First molecular epidemiological study of cutaneous leishmaniasis in Libya

Epidemiological Mapping of Cutaneous Leishmaniasis in Saudi Arabia: An Observational Descriptive Study

Cutaneous leishmaniasis (CL) is a parasitic disease that affects individuals worldwide. An epidemiological observational population-cohort study was conducted on the basis of comprehensive research on CL incidence in Saudi and non-Saudi residents. The Ministry of Health recorded the incidence of CL between January 2020 and December 2022. The chi-square test was used to analyze the data and determine CL incidence rates in age-specific incidence rates (ASIRs) and gender between Saudi and non-Saudi residents in Saudi Arabia. The study found that between 2020 and 2022, there were 2280 cases of CL in Saudi Arabia, with 1367 and 913 cases in men and women, respectively. Of Saudi nationals, 64.26% and 12.91% were male and female, respectively. The frequency of CL was higher (87.09%) among non-Saudi residents than among Saudi nationals, with a statistically significant difference (P = 0.001) between the two groups. The ASIRs for CL were higher in patients aged 15-45 years. This study revealed variations in CL incidence rates among the 13 administrative regions; Qassim, followed by Aseer, Ha'il, and Madinah, had higher rates than the other regions. These findings indicate the need for targeted interventions and public health strategies to reduce the burden on CL, particularly among non-Saudi residents.

Genetic Diversity of Leishmania major Isolated from Different Dermal Lesions Using ITS2 Region

BACKGROUND AND OBJECTIVE

Cutaneous leishmaniasis (CL) is still considered to be an uncontrolled endemic disease that spreads in many countries. The current study aimed to determine intra-species relationships of L. major using ITS2 sequencing.

METHODS

The study was conducted from the beginning of March to the end of November 2022. All medical information regarding CL was collected from patients of Thi-Qar province who attended the Dermatology Department of Al-Hussein Teaching Hospital in Nasiriyah city. Seventy-three samples were selected for the molecular identification after confirming microscopy with Giemsa stain. In this study, the primers were designed using NCBI GenBank sequence database and Primer 3 plus primer design online software.

RESULTS

The results recorded 21 (28.77%) positive samples of L. major using the internal transcribed spacer 2 region (ITS2) in ribosomal RNA gene. The local L. major IQN.1-IQN.10 were submitted to NCBI GenBank database with accession numbers OM069357.1-OM069366.1, respectively. The phylogenetic analysis revealed that local isolates of L. major showed a close relationship with NCBI-BLAST L. major Iran isolate (KU680848.1).

CONCLUSION

ITS2-PCR is suitable for identifying Leishmania spp. and determining genetic diversity. A phylogenetic data analysis may provide an idea on the genetic homogeneity of local isolates and knowing the genetic origin of the dermal lesion. However, the local isolates showed genetic proximity to the KU680848.1 isolate. This signifies the possibility of infection prevalence from Iranian areas. In general, genetic variation of L. major isolates may give several clinical manifestations of the cutaneous lesion. Therefore, determination of the heterogeneity is important for detecting the infection origin, epidemiology, therapy, and control strategies.

Cutaneous Leishmaniasis Prevalence and Clinical Overview: A Single Center Study from Saudi Arabia, Eastern Region, Al-Ahsa

Cutaneous leishmaniasis (CL) is a vector-borne parasitic disease that is transmitted via the bites of infected female sandflies. CL has been endemic in several countries worldwide for many decades, and numerous cases have been reported in Saudi Arabia, particularly across six regions; one of which is AL-Ahsa. Our research aimed to evaluate the epidemiological situation of CL among the patients in Al-Ahsa, Eastern region, Kingdom of Saudi Arabia, during the period from 2017 to 2023. The data were collected from the patients' registries and included 245 patients who were diagnosed with CL in Al-Ahsa, Saudi Arabia. Fewer than half of the cases (47.8%) were Saudi patients, with a significant number of them being males (84.5%). Over half of the cases (52.7%) were aged between 21 and 40 years, and about three-quarters (74.7%) of the cases resided in rural areas. Regarding the nature of the lesions, 38.4% of the cases had one lesion, which was mainly distributed on a lower extremity (62.0%) or an upper extremity (52.2%). A high percentage of the lesions (75.2%) were wet lesions and caused by L. major. Concerning risk factors, a greater number of patients (71.4%) had been in rural areas within the last three months. Additionally, more than half of the cases (54.3%) had close contact with rodents, followed by birds (28.2%), sheep (22.0%), dogs (16.3%), and other animals (1.2%). The results showed a low number of reported CL cases in 2020 and 2021, followed by a surge in 2022 and 2023. The study shows that cutaneous leishmaniasis is still a public health problem in Al-Ahsa and is primarily associated with rural areas.

Seasonal Patterns of Zoonotic Cutaneous Leishmaniasis Caused by L. major and Transmitted by Phlebotomus papatasi in the North Africa Region, a Systematic Review and a Meta-Analysis

BACKGROUND

In North African countries, zoonotic cutaneous leishmaniasis (ZCL) is a seasonal disease linked to Phlebotomus papatasi, Scopoli, 1786, the primary proven vector of L. major dynamics. Even if the disease is of public health importance, studies of P. papatasi seasonal dynamics are often local and dispersed in space and time. Therefore, a detailed picture of the biology and behavior of the vector linked with climatic factors and the framework of ZCL outbreaks is still lacking at the North African countries' level. Our study aims to fill this gap via a systematic review and meta-analysis of the seasonal incidence of ZCL and the activity of P. papatasi in North African countries. We address the relationship between the seasonal number of declared ZCL cases, the seasonal dynamic of P. papatasi, and climatic variables at the North African region scale.

METHODS

We selected 585 publications, dissertations, and archives data published from 1990 to July 2022. The monthly incidence data of ZCL were extracted from 15 documents and those on the seasonal dynamic of P. papatasi from 11 publications from four North African countries.

RESULTS

Our analysis disclosed that for most studied sites, the highest ZCL incidence is recorded from October to February (the hibernal season of the vector), while the P. papatasi density peaks primarily during the hot season of June to September. Overall, at the North African region scale, two to four months laps are present before the apparition of the scars reminiscent of infection by L. major.

CONCLUSIONS

Such analysis is of interest to regional decision-makers for planning control of ZCL in North African countries. They can also be a rationale on which future field studies combining ZCL disease incidence, vector activity, and climatic data can be built.

Highly sensitive nested polymerase chain reaction to improve the detection of Leishmania species in clinical specimens

Cutaneous leishmaniasis (CL) is one of the most neglected tropical diseases and an important health problem in many countries. It is an endemic disease in most regions of Iraq, while being non-endemic in the Kurdistan Region. The techniques frequently used for detection of CL are not very sensitive. Therefore, this study aimed to identify a sensitive method for diagnosis of CL in clinical samples. The present study was performed in December 2019 to December 2020 in Kalar General Hospital. Clinical samples were collected from 85 suspected CL cases. Sixty-four (75.29%), 71 (83.53%) and 84 (98.82%) cases were detected as positive for CL by microscopy, PCR, and nested PCR, respectively. Of the 84 nested PCR-confirmed CL patients, 46 (54.8%) were female and 38 (45.2%) were male. The most predominate rate of infection was in the 30-39-year age group (29.76%) and the lowest was in the ≥ 60-year group (3.57%). Forty (47.62%) patients had a single lesion. The statistical analysis showed significant differences between age groups and between the number of lesions. The sensitivities of microscopy, conventional PCR, and nested PCR were 80.77%, 86.6% and 100%, respectively, while all three methods showed 100% specificity. Furthermore, PCR-ITS1 followed by a simple restriction fragment length polymorphism (RFLP) analysis using HaeIII endonuclease indicated that Leishmania major was responsible for all CL infections in the study area.

Phlebotomine sand flies (Diptera: Psychodidae) of the Maghreb region: A systematic review of distribution, morphology, and role in the transmission of the pathogens

BACKGROUND

Phlebotomine sand flies (Diptera: Psychodidae) are important vectors of various human and animal pathogens such as Bartonella bacilliformis, Phlebovirus, and parasitic protozoa of the genus Leishmania, causative agent of leishmaniases that account among most significant vector-borne diseases. The Maghreb countries Mauritania, Morocco, Algeria, Tunisia, and Libya occupy a vast area of North Africa and belong to most affected regions by these diseases. Locally varying climatic and ecological conditions support diverse sand fly fauna that includes many proven or suspected vectors. The aim of this review is to summarize often fragmented information and to provide an updated list of sand fly species of the Maghreb region with illustration of species-specific morphological features and maps of their reported distribution.

MATERIALS AND METHODS

The literature search focused on scholar databases to review information on the sand fly species distribution and their role in the disease transmissions in Mauritania, Morocco, Algeria, Tunisia, and Libya, surveying sources from the period between 1900 and 2020. Reported distribution of each species was collated using Google Earth, and distribution maps were drawn using ArcGIS software. Morphological illustrations were compiled from various published sources.

RESULTS AND CONCLUSIONS

In total, 32 species of the genera Phlebotomus (Ph.) and Sergentomyia (Se.) were reported in the Maghreb region (15 from Libya, 18 from Tunisia, 23 from Morocco, 24 from Algeria, and 9 from Mauritania). Phlebotomus mariae and Se. africana subsp. asiatica were recorded only in Morocco, Ph. mascitti, Se. hirtus, and Se. tiberiadis only in Algeria, whereas Ph. duboscqi, Se. dubia, Se. africana africana, Se. lesleyae, Se. magna, and Se. freetownensis were reported only from Mauritania. Our review has updated and summarized the geographic distribution of 26 species reported so far in Morocco, Algeria, Tunisia, and Libya, excluding Mauritania from a detailed analysis due to the unavailability of accurate distribution data. In addition, morphological differences important for species identification are summarized with particular attention to closely related species such as Ph. papatasi and Ph. bergeroti, Ph. chabaudi, and Ph. riouxi, and Se. christophersi and Se. clydei.

Comparative Testing of Susceptibility Levels of Phlebotomus sergenti, the Main Vector of Anthroponotic Cutaneous Leishmaniasis, to Conventional Insecticides Using Two Capture Methods in Kerman City, Southeastern Iran

Background:

Collecting live sand flies from indoor sites is a major challenge for researchers in large cities due to the reluctance of families to survey their homes. This study was conducted to assess the efficacy of two methods for collecting sand flies for use in susceptibility tests in the urban area of Kerman, southeastern Iran.

Methods:

Sandflies were mainly collected using both baited traps and hand catch methods from outdoor and indoor sites. Susceptibility tests were separately done according to the standard World Health Organization testing protocol on Phlebotomus sergenti, including 60-minute exposure to DDT 4.0%, propoxur 0.1%, deltamethrin 0.05%, and malathion 5.0%.

Results:

During this research, the natural habitats and suitable indoor sites were selected to predict the density of live sand fly with perfect accuracy. The number of live Ph. sergenti caught by hand catch and baited traps methods was 42 and 361 in indoor and outdoor sites, respectively. The mortality rate of Ph. sergenti exposed to DDT 4%, deltamethrin 0.05, malathion 5%, and propoxur was 100%.

Conclusion

The baited traps showed a significant efficiency compared to hand catch for collecting live Ph. sergenti for use in susceptibility tests in urban areas. The Ph. sergenti collected from both indoor and outdoor sites were susceptible to all insecticides.

Eco-epidemiological aspects of Zoonotic cutaneous leishmaniasis in Ouarzazate Province, Morocco

Some epidemiological and ecological aspects of Zoonotic cutaneous leishmaniasis (ZCL) in Ouarzazate province, southern Morocco, were explored with the objective of analyzing ZCL distribution and associated ecological factors. Information on cutaneous leishmaniasis patients attending the local health centers of Ouarzazate during the period 2002-2009 was gathered and compiled. Urban, peri-urban, rural origin, precipitation, wind speed, temperature, water irrigation, dam volume, and altitude were studied. The findings show that the disease affected 5405 person during this period; the major part was found in the municipalities near both oases (desert oasis) and water resources, with a high concentration of cases in the peri-urban area. The highest percentage of cases was recorded mainly in September. Considerable associations were found between relative humidity and wind speed with ZCL occurrence. A large number of cases were recorded in areas with altitude ranging from 800 to 2000 m.a.s.l. and spatial precipitation from 15 to 150 mm. The statistical analysis showed a strong association between water storage volume and water irrigation with the annual ZCL occurrence recorded in the downstream area (Zagora province). The results will lead us to understand ZCL risk areas for effective control. Further work is needed mainly for gathering these variables in one single and simplest model.

Clinical, parasitological and molecular profiles of Cutaneous Leishmaniasis and its associated factors among clinically suspected patients attending Borumeda Hospital, North-East Ethiopia

BACKGROUND

Cutaneous leishmaniasis is one of the most neglected tropical diseases increasing in its public health importance. In Ethiopia over 28 million people are living at risk of infection.

METHOD

Institution based cross-sectional study was conducted at Borumeda Hospital from February to May 2019. A total 205 leishmaniasis suspected patients were included by systematic random sampling technique. Socio demographic characteristics were collected using pre-tested questionnaires. Parasitological investigation was done from skin slit sample by using Geimsa staining method. Species identification was done by PCR-RFLP. Data were entered in to EpiData version 3.1 and analyzed using SPSS version 20 software. P-value of ≤ 0.05 was considered as statistically significant.

RESULT

A total of 205 participants consisting 59% male and 41% female included in this study. The mean age (±SD) of the study participants was 31.9 (±14.29). The overall prevalence of cutaneous leishmaniasis was 22.4% (46/205). The prevalence in males (13.7%) was higher than in females (8.8%). It was more prevalent in the age group 16-45years old (15.6%). Clinically, 60% of patients' hade single lesion with 1.55 average number of lesions. About 30.7% of patients' had indurated plaque type of lesion. Most of the lesions were found on head and face (59%). House near to farmland, presence of hyrax in the village and presence of other cutaneous leishmaniasis cases in the neighborhood were independent predicator of cutaneous leishmaniasis prevalence. L.aethopica was found to be the etiologic agent of cutaneous leishmaniasis in the study participants.

CONCLUSION

The prevalence of cutaneous leishmaniasis was 22.4%, this alerts the need of intervention. It is statistically associated with house near to farm land, presence of other cutaneous leishmaniasis cases in the neighborhood and presence of hyrax in village. Head and face were the most common sites of lesion.

Detection, genotyping, and phylogenetic analysis of Leishmania isolates collected from infected Jordanian residents and Syrian refugees who suffered from cutaneous leishmaniasis

Leishmania is a parasitic protozoan which is transmitted to humans through the bite of an infected female Phlebotomus and Lutzomyia sand flies. Cutaneous leishmaniasis (CL), caused by Leishmania major and L. tropica, is an endemic disease in many areas of Jordan and considered as a major public health problem. The political instability in the Syrian Arab Republic has resulted in the immigration of large number of refugees into Jordan where most of them resided in camps near the Syrian borders. Therefore, the main objective of the present study was to inspect Leishmania species/genotypes which are responsible for CL infections among Syrian refugees and compare them with the recovered species/genotypes isolated from Jordanian patients. Three molecular-based assays (ITS1-PCR-RFLP, Nested ITS1-5.8S rDNA PCR, and Kinetoplast DNA PCR) followed by sequencing and phylogenetic analysis were undertaken and compared for their efficiency to confirm CL diagnosis and genotype the infecting Leishmania species. Thereafter, the evolutionary relationships among various Leishmania isolates from Syrian and Jordanian CL patients were elucidated. Results from the present study indicated that 20 and 9 out of the inspected 66 patients (39 Jordanian and 27 Syrian) were infected with L. major and L. tropica respectively. ITS1-PCR RFLP typing proved to be more sensitive in the detection of Leishmania species (positive in 44% of the isolates) compared to both ITS1-5.8S rDNA gene and Kinetoplast DNA PCR which were successful in identifying Leishmania species only in 23% and 33% of the isolates respectively. Sequencing and phylogenetic analysis of ITS1 and ITS1-5.8S rDNA genes revealed high levels of heterogeneity among the sequenced isolates. One sample typed as L. tropica from Jordanian patient showed high similarity with L. tropica sample isolated from a Syrian patient in a Lebanon refugee camp; therefore, the need for comprehensive studies to confirm if any new L. tropica strains might be introduced to Jordan by Syrian refugees is urgently indicated. These observations highlighted the need for further studies to clarify the risk status of species and strains which might be introduced from Syria to Jordan.

A newly emerged focus of zoonotic cutaneous leishmaniasis in South-western Iran

Leishmaniasis is rising in many countries, including Iran, due to climate change, refugee crises, urbanization and etc. The aim of this study was to explore the epidemiology, extent and identity of Leishmania species in a newly emerged focus in Abdanan County, Ilam Province, South-western Iran. This study was performed as a descriptive cross-sectional study by a systematic house-to-house approach. The Leishmania species was identified by RFLP-PCR and sequencing. Altogether, 46799 individuals consisting of 22907 (48.9) female and 23892 (51.1%) male were interviewed and physically examined for the presence of skin lesions. Overall, the incidence rate was 0.34% (n = 160). All age groups were affected and the incidence rate was the highest in <10 years of age group (0.49%) and the lowest in >50 years old individuals (0.15%), although there was no significant difference regarding the sex and age. The majority of patients had one lesion (47.5%) on hands (56%) and most of the cases occurred in Abdanan city (%54) in summer. Based on the RFLP-PCR analysis, all the Leishmania isolates were L. major of single genotype. A newly emerged focus of zoonotic CL caused by L. major occurred in South-western of Iran. Multiple risk factors created this epidemic area. Further studies on the vector and reservoir are crucial needed to provide evidences to select the prophylactic and therapeutic measures for future control strategies.

Natural Infection of Phlebotomus sergenti by Leishmania tropica in Libya

Cutaneous Leishmaniasis (CL) is a public health concern caused by Leishmania (L.) major and L.tropica in Libya. Information on sandfly vectors, as well as their associated Leishmania species, is of paramount importance because vector dispersion is one of the major factors responsible for pathogen dissemination. A number of 515 sandflies (275 males and 240 females) were collected during June-November 2012 using the Centers for Disease Control miniature light traps from Al Rabta, northwest of Libya. Two hundred and forty unfed females were identified; Phlebotomus (Ph.) papatasi (N = 97), Ph. sergenti (N = 27), Ph. longicuspis (N = 32), Sergentomyia (Se.) minuta (N = 38), and Se. fallax (N = 46). These flies were screened for Leishmania DNA using the polymerase chain reaction-restriction fragment length polymorphism analysis of the internal transcribed spacer 1 and sequencing. Two Ph. sergenti were found positive to L. tropica DNA. This finding should be considered for any further vector surveillance and epidemiological studies of CL in endemic areas across Libya.

A pyoderma gangrenous-like cutaneous leishmaniasis in a Libyan woman with rheumatoid arthritis: a case report

Background

Several case reports describe diseases presenting with skin ulcerations, which resemble pyoderma gangrenosum especially in immune-compromised patients, often proven on further workup, to have an infective or malignant etiology. However, treatment of pyoderma gangrenosum by systemic steroids or other immunosuppressive agents may worsen the condition.

Case presentation

We report here, a 45 year-old Libyan woman with rheumatoid arthritis on low dose steroids with pyoderma gangrenosum-like skin lesions and positive pathergy. Slit–smear was positive for Leishmania amastigotes and histopathological examination confirmed the diagnosis of cutaneous leishmaniasis. The lesions healed completely by parenteral sodium stibogluconate (Pentostam) 600 mg daily.

Conclusion

We report for the first time, a rare and unusual presentation of pyoderma gangrenosum like-cutaneous leishmaniasis in a patient with rheumatoid arthritis. Atypical cutaneous leishmaniasis should not be ruled out in the differential diagnosis of unresponsive skin diseases, with slit/smear and a skin biopsy is required.

Electronic supplementary material

The online version of this article (10.1186/s13104-018-3272-2) contains supplementary material, which is available to authorized users.

Molecular identification of Leishmania spp. isolates causes cutaneous leishmaniasis (CL) in Sanliurfa Province, Turkey, where CL is highly endemic

Cutaneous leishmaniasis (CL) is an important public health problem in Turkey. CL has been most frequently seen in Sanliurfa. There is an expectation of increase in the population of leishmaniasis cases with the influence of Syrian refugees arriving in Turkey. In this study we aimed to diagnosis of CL and identifying of parasite from Leishmania isolates by using ITS 1 PCR RFLP. Samples were collected from 135 CL patients in Sanliurfa. After the specimens were inoculated in medium NNN, the ones which were cultures positive were cultivated in RPMI 1640 followed by PCR-RFLP. Genomic DNA was extracted phenol-chloroform procedure. Samples were examined by using ITS 1 PCR followed by RFLP analysis. Our results indicated that two species, L. tropica (132 samples) and L. major (3 samples), are responsible for cutaneous leishmaniasis in Sanlıurfa. Our study is the first scientific study in which it is reported molecular analyses of cutaneous leishmaniasis cases caused by L. major in Sanliurfa in Southestern Anatolia Region. Because CL cases caused by L.major are detected in our study, it is considered that genotyping is important for diagnosis of Leishmania and following change of epidemiology.

Spatiotemporal and molecular epidemiology of cutaneous leishmaniasis in Libya

Background

Cutaneous leishmaniasis (CL) is a major public health problem in Libya. In this paper, we describe the eco-epidemiological parameters of CL during the armed conflict period from January 2011 till December 2012. Current spatiotemporal distributions of CL cases were explored and projected to the future using a correlative modelling approach. In addition the present results were compared with our previous data obtained for the time period 1995–2008.

Methodology/Principal findings

We investigated 312 CL patients who presented to the Dermatology Department at the Tripoli Central Hospital and came from 81 endemic areas distributed in 10 districts. The patients presented with typical localized lesions which appeared commonly on the face, arms and legs. Molecular identification of parasites by a PCR-RFLP approach targeting the ITS1 region of the rDNA was successful for 81 patients with two causative species identified: L. major and L. tropica comprised 59 (72.8%) and 22 (27.2%) cases, respectively. Around 77.3% of L. tropica CL and 57.7% of L. major CL caused single lesions. Five CL patients among our data set were seropositive for HIV. L. tropica was found mainly in three districts, Murqub (27.3%), Jabal al Gharbi (27.3%) and Misrata (13.7%) while L. major was found in two districts, in Jabal al Gharbi (61%) and Jafara (20.3%). Seasonal occurrence of CL cases showed that most cases (74.2%) admitted to the hospital between November and March, L. major cases from November till January (69.4%), and L. tropica cases mainly in January and February (41%). Two risk factors were identified for the two species; the presence of previously infected household members, and the presence of rodents and sandflies in patient’s neighborhoods. Spatiotemporal projections using correlative distribution models based on current case data and climatic conditions showed that coastal regions have a higher level of risk due to more favourable conditions for the transmitting vectors.

Conclusion

Future projection of CL until 2060 showed a trend of increasing incidence of CL in the north-western part of Libya, a spread along the coastal region and a possible emergence of new endemics in the north-eastern districts of Libya. These results should be considered for control programs to prevent the emergence of new endemic areas taking also into consideration changes in socio-economical factors such as migration, conflicts, urbanization, land use and access to health care.

Cutaneous leishmaniasis (CL) is a skin infection caused by a single-celled parasite that is transmitted by the bite of a phlebotomine sandfly. CL is the most common form of leishmaniasis characterized by localized lesions in the skin and mucous membranes. The disease is prevalent in all countries around the Mediterranean Basin. In this paper, we describe spatiotemporal and eco-epidemiological parameters of CL in Libya. Moreover, we explored current spatiotemporal distributions of CL cases and explored the future projection of the disease. Our study indicates the presence of higher risk of CL in the coastal regions of Libya. Future projection until 2060 showed a trend of increasing incidence of CL in the north-western part of Libya, a spread along the coastal region and a possible emergence of new endemics in the north-eastern districts of Libya. These scenarios should be considered by health authorities in order to develop appropriate intervention strategies and plan effective control programs.

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.

Molecular Characterization of Leishmania Parasites in Giemsa-Stained Slides from Cases of Human Cutaneous and Visceral Leishmaniasis, Eastern Algeria

BACKGROUND

In Algeria, visceral leishmaniasis (VL) is due to Leishmania (L.) infantum, while three cutaneous forms (CL) are caused by Leishmania major, Leishmania tropica and Leishmania infantum. In this study, the use of Giemsa-stained slides was evaluated with two PCR techniques, in Eastern Algeria.

MATERIALS AND METHODS

A total of 136 samples corresponding to 100 CL smears (skin scrapings) and 36 VL slides (bone marrow aspirates) collected from 2008 to 2014 were tested. Upon DNA extraction, two PCRs were used to amplify the ribosomal Internal Transcribed Spacer 1 (ITS1) and mini-exon genes. Amplified products were digested (PCR-RFLP) and profiles analyzed for Leishmania species identification. A statistical analysis was also performed.

RESULTS

ITS1-PCR was found significantly more sensitive than mini-exon-PCR (77.95% positives vs. 67.65%; p = 0.001). Comparison of PCR positivity showed statistically significant differences between old and recently prepared slides suggesting a better use of recent slides in PCR analyses. For species identification, PCR-restriction fragment length polymorphism (RFLP) results of ITS1 and mini-exon were concordant. L. infantum was identified from VL cases and L. infantum, L. major, and L. tropica from CL ones. According to geographical origin, L. infantum was found in North-Eastern provinces, while L. major was distributed from the North to the Center-East of Algeria. Interestingly, two L. tropica samples were identified in Annaba, located far North-East Algeria.

CONCLUSION

Distribution of leishmaniasis in Eastern parts of Algeria, besides finding of L. tropica in the far North, is in this study described for the first time using molecular tools, thus confirming the usefulness of slides for PCR identification of Leishmania parasites in retrospective epidemiological investigations.

Clinicoepidemiologic pattern of cutaneous leishmaniasis and molecular characterization of its causative agent in Hajjah governorate, northwest of Yemen

The clinicoepidemiologic profile of 143 cases (93 males and 50 females) with cutaneous leishmaniasis from 18 villages of Hajjah governorate, Yemen was studied. Dry-type lesions were seen in 98.6% and wet-type lesions in 1.4% of patients. Lesions were localized in all cases with different morphological patterns. Microscopic examination of Giemsa-stained slit smears revealed amastigotes in 74.1% of patients with dry-type lesions and 0% in patients with wet-type lesions. The burden of the parasites in the lesions was high indicating active transmission of the disease. Most cases were from villages with moderate altitude range (8001-1600m). All age groups were affected, but most cases were seen in ages from 5 to 15 years. Leishmania species identification was done for all cases by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The biopsic material was scraped from both Giemsa-stained and methanol-fixed smears. The molecular characterization of Leishmania species revealed Leishmania tropica as the causative agent of cutaneous leishmaniasis in Hajjah, Yemen. The risk factors associated with the transmission of the disease and recommendations for improving case detection were discussed.

Coarse-resolution Ecology of Etiological Agent, Vector, and Reservoirs of Zoonotic Cutaneous Leishmaniasis in Libya

Cutaneous leishmaniasis ranks among the tropical diseases least known and most neglected in Libya. World Health Organization reports recognized associations of Phlebotomus papatasi, Psammomys obesus, and Meriones spp., with transmission of zoonotic cutaneous leishmaniasis (ZCL; caused by Leishmania major) across Libya. Here, we map risk of ZCL infection based on occurrence records of L. major, P. papatasi, and four potential animal reservoirs (Meriones libycus, Meriones shawi, Psammomys obesus, and Gerbillus gerbillus). Ecological niche models identified limited risk areas for ZCL across the northern coast of the country; most species associated with ZCL transmission were confined to this same region, but some had ranges extending to central Libya. All ENM predictions were significant based on partial ROC tests. As a further evaluation of L. major ENM predictions, we compared predictions with 98 additional independent records provided by the Libyan National Centre for Disease Control (NCDC); all of these records fell inside the belt predicted as suitable for ZCL. We tested ecological niche similarity among vector, parasite, and reservoir species and could not reject any null hypotheses of niche similarity. Finally, we tested among possible combinations of vector and reservoir that could predict all recent human ZCL cases reported by NCDC; only three combinations could anticipate the distribution of human cases across the country.

Molecular prevalence and estimated risk of cutaneous leishmaniasis in Libya

BACKGROUND/PURPOSE

Cutanoeus leishmaniasis (CL) is an endemic disease in the Mediterranean area including Libya. The aim of the present study is to detect the prevalent Leishmania species obtained from smeared cutaneous lesions in addition to studying the diverse sociodemographic risk factors of the reported cases from different provinces of Libya.

METHODS

A total of 250 archived microscopic slides from clinically suspected cases of CL attending the leishmaniasis clinic in the Dermatology Department, Tripoli Central Hospital, Tripoli, Libya, were microscopically examined. Leishmania-DNA was amplified using combined polymerase chain reaction (PCR) targeting kinetoplast-DNA (kDNA) and ribosomal internal transcribed spacer 1 (ITS1)-DNA with restriction fragment length polymorphism analysis for direct Leishmania species identification.

RESULTS

Using kDNA and ITS1-PCR, 22.5% and 20% of cases were positive, respectively. Only 14.4% of cases were positive using microscopy. Nominating ITS1-PCR as the reference standard, kDNA-PCR assay was highly sensitive while microscopy was 100% specific but of limited sensitivity (72%) with a substantial agreement and an overall accuracy of 94.4%. Leishmania major and Leishmania tropica were the predominant species reported from the north-western provinces including Tripoli, Zintan, and Gharyan with their related subprovinces; Asabaa, Mizdan, Alkawasem, and Alorban. CL prevailed more among men and residents of rural areas. House wives and students were the most affected professions. Children were the least affected, while the middle-aged were the most affected age group.

CONCLUSION

L. major and L. tropica are the predominant species in the north-western regions of Libya. ITS1-PCR-restriction fragment length polymorphism assay offered a sensitive, specific, and faster diagnostic method especially with negative parasitologic examination.

Entomological studies of phlebotomine sand flies (Diptera: Psychodidae) in relation to cutaneous leishmaniasis transmission in Al Rabta, North West of Libya

Al Rabta in the North-West of Libya is a rural area where cutaneous leishmaniasis (CL) is endemic for long time. Few reports are available on sand flies in this area which is an important focus of CL. Therefore, this study aimed at updating the species composition, and monthly fluctuation of sand flies in this area. Sand flies were biweekly collected by CDC light traps from June to November 2012 and April to November 2013 in two villages, Al Rabta East (RE) and Al Rabta West (RW). Nine species (6 Phlebotomus and 3 Sergentomyia) were reported in the two villages. A total of 5605 and 5446 flies were collected of which Phlebotomus represented 59.30 and 56.63% in RE and RW, respectively. Sergentomyia minuta and Phlebotomus papatasi were the abundant species. Generally, more males were collected than females for all species. The overall ratios (males: females) for most of species were not deviated from the expected 1:1 ratio (Chi-squared, P>0.05). Sand fly abundance (fly/trap) is directly related to the temperature and RH (P<0. 01) while it inversely related to wind velocity (P>0.05). Flies were active from April to November with increased activity from June to October. Prominent peaks were in September and June. The abundance of P. papatasi and Phlebotomus sergenti, vectors of CL (August-October) coincided with the reported higher numbers of CL cases (August- November). The obtained results could be important for the successful planning and implementation of leishmaniasis control programs.

Resurgence of cutaneous leishmaniasis in Israel, 2001-2012

Cutaneous leishmaniasis has long been endemic in Israel. After a 15-year period of moderate illness rates, reported incidence increased from 0.4 cases per 100,000 population in 2001 to 4.4 cases per 100,000 population in 2012, and the disease emerged in areas where its presence had previously been minimal. We analyzed all cases reported to the national surveillance system and found that outbreak patterns revealed an expansion of Leishmania major infections over large areas in the southern part of the country and the occurrence of spatially focused L. tropica outbreaks in the northern part of the country. Outbreaks often followed new construction in populated areas. Further study of factors affecting the transmission of cutaneous leishmaniasis is needed in Israel, as well as the development of effective methods to control the disease, an increase in awareness among health care professionals, and intensive public education regarding control measures in areas of known leishmaniasis foci.

Comparison of PCR methods for detection of Leishmania siamensis infection

BACKGROUND

Leishmania siamensis, a newly identified species, has been reported as a causative agent of leishmaniasis in Thailand. This organism has been identified and genetically characterized using PCR techniques based on several target genes. However, the sensitivities and specificities of these methods for the diagnosis of L. siamensis infection have never been evaluated.

METHODS

To evaluate the sensitivities and specificities of PCR methods to detect L. siamensis infection, PCR for different genetic markers, i.e., the small subunit ribosomal RNA region (SSU-rRNA), the internal transcribed spacer 1 region (ITS1), cysteine protease B (cpb), cytochrome b (cyt b), heat shock protein 70 (hsp70), the spliced leader mini-exon, and the triose-phosphate isomerase (tim) genes were compared.

RESULTS

Both the ITS1-PCR and the SSU rRNA-PCR could detect promastigote of L. siamensis at concentrations as low as 0.05 parasites/μl or the DNA concentration at 2.3 pg/μl. Though the ITS1-PCR method only recognized 8 samples as positive, all of these could be assessed as true positive according to microscopic diagnosis and/or amplifying the results of the PCR and their sequencing, while other methods also produced false positive results. Compared with the ITS1-PCR method, the PCR amplified SSU-rRNA and cpb gene showed 100% sensitivity for the detection of L. siamensis in clinical specimens. The PCR amplified mini-exon and hsp70 gene also gave a high sensitivity of 87.5%. In contrast, the PCR methods for cyt b and tim gene showed low sensitivity. The PCR methods for cyt b, mini-exon and tim gene showed 100% specificity compared with the ITS1-PCR.

CONCLUSION

As a result, the ITS1-PCR method is a suitable target for PCR-based detection of L. siamensis infection in clinical specimens due to its high sensitivity and specificity. The results of this study can be used for molecular diagnosis as well as in epidemiological studies of L. siamensis in affected areas.

Contact dermatitis-like cutaneous leishmaniasis in a Libyan HIV patient

Background

Cutaneous leishmaniasis (CL) is one of the common tropical protozoal diseases caused by various Leishmania species, and transmitted by the sand-fly vectors, Phlebotomus and Lutzomyia species. Herein, we report for the first time a case of CL that presented as large eczematous plaques occurring on the dorsi of both feet in a Libyan drug addicted, alcoholic patient with HIV infection.

Findings

A 34 year-old HIV-positive, alcoholic, drug addicted Libyan male presented to us with a history of a non-itchy skin lesions on the dorsi of both feet of 5-weeks duration. Systemic and topical antibiotics were given without improvement. Diagnosis of this patient was confirmed by observation of Leishmania amastigote bodies in stained slit-skin smear skin biopsy. After parenteral administration of sodium stiboglyconate (Pentostam) (20 mg/kg/day) for 28 days the lesions did not show any marked improvement. Concurrently, combination therapy of oral rifampicin (600 mg/day) and isoniazide (300 mg/day) was given for 8 weeks. Complete healing of lesions was achieved after this treatment and skin-slit smears turned negative.

Conclusions

Localized cutaneous leishmaniasis should be remembered in deferential diagnosis of unresponsive contact dermatitis especially for HIV-positive patients in CL endemic areas.

This patient was not responding to Pentostam therapy, which is not very common in Libya. Interestingly, combination of oral rifampicin (600 mg/day) and isoniazide (300 mg/day) can be a successful alternative therapy.

Leishmaniasis transmission: distribution and coarse-resolution ecology of two vectors and two parasites in Egypt

INTRODUCTION

In past decades, leishmaniasis burden has been low across Egypt; however, changing environment and land use has placed several parts of the country at risk. As a consequence, leishmaniasis has become a particularly difficult health problem, both for local inhabitants and for multinational military personnel.

METHODS

To evaluate coarse-resolution aspects of the ecology of leishmaniasis transmission, collection records for sandflies and Leishmania species were obtained from diverse sources. To characterize environmental variation across the country, we used multitemporal Land Surface Temperature (LST) and Normalized Difference Vegetation Index (NDVI) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) for 2005-2011. Ecological niche models were generated using MaxEnt, and results were analyzed using background similarity tests to assess whether associations among vectors and parasites (i.e., niche similarity) can be detected across broad geographic regions.

RESULTS

We found niche similarity only between one vector species and its corresponding parasite species (i.e., Phlebotomus papatasi with Leishmania major), suggesting that geographic ranges of zoonotic cutaneous leishmaniasis and its potential vector may overlap, but under distinct environmental associations. Other associations (e.g., P. sergenti with L. major) were not supported. Mapping suitable areas for each species suggested that northeastern Egypt is particularly at risk because both parasites have potential to circulate.

CONCLUSIONS

Ecological niche modeling approaches can be used as a first-pass assessment of vector-parasite interactions, offering useful insights into constraints on the geography of transmission patterns of leishmaniasis.

Leishmaniases in Maghreb: an endemic neglected disease

Maghreb is known to be one of the most endemic areas of leishmaniases where both visceral and cutaneous forms are reported. Cutaneous leishmaniasis (CL) is older and has a higher prevalence than visceral one (VL). It is caused by four taxa (Leishmania (L.) major, L. infantum, L. tropica and L. killicki) which are responsible for a large clinical spectrum of lesions. Most transmission cycles of these taxa are known and many phlebotomine sandflies vectors and reservoir hosts are identified. The zoonotic transmission is well established for L. major. However, for L. infantum and L. killicki it needs more investigations to be proven. Regarding L. tropica, studies suggest it to be of both zoonotic and anthroponotic types. The isoenzymatic characterization of these four taxa showed a large enzymatic polymorphism varying from two zymodemes for L. major to 10 zymodemes for L. tropica. Cutaneous leishmaniasis is widely distributed and covers all bioclimatic stages with the coexistence of more than one taxon in the same foci. Visceral leishmaniasis is the second form of leishmaniases in Maghreb. Only L. infantum is known to cause this disease. The transmission cycle of this parasite is zoonotic but still not well known. The isoenzymatic identification of L. infantum causing VL showed the presence of six zymodemes. Geographically, VL is distributed in all bioclimatic stages of Maghreb countries. Despite all the previous studies realized on leishmaniases in Maghreb, they are still considered as neglected diseases because of the rarity or the absence of efficient control strategies.

Cutaneous leishmaniasis in North Africa: a review

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

First detection of Leishmania tropica DNA and Trypanosoma species in Sergentomyia sand flies (Diptera: Psychodidae) from an outbreak area of cutaneous leishmaniasis in Ghana

Background

Leishmania major and an uncharacterized species have been reported from human patients in a cutaneous leishmaniasis (CL) outbreak area in Ghana. Reports from the area indicate the presence of anthropophilic Sergentomyia species that were found with Leishmania DNA.

Methodology/Principal Findings

In this study, we analyzed the Leishmania DNA positive sand fly pools by PCR-RFLP and ITS1 gene sequencing. The trypanosome was determined using the SSU rRNA gene sequence. We observed DNA of L. major, L. tropica and Trypanosoma species to be associated with the sand fly infections. This study provides the first detection of L. tropica DNA and Trypanosoma species as well as the confirmation of L. major DNA within Sergentomyia sand flies in Ghana and suggests that S. ingrami and S. hamoni are possible vectors of CL in the study area.

Conclusions/Significance

The detection of L. tropica DNA in this CL focus is a novel finding in Ghana as well as West Africa. In addition, the unexpected infection of Trypanosoma DNA within S. africana africana indicates that more attention is necessary when identifying parasitic organisms by PCR within sand fly vectors in Ghana and other areas where leishmaniasis is endemic.

Cutaneous leishmaniasis (CL) is one of the world's most neglected diseases transmitted by female sand flies and affecting mostly developing countries with about 1.2 million cases every year. In most African countries, the disease is typically caused by one of two species of Leishmania parasite: L. major or L. tropica. Clinical symptoms of both infections are similar, producing ulcerative and nodular lesions. Notwithstanding their similarity, lesions caused by L. major self-heal and bestow immunity to re-infection and therapy, if applied, is often by antimonials administered intra-lesionally, whereas the treatment of CL caused by L. tropica is difficult. Differentiating between these agents in any CL focus is important. Following the outbreak of CL in Ghana, we focused on the sand fly species present in the area in order to detect Leishmania DNA in potential vectors. Our study provides evidence on the occurrence of L. tropica and L. major DNA, and the detection of Trypanosoma DNA in Sergentomyia sand flies in Ghana. These findings have considerable implications in determining the epidemiology and dynamics of the disease. Significantly, our study supports the possibility of Sergentomyia sand flies as the vectors of CL in Ghana other than Phlebotomus, which contains all currently known vectors for Leishmania in the Old World.

Phlebotomine sandflies and the spreading of leishmaniases and other diseases of public health concern

Phlebotomine sandflies transmit pathogens that affect humans and animals worldwide. We review the roles of phlebotomines in the spreading of leishmaniases, sandfly fever, summer meningitis, vesicular stomatitis, Chandipura virus encephalitis and Carrión's disease. Among over 800 species of sandfly recorded, 98 are proven or suspected vectors of human leishmaniases; these include 42 Phlebotomus species in the Old World and 56 Lutzomyia species in the New World (all: Diptera: Psychodidae). Based on incrimination criteria, we provide an updated list of proven or suspected vector species by endemic country where data are available. Increases in sandfly diffusion and density resulting from increases in breeding sites and blood sources, and the interruption of vector control activities contribute to the spreading of leishmaniasis in the settings of human migration, deforestation, urbanization and conflict. In addition, climatic changes can be expected to affect the density and dispersion of sandflies. Phlebovirus infections and diseases are present in large areas of the Old World, especially in the Mediterranean subregion, in which virus diversity has proven to be higher than initially suspected. Vesiculovirus diseases are important to livestock and humans in the southeastern U.S.A. and Latin America, and represent emerging human threats in parts of India. Carrión's disease, formerly restricted to regions of elevated altitude in Peru, Ecuador and Colombia, has shown recent expansion to non-endemic areas of the Amazon basin.