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

Leishmania and HIV co-infection: first naturally Leishmania strain presenting decreased susceptibility to miltefosine, recovered from a patient in Portugal

BACKGROUND

In Europe, up to 70% of visceral leishmaniasis (VL) cases occurring in adults living with HIV. People living with HIV with VL co-infection often display persistent parasitemia, requiring chronic intermittent anti-Leishmania therapies. Consequently, frequent VL relapses and higher mortality rates are common in these individuals. As such, it is of paramount importance to understand the reasons for parasite persistence to improve infection management.

METHODS

To outline possible causes for treatment failure in the context of HIV-VL, we followed a person living with HIV-VL co-infection for nine years in a 12-month period. We characterized: HIV-related clinicopathological alterations (CD4+ T counts and viremia) and Leishmania-specific seroreactivity, parasitemia, quantification of pro-inflammatory cytokines upon stimulation and studied a Leishmania clinical isolate recovered during this period.

RESULTS

The subject presented controlled viremia and low CD4+ counts. The subject remained PCR positive for Leishmania and also seropositive. The cellular response to parasite antigens was erratic. The isolate was identified as the first Leishmania infantum case with evidence of decreased miltefosine susceptibility in Portugal.

CONCLUSION

Treatment failure is a multifactorial process driven by host and parasite determinants. Still, the real-time determination of drug susceptibility profiles in clinical isolates is an unexplored resource in the monitoring of VL.

Epidemiological and Clinical Aspects of Cutaneous and Mucosal Leishmaniases in Portugal: Retrospective Analysis of Cases Diagnosed in Public Hospitals and Reported in the Literature between 2010 and 2020

Leishmania infantum, a zoonotic vector-born parasite, is endemic in the Mediterranean region, presenting mostly as visceral (VL), but also as cutaneous (CL) and mucosal leishmaniasis (ML). This study aimed to describe the epidemiological and clinical aspects of the CL and ML cases diagnosed in mainland Portugal between 2010 and 2020. Collaboration was requested from every hospital of the Portuguese National Health System. Cases were screened through a search of diagnostic discharge codes or positive laboratory results for Leishmania infection. Simultaneously, a comprehensive literature search was performed. Descriptive statistics and hypothesis testing were performed using IBM® SPSS® Statistics. A total of 43 CL and 7 ML cases were identified, with a predominance of autochthonous cases (86%). In CL, immunosuppressed individuals constituted a significant proportion of patients (48%), and in this group, disseminated CL (22%) and simultaneous VL (54%) were common. In autochthonous cases, lesions, mostly papules/nodules (62%), were frequently observed on the head (48%). The approach to treatment was very heterogeneous. ML cases were all autochthonous, were diagnosed primarily in older immunosuppressed individuals, and were generally treated with liposomal amphotericin B. The findings suggest a need for enhanced surveillance and reporting, clinical awareness, and diagnostic capacity of these forms of leishmaniasis to mitigate underdiagnosis and improve patient outcomes. A holistic One Health approach is advocated to address the multifaceted challenges posed by leishmaniases in Portugal and beyond.

Typing of Leishmania isolates from vectors and leporids of the Madrid (Spain) outbreak

In 2009, a large outbreak of leishmaniasis, associated with environmental changes, was declared near Madrid (Spain), in which Phlebotomus perniciosus was the vector, whereas the main reservoirs were hares and rabbits. Analysis of isolates from humans, vectors and leporids from the focus identified the Leishmania infantum ITS-Lombardi genotype. However, multilocus enzyme electrophoresis (MLEE), the reference technique for Leishmania typing, and sequencing of the hsp70 gene, a commonly used marker, were not performed. In the present study, 19 isolates from P. perniciosus (n = 11), hares (n = 5) and rabbits (n = 3) from the outbreak area, all characterized as ITS-Lombardi in previous studies, were analysed by MLEE and hsp70 sequencing. The hsp70 results confirmed that all the analysed strains are L. infantum. However, by MLEE, 4 different zymodemes of L. infantum were identified based on variable mobilities of the NP1 enzyme: MON-34 (NP1100, n = 11), MON-80 (NP1130, n = 6), MON-24 (NP1140, n = 1) and MON-331 (NP1150, n = 1). The relative frequency of these zymodemes does not correspond to their usual occurrence in Spain. Moreover, MON-34 and MON-80 were found in P. perniciosus, hares and rabbits for the first time. These findings continue to provide insights into the outbreak and call for further studies with a higher number of strains.

A Rare Case of Imported Cutaneous Leishmaniasis Caused by Leishmania infantum in the Republic of Korea, 2021

Leishmaniasis is a neglected tropical disease and an infectious disease transmitted by sandflies that occurs worldwide. In the absence of physicians seeking to identify the causes of disease in non-endemic areas, appropriate diagnoses cannot be made, thereby hampering effective treatment. In this report, we examined a nodular lesion on a patient's chin by performing a biopsy and molecular analysis. The biopsy finding led to the identification of a Leishmania amastigote. On the basis of PCR analysis of the internal transcribed spacer 1 gene and 5.8 S ribosomal RNA with a subsequent BLAST search, we identified the causal organism as Leishmania infantum. The patient, who had visited Spain from 1 July to 31 August 2018, was accordingly diagnosed with cutaneous leishmaniasis and was administered liposomal amphotericin B, which successfully treated the skin lesion. Travel history plays an important role in the diagnosis of leishmaniasis, and physicians should bear in mind that travelers can also introduce diseases and pathogens to non-endemic areas. Identification of Leishmania at the species level will increase the efficacy of treatment.

Wild Mesocarnivores as Reservoirs of Endoparasites Causing Important Zoonoses and Emerging Bridging Infections across Europe

Mesocarnivores are small- or mid-sized carnivore species that display a variety of ecologies and behaviours. In Europe, wild mesocarnivores are represented by the red fox (Vulpes vulpes), the golden jackal (Canis aureus), the European wildcat (Felis silvestris), the Mustelidae of the genera Meles, Martes, Mustela, Lutra, the invasive species of raccoon dog (Nyctereutes procyonoides), raccoons (Procyon lotor), and American mink (Neogale vison). These abundant animals thrive in various habitats and often develop their activity close to human settlements. Thus, they may play an important role in the introduction, maintenance, and transmission of major parasitic zoonoses and promote bridging infections with domestic animals. Against this background, this article reports and discusses some of the most important endoparasites of wild mesocarnivores living in Europe, on the basis of their actual role as reservoirs, spreaders, or sentinels. The data derived from epizootiological studies in different European countries, and the proven or speculated implications of the detected endoparasites in human and domestic animals' health, are discussed. Through older and recent literature review, the state-of-the-art knowledge on the occurrence and prevalence of the parasites under consideration is presented, showing further, warranted investigations and the need for surveillance and vigilance.

Synthesis, Structure and Antileishmanial Evaluation of Endoperoxide–Pyrazole Hybrids

Leishmaniases are among the most impacting neglected tropical diseases. In attempts to repurpose antimalarial drugs or candidates, it was found that selected 1,2,4-trioxanes, 1,2,4,5-tetraoxanes, and pyrazole-containing chemotypes demonstrated activity against Leishmania parasites. This study reports the synthesis and structure of trioxolane–pyrazole (OZ1, OZ2) and tetraoxane–pyrazole (T1, T2) hybrids obtained from the reaction of 3(5)-aminopyrazole with endoperoxide-containing building blocks. Interestingly, only the endocyclic amine of 3(5)-aminopyrazole was found to act as nucleophile for amide coupling. However, the fate of the reaction was influenced by prototropic tautomerism of the pyrazole heterocycle, yielding 3- and 5-aminopyrazole containing hybrids which were characterized by different techniques, including X-ray crystallography. The compounds were evaluated for in vitro antileishmanial activity against promastigotes of L. tropica and L. infantum, and for cytotoxicity against THP-1 cells. Selected compounds were also evaluated against intramacrophage amastigote forms of L. infantum. Trioxolane–pyrazole hybrids OZ1 and OZ2 exhibited some activity against Leishmania promastigotes, while tetraoxane–pyrazole hybrids proved inactive, most likely due to solubility issues. Eight salt forms, specifically tosylate, mesylate, and hydrochloride salts, were then prepared to improve the solubility of the corresponding peroxide hybrids and were uniformly tested. Biological evaluations in promastigotes showed that the compound OZ1•HCl was the most active against both strains of Leishmania. Such finding was corroborated by the results obtained in assessments of the L. infantum amastigote susceptibility. It is noteworthy that the salt forms of the endoperoxide–pyrazole hybrids displayed a broader spectrum of action, showing activity in both strains of Leishmania. Our preliminary biological findings encourage further optimization of peroxide–pyrazole hybrids to identify a promising antileishmanial lead.

Genotypic and phylogenic analyses of cutaneous leishmaniasis in Al Ahsa, Eastern Saudi Arabia during the coronavirus disease 2019 pandemic: First cases of Leishmania tropica with the predominance of Leishmania major

During the coronavirus disease 2019 lockdown period, a surge in sandflies and cutaneous leishmaniasis (CL) cases was observed in Al-Ahsa, Saudi Arabia. Skin punch biopsies were obtained from 100 patients clinically diagnosed with CL in Al-Ahsa who had no travel history in the last 6 months. Impression smears were used following a three-step polymerase chain reaction (PCR) protocol using genus-specific primers targeting kDNA and ITS1. Leishmania speciation was determined by ITS1 PCR/nested PCR-restriction fragment length polymorphism and sequencing. A phylogenetic tree was constructed. The associated patient characteristics were analyzed. Using internal transcribed spacer one (ITS1)-PCR/nested PCR, 98 cases were considered true-positive CL. Leishmania major was the predominant species, and Leishmania tropica was identified in three cases. Microscopy had poor sensitivity and perfect specificity. Direct ITS1-PCR missed nine cases. Sex, residence, and treatment outcome were significantly associated with the occurrence of Leishmania; distribution of skin lesion(s) and treatment outcome were significantly associated with Leishmania genotype. This is the first time that L. tropica was identified as a cause of CL in human in Al-Ahsa, in addition to the predominant zoonotic species, L. major. We recommend using ITS1-nested PCR for negative cases by ITS1-PCR. Further exploration of Leishmania transmission dynamics in vectors and reservoir animals is essential for designing effective preventive measures.

Human seroprevalence of Toscana virus and Sicilian phlebovirus in the southwest of Portugal

Toscana virus (TOSV) is emergent in the Mediterranean region and responsible for outbreaks of encephalitis or meningoencephalitis. Sicilian phlebovirus (SFSV) cause epidemics of febrile illness during the summer. The aim of this study was to evaluate the presence of antibodies against TOSV and SFSV in humans in the southwest of Portugal. Neutralizing antibodies to TOSV and SFSV were respectively detected in 5.3% and 4.3% out of 400 human sera tested highlighting the need to increase public health awareness regarding phleboviruses and to include them in the differential diagnosis in patients presenting with fever of short duration and neurological manifestations.

Autochthonous and imported tegumentary leishmaniasis in Catalonia (Spain): Aetiological evolution in the last four decades and usefulness of different typing approaches based on biochemical, molecular and proteomic markers

Leishmaniasis is a transmissible disease caused by Leishmania protozoa. Spain is endemic for both visceral and cutaneous leishmaniasis, the autochthonous aetiological agent being Leishmania infantum. Around the world, the L. donovani complex is associated with visceral symptoms, while any species of the Leishmania or Viannia subgenera affecting human can produce tegumentary forms. In a context of growing numbers of imported cases, associated with globalisation, the aim of this study was to analyse the aetiological evolution of human tegumentary leishmaniasis in a region of Spain (Catalonia). Fifty-six Leishmania strains, isolated from 1981 to 2018, were analysed using MLEE, gene sequencing (hsp70, rpoIILS, fh and ITS2) and MALDI-TOF. The utility of these different analytical methods was compared. The results showed an increase in leishmaniasis over the two last decades, particularly imported cases, which represented 39% of all cases studied. Leishmania infantum, L. major, L. tropica, L. braziliensis, L. guyanensis and L. panamensis were identified. The combination of molecular and enzymatic methods allowed the identification of 29 different strain types (A to AC). Strain diversity was higher in L. (Viannia), whilst the different L. major types were relatable with geo-temporal data. Among the autochthonous cases, type C prevailed throughout the studied period (39%). Minor types generally appeared within a short time interval. While all the techniques provided identical identification at the species complex level, MALDI-TOF and rpoIILS or fh sequencing would be the most suitable identification tools for clinical practice, and the tandem hsp70-ITS2 could substitute MLEE in the epidemiological field.

Genetic diversity and phylogenetic relationships between Leishmania infantum from dogs, humans and wildlife in south-east Spain

Leishmania infantum causes human and canine leishmaniosis. The parasite, transmitted by phlebotomine sand flies, infects species other than dogs and people, including wildlife, although their role as reservoirs of infection remains unknown for most species. Molecular typing of parasites to investigate genetic variability and evolutionary proximity can help understand transmission cycles and designing control strategies. We investigated Leishmania DNA variability in kinetoplast (kDNA) and internal transcribed spacer 2 (ITS2) sequences in asymptomatically infected wildlife (n = 58) and symptomatically and asymptomatically infected humans (n = 38) and dogs (n = 15) from south-east Spain, using single nucleotide polymorphisms (SNPs) and in silico restriction fragment length polymorphism (RFLP) analyses. All ITS2 sequences (n = 76) displayed a 99%-100% nucleotide identity with a L. infantum reference sequence, except one with a 98% identity to a reference Leishmania panamensis sequence, from an Ecuadorian patient. No heterogeneity was recorded in the 73 L. infantum ITS2 sequences except for one SNP in a human parasite sequence. In contrast, kDNA analysis of 44 L. infantum sequences revealed 11 SNP genotypes (nucleotide variability up to 4.3%) and four RFLP genotypes including B, F and newly described S and T genotypes. Genotype frequency was significantly greater in symptomatic compared to asymptomatic individuals. Both methods similarly grouped parasites as predominantly or exclusively found in humans, in dogs, in wildlife or in all three of them. Accordingly, the phylogenetic analysis of kDNA sequences revealed three main clusters, two as a paraphyletic human parasites clade and a third including dogs, people and wildlife parasites. Results suggest that Leishmania infantum genetics is complex even in small geographical areas and that, probably, several independent transmission cycles take place simultaneously including some connecting animals and humans. Investigating these transmission networks may be useful in understanding the transmission dynamics, infection risk and therefore in planning L. infantum control strategies.

Exploiting genetic polymorphisms in metabolic enzymes for rapid screening of Leishmania infantum genotypes

Background

Leishmania infantum is the aetiological agent of visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL). Numerous strains and/or zymodemes have been identified and characterized by multilocus enzyme electrophoresis (MLEE). MLEE is considered the reference method for L. infantum parasite typing and it is based upon enzyme electrophoretic mobility analysis from promastigote cultures. However, the MLEE technique is cumbersome, time-consuming and does not detect silent genetic mutations or nucleotide changes that give rise to amino acid changes that do not alter electrophoretic mobility. As a result of these difficulties, many DNA-based typing methods have been developed over the past few years. However, relative to the enzymes utilized in MLEE analysis, we observed a shortage of DNA sequences available in the GenBank database or an absolute lack of sequences belonging to specific zymodemes. The aims of the present study were to (i) implement the number of sequences coding for metabolic enzymes used in MLEE; (ii) identify polymorphisms that characterize L. infantum zymodemes most prevalent in the Mediterranean basin; and (iii) exploit these polymorphisms to develop a rapid screening test that would give results comparable with existing MLEE typing.

Results

Partial sequences of seven metabolic enzyme genes (malic enzyme, 6-phosphogluconate dehydrogenase, mitochondrial isocitrate dehydrogenase, glucose-6-phosphate isomerase, glucose-6-phosphate dehydrogenase, phosphoglucomutase and mannose phosphate isomerase) were obtained from 11 L. infantum strains. The comparison of these sequences with those obtained from GenBank allowed for the identification of a few polymorphisms that could distinguish several zymodemes. In particular, the polymorphism 390T>G in the malic enzyme gene has been exploited to develop a high-resolution melt (HRM)-based assay to rapidly differentiate the genotype 390T, associated with zymodemes MON-1, MON-72 and MON-201, evidencing a partial agreement between genotyping results and MLEE. The assay has been successfully applied to L. infantum clinical isolates and clinical samples.

Conclusions

A HRM-based assay for rapid identification of genotypes associated with the most common L. infantum zymodemes in the Mediterranean basin has been developed and its potential application in epidemiological research for L. infantum population screening, without parasite isolation and culturing, has been demonstrated.

Electronic supplementary material

The online version of this article (10.1186/s13071-018-3143-7) contains supplementary material, which is available to authorized users.

Phlebotomine sand fly-borne pathogens in the Mediterranean Basin: Human leishmaniasis and phlebovirus infections

Pathogens transmitted to humans by phlebotomine sand flies are neglected, as they cause infectious diseases that are not on the priority list of national and international public health systems. However, the infections caused by protozoa of the Leishmania genus and viruses belonging to the Phlebovirus genus (family Phenuiviridae)—the most significant group of viruses transmitted by sand flies—have a relevant role for human pathology. These infections are emerging in the Mediterranean region and will likely spread in forthcoming decades, posing a complex threat to human health. Four species and 2 hybrid strains of Leishmania are pathogenic for humans in the Mediterranean Basin, with an estimated annual incidence of 239,500–393,600 cases of cutaneous leishmaniasis and 1,200–2,000 cases of visceral leishmaniasis. Among the phleboviruses, Toscana virus can cause neuroinvasive infections, while other phleboviruses are responsible for a typical “3-day fever”; the actual incidence of Phlebovirus infections in the Mediterranean area is unknown, although at least 250 million people are exposed. Here, we reviewed the current literature on epidemiology of sand fly–borne infections in the Mediterranean Basin, with a focus on humans. Our analysis indicates the need for increased public health activities directed to determine the disease burden of these infections as well as to improve their surveillance. Among the emerging challenges concerning sand fly–borne pathogens, the relationships between sand fly–borne protozoa and viruses should be considered in future studies, including epidemiological links between Leishmania and phleboviruses as well as the conditional capacity for these pathogens to be involved in interactions that may evolve towards increased virulence.

Serological association between Leishmania infantum and sand fly fever Sicilian (but not Toscana) virus in sheltered dogs from southern Portugal

Background

Phlebotomine sand fly-borne diseases such as leishmanioses and phleboviruses are emerging threats to animal and public health. Canine leishmaniosis caused by Leishmania infantum is an endemic zoonosis in Portugal. Antibodies to Toscana virus (TOSV) and sand fly fever Sicilian virus (SFSV) were also reported in dogs from the south of the country. The aim of this work was to evaluate a possible association between exposure to L. infantum, TOSV and SFSV in sheltered dogs from the south of Portugal.

Results

Seventy-six (13.1%) out of 581 dogs were seropositive for L. infantum, 327 (56.3%) for SFSV and 36 (6.2%) for TOSV. Six dogs were co-exposed with L. infantum and TOSV, 51 with L. infantum and SFSV and 25 with TOSV and SFSV. One dog had antibodies to the three pathogens. Leishmania infantum seroprevalence was significantly higher in pure breed dogs than in mongrels and in dogs with clinical signs while SFSV positivity was significantly higher in males, in pure and cross-breed dogs than in mongrels and in those not treated with insecticides. Seroprevalence for both viruses was significantly higher in dogs over than 7 years-old than in those aged 1–7. A significant association was observed between the presence of antibodies to L. infantum and SFSV.

Conclusions

The presence of antibodies to several phlebotomine sand fly-borne pathogens in dogs, reinforces the need to implement efficient prophylactic measures to prevent infection among vertebrate hosts including humans. The results also indicate that dogs are good sentinels for assessing human exposure to TOSV and SFSV. Further studies must be performed to elucidate the role of dogs in the dynamics of transmission and if they can play a role as amplifying or reservoir hosts in the natural cycle of these viruses. Public and animal health impacts of these phleboviruses in Portugal should be addressed via serological and virological studies on both phlebotomine sand flies and vertebrate hosts, especially on humans.

Neutralization-based seroprevalence of Toscana virus and sandfly fever Sicilian virus in dogs and cats from Portugal

Sandfly-borne phleboviruses are endemic in the Mediterranean basin. However, levels of exposure of human and animal populations are inadequately researched. Toscana virus (TOSV) is present in Portugal where it causes human infection and disease; in contrast there are few data for sandfly fever Sicilian virus (SFSV) which has neither been isolated nor detected by molecular tests and for which there are only limited serological data. The sera collected from 1160 dogs and 189 cats in southern Portugal were tested for the presence of neutralizing antibodies against TOSV and SFSV, two viruses recognized as distinct serocomplexes in the Mediterranean region. Our data showed (i) seropositivity to TOSV and SFSV in dogs at a rate of 6.8 and 50.8 %, respectively, and (ii) that 3.7 % of cats were seropositive for TOSV. TOSV findings are in line with previous results obtained with less stringent serological assays. Our results for SFSV in dogs clearly indicate that the virus is circulating widely and that humans may be exposed to infection via the dogs. Although the presence of SFSV was suggested by haemagglutination inhibition in 4/1690 human sera in 1974, this is the first time, as far as we know, that SFSV has been shown to circulate so widely in dogs in Portugal. Future studies should be directed at isolating strains of SFSV in Portugal from dogs, humans and sandflies collected in high prevalence regions. As dogs appear to be good sentinels for SFSV, their role as a possible reservoir in the natural cycle should also be considered.

The Montpellier Leishmania Collection, from a Laboratory Collection to a Biological Resource Center: A 39-Year-Long Story

We report the development of a laboratory collection of Leishmania that was initiated in 1975 and, after 39 years, has become an international Biological Resource Center (BRC-Leish, Montpellier, France, BioBank No. BB-0033-00052), which includes 6353 strains belonging to 36 Leishmania taxa. This is a retrospective analysis of the technical and organizational changes that have been adopted over time to take into account the technological advances and related modifications in the collection management and quality system. The technical improvements concerned the culture and cryopreservation techniques, strain identification by isoenzymatic and molecular techniques, data computerization and quality management to meet the changes in international standards, and in the cryogenic and microbiological safety procedures. The BRC is working toward obtaining the NF-S 96-900 certification in the coming years. Our long-term expertise in Leishmania storage and typing and collection maintenance should encourage field epidemiologists and clinical practitioners in endemic countries to secure their own strain collection with the help of the French BRC-Leish.

Seasonal Dynamics of Phlebotomine Sand Fly Species Proven Vectors of Mediterranean Leishmaniasis Caused by Leishmania infantum

Background

The recent geographical expansion of phlebotomine vectors of Leishmania infantum in the Mediterranean subregion has been attributed to ongoing climate changes. At these latitudes, the activity of sand flies is typically seasonal; because seasonal phenomena are also sensitive to general variations in climate, current phenological data sets can provide a baseline for continuing investigations on sand fly population dynamics that may impact on future scenarios of leishmaniasis transmission. With this aim, in 2011–2013 a consortium of partners from eight Mediterranean countries carried out entomological investigations in sites where L. infantum transmission was recently reported.

Methods/Principal Findings

A common protocol for sand fly collection included monthly captures by CDC light traps, complemented by sticky traps in most of the sites. Collections were replicated for more than one season in order to reduce the effects of local weather events. In each site, the trapping effort was left unchanged throughout the survey to legitimate inter-seasonal comparisons. Data from 99,000 collected specimens were analyzed, resulting in the description of seasonal dynamics of 56,000 sand flies belonging to L. infantum vector species throughout a wide geographical area, namely P. perniciosus (Portugal, Spain and Italy), P. ariasi (France), P. neglectus (Greece), P. tobbi (Cyprus and Turkey), P. balcanicus and P. kandelakii (Georgia). Time of sand fly appearance/disappearance in collections differed between sites, and seasonal densities showed variations in each site. Significant correlations were found between latitude/mean annual temperature of sites and i) the first month of sand fly appearance, that ranged from early April to the first half of June; ii) the type of density trend, varying from a single peak in July/August to multiple peaks increasing in magnitude from May through September. A 3-modal trend, recorded for P. tobbi in Cyprus, represents a novel finding for a L. infantum vector. Adults ended the activity starting from mid September through November, without significant correlation with latitude/mean annual temperature of sites. The period of potential exposure to L.infantum in the Mediterranean subregion, as inferred by adult densities calculated from 3 years, 37 sites and 6 competent vector species, was associated to a regular bell-shaped density curve having a wide peak center encompassing the July-September period, and falling between early May to late October for more than 99% of values. Apparently no risk for leishmaniasis transmission took place from December through March in the years considered. We found a common pattern of nocturnal females activity, whose density peaked between 11 pm and 2 am.

Conclusions

Despite annual variations, multiple collections performed over consecutive years provided homogeneous patterns of the potential behavior of leishmaniasis vectors in selected sites, which we propose may represent sentinel areas for future monitoring. In the investigated years, higher potential risk for L. infantum transmission in the Mediterranean was identified in the June-October period (97% relative vector density), however such risk was not equally distributed throughout the region, since density waves of adults occurred earlier and were more frequent in southern territories.

Recent projections on global warming indicate a constant rise of temperatures in the Mediterranean subregion in the near-mid future. While this phenomenon already caused geographical expansion of several arthropod-borne diseases, it is likely to affect also temporal parameters of seasonally transmitted diseases such as leishmaniasis, a protozoan infection spread by the bite of phlebotomine sand flies. Phenology of sand flies consists in the periods of emergence of adults and their disappearance from collections following an activity period during warm months, which can be characterized by peaks of abundance. Current phenological observations can be important for continuing investigations on sand fly dynamics that may impact on leishmaniasis transmission in the future. With this aim, partners from eight Mediterranean countries identified sites with documented Leishmania infantum transmission by six different vector species and performed multiannual trappings. From the high number of 56,000 specimens collected throughout an area spanning from Portugal at west to Georgia at east, the current seasonal dynamics of Mediterranean vectors was obtained. Both, period of adults emergence and type of density trend were found to be significantly correlated with latitude or mean annual temperature of trapping sites. At the southernmost latitudes, vector activity started as early as begin of April and ended by late November, showing that the no-risk period of potential exposure to L. infantum lasted only 4 months.

First case of feline leishmaniosis caused by Leishmania infantum genotype E in a cat with a concurrent nasal squamous cell carcinoma

Case summary

This is the first clinical report of feline viscerocutaneous leishmaniosis caused by Leishmania infantum genotype E associated with an invasive squamous cell carcinoma (SCC) in a domestic cat from Portugal. Initially, the cat presented a single cutaneous lesion in the right nostril. A fine-needle aspiration was performed and Leishmania amastigotes were observed without the presence of cells compatible with neoplasia. Systemic treatment with allopurinol was started. One year later, the cat presented a crateriform non-encapsulated and badly delineated mass in the nasal planum, with naso-oral fistulation and nasal destruction. Histologically, the skin mass consisted on an ulcerative plaque-like lesion with a nasal SCC. Leishmania infantum MON-1 parasites were detected by histopathology, culture and PCR of the skin mass, submandibular and popliteal lymph nodes, liver and spleen. Restriction enzyme analysis revealed genotype E, previously identified in humans and dogs living in the same region.

Relevance and novel information

This is, to the best of our knowledge, the first clinical report of feline viscerocutaneous leishmaniosis caused by L infantum genotype E. The detection and isolation of parasites from a cat that are genetically identical to the ones obtained from humans and dogs with visceral leishmaniosis highlights the need to clarify whether cats play a role in the epidemiology of this parasitic zoonosis. From a clinical point of view, this case reinforces the importance of including leishmaniosis in the differential diagnoses of feline pathology, especially in cats with cutaneous lesions.

Biological Activities and Chemical Composition of Methanolic Extracts of Selected Autochthonous Microalgae Strains from the Red Sea

Four lipid-rich microalgal species from the Red Sea belonging to three different genera (Nannochloris, Picochlorum and Desmochloris), previously isolated as novel biodiesel feedstocks, were bioprospected for high-value, bioactive molecules. Methanol extracts were thus prepared from freeze-dried biomass and screened for different biological activities. Nannochloris sp. SBL1 and Desmochloris sp. SBL3 had the highest radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl, and the best copper and iron chelating activities. All species had potent butyrylcholinesterase inhibitory activity (>50%) and mildly inhibited tyrosinase. Picochlorum sp. SBL2 and Nannochloris sp. SBL4 extracts significantly reduced the viability of tumoral (HepG2 and HeLa) cells with lower toxicity against the non-tumoral murine stromal (S17) cells. Nannochloris sp. SBL1 significantly reduced the viability of Leishmania infantum down to 62% (250 µg/mL). Picochlorum sp. SBL2 had the highest total phenolic content, the major phenolic compounds identified being salicylic, coumaric and gallic acids. Neoxanthin, violaxanthin, zeaxanthin, lutein and β-carotene were identified in the extracts of all strains, while canthaxanthin was only identified in Picochlorum sp. SBL2. Taken together, these results strongly suggest that the microalgae included in this work could be used as sources of added-value products that could be used to upgrade the final biomass value.

Molecular detection of Leishmania DNA and identification of blood meals in wild caught phlebotomine sand flies (Diptera: Psychodidae) from southern Portugal

Background

Zoonotic visceral leishmaniasis caused by Leishmania infantum which is transmitted by phlebotomine sand flies (Diptera, Psychodidae) is endemic in the Mediterranean basin. The main objectives of this study were to (i) detect Leishmania DNA and (ii) identify blood meal sources in wild caught female sand flies in the zoonotic leishmaniasis region of Algarve, Portugal/Southwestern Europe.

Methods

Phlebotomine sand flies were collected using CDC miniature light traps and sticky papers. Sand flies were identified morphologically and tested for Leishmania sp. by PCR using ITS-1 as the target sequence. The source of blood meal of the engorged females was determined using the cyt-b sequence.

Results

Out of the 4,971 (2,584 males and 2,387 females) collected sand flies, Leishmania DNA was detected by PCR in three females (0.13%), specifically in two specimens identified on the basis of morphological features as Sergentomyia minuta and one as Phlebotomus perniciosus. Haematic preferences, as defined by the analysis of cyt-b DNA amplified from the blood-meals detected in the engorged female specimens, showed that P. perniciosus fed on a wide range of domestic animals while human and lizard DNA was detected in engorged S. minuta.

Conclusions

The anthropophilic behavior of S. minuta together with the detection of Leishmania DNA highlights the need to determine the role played by this species in the transmission of Leishmania parasites to humans. In addition, on-going surveillance on Leishmania vectors is crucial as the increased migration and travelling flow elevate the risk of introduction and spread of infections by Leishmania species which are non-endemic.

A case of imported Leishmania infantum cutaneous leishmaniasis; an unusual presentation occurring 19 years after travel

Background

Leishmania infantum is a flagellated protozoan parasite that is able to parasitize blood and tissue. Leishmania species cause a spectrum of clinical disease with cutaneous, visceral or mucosal involvement. L. infantum is recognised as a cause of visceral leishmaniasis (VL) and is less commonly reported as a cause of cutaneous leishmaniasis (CL) from countries around the Mediterranean basin. This is the first report of imported L. infantum CL to Australia and is remarkable for a 19 year period between the patient's exposure to an endemic region, and the manifestation of symptoms.

Case presentation

A 76 year old Italian-born man presented to our institution with a non-healing lesion over his upper lip, abutting his nasal mucosa. The patient had travelled to Italy, an endemic area for L. infantum 19 years earlier but had resided in Australia, a non-endemic area since. Histopathology performed on a biopsy of the lesion demonstrated findings consistent with CL. A species specific polymerase chain reaction (PCR) performed on the tissue detected L. infantum. The patient had complete clinical recovery following treatment with Liposomal amphotericin B at a dose of 3 mg/kg for five days followed by a subsequent 3 mg/kg dose at day ten.

Conclusions

L. infantum should be recognised as a cause of imported CL in returned travellers from the Mediterranean. In this case, the incubation period for L. infantum CL was at least 19 years. This case adds to the described spectrum of clinical presentations of leishmaniasis and supports the theory of parasite persistence underlying natural immunity and recurrence of disease. Clinicians should consider L. infantum CL in the differential diagnosis of a non-healing skin lesion in any patient who reports travel to the Mediterranean, even when travel occurred several years before clinical presentation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0597-x) contains supplementary material, which is available to authorized users.

Predicting the risk of an endemic focus of Leishmania tropica becoming established in south-western Europe through the presence of its main vector, Phlebotomus sergenti Parrot, 1917

The aim of the study was the construction of risk maps for exposure to Phlebotomus sergenti, the main vector of Leishmania tropica, with a view to identifying hot spots for the potential establishment of this parasite in the southwest of Europe. Data were collected on the presence/absence of this vector and the ecological and climatic characteristics of 662 sampling sites located in the southeast, centre and northeast of the Iberian Peninsula (south-western Europe). The environmental factors associated with the distribution of P. sergenti were determined. The best predictors for the presence of this dipteran were ‘altitude’, ‘land use’, ‘land surface temperature’, ‘aspect’, ‘adjacent land cover’, ‘absence of vegetation in wall’ and the ‘absence of PVC pipes in the drainage holes of retaining walls’. Risk maps for exposure to the vector were drawn up based on these variables. The validation of the predictive risk model confirmed its usefulness in the detection of areas with a high risk of P. sergenti being present. These locations represent potential hot spots for an autochthonous focus of L. tropica becoming established. The risk maps produced for P. sergenti presence revealed several areas in the centre and south of the Iberian Peninsula to be the most prone to this process, which would make it possible for the disease to enter south-western Europe.

In vitro drug susceptibility of Leishmania infantum isolated from humans and dogs

Visceral leishmaniasis (VL) caused by parasites of Leishmania donovani complex is a severe human disease which often leads to death if left untreated. Domestic dogs are the main reservoir hosts for zoonotic human visceral infection caused by Leishmania infantum. In the absence of effective human and dog vaccines, the only feasible way to treat and control leishmaniasis is through the use of suitable medications. To know the drug susceptibility of human and canine Leishmania strains from Lisbon-Portugal, a study on a panel of strains was conducted by testing the susceptibility of promastigotes and intracellular amastigotes to the common drugs used in canine leishmaniasis (CanL) and human VL (meglumine antimoniate, amphotericin B, miltefosine and allopurinol). Although a high heterogeneity of susceptibilities was obtained to each drug on both axenic promastigote and intracellular amastigote assays, intracellular amastigotes system correlated better with treatment outcome. Parasites isolated from the refractory human case were the least susceptible to the drugs used highlighting that the emergence of cross-resistance to the drugs available for human therapy should not be neglected. Furthermore, parasites isolated from dogs showed low susceptibility to the main drugs used in CanL treatment. Our results focus the importance of reducing/avoiding the emergence and spread of resistant parasites in the canine and human populations, a factor that requires special consideration when dogs are treated using the same available anti-Leishmania drugs for human VL. In addition, efforts should be made in order to standardize the conditions used to test drug susceptibility (methodologies, drug formulations and media) in order to compare results between laboratories.

The first detection of Leishmania major in naturally infected Sergentomyia minuta in Portugal

Phlebotomine sandflies of the genus Sergentomyia are widely distributed throughout the Old World. It has been suggested that Sergentomyia spp are involved in the transmission of Leishmania in India and Africa, whereas Phlebotomus spp are thought to be the sole vectors of Leishmania in the Old World. In this study, Leishmania major DNA was detected in one Sergentomyia minuta specimen that was collected in the southern region of Portugal. This study challenges the dogma that Leishmania is exclusively transmitted by species of the genus Phlebotomus in the Old World.

Spatial distribution and population genetics of Leishmania infantum genotypes in São Paulo State, Brazil, employing multilocus microsatellite typing directly in dog infected tissues

This study investigated the genetic characteristics of Leishmania infantum samples from São Paulo (SP) State, Brazil in order to collaborate with information about the possible origins of the parasites, as well as, the introduction and spread of visceral leishmaniasis in this Brazilian State. Multilocus microsatellite typing (MLMT) was performed using a set of 17 microsatellite markers. DNA was extracted from 250 samples collected from dogs diagnosed with visceral leishmaniasis and 112 (45%) were genotyped: 67 from the northwest region (NWSP), and 29 from the southeast region (SESP) of SP. The results were correlated with other 16 samples from Mato Grosso do Sul State (MS) (which borders NWSP). Although, a small portion of samples was genotyped, it was possible to genotype multiple loci using small amounts of Leishmania DNA extracted directly from dog tissues. Despite the fact that MLMT analysis defined 33 different genotypes, a low polymorphism was detected within the parasites studied with 10 polymorphic loci. There are two main genetic clusters circulating in SP with strong genetic differentiation, one (POP-A) is composed by samples from SESP and NWSP and presented a weak signal of geographical substructure. The other, belongs to the same cluster found in the state of MS (POP-B), which was the main one. The majority (93.75%) of MS parasite genotypes belonged to POP-B, with just one sample (6.25%) grouped in POP-A. POP-B also comprised 10.34% of SESP and 26.87% of NWSP samples. Besides one sample from MS, POP-A is composed by 73.13% of NWSP and 89.66% of SESP samples. The MLMT analysis supported the idea of canine visceral leishmaniasis being introduced in the Northwest region of SP State by the traffic of humans and dogs from MS. In the southeast region of SP occurred an introduction of a new L. infantum genetic cluster. Probably the transmission was spread by traffic of infected dogs from other Brazilian regions, or by introduction of imported dogs from other countries. All these data together contributed to the detection of the genetic profile of L. infantum population in SP State.

Seroepidemiology of canine leishmaniosis in Évora (southern Portugal): 20-year trends

Background

Canine leishmaniosis (CanL) is an endemic zoonosis in the southern regions of Europe. This paper reports the trend in CanL seroprevalence in the municipality of Évora (southern Portugal), where the disease is endemic, over a period of 20 years. The work comprises three different studies that were conducted in the years of 1990 (n = 3,614), 1999 (n = 3,563) and 2010 (n = 1,485 dogs). Blood samples were collected during the anti-rabies vaccination campaigns. Anti-Leishmania antibodies were detected with the direct agglutination test (DAT).

Findings

The total percentages of DAT seropositive dogs were 3.9% (in 1990), 9.4% (in 1999) and 5.6% (in 2010). The overall seroprevalence was significantly higher in 1999 compared to 1990, but in 2010 a significant decrease was found in comparison with 1999. However, compared to 1990 the overall seroprevalence was still significantly higher in 2010. From 1990 to 2010 seroprevalence has switched from significantly lower to higher in the rural areas. Relatively few dogs showed clinical signs of overt disease (0.8% to 2.0%) with lymphadenopathy, onychogryphosis and skin involvement as most frequently observed. Gender associated differences in seroprevalence were not found, and most commonly seropositive dogs were working or stray animals. The mean age of seropositive dogs was significantly higher than seronegative dogs in all three sampling rounds.

Conclusions

A high proportion of dogs, which are apparently healthy, yet seropositive, may remain an important factor in limiting the outcome of zoonotic leishmaniosis control efforts.

Entomological and ecological studies in a new potential zoonotic leishmaniasis focus in Torres Novas municipality, Central Region, Portugal

In Portugal human and canine leishmaniasis are caused by Leishmania infantum, and Phlebotomus perniciosus and P. ariasi are the proven vectors. Three main foci were identified in eighty's decade: Trás-os-Montes and Alto Douro region, Lisbon region and Algarve region, but according to OnLeish observatory data, canine leishmaniasis cases have been reported from several other regions, for which sand fly species and their infection rates are unknown. This study is the first phlebotomine survey in Torres Novas municipality, Santarém District, Portugal. The main objectives were to identify the phlebotomine species, their bioecological aspects, Leishmania infection rate and the risk factors for the presence of phlebotomine species in the municipality. From June to November, 2010, 275 biotopes were surveyed with CDC light-traps. Captures covered the 17 parishes of the municipality and included domestic, peridomestic and sylvatic biotopes. Specimens were identified morphologically and females were used for molecular detection of Leishmania and bloodmeal identification. Simple and multiple logistic regression analysis were used to identify risk factors for phlebotomine presence. Nonparametric tests were used to compare densities of independent groups. A total of 1262 sand flies were captured and identified, and four species detected: P. perniciosus (73.69%), P. ariasi (8.16%), P. sergenti (6.58%) and Sergentomyia minuta (11.57%). In 71.4% localities at least one L. infantum proven vector species was present. Risk factors were identified as: high average temperatures and low relative humidities, sheltered locations and absence of strong wind, presence of pine trees as dominant vegetation, peridomestic biotopes, particularly sheep pens or proximity of sheep, poultry and house martin nests. L. infantum infection rate was 4% for P. ariasi and 0.48% for the total of Larroussius females. P. perniciosus females exhibited an opportunistic behavior, feeding in a wide variety of vertebrate hosts. The high abundance and distribution of proven vector species, together with a canine leishmaniasis seroprevalence of 7.93% in the District, and the capture of a gravid infective sand fly female, suggests that Torres Novas municipality is a potential zoonotic leishmaniasis focus in the country.

Geographical distribution updating of Tunisian leishmaniasis foci: about the isoenzymatic analysis of 694 strains

Over a period of ten years, a series of 694 Leishmania strains from Tunisian leishmaniasis foci were isolated and identified by isoenzymatic analysis. Strains were obtained from human cutaneous and visceral leishmaniasis in immunocompetent subjects, visceral leishmaniasis in imunocompromised individuals and from dogs with visceral leishmaniasis. Two classically dermotropic species, Leishmania (L.) major and Leishmania killicki were found. L. major with the single zymodeme MON-25 was the most isolated in cutaneous leishmaniasis foci of the Centre and South of Tunisia with a recent northern extension. L. killicki zymodeme MON-8 was sporadically found both in its classical microfocus of Tataouine in southeastern Tunisia as well as in some new foci in Southwestern, Central and Northern Tunisia. Leishmania infantum with its three zymodemes MON-1, MON-24 and MON-80 was isolated from both visceral and cutaneous human cases. The majority of L. infantum strains were found in the Northern part of the country; however, some strains were reported for the first time in the Southern part. L. infantum MON-1 was the only zymodeme isolated from canine leishmaniasis.

Geographical distribution and epidemiological features of Old World Leishmania infantum and Leishmania donovani foci, based on the isoenzyme analysis of 2277 strains

A series of 2277 Leishmania strains from Old World visceral leishmaniasis foci, isolated between 1973 and 2008, were studied by isoenzyme analysis. The strains were obtained from humans, domestic and wild carnivores, rodents and phlebotomine sandflies, and came from 36 countries. In all, 60 different zymodemes were identified and clustered by a phenetic analysis into 3 different groups corresponding to the typically visceralizing species L. donovani (20 zymodemes, 169 strains), L. archibaldi (3 zymodemes, 46 strains) and L. infantum (37 zymodemes, 2,062 strains). The taxonomic position of these isoenzymatic groups is discussed in view of contradictory results obtained from recent molecular studies.

KDNA genetic signatures obtained by LSSP-PCR analysis of Leishmania (Leishmania) infantum isolated from the new and the old world

BACKGROUND

Visceral Leishmaniasis (VL) caused by species from the Leishmania donovani complex is the most severe form of the disease, lethal if untreated. VL caused by Leishmania infantum is a zoonosis with an increasing number of human cases and millions of dogs infected in the Old and the New World. In this study, L. infantum (syn. L.chagasi) strains were isolated from human and canine VL cases. The strains were obtained from endemic areas from Brazil and Portugal and their genetic polymorphism was ascertained using the LSSP-PCR (Low-Stringency Single Specific Primer PCR) technique for analyzing the kinetoplastid DNA (kDNA) minicircles hypervariable region.

PRINCIPAL FINDINGS

KDNA genetic signatures obtained by minicircle LSSP-PCR analysis of forty L. infantum strains allowed the grouping of strains in several clades. Furthermore, LSSP-PCR profiles of L. infantum subpopulations were closely related to the host origin (human or canine). To our knowledge this is the first study which used this technique to compare genetic polymorphisms among strains of L. infantum originated from both the Old and the New World.

CONCLUSIONS

LSSP-PCR profiles obtained by analysis of L. infantum kDNA hypervariable region of parasites isolated from human cases and infected dogs from Brazil and Portugal exhibited a genetic correlation among isolates originated from the same reservoir, human or canine. However, no association has been detected among the kDNA signatures and the geographical origin of L. infantum strains.

Risk factors for canine leishmaniasis in an endemic Mediterranean region

Human visceral leishmaniasis is an emergent/re-emergent parasitic zoonotic disease in Europe caused by Leishmania infantum, with domestic dog as its main reservoir host. This study presents the results of a canine epidemiological survey in a mediterranean region where human and canine leishmaniasis (CanL) are endemic - Portugal. The main goal was to identify risk factors, which can be relevant for Leishmania infection control. The national survey was carried out in January 2009 with a screening of 3974 dogs from all 18 districts of mainland Portugal. Direct Agglutination Test was used for the detection of anti-Leishmania antibodies in canine blood. An overall CanL true prevalence of 6.31% was observed. Apparent prevalence at district level ranged from 0.88% to 16.16%, with the highest prevalence in the interior regions. Identified risk factors for positivity were: dogs of 2 years and older (adjusted odds ratio OR=5.39); spending exclusively/most of the time outdoors (OR=2.51); origin from the interior of Portugal in comparison to littoral/coast districts (OR=2.51); not having long fur (OR=2.03); and being pure exotic (OR=1.67). The results confirm the leishmaniasis endemicity in Portugal and the dynamic character of prevalence as new foci emerged and old foci lost their importance. The dog's age, fur size, district and living outdoors as opposed to indoors were more important than dog breeds and insecticide treatment in the transmission of Leishmania infection. The future of CanL prevention and control rely on an integrated approach involving veterinarians, dog owners and health authorities in order to reduce the canine infection risk and consequently, the human zoonotic visceral leishmaniasis.

Epidemiology of imported cutaneous leishmaniasis at the Hospital for Tropical Diseases, London, United Kingdom: use of polymerase chain reaction to identify the species

This study reviewed all patients diagnosed with imported cutaneous leishmaniasis (CL) at the Hospital for Tropical Diseases in London, United Kingdom, over an 11-year period. Diagnostic and epidemiologic information was collected prospectively for all patients with imported CL to this hospital during 1998-2009. A total of 223 patients were given a diagnosis of CL. Ninety patients were diagnosed with Old World CL, which was caused most commonly by Leishmania donovani complex (n = 20). A total of 71% were tourists to the Mediterranean region, 36% were migrants or visiting friends and relatives, and 17% were soldiers. One hundred thirty-three patients were given a diagnosis of New World CL. The Leishmania subgenus Viannia caused 97 of these cases; 44% of these were in backpackers and 29% were in soldiers. Polymerase chain reaction was more sensitive and faster for detecting Leishmania DNA (86% for Old World CL and 96% for New World CL) than culture. This is the largest study of imported leishmaniasis, and demonstrates that tourists to the Mediterranean and backpackers in Central and South America are at risk for this disease.

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.

Leishmania infantum: Lipophosphoglycan intraspecific variation and interaction with vertebrate and invertebrate hosts

Interspecies variations in lipophosphoglycan (LPG) have been the focus of intense study over the years due its role in specificity during sand fly-Leishmania interaction. This cell surface glycoconjugate is highly polymorphic among species with variations in sugars that branch off the conserved Gal(β1,4)Man(α1)-PO(4) backbone of repeat units. However, the degree of intraspecies polymorphism in LPG of Leishmania infantum (syn. Leishmania chagasi) is not known. In this study, intraspecific variation in the repeat units of LPG was evaluated in 16 strains of L. infantum from Brazil, France, Algeria and Tunisia. The structural polymorphism in the L. infantum LPG repeat units was relatively slight and consisted of three types: type I does not have side chains; type II has one β-glucose residue that branches off the disaccharide-phosphate repeat units and type III has up to three glucose residues (oligo-glucosylated). The significance of these modifications was investigated during in vivo interaction of L. infantum with Lutzomyia longipalpis, and in vitro interaction of the parasites and respective LPGs with murine macrophages. There were no consequential differences in the parasite densities in sand fly midguts infected with Leishmania strains exhibiting type I, II and III LPGs. However, higher nitric oxide production was observed in macrophages exposed to glucosylated type II LPG.

Genetic diversity of human zoonotic leishmaniasis in Iberian Peninsula

Leishmaniasis caused by Leishmania (Leishmania) infantum is a zoonotic disease endemic in South Europe, from Portugal to the Middle East. The aim of the present study was to investigate the genetic diversity of L. infantum parasites in Iberian Peninsula. Twenty-four L. infantum strains isolated from immunocompetent patients with leishmaniasis from several localities of Portugal and Spain were studied. The use of kinetoplast DNA-PCR-restriction fragment length polymorphism as a molecular marker revealed intra-specific variation. No association was found between genotype and clinical form of the disease or patients age group. Two main clusters were identified with this marker: (i) zymodeme MON-1 strains and (ii) non-MON-1 strains. However, no association was found between strains variability and geographical distribution suggesting that parasite populations of different regions in the Iberian Peninsula are homogenous.

Low seroprevalence of Leishmania infantum infection in cats from northern Portugal based on DAT and ELISA

Cats have been considered playing a role in the epidemiology of leishmaniasis caused by Leishmania infantum, an endemic zoonosis in countries of the Mediterranean basin. The present study assessed the prevalence of antibodies to L. infantum in 316 domestic cats from northern Portugal, by means of the direct agglutination test (DAT) and an enzyme-linked immunosorbent assay (ELISA). Seroreactivity to DAT was found in six cats, and nine cats were positive in the ELISA, including the six DAT-positive animals. The overall seroprevalence of Leishmania infection was 2.8%, based on ELISA and DAT. A substantial agreement (99%; κ value=0.80) was found between DAT and ELISA results. The difference between seroprevalence values in females (0.7%) and males (4.7%) was statistically significant (p=0.045). The age of seropositive cats ranged from 31 to 84 months. Cats with 5-6 years (60-71 months) and 6-7 years (72-83 months) presented the highest level of seropositivity (15.4% and 33.3%, respectively). A significant difference was found comparing the seroprevalences in cats aged less than 24 months (0.0%) and in those with 24 months or more (7.3%) (p=0.022). Seroprevalences in cats living in a rural environment (10.5%) or in urban areas (0.0%) were also found to be significantly different (p<0.001). No significant differences were detected between serological status to Leishmania in pure non-European and European or mixed breeds (p=0.442), cats that lived totally indoors and those that had access to outdoors (p=0.412), cats seropositive and seronegative to Toxoplasma gondii (p=0.276), or apparently healthy animals and those with clinical illness (p=0.271). This study is the largest epidemiological investigation performed on feline Leishmania infection in Portugal. The seroprevalence of Leishmania infection was low in cats living in northern Portugal, a region where canine leishmaniasis is endemic. Nevertheless, Leishmania infection must not be underestimated and leishmaniasis may be included in the differential diagnosis of cutaneous or systemic clinical signs in cats.

Practical approach for typing strains of Leishmania infantum by enzyme polymorphism: a cross sectional study in Northwest of Iran

In present study, All samples collected from Kalybar and Ahar districts in Northwest of Iran from 12 patients (bone marrow aspirates), 26 dogs (spleenic and hepatic aspirates) and more than 100 sand flies between years 2004-2006. All patients were clinically diagnosed to have visceral leishmaniasis. Serological profiles of all sera samples from both human and dogs were in accordance with leishmaniasis (DAT). Isoenzyme profiles of these isolates were compared with those of reference using 12 enzyme systems. L. infuntum MON-1 is the only zymodeme present in all samples of dogs, sand flies and human. The enzymatic polymorphism is compared to that of neighboring countries (Azarbaijan, Iraq and Turkey etc.) and we concluded that the Visceral Leishmaniasis (VL) focus in northwest of Iran is evidently Mediterranean focus of zoonotic VL, which extends from Portugal and Morocco to Pakistan and the central Asian republics. Domestic doges act as the reservoir host, where Phlebotomus kandellakii and Perfiliewi ariasi are vectors.

Differentiation and gene flow among European populations of Leishmania infantum MON-1

BACKGROUND

Leishmania infantum is the causative agent of visceral and cutaneous leishmaniasis in the Mediterranean region, South America, and China. MON-1 L. infantum is the predominating zymodeme in all endemic regions, both in humans and dogs, the reservoir host. In order to answer important epidemiological questions it is essential to discriminate strains of MON-1.

METHODOLOGY/PRINCIPAL FINDINGS

We have used a set of 14 microsatellite markers to analyse 141 strains of L. infantum mainly from Spain, Portugal, and Greece of which 107 strains were typed by MLEE as MON-1. The highly variable microsatellites have the potential to discriminate MON-1 strains from other L. infantum zymodemes and even within MON-1 strains. Model- and distance-based analysis detected a considerable amount of structure within European L. infantum. Two major monophyletic groups-MON-1 and non-MON-1-could be distinguished, with non-MON-1 being more polymorphic. Strains of MON-98, 77, and 108 were always part of the MON-1 group. Among MON-1, three geographically determined and genetically differentiated populations could be identified: (1) Greece; (2) Spain islands-Majorca/Ibiza; (3) mainland Portugal/Spain. All four populations showed a predominantly clonal structure; however, there are indications of occasional recombination events and gene flow even between MON-1 and non-MON-1. Sand fly vectors seem to play an important role in sustaining genetic diversity. No correlation was observed between Leishmania genotypes, host specificity, and clinical manifestation. In the case of relapse/re-infection, only re-infections by a strain with a different MLMT profile can be unequivocally identified, since not all strains have individual MLMT profiles.

CONCLUSION

In the present study for the first time several key epidemiological questions could be addressed for the MON-1 zymodeme, because of the high discriminatory power of microsatellite markers, thus creating a basis for further epidemiological investigations.

The relationship between leishmaniasis and AIDS: the second 10 years

To date, most Leishmania and human immunodeficiency virus (HIV) coinfection cases reported to WHO come from Southern Europe. Up to the year 2001, nearly 2,000 cases of coinfection were identified, of which 90% were from Spain, Italy, France, and Portugal. However, these figures are misleading because they do not account for the large proportion of cases in many African and Asian countries that are missed due to a lack of diagnostic facilities and poor reporting systems. Most cases of coinfection in the Americas are reported in Brazil, where the incidence of leishmaniasis has spread in recent years due to overlap with major areas of HIV transmission. In some areas of Africa, the number of coinfection cases has increased dramatically due to social phenomena such as mass migration and wars. In northwest Ethiopia, up to 30% of all visceral leishmaniasis patients are also infected with HIV. In Asia, coinfections are increasingly being reported in India, which also has the highest global burden of leishmaniasis and a high rate of resistance to antimonial drugs. Based on the previous experience of 20 years of coinfection in Europe, this review focuses on the management of Leishmania-HIV-coinfected patients in low-income countries where leishmaniasis is endemic.

Isoenzymatic variability of Leishmania infantum in Tunisia concerning 254 human strains

The different clinical forms of leishmaniasis are the result of both the immunological status of individuals and the species of the parasite causing the infection. In Mediterranean countries, the Leishmania infantum complex groups zymodemes which are responsible for visceral, cutaneous and exceptionally cutaneomucosal or mucosal leishmaniasis. We report in this study a synthesis concerning 254 cases of L. infantum that have been characterized at the "Laboratoire de Parasitologie" of the Rabta Hospital. The strains were isolated from human cases of visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL) by culture on NNN medium: 156 VL cases and 98 CL cases. The isoenzymatic characterization revealed three zymodemes of L. infantum. * L. infantum MON 1, a common zymodeme of VL,occurred in 154 cases (61%): 147 VL (95%) and 7 CL (5%). All CL cases were from the northern provinces, six of them occurring during an epidemic disease in 2001. * L. infantum MON 24, a common zymodeme of CL in the north, occurred in 98 cases (38.5%): 91 CL (93%) and 7 VL (7%). The seven VL cases were immunocompetent children aged from 8 months to 9 years and native of northern Tunisia. Two of the CL cases were from central regions of the country. This is the first time that cases from these regions are reported. * L. infantum MON 80, an uncommon zymodeme in Tunisia, occurred in two VL cases (0.5%): two children aged 7 and 5. The small number of strains of this zymodeme does not allow understanding of its epidemiological role. The results of this study indicate a low enzymatic variability of L. infantum in the country. However, our study includes only human strains and should be extended to animal ones (dogs, rodents and sand flies). This would lead to a better understanding of the epidemiology of leishmaniasis in Tunisia.

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.