Epidemiology of Imported Leishmaniasis in Italy: Implications for a European Endemic Country

qPCR as a Tool for the Diagnosis of Visceral and Cutaneous Leishmaniasis: A Systematic Review and Meta-Analysis

INTRODUCTION

Ensuring accuracy in the diagnosis of leishmaniasis is crucial due to the myriad of potential differential diagnoses. Given the inherent limitations of serological techniques, real-time polymerase chain reaction (qPCR) emerges as a superior alternative. Furthermore, parasitological methods, conventionally regarded as the gold standard owing to their high specificity, encounter challenges concerning sensitivity and invasiveness for patients. In this context, the present study aims to assess, via meta-analysis, the performance of qPCR in diagnosing visceral and cutaneous leishmaniasis.

METHOD

This meta-analysis encompassed studies published between January 2011 and December 2022, sourced from six databases (PubMed, LILACS, Scopus, Scielo, EMBASE, and Web of Science), utilizing the keywords "qPCR," "molecular diagnosis," and "leishmaniasis." Epidemiological studies focusing on the efficacy of qPCR for leishmaniasis diagnosis were included. Data such as study demographics, geographic locations, sampling techniques, and the number of positive qPCR results were aggregated and analyzed to derive overall positivity rates, sensitivity, and specificity values associated with qPCR. Heterogeneity analysis was conducted on the data to select appropriate models, and the collective efficacy data of qPCR were illustrated in forest plots.

RESULTS

Fifty-four studies met all inclusion criteria. The positivity rates for human visceral and cutaneous leishmaniasis were 27.07% (95% CI: 17.81-36.33%) and 60.40% (95% CI: 30.23-90.57%), respectively. In cases of visceral leishmaniasis in dogs, cats, and wild animals, the positivity rates were 26.55% (95% CI: 21.40-31.70%), 0.92% (95% CI: 0.09-1.75%), and 28.98% (95% CI: 21.86-35.10%), respectively. Analysis of the selected studies revealed high overall sensitivity and specificity values achieved with qPCR, at 91.08% (95% CI: 81.77-100.39%) and 98.08% (95% CI: 97.13-99.03%), respectively.

CONCLUSION

This study indicates that qPCR is a highly sensitive and specific tool, adequately suitable for the diagnosis of human visceral and cutaneous leishmaniasis, as well as visceral leishmaniasis in animals.

Exploring hydrophilic 2,2-di(indol-3-yl)ethanamine derivatives against Leishmania infantum

Herein we report the design and the synthesis of a library of new and more hydrophilic bisindole analogues based on our previously identified antileishmanial compound URB1483 that failed the preliminary in vivo test. The novel bisindoles were phenotypically screened for efficacy against Leishmania infantum promastigotes and simultaneously for toxicity on human macrophage-like THP-1 cells. Among the less toxic compounds, eight bisindoles showed IC50 below 10 μM. The most selective compound 1h (selectivity index = 10.1, comparable to miltefosine) and the most potent compound 2c (IC50 = 2.7 μM) were tested for their efficacy on L. infantum intracellular amastigotes. The compounds also demonstrated their efficacy in the in vitro infection model, showing IC50 of 11.1 and 6.8 μM for 1h and 2c, respectively. Moreover, 1h showed a better toxicity profile than the commercial drug miltefosine. For all these reasons, 1h could be a possible new starting point for hydrophilic antileishmanial agents with low cytotoxicity on human macrophage-like cells.

Easy one-pot synthesis of multifunctionalized indole-pyrrole hybrids as a new class of antileishmanial agents

A chemoselective one-pot synthesis of pharmaceutically prospective indole-pyrrole hybrids by the formal [3 + 2] cycloaddition of 3-cyanoacetyl indoles (CAIs) with 1,2-diaza-1,3-dienes (DDs) has been developed. The new indole-pyrrole hybrids were phenotypically screened for efficacy against Leishmania infantum promastigotes. The most active compounds 3c, 3d, and 3j showed IC50 < 20 μM and moderate cytotoxicity, lower than miltefosine. Compound 3d was the most active with IC50 = 9.6 μM and a selectivity index of 5. Consequently, 3d could be a new lead compound for the generation of a new class of antileishmanial hybrids.

Alternative hosts of Leishmania infantum: a neglected parasite in Europe

Multi-host pathogens that infect various animal species and humans are considered of great importance for public and animal health. Leishmania spp. parasites are a characteristic example of such pathogens. Although leishmaniosis in humans is endemic for about 100 countries around the world it is classified as a neglected tropical disease. There are three main forms of leishmaniosis in humans: cutaneous (CL), visceral (VL) and mucocutaneous leishmaniosis (MCL). Each year, about 30,000 new cases of VL and more than 1 million new cases of CL are recorded. In Europe L. infantum is the dominant species with dogs being reservoir hosts. Apart from dogs, infection has been recorded in various animals, which suggests that other species could play a role in the maintenance of the parasite in nature. Herein we provide an in-depth review of the literature with respect to studies that deal with Leishmania infantum infections in domestic and wild animal species in Europe. Given the fact that domesticated and wild animals could contribute to the incidences of leishmaniosis in humans, the aim of this paper is to provide a comprehensive review which could potentially be used for the development of measures when it comes to the control of the Leishmania infantum parasite.

Evaluation of the Diagnostic Sensitivity of the VIASURE Leishmania Real-Time PCR Detection Kit Prototype for the Diagnosis of Cutaneous and Visceral Leishmaniasis

Leishmaniasis is a parasitic disease with clinical presentations that vary from asymptomatic infection to cutaneous, mucocutaneous, or visceral disease. Global change, with migratory movements and travels, among others, has had an impact on the presentation of the clinical forms of leishmaniasis in a given area, hindering its diagnosis. The traditional parasitological techniques have limited sensitivity, and currently, there is no reference or gold-standard molecular diagnostic method. The aim of this study was to evaluate the effectivity of the VIASURE Leishmania Real-Time PCR Detection Kit prototype (CerTest Biotec, Zaragoza, Spain) for the diagnosis of autochthonous and imported leishmaniasis in comparison with two other commercialized molecular kits: STAT-NAT® Leishmania spp. (Sentinel, Milano, Italy) and Leishmania spp. Real-TM PCR Kit (Sacace Biotechnologies, Como, Italy). Four species of Leishmania, L. infantum, L. major, L. braziliensis, and L. panamensis, were targeted to assess analytical sensitivity, whereas diagnostic sensitivity was evaluated by studying a panel of 49 DNA samples from patients with suspected or confirmed Leishmania infection. The prototype could detect all the New and Old World species studied and achieved a limit of detection of 5 × 10-5 ng DNA/μL in all species. Also, it allowed the diagnosis of autochthonous and imported cases of cutaneous and visceral leishmaniasis (VL). Diagnostic sensitivity was 81.8% for the prototype and 100% for the Sacace kit (27 and 33 positive samples detected, respectively). The STAT-NAT® kit failed to detect Vianna species. The VIASURE Leishmania Real-Time PCR Detection Kit prototype was found to have good analytical and diagnostic sensitivity. Using a simple protocol and ready-to-use reagents, results are obtained quickly and are easy to interpret. The evaluation results indicate that the test is a promising candidate for routine diagnosis of cutaneous leishmaniasis and VL in endemic countries, but more studies are necessary to address its sensitivity and specificity.

Delayed diagnosis among patients with visceral leishmaniasis

We aimed to estimate the diagnostic latency of patients with visceral leishmaniasis (VL). A monocentric retrospective observational study was conducted including all confirmed cases of VL diagnosed from January 2005 to March 2022. Epidemiological and clinical characteristics of patients with VL were collected. The diagnostic latency was defined as the number of days between the first contact with a health-care provider for signs and/or symptoms referable to VL and the laboratory diagnosis of leishmaniasis. Twenty-four cases of VL were included in the study, mostly male (75%) and Italians (79.2%), with a median age of 40 years [Inter Quartile Range (IQR 30-48)]. Fourteen (58.3%) VL cases were people living with HIV (PLWH) and 4 (16.6%) subjects were on immunosuppressive therapy. For VL the median diagnostic latency was 54 days (IQR 28-162). The shorter diagnostic latency was observed in PLWH [31 days (IQR 20-47)] followed by immunocompetent patients [160 days (IQR 133-247)] and those on immunosuppressive therapy [329 days (IQR 200-678)]. Twelve patients (50%) reported at least one medical encounter before the diagnosis of VL and 6 patients received a wrong therapy. Diagnostic delay in VL was significant in patients under immune suppressive treatment.

Assessment of the diagnostic performance of serological tests in areas where Leishmania infantum and Leishmania tarentolae occur in sympatry

BACKGROUND

Visceral leishmaniosis caused by infection with the zoonotic protozoan Leishmania infantum is a life-threatening disease affecting dogs and humans. The sympatric occurrence of L. infantum and Leishmania tarentolae in an area of southern Italy endemic for canine leishmaniosis, where dogs are also exposed to the latter species, suggests the persistence of herpetophilic L. tarentolae in a non-permissive host, therefore raising questions about the performance of serological diagnostic tests routinely employed.

METHODS

The diagnostic performance of serological tests such as the immunofluorescence antibody test (IFAT), two commercial immunoenzymatic assays (i.e. NovaTec VetLine Leishmania ELISA® and rK39 ICT®) and an in-house enzyme-linked immunosorbent assay (ELISA) was evaluated in healthy dogs seropositive to L. infantum, whereas the only IFAT available was used to detect antibodies to L. tarentolae.

RESULTS

With the IFAT, out of a total of 104 dogs tested, 15 were seronegative for L. infantum of which three were L. tarentolae seropositive' and 89 were L. infantum seropositive. Of the latter 89 dogs, representing the highest proportion of seropositive animals (85.6%) detected by IFAT' 66 were also seropositive for L. tarentolae. Cohen's kappa (κ) agreement coefficient between the IFAT results and those of all the other tests was very low, and the IFAT results were significantly different from those of all the other serological tests as calculated by Cochran's Q-test. Analysis using the Bayesian latent class (Bayes-LCA) showed that the in-house ELISA and IFAT contributed the most towards identifying infected and non-infected dogs, respectively. The IFAT test showed low positive predictive value (59.5%), but high negative predictive value (100%).

CONCLUSIONS

These results demonstrate that the IFAT for L. infantum, although highly sensitive, may not be considered a useful diagnostic test due to its low specificity. Therefore, an accurate serological tool with high specificity is mandatory for avoiding cross-reaction in epidemiological contexts where the two species of Leishmania occur in sympatry.

Evolution of RNA viruses in trypanosomatids: new insights from the analysis of Sauroleishmania

RNA viruses play an important role in Leishmania biology and virulence. Their presence was documented in three (out of four) Leishmania subgenera. Sauroleishmania of reptiles remained the only underinvestigated group. In this work, we analyzed the viral occurrence in Sauroleishmania spp. and detected RNA viruses in three out of seven isolates under study. These viruses were of two families-Narnaviridae and Totiviridae. Phylogenetic inferences demonstrated that totiviruses from L. adleri and L. tarentolae group together within a larger cluster of LRV2s, while a narnavirus of L. gymnodactyli appeared as a phylogenetic relative of narnaviruses of Blechomonas spp. Taken together, our work not only expanded the range of trypanosomatids that can host RNA viruses but also shed new light on the evolution and potential routes of viral transmission in these flagellates.

Seroprevalence of Leishmania infantum in outdoor workers from southern Italian endemic regions

Visceral leishmaniasis is a zoonotic vector-borne disease caused by Leishmania infantum. The infection often remains asymptomatic, though clinical forms may occur in immunosuppressed individuals. Although data on leishmaniasis in humans are available worldwide, the exposure to L. infantum of workers conducting outdoor activities has been scantly investigated, and it is limited to military personnel operating in endemic regions. This study aimed to assess the seroprevalence of L. infantum in different groups of outdoor workers and the occupational risk factors. The cross-sectional study was performed on 229 workers including forestry guards, farmers, veterinarians, geologists and agronomists from three regions of southern Italy (i.e., Apulia, Basilicata and Campania). All serum samples were screened for L. infantum-specific IgG/IgM by using automated indirect chemiluminescent immunoassays. Overall, 5.7% (13/229) of workers was positive to anti-L. infantum antibodies, with the highest seroprevalence in veterinarians (13.6%). An increased occupational health surveillance for L. infantum infection in outdoor workers is essential to better understand the risk of exposure in specific jobs. Furthermore, guidelines and education along with a One Health collaboration among veterinarians, physicians, parasitologists and occupational health care professionals are crucial for the prevention of this disease.

Climate Variables Related to the Incidence of Human Leishmaniosis in Montenegro in Southeastern Europe during Seven Decades (1945-2014)

Leishmaniosis (or leishmaniasis) is a neglected parasitosis most commonly transmitted by the sandfly bite. Changes in temperature, precipitation, and humidity can greatly affect the vectors and reservoir hosts. This study aimed to determine the association between temperature, air humidity, and weather conditions with the incidence of leishmaniasis in Montenegro during a seven-decade period (1945-2014) and to statistically compare and correlate the obtained data. In the studied period, there were 165 registered cases of leishmaniosis, 96.4%, in the coastal and central region of Montenegro, with an average incidence rate of 0.45/100.000. The visceral form of leishmaniosis predominated (99% of the cases), with only one case of cutaneous disease. Climate factors (average temperature, air humidity, and precipitation) had an impact on the occurrence of leishmaniosis in Montenegro. Air temperature elevated by 1 °C in all regions of Montenegro was significantly correlated with an increased incidence of leishmaniosis, by 0.150 (0.013 to 0.287; p < 0.05). In order to improve prevention and control of this disease, it is also necessary to investigate other factors with a possible impact on the number of cases of this neglected parasitosis.

Non-Endemic Leishmaniases Reported Globally in Humans between 2000 and 2021—A Comprehensive Review

Leishmaniases are human and animal parasitic diseases transmitted by phlebotomine sand flies. Globalization is an important driver of the burden and in the current dynamics of these diseases. A systematic review of articles published between 2000 and 2021 was conducted using the PubMed search engine to identify the epidemiology and clinical management of imported human leishmaniases as a fundamental step to better manage individual cases and traveler and migrant health from a global perspective. A total of 275 articles were selected, representing 10,341 human imported cases. Identified drivers of changing patterns in epidemiology include conflict and war, as well as host factors, such as immunosuppression, natural and iatrogenic. Leishmania species diversity associated with different clinical presentations implies diagnostic and treatment strategies often complex to select and apply, especially in non-endemic settings. Thus, diagnostic and management algorithms for medical clinical decision support are proposed. Increased surveillance of non-endemic cases, whether in vulnerable populations such as refugees/migrants and immunocompromised individuals or travelers, could improve individual health and mitigate the public health risk of introducing Leishmania species into new areas.

Phenotype Screening of an Azole-bisindole Chemical Library Identifies URB1483 as a New Antileishmanial Agent Devoid of Toxicity on Human Cells

We report the evaluation of a small library of azole-bisindoles for their antileishmanial potential, in terms of efficacy on Leishmania infantum promastigotes and intracellular amastigotes. Nine compounds showed good activity on L. infantum MHOM/TN/80/IPT1 promastigotes with IC₅₀ values ranging from 4 to 10 μM. These active compounds were also tested on human (THP-1, HEPG2, HaCaT, and human primary fibroblasts) and canine (DH82) cell lines. URB1483 was selected as the best compound, with no quantifiable cytotoxicity in mammalian cells, to test the efficacy on intracellular amastigotes. URB1483 significantly reduced the infection index of both human and canine macrophages with an effect comparable to the clinically used drug pentamidine. URB1483 emerges as a new anti-infective agent with remarkable antileishmanial activity and no cytotoxic effects on human and canine cells.

Changes in the microbiological diagnosis and epidemiology of cutaneous leishmaniasis in real-time PCR era: A six-year experience in a referral center in Barcelona

BACKGROUND

Leishmaniasis is a neglected disease caused by different species of the protozoa Leishmania spp. Cutaneous lesions are the most common clinical manifestation. This disease is prevalent in tropical and subtropical areas, including the Mediterranean basin. In Spain, Leishmania (L.) infantum is the only endemic species, but imported cases are often diagnosed. Different classical parasitological methods can be performed for cutaneous leishmaniasis (CL) diagnosis; but currently molecular techniques serve as a relevant tool for the detection and characterization of Leishmania parasites. We aimed to evaluate clinical and epidemiological characteristics of CL diagnosed patients by real-time PCR in a tertiary hospital over a six-year period.

METHODOLOGY/PRINCIPAL FINDINGS

Clinical, epidemiological and microbiological data were retrospectively collected and analyzed. In our study, CL was confirmed in 59 (31.4%) out of 188 patients by real-time PCR, showing an increase over recent years: 11 cases of CL between 2014 and 2016 and 48 between 2017 and 2019. Real-time PCR was performed on skin swabs and/or biopsies samples, with a positivity of 38.5% and 26.5%, respectively. Results were 100% concordant when biopsy and skin swab were performed simultaneously. L. (L.) infantum was the most frequent species detected (50%), followed by L. (L.) major (45%) and Viannia subgenus (5%), which were detected only in imported cases. L. (L.) major was almost entirely detected in travelers/migrants from Morocco. Multiple and atypical skin lesions were more common in imported cases than in autochthonous cases (44.4% vs. 21.8%).

CONCLUSIONS/SIGNIFICANCE

An increase in both autochthonous and imported CL cases has been observed in past years in our hospital. Molecular techniques assist in improving CL diagnosis and characterization of the Leishmania species, mainly in imported cases.

Development of Various Leishmania (Sauroleishmania) tarentolae Strains in Three Phlebotomus Species

Leishmania (Sauroleishmania) tarentolae is transmitted by reptile-biting sand flies of the genus Sergentomyia, but the role of Phlebotomus sand flies in circulation of this parasite is unknown. Here, we compared the development of L. (S.) tarentolae strains in three Phlebotomus species: P. papatasi, P. sergenti, and P. perniciosus. Laboratory-bred sand flies were membrane-fed on blood with parasite suspension and dissected on days 1 and 7 post blood meal. Parasites were measured on Giemsa-stained gut smears and five morphological forms were distinguished. In all parasite-vector combinations, promastigotes were found in Malpighian tubules, often in high numbers, which suggests that this tissue is a typical location for L. (S.) tarentolae development in sand flies. All three studied strains colonized the hindgut, but also migrated anteriorly to both parts of the midgut and colonized the stomodeal valve. Significant differences were demonstrated between sand fly species: highest infection rates, high parasite loads, and the most frequent anterior migration with colonization of the stomodeal valve were found in P. perniciosus, while all these parameters were lowest in P. sergenti. In conclusion, the peripylarian type of development was demonstrated for three L. (S.) tarentolae strains in three Phlebotomus sand flies. We suggest paying more attention to Phlebotomus species, particularly P. perniciosus and P. papatasi, as potential secondary vectors of Sauroleishmania.

Comparative genomics of Leishmania isolates from Brazil confirms the presence of Leishmania major in the Americas

Leishmania (Leishmania) major is an important agent of cutaneous leishmaniasis, having as a vector sandflies belonging to the genus Phlebotomus. Although this species has been described as restricted to the Old World, parasites similar to L. major have been isolated from South American patients who have never travelled abroad. These parasites were named "L. major-like", and several studies have been carried out to characterise them biochemically, molecularly, and biologically. However, the phylogenetic origin of these isolates is still unknown. In the present study we characterised three L. major-like isolates, named BH49, BH121 and BH129, using comparative genomics approaches. We evaluated the presence of gene and segmental duplications/deletions and the presence of aneuploidies that could explain the differences in infectivity observed in the BH49 and BH121 isolates. All isolates presented a pattern of mosaic aneuploidy and gene copy number variation, which are common in the genus Leishmania. Virulence factors such as phosphatases and peptidases were found to have increased gene copy numbers in the infective isolate, which could explain the difference in infectivity previously observed between BH121 and BH49. Phylogenetic analyses revealed that BH49, BH121 and BH129 L. major-like grouped with L. major isolates, and suggest they were imported from the Old World in at least two independent events. We suggest that new epidemiological inquiries should also evaluate L. major infections in South America, to assess the epidemiological importance of this species in the New World.

Trends in the Epidemiology of Leishmaniasis in the City of Barcelona (1996-2019)

Background: Leishmaniasis is a neglected zoonosis produced by 20 different flagellated parasites of the Leishmania genus, a protozoan transmitted to humans and other vertebrates by the bite of dipteran insects of the Phlebotominae subfamily. It is endemic in Mediterranean countries and the number of cases is expected to increase due to climate change and migration. Prioritizing public health interventions for prevention and control is essential. The objective was to characterize the epidemiology and temporal trends in the incidence of human leishmaniasis in the city of Barcelona, between the years 1996 and 2019. Methods: A population-based, analytical observational study among residents in the city of Barcelona was conducted of all the cases of leishmaniasis reported between 1996 and 2019 to the Public Health Agency. The epidemiological survey contains clinical, diagnostic, and epidemiological data, including contact with suspicious mammals or insects. Annual incidence-rates were calculated by sex, age, and country of origin. Chi-square tests were used to assess association between studied risk factors, periods of time and type of leishmaniasis. Results: During the study period a total of 177 cases of leishmaniasis were reported in Barcelona, being 74.6% (n = 132) of the total cases in Spanish born, although within the foreign-born population the incidence was higher. Median age was 34 years (IQR = 10-48) and 121 (66.8%) were male. The main type was cutaneous (46%) followed by visceral (35.1%). The cumulative incidence was 0.47 per 100,000 inhabitants, with the highest incidence found in 2017 (1.60 per 100,000 inhabitants). A higher incidence was observed in the 0-4-year-old group (1.73 per 100,000 inhabitants), but increased during the study period for all age groups. There was an increase of foreign origin cases, and a decrease in the number of cases associated to any immunosuppression. Conclusion: In Barcelona, leishmaniasis incidence continues to be higher in people under 5 years of age, and 25-64 years old males, but it has also increased in population from foreign country of birth. There is an increase of the cases since 2016, probably due to the changes in the notification system, increasing the diagnosis of cutaneous leishmaniasis. Improvements in the current surveillance system are needed. Notification of the disease, vector, and reservoir control activities are also essential for the control of the disease.

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.

Canine Leishmaniasis: Serological Results in Private and Kennel Dogs Tested over a Six-Year Period (2009-2014) in Abruzzo and Molise Regions, Italy

This paper reports the results of serological tests for the detection of antibodies against Leishmania spp. in Abruzzo and Molise regions from 2009 to 2014, with the aim of evaluating the presence and distribution of canine leishmaniasis. Data were extracted from the Laboratory Information Management System (LIMS) of the Istituto Zooprofilattico Sperimentale of Abruzzo and Molise, and then the dog identification numbers were matched with those stored in the Canine Registries of the two regions to get information about the age of dogs at time of testing. Dogs were considered positive when having an IFAT (Indirect Fluorescent Antibody Test) titer ≥1:80. In total, 41,631 dogs were tested, 85.3% from Abruzzo and 14.7% from Molise. At the provincial level, the percentage of positive dogs ranged from 5.2% (L’Aquila, Abruzzo region) to 21.8% (Campobasso, Molise region). Findings are consistent with the hypothesis that in the coastal areas, the relationships between the host, the vector, and the agent are more favorable for the spreading of CanL, and it seems that densely populated urban internal areas have less favorable conditions. Being a dog hosted in a kennel seems not to be a factor increasing the probability that dogs show positivity, even in long-term sheltering conditions.

Prevalence of asymptomatic Leishmania infection and associated risk factors, after an outbreak in the south-western Madrid region, Spain, 2015

BackgroundA large outbreak of leishmaniasis with 758 cutaneous and visceral leishmaniasis cases occurred in 2009 in Fuenlabrada, in the south-west of the Madrid region of Spain.AimWe aimed to determine the prevalence of asymptomatic Leishmania infection after this outbreak, and its associated risk factors.MethodsA cross-sectional study of 804 healthy individuals living in Fuenlabrada who had no history of leishmaniasis, was conducted between January and July 2015. Asymptomatic infections were sought by either a combination of PCR, immunofluorescent antibody titre, and direct agglutination tests, or by whole blood stimulation assay (WBA) with interleukin-2 (IL-2) quantification.ResultsUsing the first approach, prevalence of asymptomatic individuals was 1.1% (9/804), while the second returned a value of 20.7% (143/804). Older age, being male, proximity to the park where the focus of infection was identified, and living in a detached house, were all strongly associated with the prevalence of asymptomatic infection.ConclusionsThe true number of infected individuals may be underestimated if only serological methods are used. The combination of WBA with IL-2 quantification may allow to better determine the prevalence of asymptomatic Leishmania infection, which would be useful in establishing control measures and in quantifying their impact. In our study, the use of WBA with IL-2 quantification also helped establish the risk factors that influence exposure to and infection by Leishmania.

Spatial autocorrelation and epidemiological survey of visceral leishmaniasis in an endemic area of Azerbaijan region, the northwest of Iran

Visceral leishmaniasis (VL) is a common infectious disease that is endemic in Iran. This study aimed to investigate the spatial autocorrelation of VL in the northwest of Iran. In this cross-sectional study, the data of all patients were collected in 2009–2017 and analyzed by SPSS23 and Moran's and General G Index. The MaxEnt3.3.3 software was used to determine the ecological niche. A big hot spot area was identified in five counties in the northwest of Iran. More than 70% of the cases were reported from these regions, and the incidence rate increased in the northwest of Iran from 2013 to 2017. Seasonal rainfall and average daily temperature were the most important climate variables affecting the incidence of VL in this region (p < 0.05). Therefore, it can be concluded that VL in the northwest of Iran is expanding to new areas along the border with the Republic of Azerbaijan, and the northeastern section of this region is a high-risk area.

Autochthonous Cases of Mucosal Leishmaniasis in Northeastern Italy: Clinical Management and Novel Treatment Approaches

Mucosal leishmaniasis (ML) is a rare clinical variant of tegumentary leishmaniasis in Mediterranean Europe. Here we report on three autochthonous cases of head and neck ML in patients living in Northeastern Italy. Patients presented with non-specific, long-standing symptoms of upper respiratory tract involvement, mimicking other diseases. Parasitological diagnosis was reached by histopathology, immunohistochemistry and molecular biology on tissue specimens. Leishmania infantum was identified by molecular typing in all three cases. All patients reached a complete remission with protracted multivalent antileishmanial drugs; in one case, a novel approach of combined medical and endoscopic surgical treatment was carried out. High clinical suspicion led to a prompt diagnosis and deployment of a multivalent treatment. ML should be considered in the differential diagnosis of nasal, oral, and pharyngolaryngeal lesions in endemic areas. A prompt diagnosis is mandatory to establish a correct management; different antileishmanial medications as well as endoscopic surgical options may be required to reach a complete remission.

Epidemiology of Visceral Leishmaniasis with Emphasis on the Dynamic Activity of Sand Flies in an Important Endemic Focus of Disease in Northwestern Iran

Background

Leishmaniasis diseases are known to be one of the most important public health problems in World and Iran. Visceral leishmaniasis is considered to be the most serious form and transmitted by sand flies species. The aim of this study was to investigate the dynamic activities of sandflies in northwestern Iran.

Methods

This crass-sectional study was conducted from April to December 2018 in Meshkinshahr County, Ardabil Province. Sticky traps have been used to collect sand flies. They are stored in 70% alcohol and finally identified using valid keys. The aspects of the synoptic information were inquired from the Meshkin Shahr weather department and results analyzed for SPSS24.

Results

Totally 259 sandflies were collected during study period. From collected samples 78.7% were male and 21.3% female. There were 8 different species. Phlebotomus kandelakii was the most prevalent one (30.8%). The average temperature, relative humidity, and average wind speed was 13.5 °C, 84%, and 2 meters per hour on the onset of sandflies' activity, respectively. These values were 18.3 °C, 85% and 1.5 meters per hour at the peak of their activity and 16 °C, 62% and 5 meters per hour at the final stage of their activity. Sand flies had one peak in July which is strongly influenced by temperature and humidity conditions. Two species of Ph. kandelakii and Phlebotomus perfilewi transcaucasicus, had the highest activity in this endemic area.

Conclusion

The results of current study will provide a guideline for control of diseases in the country.

The Delay in the Licensing of Protozoal Vaccines: A Comparative History

Although viruses and bacteria have been known as agents of diseases since 1546, 250 years went by until the first vaccines against these pathogens were developed (1796 and 1800s). In contrast, Malaria, which is a protozoan-neglected disease, has been known since the 5th century BCE and, despite 2,500 years having passed since then, no human vaccine has yet been licensed for Malaria. Additionally, no modern human vaccine is currently licensed against Visceral or Cutaneous leishmaniasis. Vaccination against Malaria evolved from the inoculation of irradiated sporozoites through the bite of Anopheles mosquitoes in 1930's, which failed to give protection, to the use of controlled human Malaria infection (CHMI) provoked by live sporozoites of Plasmodium falciparum and curtailed with specific chemotherapy since 1940's. Although the use of CHMI for vaccination was relatively efficacious, it has some ethical limitations and was substituted by the use of injected recombinant vaccines expressing the main antigens of the parasite cycle, starting in 1980. Pre-erythrocytic (PEV), Blood stage (BSV), transmission-blocking (TBV), antitoxic (AT), and pregnancy-associated Malaria vaccines are under development. Currently, the RTS,S-PEV vaccine, based on the circumsporozoite protein, is the only one that has arrived at the Phase III trial stage. The "R" stands for the central repeat region of Plasmodium (P.) falciparum circumsporozoite protein (CSP); the "T" for the T-cell epitopes of the CSP; and the "S" for hepatitis B surface antigen (HBsAg). In Africa, this latter vaccine achieved only 36.7% vaccine efficacy (VE) in 5-7 years old children and was associated with an increase in clinical cases in one assay. Therefore, in spite of 35 years of research, there is no currently licensed vaccine against Malaria. In contrast, more progress has been achieved regarding prevention of leishmaniasis by vaccine, which also started with the use of live vaccines. For ethical reasons, these were substituted by second-generation subunit or recombinant DNA and protein vaccines. Currently, there is one live vaccine for humans licensed in Uzbekistan, and four licensed veterinary vaccines against visceral leishmaniasis: Leishmune® (76-80% VE) and CaniLeish® (68.4% VE), which give protection against strong endpoints (severe disease and deaths under natural conditions), and, under less severe endpoints (parasitologically and PCR-positive cases), Leishtec® developed 71.4% VE in a low infective pressure area but only 35.7% VE and transient protection in a high infective pressure area, while Letifend® promoted 72% VE. A human recombinant vaccine based on the Nucleoside hydrolase NH36 of Leishmania (L.) donovani, the main antigen of the Leishmune® vaccine, and the sterol 24-c-methyltransferase (SMT) from L. (L.) infantum has reached the Phase I clinical trial phase but has not yet been licensed against the disease. This review describes the history of vaccine development and is focused on licensed formulations that have been used in preventive medicine. Special attention has been given to the delay in the development and licensing of human vaccines against Protozoan infections, which show high incidence worldwide and still remain severe threats to Public Health.

Arab world's growing contribution to global leishmaniasis research (1998-2017): a bibliometric study

BACKGROUND

Leishmaniasis is a parasitic disease caused by a protozoan of the Leishmania genus, and is considered a neglected tropical disease. It still remains a main public health concern at global level and in Arab world mainly in low-income countries. Therefore, this study was designed to evaluate the Arab world's growing contribution to global leishmaniasis research.

METHODS

This study describes a bibliometric review of all leishmaniasis research publications published between January 1998 and December 2017 indexed on the Scopus database.

RESULTS

The total number of publications published at global level was 17,570 papers, which achieves an average annual productivity of 878.50 papers publications. Brazil was responsible for the greatest output with the total number of publications of 3865 followed by the Unites States (n = 2729), India (n = 2119), the United Kingdom (n = 1363), and Spain (n = 1274). By limiting the analysis to the publications that have been published by Arab world, the research productivity was 993 papers, which represents 5.65% of total research output at global level in research regarding leishmaniasis. Tunisia was responsible for the greatest output from Arab world with the total number of publications of 297 followed by Sudan (n = 192), Saudi Arabia (n = 131), Morocco (n = 119) and Egypt (n = 67). Since 1998, the growth of publications on leishmaniasis fluctuates, overall showing a rising trend in both global and Arab world. There is a highly significant correlation between publication productivity related to leishmaniasis at global level and the Arab world (r = 0.936; p-value< 0.001). Leishmaniasis treatment, intracellular mechanism of infection, and lifecycle of leishmania are the major current hot topics for the research in this subject at global level and the Arab world.

CONCLUSIONS

The current study presents a novel review of the current Arab leishmaniasis-related research, and how these results are related to worldwide output. In comparison to the global research output, the Arab world produced less leishmaniasis research. The data presented in the current study by this innovative approach may serve relevant researchers to direct the global leishmaniasis research to Arab counties in which leishmaniasis is endemic.

Visceral leishmaniasis in a patient with lung tumour: a case report

An increasing use of immunosuppressant medication mandates clinicians to look for leishmaniasis even in non-HIV febrile patients. We report this case to highlight leishmaniasis as a cause of fever in patients undergoing chemotherapy in an endemic area.

Serological and entomological survey of canine leishmaniasis in Lampedusa island, Italy

BACKGROUND

During last decade Lampedusa island (Italy) has been interested by a deep social change caused by the massive arrival of migrants from north Africa. The goal of this study was to evaluate current CanL burden and risk factors for Visceral Leishmaniosis (VL) on Lampedusa, actually based on very few data obtained in a previous study performed fifteen years ago. Two hundred and forty-two dogs were enrolled for the detection of Leishmania infantum infection by serology. In addition, an entomological investigation was performed to confirm the presence of Leishmania-vectors.

RESULTS

Seroprevalence was of 54.13%. 223 sand flies specimens were collected. Among them, 4 species were identified: Phlebotomus perniciosus, P. papatasi, P. neglectus, Sergentomia minuta, with P. perniciosus the most abundant (67.7%; p < 0.01).

CONCLUSION

The high proportion of seropositive dogs together with the presence of the most competent vector for L. infantum, P. perniciosus, demonstrate that L. infantum abundantly circulates in the island and may constitute a risk for people, particularly for hosted migrants.

Subclinical Leishmania infection in patients with rheumatic diseases under biological drugs

PURPOSE

Climate changes and immunosuppression are influencing the spread of leishmaniasis and re-emergence in Northern Italy, respectively. We evaluated the prevalence of subclinical leishmaniasis in patients from a Northern Italian region with chronic inflammatory rheumatism (CIRD) receiving biological drugs (BD) and correlated it to the area of residence.

METHODS

DNA from PBMC of patients affected by CIRD treated with either BD for at least 5 years (Group A) or other immunosuppressive drugs (Group B) was investigated by a qPCR for Leishmania infantum kDNA and compared to healthy subjects (Group C). Variables such as sex and age, rural areas, dog ownership, type of BD administered and association between BD and steroids, were evaluated by statistical analysis.

RESULTS

A higher proportion of L. infantum DNA positivity was found in Group A than in Group C (p < 0.05), while no parasite DNA was detected in Group B. In Group A, 18/50 patients (36%) had higher rates of parasite DNA (from 1 to 136 to 1.000.000 copies/ml) than Group C (from 1 to 10 copies/ml). 14/18 (77.7%) of positive patients from Group A lived in rural areas, but no statistical differences occurred in relation to dog ownership or BD type (p < 0.0003).

CONCLUSIONS

We can speculate that exposure to rural areas appears to be a factor closely linked with the risk of developing Leishmania subclinical infection. A screening with molecular methods in patients with CIRD treated with BD living in these areas and monitoring Leishmania DNA during such therapies, would be mandatory to prevent delay in diagnosis should VL symptoms appear.

Imported leishmaniasis in Sweden 1993-2016

In Sweden, leishmaniasis is an imported disease and its epidemiology and incidence were not known until now. We conducted a retrospective, nationwide, epidemiological study from 1993 to 2016. Probable cases were patients with leishmaniasis diagnoses reported to the Swedish Patient registry, collecting data on admitted patients in Swedish healthcare since 1993 and out-patient visits since 2001. Confirmed cases were those with a laboratory test positive for leishmaniasis during 1993–2016. 299 probable cases and 182 confirmed cases were identified. Annual incidence ranged from 0.023 to 0.35 per 100 000 with a rapid increase in the last 4 years. Of 182 laboratory-verified cases, 96 were diagnosed from 2013 to 2016, and in this group, almost half of the patients were children under 18 years. Patients presented in different healthcare settings in all regions of Sweden. Cutaneous leishmaniasis was the most common clinical manifestation and the majority of infections were acquired in Asia including the Middle East, specifically Syria and Afghanistan. Leishmania tropica was responsible for the majority of cases (42%). A combination of laboratory methods increased the sensitivity of diagnosis among confirmed cases. In 2016, one-tenth of the Swedish population were born in Leishmania-endemic countries and many Swedes travel to these countries for work or vacation. Swedish residents who have spent time in Leishmania-endemic areas, could be at risk of developing disease some time during their lives. Increased awareness and knowledge are needed for correct diagnosis and management of leishmaniasis in Sweden.

Situational Analysis of Visceral Leishmaniasis in the Most Important Endemic Area of the Disease in Iran

BACKGROUND

Visceral leishmaniasis is one of the most important vector borne diseases in the world, transmitted by sand flies. Despite efforts to prevent the spread of the disease, cases continue worldwide. In Iran, the disease usually occurs in children under 10 years. In the absence of timely diagnosis and treatment, the mortality rate is 95-100%. The main objective of this study was to determine the spatial and temporal distribution of visceral leishmaniasis as well as its correlation with climatic factors for determining high-risk areas in an endemic focus in northwestern Iran.

METHODS

In this cross-sectional study, data on VL cases were collected from local health centers in Ardabil Province, Iran during 2001-2015 to establish a geodatabase using ArcGIS10.3. Data analysis was conducted using SPSS23 and ArcMap Spatial Analyst. MaxEnt model was used to determine ecologically suitable nichesfor the disease.

RESULTS

Two hotspots were found in Meshkinshahr and Germi counties with 59% and 23% of total cases, respectively. There was an increase in the incidence rate of VL in Ardabil County from 2.9 in 2009 to 9.2/100,000 population in 2015. There was no spatial autocorrelation between county and total number of cases (P> 0.05). Higher NDVI, lower altitude and southern aspects had positive effects on the presence probability of VL.

CONCLUSION

The number of cases of this disease have been rising since 2013 and doubled in 2015. According to the derived distribution maps, the disease is spreading to new locations such as Ardabil and Namin counties.

An overview of skin lesions adapted to Cutaneous Leishmaniasis in Persian Medicine

Background

Cutaneous Leishmaniasis (CL) which is prevalent in all continents and is classified by the WHO as one of the neglected tropical diseases, existed in the past also, and discovered ancient works confirm this issue. The lack of adaptation of diseases between Persian Medicine (PM) and Modern medicine, led to no usage of effective therapeutic experiences of prior physicians.

Objective

The purpose of this study is finding skin lesions adapted to CL in PM for usage of same disease treatment in the next clinical trials, and the use of approved therapies in CL.

Methods

In a narrative review, without time limitation, documentary study was conducted for different names and clinical aspects of CL in printed and electronic resources of modern medicine such as: Rook’s Textbook of Dermatology, Harper’s Textbook of Pediatric Dermatology, PubMed, and Embase. Then, found names were searched in printed and electronic resources of PM such as: Al-Qanun fi al-tibb, Al-Tasrif leman ajeza an-e-Taliff, JamiTib 1.5 published by Noorsoft.org. Then, skin lesions which were similar to CL with these aspects were searched: clinical manifestation and forms, chronicity, curability, mosquito bite, were studied in references of PM. Finally, matching, syllogism and logical inference were performed and conclusion was made.

Results

Forty-five names for CL were found in the searched resources. However, only Balkhieh, Kheyroonieh and Baghdadi button were names found in PM resources. Also, from 61 studied skin lesions in PM resources, only 6 cases had similarities to CL.

Conclusion

In spite of the existence of CL’s similarity with Balkhieh, Kheyroonieh and the Baghdadi button, there are serious differentiations. Zat-ol-asl rashes and reddish solb rashes, kinds of stranger rashes, probably adapted with CL.

Distinct Leishmania infantum Strains Circulate in Humans and Dogs in the Emilia-Romagna Region, Northeastern Italy

Human leishmaniasis is an emerging problem in Italy and is on the increase in the Emilia-Romagna region, northeastern part of the country. Nevertheless, studies dealing with the molecular characterization of Leishmania spp. circulating in these areas are limited. In the present work, we explored the genetic polymorphism of Leishmania isolates from 28 cases of canine leishmaniasis and three cases of human visceral leishmaniasis (VL), which occurred in 2013-2014 in the Emilia-Romagna region. The characterization was carried out in comparison with nine human isolates of Leishmania from other VL endemic Italian regions and two reference strains. Nucleic acid from 31 Leishmania-positive phlebotomine sandfly pools, sampled in 2012-2013 in the Emilia-Romagna region, were also evaluated. DNA amplification and sequencing of the ribosomal internal transcribed spacer-1 and of a repetitive nuclear region on chromosome 31 were carried out for genotyping. Two size polymorphic targets were also analyzed by PCR, the cpb E/F-gene and the k26-gene. Altogether, the analysis showed the circulation of different Leishmania infantum genotypes in the Emilia-Romagna region: two genotypes found in dogs from public kennels were similar to VL isolates from other Italian regions, whereas a third genotype was detected in VL cases of the Emilia-Romagna region and in all but one of the sandfly pools. The combined molecular tools applied in this study can constitute a helpful support for parasite tracking (e.g., in outbreak investigations) and for a better understanding of the epidemiological evolution of leishmaniasis in northeastern Italy.

Non-invasive diagnosis of cutaneous leishmaniasis by the direct boil loop-mediated isothermal amplification method and MinION™ nanopore sequencing

Cutaneous leishmaniasis (CL) is gaining attention as a public health problem. We present two cases of CL imported from Syria and Venezuela in Japan. We diagnosed them as CL non-invasively by the direct boil loop-mediated isothermal amplification method and an innovative sequencing method using the MinION™ sequencer. This report demonstrates that our procedure could be useful for the diagnosis of CL in both clinical and epidemiological settings.

Visceral leishmaniasis: a forgotten epidemic

Visceral leishmaniasis (VL or kala-azar) is most endemic in Asia and Africa and commonly affects young children. It is usually caused by Leishmania donovani or Leishmania infantum that are transmitted by Phlebotomine sand flies. Transmission may be anthroponotic or zoonotic or both, depending on the endemic area. Clinical features include fever, hepatosplenomegaly, weight loss and pancytopenia. Younger age, malnutrition and immunosuppression (HIV infection, use of immunosuppressive drugs) are risk factors. Many infections remain asymptomatic. Diagnosis is made by demonstration of the Leishmania parasite in aspirates of lymph node, bone marrow or spleen. Serological tests such as rK39 strip test are widely used but the sensitivity varies. qPCR is useful to detect low numbers of parasites and to monitor treatment. Treatment is with AmBisome monotherapy in most areas but with drug combinations elsewhere. HIV co-infected patients are most difficult to treat and often relapse. Control efforts focus on case finding, availability of diagnostic tools, reservoir control and protection from sand flies (insecticides, bed nets). There is no human vaccine.