is characterized by a higher rate of recurrence or reinfection and is more difficult to treat than that in HIV- subjects.

First identification of the causative agent of visceral leishmaniasis in Djibouti: Leishmania donovani

The first identification of the Leishmania species responsible for visceral leishmaniasis in Djibouti is described. Four strains, obtained from three autochthonous cases, were identified by starch-gel electrophoresis and iso-enzyme analysis of 15 enzymatic systems. The strains were found to belong to two newly recognized zymodemes of L. donovani: MON-268 and MON-287.

Identification of Leishmania strains from Jordan

The enzymatic profiles of 22 Jordanian Leishmania isolates obtained from humans, Psammomys obesus and Phlebotomus papatasi were determined using starch-gel electrophoresis and a 15-enzyme system. Thirteen of the isolates were typed as L. major and the other nine, all from Mediterranean or sub-Mediterranean regions, as L. tropica. The two zymodemes of L. major encountered, MON-26 and MON-103, differed in terms of purine nucleoside phosphorylase 2. The MON-26 isolates came from the Jordanian plateau whereas those of MON-103 were only collected from the Jordan valley. The four zymodemes of L. tropica observed (MON-7, MON-137, MON-200 and MON-265) were identical for only two of the 15 enzymes studied (i.e. isocitrate dehydrogenase and glucose phosphate isomerase), confirming the high level of enzymatic polymorphism of L. tropica. So far, MON-200 and MON-265 have only been found in Jordan.

Disseminated cutaneous leishmaniasis due to Leishmania guyanensis: case of a patient with 425 lesions

Disseminated cutaneous leishmaniasis is characterized by the presence of a large (> or =10) number of lesions at several anatomic sites (head, limbs, and trunk). Most of the lesions are small, papular, and appear simultaneously with or secondarily to one or several ulcerated lesions of localized cutaneous leishmaniasis. We report the first case of disseminated cutaneous leishmaniasis in French Guiana. It concerns a 24-year-old woman who tested negative for human immunodeficiency virus (HIV). The disease began with three lesions that became ulcerated. One week later, multiple papulo-nodular lesions appeared. We counted a total of 425 lesions. Leishmania were observed in the lesions. The species involved was L. guyanensis, which has never been described in a case of disseminated cutaneous leishmaniasis. The patient was rapidly cured by a single course of pentamidine. Disseminated cutaneous leishmaniasis should be distinguished from other types of leishmaniasis with multiple lesions. These include anergic diffuse cutaneous leishmaniasis, post-kala-azar leishmaniasis, and leishmaniasis associated with HIV infection.

Sri Lankan cutaneous leishmaniasis is caused by Leishmania donovani zymodeme MON-37

Sri Lankan cutaneous leishmaniasis (CL), once considered sporadic, is fairly widespread in some parts of the country. Identification of 5 isolates from 4 CL patients by enzyme analysis during 2002 showed that they were all Leishmania donovani zymodeme MON-37, the parasite which also causes visceral leishmaniasis in India and East Africa.

Short report: Treatment failure due to mixed infection by different strains of the parasite Leishmania infantum

Therapeutic failure in a human immunodeficiency virus-negative patient with visceral leishmaniasis was due to mixed infection by two different Leishmania infantum zymodemes: L. infantum zymodeme MON-98, which is a rare zymodeme and is reported for the first time in Greece, and zymodeme MON-1, which is common in the Mediterranean region. The two strains were isolated from two samples of bone marrow from the patient obtained before the administration of treatment and 20 days later, since there was no improvement in the clinical signs. The zymodemes MON-98 and MON-1 exhibited different behaviors in vitro and showed different sensitivities to meglumine antimoniate in vitro and in vivo, as shown by clinical findings. Mixed infections with different Leishmania strains may explain the differences in the clinical course of leishmaniasis in many patients and may be the reason for treatment failures.

Leishmaniasis due to Leishmania tropica MON-102 in a new Moroccan focus

In Morocco, between March and April 2002, large numbers of human leihsmaniasis cases were detected during a survey at Zouagha My Yacoub province in Fès State. Among 95 cases, 76 were positive by direct observation of Giemsa-stained smears. Sixteen stocks were isolated in NNN medium and identified as Leishmania tropica MON-102, using isoenzyme techniques on starch gel electrophoresis.

Enzymatic polymorphism during Leishmania/HIV co-infection: a study of 381 Leishmania strains received between 1986 and 2000 at the international cryobank in Montpellier, France

Between 1986 and 2000, 381 Leishmania strains isolated from 288 HIV-positive patients were studied at the international cryobank in Montpellier, France. Most (95.1%) of the strains came from cases of visceral leishmaniasis but 4.9% were from HIV-positives with cutaneous leishmaniasis. The majority of the strains came from patients infected in the Mediterranean region, with a few originating in sub-Saharan Africa and South America. Isoenzymatic characterization revealed 28 zymodemes in four different species: L. infantum (which was predominant), L. donovani, L. major and L. guyanensis. The strains belonging to the L. infantum complex included 20 zymodemes, some of which have so far only been found in cases of Leishmania/HIV co-infection.

Visceral leishmaniasis. Persistence of parasites in lymph nodes after clinical cure

Visceral leishmaniasis (VL) is generally associated with severe immunodeficiency (AIDS; renal, liver, and heart transplantations; haemopoietic malignancies). More rarely it can be related to an immunotolerence status such as pregnancy. Various observations report the development of leishmaniasis several months or even years after exposure to the parasite. Relapses occur rarely in patients not known to be immunocompromised, but are common after incomplete treatment. They are frequent in patients with Leishmania/HIV co-infection. Asymptomatic phases and relapses suggest that parasite can exist in the tissues for a long time before and/or after clinical onset of the disease. The mechanisms of onset of clinical leishmaniasis following exposure and infestation are highly relevant to understanding the pathology of the disease. The survival of Leishmania parasite between infection and disease or after cure is a very important issue for clinicians and epidemiologists. We describe two cases of VL occurring in a patient with lymphoma and in a pregnant woman. In both cases, parasites remained present in the lymph nodes after clinical cure.

Human cutaneous leishmaniasis due to Leishmania infantum in the Sidi Bourouis focus (Northern Tunisia): epidemiological study and isoenzymatic characterization of the parasites

The authors report an increase of the number of case of cutaneous leishmaniasis in the Sidi Bourouis region community of Siliana Governorate (Tunisia), with 38 cases diagnosed in 6 months (1st November 2000-30th April 2001), contrary to its usual sporadic character. The isoenzymatic identification of 15 isolated strains emphasizes the role of the Leishmania infantum zymodeme MON-1 as an important factor in the genesis of the sporadic cutaneous leishmaniasis of Northern Tunisia. In fact it was isolated in 6 cases while L. infantum MON-24, the usual agent was isolated in 9 cases.

Human cutaneous leishmaniasis caused by Leishmania naiffi is wide-spread in South America

Four human cases of localized cutaneous leishmaniasis caused by Leishmania naiffi are reported. Two of the cases were infected in French Guiana, one in French Guiana or Martinique, and the other in Ecuador or Peru. The geographical distribution of L. naiffi is clearly larger than that initially reported. Three zymodemes were represented by the four isolates, confirming that there is intraspecific polymorphism in L. naiffi.

Visceral leishmaniasis in Tunisia: result of the isoenzymatic characterization of 65 Leishmania infantum strains

The isoenzymatic characterization of 65 Tunisian strains of Leishmania, isolated from human cases of visceral leishmaniasis between June 1998 and August 2001, revealed the existence of 3 zymodemes of the L. infantum complex: MON-1 the most common (93.8%), followed by MON-24 (3.1%) and MON-80 (3.1%). 72% of the strains were obtained from children under the age of 5 years. The majority of the studied strains originated from 8 provinces of northern Tunisia, particularly the province of Zaghouan.

Value of two PCR methods for the diagnosis of canine visceral leishmaniasis and the detection of asymptomatic carriers

The value of 2 PCR methods, targeting genomic and kinetoplast minicircle DNA respectively, was investigated for both diagnosis and prevalence studies of canine visceral leishmaniasis (CVL). The first method (R) was 5000-fold less sensitive than the second (method KRV). Both were tested for diagnosis of CVL in 44 sick dogs with confirmed disease using different biological samples. Method R was highly efficient when using invasive samples, but the use of method KRV proved necessary for a 100% sensitive diagnosis using peripheral blood. This method was applied to peripheral blood and skin samples in 263 dogs during a mass survey in the Cévennes focus. PCR was compared to serology and all results were analysed according to clinical status. The 'CVL-infection' prevalence was found to be 79.8% by PCR compared with 29.6% by serology: 89.4% of symptomatic and 65.2% of asymptomatic dogs harboured parasites in peripheral blood. This study confirms the high prevalence of asymptomatic carriers of Leishmania. In total, for the diagnosis of CVL in sick dogs, method R is recommended in view of its 100% positive predictive value (compared with 30% for method KRV). A strategy best adapted for prevalence surveys might combine serology and highly sensitive PCR on peripheral blood.

The sandfly fauna in the visceral-leishmaniasis focus of Gedaref, in the Atbara-River area of eastern Sudan

Visceral leishmaniasis (VL) is an acute public-health problem in Sudan. Between 1997 and 2000, four, brief entomological surveys were carried out in Barbar El Fugarra, a village in the state of Gedaref, in the Atbara-River area of eastern Sudan. Between 1996 and 1999, 658 cases of VL occurred among the village's population of about 4000. CDC miniature light-traps set inside and outside human dwellings were used to collect a total of 12,745 sandflies, including five species of the genus Phlebotomus and 19 of Sergentomyia. Phlebotomus papatasi and P. orientalis made up 7% and 5% of the collected sandflies, respectively. Seasonal variation was observed in the numbers of P. orientalis, P. papatasi, S. schwetzi and S. magna caught. Almost all (88%) of the sandflies collected were caught inside houses or granaries and there appeared to be particularly large indoor populations of P. orientalis, P. papatasi, S. schwetzi, S. magna and S. clydei. Phlebotomus orientalis could be responsible for the indoor transmission of the parasites causing the local VL, between humans and between humans and local dogs (which have been found infected by some of the Leishmania zymodemes found in humans). The co-occurrence in this focus of P. papatasi and Arvicanthis niloticus, which are known vectors and reservoir hosts, respectively, of L. major, indicates the possibility that outbreaks of human cutaneous leishmaniasis might occur in the area.

Leishmania infantum MON-98: infection in a dog from Alto Douro, Portugal

We report the isolation of Leishmania infantum zymodeme MON-98 in Portugal, its first known occurrence outside the focus of El Agamy, Egypt. One dog found to be infected with Acanthocheilonema dracunculoides during a survey of canine filariosis in the Alto Douro region, north-east Portugal, was also discovered to have Leishmania in bone marrow. The isolated strain was identified by isoenzyme analysis. A search for other possible cases of L. infantum MON-98 infection in dogs, vectors and particularly humans is necessary to establish the real epidemiological importance of this zymodeme in the endemic region of Alto Douro.

[Epidemiologic surveillance of cutaneous leishmaniasis in Guiana. Summary of military data collected over 10 years]

This report describes the results of epidemiological surveillance of cutaneous leishmaniasis in French military personnel in French Guiana. Data was collected regarding microscopic diagnosis, clinical manifestations, and lesion location as well as compliance with vector control measures. Year-to-year variations in the incidence in the general population have been attributed to changes in climatic conditions. Monitoring incidence and density curves, correlation of findings with local epidemiological data, and analysis of the most recent epidemic in 1998/99 (326 cases, attack rate 3.2% men years) highlight the importance of behavioral factors. The proportion of total cases involving military personnel varied widely from 20 to 85%. Investigation consistently showed that failure to apply elementary protective measures against sandfly bites was the most determinant factor in this proportion. Strict compliance with these measures appears to reduce the risk of infection considerably.

Isoenzymatic identification of Leishmania isolates from repeated clinical human leishmaniasis episodes in Catalonia (Spain)

Forty human strains of Leishmania infantum isolated in 1985-99 from 17 patients with repeated cutaneous, mucosal or visceral leishmaniasis episodes in Catalonia (Spain) were examined by isoenzyme electrophoresis. Six zymodemes were revealed: MON-1, MON-24, MON-28, MON-29, MON-33 and MON-34. In 2 patients 2 different zymodemes were identified in consecutive episodes.

A previously unclassified trypanosomatid responsible for human cutaneous lesions in Martinique (French West Indies) is the most divergent member of the genus Leishmania ss

Two cases of skin lesions similar to those caused by Leishmania parasites have been reported from Martinique. Parasites isolated from these lesions were unlike Leishmania reference strains by isoenzyme analysis and electron microscopy and were assumed to be monoxenous trypanosomatids which normally only infect invertebrates. Both strains have now been retyped by isoenzyme analysis and found to be identical to each other and distantly related to all other Leishmania species. The sequence of the 18S ribosomal RNA gene and partial sequences of the DNA polymerase alpha and RNA polymerase II largest subunit genes were obtained. These sequences indicated that the Martinique parasites clustered with L. enriettii and were basal to all other euleishmania. However, support for both the position basal to all euleishmania and the clustering with L. enriettii was low. The Martinique parasites may cluster with L. (Leishmania) or L. (Viannia) or form a novel clade within the euleishmania either with or without L. enriettii.

[Visceral leishmaniasis in Cameroon. Seroepidemiologic survey in the Kousseri region, north Cameroon]

A sero-epidemiological survey of school children was carried out in Kousseri, a focus for visceral leishmaniasis. Sero-immunological assays for the detection of anti-Leishmania antibodies were based on the indirect immunofluorescence assay test and counter-immunoelectrophoresis. 9 out of 223 school children tested positive for visceral leishmaniasis (seroprevalence rate of 4%). These 9 cases had no history of the disease. The data obtained confirm the endemicity of visceral leishmaniasis in this focus and call for extensive studies in order to determine the prevalence of the disease in the entire population as well as the main components of the transmission cycle.

Virulence of Leishmania infantum is expressed as a clonal and dominant phenotype in experimental infections

Human Leishmania infantum infection results in a spectrum of clinical expressions ranging from cutaneous to either asymptomatic or fatal visceral disease. In this context, characterization of parasite virulence appears to be relevant as a biological marker of intrinsic parasitic factors that can affect the pathology of leishmaniasis. Since parasite populations in naturally infected hosts are likely to be composed of multiclonal associations, we first explored the biodiversity of parasite virulence at the intrastrain level in vitro and in vivo by using 11 clones isolated from three strains previously known to express different virulence phenotypes in mice. Subsequently, we studied the course of infection in mice inoculated simultaneously or successively with strains or clones showing various virulence phenotypes. Analysis of in vitro growth characteristics showed no differences among clones from the different parental strains. By contrast, in vivo experiments evidenced a marked intrastrain heterogeneity of virulence to mice. One out of five clones obtained from a virulent strain showed a typical virulence phenotype, while the remaining four clones had low-virulence profiles, as did the six clones isolated from two low-virulence strains. In mixed multiclonal infections, the virulence phenotype was expressed as a dominant character over the associated low-virulence clones. After a challenge with either a homologous or a heterologous strain or clone, virulence phenotypes were conserved and expressed as in naive mice independently from the preexisting population. These results strongly suggest that parasite virulence in L. infantum visceral leishmaniasis is clonal and dominant in nature.

Leishmania species, drug unresponsiveness and visceral leishmaniasis in Bihar, India

Sixteen isolates obtained, in January 1998-December 1999, from splenic aspirates from sodium stibogluconate-resistant cases of visceral leishmaniasis (VL; Indian kala-azar) and drawn from different districts of Bihar (India) were identified as Leishmania donovani. By isoenzyme analysis, all the strains were found identical to the WHO reference strain L. donovani MON-2 and differed from L. tropica MON-5. This study suggested that resistant cases of VL in Bihar were caused by L. donovani and not by L. tropica. No new strain responsible for drug unresponsiveness emerged during this period and other cause or causes of emergence of drug resistance should be sought. All the patients were cured with amphotericin B.

Sudan: the possible original focus of visceral leishmaniasis

Fifty-two Leishmania strains, obtained from human patients and dogs in a visceral leishmaniasis focus in Sudan, were characterized by isoenzyme electrophoresis (15 enzymes). The phylogenetic analysis showed that the 7 Leishmania zymodemes obtained hold ancestral positions on the phylogenetic tree, supporting the hypothesis of an East African origin of visceral leishmaniasis.

Experimental pathogenicity of a presumed monoxenous trypanosomatid isolated from humans in a murine model

Two strains of a presumed lower trypanosomatid isolated from immunocompetent and HIV-infected humans in French West Indies were investigated in vitro and in vivo in a murine experimental model. The ability of parasites to grow in vitro in bone marrow-derived macrophages and their virulence in vivo were assessed. For in vivo infection, two groups of BALB/c mice were inoculated either by the subcutaneous or intravenous route with 10(7) promastigotes at day 0. Infection was monitored by measuring parasite load in liver, spleen, foot pad, popliteal, and mesenteric lymph nodes and brain from day 7 to day 150 post-infection using a microtitration technique. Parasites multiplied in mouse macrophages in vitro. In vivo, both strains proved infective to mice and capable of visceralization and dissemination in the popliteal and mesenteric lymph nodes, liver, spleen, and even brain. Both strains elicited a strong humoral response against trypanosomatid antigen in mice, which cross-reacted with Leishmania antigen. Contrasting with the straightforward dissemination of parasites, the infection was strikingly well tolerated by the murine host with no clinical signs and minimal tissue changes around parasitized macrophage infiltrates.

[Infantile visceral leishmaniasis caused by Leishmania infantum zymodeme MON-24 in Algeria]

In Algeria, visceral leishmaniasis is caused principally by Leishmania infantum MON-1, a common agent of the disease on the edges of the mediterranean basin. Other zymodemes (MON-34 and MON-80) of the same complex have also been isolated from immunologically competent patients. In the present study, the authors report the presence of Leishmania infantum MON-24, the main agent of cutaneous leishmaniasis in northern Algeria, in five children with visceral leishmaniasis.

Treatment of Old World cutaneous leishmaniasis by pentamidine isethionate. An open study of 11 patients

BACKGROUND

Pentavalent antimonial derivatives (PAD), especially meglumine antimoniate (Glucantime((R))), are usually considered as the first-line drugs for Old World leishmaniasis, but their potential toxicity and the number of required injection, either intralesional or intramuscular, prompt to search for alternative treatments.

OBJECTIVE

To evaluate the efficiency and tolerance of pentamidine isethionate in Old World leishmaniasis.

METHODS

An open pilot study included 11 patients from two regional academic centers, with varied parasitological forms of Old World leishmaniasis, treated with three strictly intramuscular injections of 4 mg/kg of base-pentamidine every other day.

RESULTS

Tolerance was good overall, and 8/11 (73%) of patients responded well with a quick healing of their lesions, little scarring and no relapse.

CONCLUSION

Pentamidine isethionate is a safe and effective first-line treatment for Old World leishmaniasis. Larger-scale prospective studies comparing several dosage regimens of pentamidine and pentamidine isethionate to PAD are warranted.

[Leishmaniasis: update]

PARASITE IDENTIFICATION: Leishmaniases are a group of parasitic diseases affecting 88 countries in four continents. Isoenzymatic electrophoresis, presently the gold standard technique for Leishmania identification, has led to the development of the phenetic and phylogenetic classifications commonly in use. Study of the genome of these parasites is particularly important because of the features it presents.

PARASITE CYCLE

Parasite transmission to mammals is facilitated by sandfly saliva. The parasite invades the human dermis by complex mechanisms involving molecular interactions allowing the parasite to survive after intracellular penetration.

CLINICAL EXPRESSION

Clinical outcome of leishmaniases depends on both the Leishmania species tropism and the host's immune response. Immunosuppressive status, whatever its origin, facilitates Leishmania infection and worsens the clinical picture.

TREATMENT

No new developments have occurred for a long time in the treatment of leishmaniases. Individual prophylactic measures are limited to insecticide impregnated bednets for human use and insecticide collars for prevention of canine leishmaniases.

[Infantile visceral leishmaniasis from Leishmania infantum MON-24: a reality in Tunisia]

The authors report the first documented observation of infantile visceral leishmaniasis due to Leishmania infantum MON-24 zymodeme in Tunisia. This zymodeme was isolated from a non-immunodepressed two-year-old child, with visceral leishmaniasis, originating from Zaghouan, in northern Tunisia. This case shows that beside L. infantum MON-1 and MON-80, L. infantum MON-24, the usual parasite of cutaneous leishmaniasis, there exists also a causative agent of visceral leishmaniasis in our country.