World Cutaneous Leishmaniasis Research Articles

Efficacy of adjunctive topical liposomal clarithromycin on systemic Glucantime in Old World cutaneous leishmaniasis: a pilot clinical study.

Aim: This study aimed to investigate the effects of topical liposomal clarithromycin in combination with meglumine antimoniate (Glucantime®) on cutaneous leishmaniasis (CL) lesions. Methods: This pilot, randomized, double-blinded clinical trial was conducted on patients with CL lesions. Patients were randomly assigned to two groups: the first group received liposomal clarithromycin in combination with Glucantime for 28days, while the second group received Glucantime and a placebo. Afterward, patients were followed up at 1.5, 3, and 6months after treatment initiation and were evaluated for recovery time, induration, and size of the lesions. Results: Sixty patients with CL lesions were divided into two separate groups with 30 members each and were examined. Within-group analysis revealed that recovery time in the clarithromycin group was 26.65 ± 5.12days, while in the placebo group, it was 32.84 ± 24.43, which was statistically insignificant (p = 0.18). Lesion size comparison in the first and last follow-ups reduced in both groups: 7.73 ± 4.31 to 0.48 ± 0.50 in the clarithromycin group (p = 0.006) and 5.47 ± 5.83 to 0.76 ± 0.88 in the placebo group (p = 0.03). Moreover, the size of lesions in the intervention group was significantly reduced compared to that in the placebo group (p = 0.02). Recognizable induration reduction was observed in the clarithromycin group (2.60 ± 0.77 to 1.0 ± 0.00). No adverse effects attributable to clarithromycin were reported. Conclusion: The administration of liposomal clarithromycin in combination with systemic Glucantime had a significant beneficial effect on reducing lesion size in leishmaniasis. Further studies on larger populations are recommended. Systematic Review Registration: https://www.irct.ir/trial/46611.

Self-application of aminoglycoside-based creams to treat cutaneous leishmaniasis in travelers.

In endemic foci, the use of an aquaphilic cream containing paromomycin with/without gentamicin to treat cutaneous leishmaniasis (CL) is safe, painless and cures 78-82% of patients with New and Old World CL. Self-application in travelers requires evaluation. Travelers with 1-10 lesions of confirmed CL were prospectively treated with the paromomycin-gentamicin formulation (WR279396, 2012-2017, Group 1) and carefully follow up, or treated with a locally produced paromomycin-only cream (2018-2022, Group 2). The cream was applied once under supervision, then self-applied daily for 20-30 days. A cured lesion was defined as 100% re-epithelialization at day 42 without relapse at three months. Medical features were similar in Group 1 (17 patients), and Group 2 (23 patients). Patients were infected with either Leishmania major, L. infantum, L. killicki, L. guyanensis, L. braziliensis, or L. naiffi. Intention-to-treat and per-protocol cure rates were 82% (95% confidence interval (CI) [64.23;100.00]) and 87% (95% CI [71,29;100.00]) in Group 1, and 69% (95% CI [50.76; 88.37]) and 76% (95% CI [57.97; 94.41]) in Group 2. In the pooled Group 1&2, 75% (95% CI [61.58;88.42]) (30/40) and 81% (95% CI [68,46;93.6]) (30/37) of patients were cured in intention-to-treat and per-protocol, respectively. There were no significant differences observed in the success rates between Old World and New World CL (83.3% vs. 60%, p = 0.14). Prospective observations in Group 1 showed that adverse events were mainly pruritus (24%) and pain (18%) on lesions (all mild or moderate). No mucosal involvement was observed in either group. In this representative population of travelers who acquired CL either in the Old or New World, the 81% per-protocol cure rate of a self-applied aminoglycoside cream was similar to that observed in clinical trials.

Clinical and immunological spectra of human cutaneous leishmaniasis in North Africa and French Guiana.

Cutaneous leishmaniasis (CL) caused by infection with the parasite Leishmania exhibits a large spectrum of clinical manifestations ranging from single healing to severe chronic lesions with the manifestation of resistance or not to treatment. Depending on the specie and multiple environmental parameters, the evolution of lesions is determined by a complex interaction between parasite factors and the early immune responses triggered, including innate and adaptive mechanisms. Moreover, lesion resolution requires parasite control as well as modulation of the pathologic local inflammation responses and the initiation of wound healing responses. Here, we have summarized recent advances in understanding the in situ immune response to cutaneous leishmaniasis: i) in North Africa caused by Leishmania (L.) major, L. tropica, and L. infantum, which caused in most cases localized autoresolutives forms, and ii) in French Guiana resulting from L. guyanensis and L. braziliensis, two of the most prevalent strains that may induce potentially mucosal forms of the disease. This review will allow a better understanding of local immune parameters, including cellular and cytokines release in the lesion, that controls infection and/or protect against the pathogenesis in new world compared to old world CL.

Evaluation of a diagnostic device, CL Detect rapid test for the diagnosis of new world cutaneous leishmaniasis in Peru.

Cutaneous leishmaniasis (CL) is a neglected disease and a public health problem in Latin America. The diagnosis of CL in poor hyperendemic regions relies to large extent on the identification of amastigotes in Giemsa-stained smears. There is an urgent need for a rapid, sensitive and low cost diagnostic method for use in field conditions for CL as current modalities are not readily available. The primary objective of this study was to determine the sensitivity and specificity of the FDA-cleared CL Detect Rapid Test in Peru, using modified test procedures rather than the instructions-for-use, by 1) increasing the extraction time and 2) increasing the volume of the sample added to the test strip. CL Detect Rapid Test results were compared against microscopy and kDNA-PCR, for the diagnosis of CL in ulcerated lesions. In addition, we compared two collection methods the dental broach used and mentioned in the CL Detect insert and the standard less invasive and easier to conduct scrapping method. Participants were patients who presented for medical consultation due to a suspected CL lesion. Four samples from the index lesion were collected using a dental broach, per package insert, and lancet scraping and tested by the modified CL Detect Rapid Test, microscopy, and PCR. A total of 156 subjects were eligible and evaluated. The modified CL Detect sensitivity was higher in specimens obtained by scraping (83.3%) than those from dental broach (64.2%). The specificity was lower in scrapings (77.8%) with a false positive rate of 22.2% compared with dental broach samples (91.7%) with a false positive rate of 8.3%. However, molecular analysis showed that all 8 false negative microscopy scrapings (those positive by modified CL Detect and negative by microscopy) were positive by kDNA-PCR, meaning that the modified CL Detect was more sensitive than microscopy. These modifications to the package insert that resulted in a diagnostic sensitivity (83.3%) comparable to microscopy for species found in Peru may enable earlier anti-leishmanial drug treatment decisions based on a positive result from the CL Detect Rapid Test alone until further diagnostic tests like microscopy and PCR can be performed. NCT03762070; Clinicaltrials.gov.

1171. Epidemiology of Old World Cutaneous Leishmaniasis among Members of the U.S. Military

Abstract Background Cutaneous leishmaniasis (CL) is a threat to U.S. Military personnel as they deploy to endemic areas. As treatment may require evacuation, CL undermines operations. Elucidating the epidemiology of CL in this population is key for prevention. Methods We retrospectively reviewed data from a CL sodium stibogluconate treatment trial at Walter Reed Army Medical Center, Washington DC. 412 military members with parasitologically confirmed CL and deployment to Southwest Asia from May 2002 - August 2004 enrolled. Subjects’ CL lesions were counted and measured. 334 subjects completed a risk survey. Given no control group, we used number of CL lesions (NL), total lesion area (TLA), and lesion location as outcomes to assess CL risks. Non-parametric tests and logistic regression were used as appropriate. Results Permethrin treated bed net use was associated with lower NL (p = 0.000), TLA (p = 0.024), and odds of head/face lesion (OR 0.12, p = 0.047). Sleeping in a combat uniform was associated with lower TLA (p = 0.000) and odds of leg/foot lesion (OR 0.39, p = 0.023). Use of a permethrin treated uniform (p = 0.002) and N,N-diethyl-meta-toluamide (DEET) insect repellent at night (p = 0.046) were associated with lower NL. Noting unit members with similar lesions was associated with higher NL (p = 0.007) and odds of head/face lesion (OR 12.1, p = 0.019). National Guard status followed by Active Duty was associated with higher NL (p = 0.002) and TLA (p = 0.000) than Reserve. Sleeping in a building was associated with higher TLA (p = 0.008) and odds of arm lesion (OR 2.28, p = 0.016). Sleeping near animal burrows was associated with higher NL (p = 0.031). Sleeping on a cot (p = 0.006), certain ethnicities (p = 0.020) and certain military occupational specialties (p =0.038) were associated with higher TLA. Increasing age (p = 0.001) and years of service (p = 0.000) were positively correlated with TLA. Conclusion This is the largest group of U.S. Military members with CL reported and provides insight into risks for CL which will guide preventive efforts to reduce the burden of illness in this population. The opinions and assertions expressed herein are those of the author(s) and do not reflect the official policy or position of the Uniformed Services University of the Health Sciences, the Department of Defense, or the U.S. Government. Disclosures Naomi E. Aronson, M.D., Elsevier: Royalties as text editor, honoraria for chapter writing|UpToDate: royalties for writing chapters.

Comparison between Colorimetric In Situ Hybridization, Histopathology, and Immunohistochemistry for the Diagnosis of New World Cutaneous Leishmaniasis in Human Skin Samples.

New world cutaneous leishmaniasis (NWCL) is an anthropozoonosis caused by different species of the protozoan Leishmania. Colorimetric in situ hybridization (CISH) was shown to satisfactorily detect amastigote forms of Leishmania spp. in animal tissues, yet it was not tested for the diagnosis of human NWCL. The aim of this study was to compare CISH, histopathology (HP), and immunohistochemistry (IHC) techniques to diagnose NWCL in human cutaneous lesions. The sample comprised fifty formalin-fixed, paraffin-embedded skin biopsy specimens from patients with NWCL caused by L. (V.) braziliensis. These specimens were analyzed by CISH, using a generic probe for Leishmania, IHC, and HP to assess the sensitivity of these methods by using a parasitological culture as a standard reference. Additional specimens from three patients diagnosed with cutaneous mycoses were also included to evaluate cross-reactions between CISH and IHC. The sensitivities of IHC, CISH, and HP for detecting amastigotes was 66%, 54%, and 50%, respectively. IHC, unlike CISH, cross-reacted with different species of fungi. Together, these results demonstrate that CISH may be a complementary assay for the detection of amastigote in the laboratorial diagnosis routine of human NWCL caused by L. (V.) braziliensis.

Successful treatment of Old World cutaneous leishmaniasis with red or green light photodynamic therapy

Cutaneous leishmaniasis is one of the most common travel dermatoses in Germany, which can be acquired not only in Africa, Asia or the American continent, but also in southern European countries. In addition to the currently available topical and systemic therapy options, there have been increasing reports of successful treatment of cutaneous leishmaniasis with photodynamic therapy (PDT) using numerous therapy regimens and different photosensitizers in recent years. We report on successful photodynamic therapy of Old World cutaneous leishmaniasis with red and green light PDT with 10% 5‑aminolevulinic acid.

Treatment of Bolivian Leishmania braziliensis Cutaneous and Mucosal Leishmaniasis.

Although infection with Leishmania braziliensis is perhaps the key reason to treat New World cutaneous leishmaniasis (CL) and mucosal leishmaniasis (ML), the total literature contains relatively few reported cases. With the aim of supplementing the meager clinical information available, we searched the records of Jorochito (Dermatology) Hospital, Bolivia, for the years 1999-2020 and identified treatment records for 1,696 naive CL patients and 355 naive ML patients. Because follow-up was poor for this real-world treatment experience in the developing world, only 255 CL patients (15%) and 114 ML patients (32%) attended follow-up at Hospital. We therefore engaged in an Active Search for "lost" patients, located a further 542 CL patients (32%) and 142 ML patients (44%), thus eventually accomplished follow up on 697 CL patients (41%) and 256 ML patients (72%). Granular adverse event data derived from hospital records is listed for the 902 CL and 86 ML patients administered Glucantime intramuscularly, the 401 CL and 202 ML patients administered Glucantime intravenously, and the 163 CL and 89 ML patients administered miltefosine orally. Efficacy was obtained from hospital records for patients seen at hospital and from patient recall communicated by telephone for the patients found in the Active Search. The overall CL cure rate was 508 of 697 CL patients (73%) with follow-up: intramuscular Glucantime-196/293 (67%); intravenous Glucantime-90/126 (71%); intralesional Glucantime-34/54 (63%); oral miltefosine-52/69 (75%). The overall ML cure rate was 161 of 256 ML patients (63%) with follow-up: intramuscular Glucantime-26/48 (54%); intravenous Glucantime-66/104 (63%); intravenous amphotericin B deoxycholate-19/35 (54%); oral miltefosine-50/71 (70%). We offer this extensive adverse event and efficacy experience as useful guides for clinicians presented with a L. braziliensis infection. The cure rates also illustrate the quandary of New World CL and ML chemotherapy: sufficiently high to be useful but nevertheless needing augmentation with new agents.

Centrin-deficient Leishmania mexicana confers protection against New World cutaneous leishmaniasis

Leishmaniasis is a neglected protozoan disease affecting over 12 million people globally with no approved vaccines for human use. New World cutaneous leishmaniasis (CL) caused by L. mexicana is characterized by the development of chronic non-healing skin lesions. Using the CRISPR/Cas9 technique, we have generated live attenuated centrin knockout L. mexicana (LmexCen−/−) parasites. Centrin is a cytoskeletal protein important for cellular division in eukaryotes and, in Leishmania, is required only for intracellular amastigote replication. We have investigated the safety and immunogenicity characteristics of LmexCen−/− parasites by evaluating their survival and the cytokine production in bone-marrow-derived macrophages (BMDMs) and dendritic cells (BMDCs) in vitro. Our data shows that LmexCen−/− amastigotes present a growth defect, which results in significantly lower parasitic burdens and increased protective cytokine production in infected BMDMs and BMDCs, compared to the wild type (WT) parasites. We have also determined the safety and efficacy of LmexCen−/− in vivo using experimental murine models of L. mexicana. We demonstrate that LmexCen−/− parasites are safe and do not cause lesions in susceptible mouse models. Immunization with LmexCen−/− is also efficacious against challenge with WT L. mexicana parasites in genetically different BALB/c and C57BL/6 mouse models. Vaccinated mice did not develop cutaneous lesions, displayed protective immunity, and showed significantly lower parasitic burdens at the infection site and draining lymph nodes compared to the control group. Overall, we demonstrate that LmexCen−/− parasites are safe and efficacious against New World cutaneous leishmaniasis in pre-clinical models.

In vitro selection of ketoconazole-pentamidine-resistant Leishmania (Viannia) braziliensis strains

The use of ketoconazole (KTZ) plus pentamidine (PMD) could be an interesting treatment option for New World cutaneous leishmaniasis. The aim of this work was to generate KTZ- and PMD-resistant strains and to determine some characteristics of the selection process and the resulting parasites. Resistance to one or two drugs was selected on promastigotes by progressively increasing drug concentrations for eleven months. The resistance levels (IC50) to one or two drugs (synergism assay) were determined using a colorimetric resazurin methodology. The stability of the resistance phenotype (without drug pressure or after mouse passage), cross resistance with paromomycin and miltefosine, and resistance transference to intracellular amastigotes were determined. In addition, some parasite attributes compared with WT, such as growth kinetics, amastigogenesis, THP-1 cells, and mouse infection, were determined. Promastigotes resistant to KTZ or PMD were obtained three times earlier than the combined KTZ + PMD-resistant strains. Resistant parasites (promastigotes and intracellular amastigotes) were three to twelve times less susceptible to KTZ and PMD than WT parasites. The resistance phenotype on parasites was unstable, and no cross resistance was observed. Similar parasite fitness related to our evaluated characteristics was observed except for in vivo infection, where a delay of the onset of cutaneous lesions was observed after KTZ + PMD-resistant parasite infection. ConclusionCombined treatment with KTZ and PMD delayed the onset of parasite resistance and was more effective in vitro than each drug separately for WT and all resistant strains. Parasites resistant to KTZ and PMD acquired similar in vitro behaviour to WT parasites, were less virulent to mice and maintained their resistance phenotype on intracellular amastigotes but not without drug pressure or after mouse infection.

Influence of Intestinal Helminth Burden on Clinical Manifestations, Therapeutic Response, and Leishmania braziliensis Load in Patients with New World Cutaneous Leishmaniasis.

Leishmania braziliensis is the most important cause of cutaneous leishmaniasis (CL) in the Americas. A Th1-type immune response is required to control Leishmania infection, but an exaggerated inflammatory response leads to the development of ulcers seen in CL. Infection with intestinal helminths has the potential to inhibit the Th1 response in a manner that depends both on the species of helminth present as well as the burden of helminthiasis. We conducted a prospective cohort study of CL patients from an endemic area between January and December 2017 with either negative or high intestinal helminth burden to characterize relationships between helminth burden, L. braziliensis quantification within CL lesions, clinical aspects of CL, and therapeutic response. Of 234 participants with leishmaniasis who underwent stool examination at the time of diagnosis, 45% had detectable helminth infection. The overall cure rate after 90 days was 66%, with a median time to resolution of disease of 40 days (interquartile range: 30-65 days). There was no significant association between the type of helminth infection or the magnitude of intestinal helminth burden at the time of diagnosis and L. braziliensis genomic DNA (gDNA) detected in biopsies from CL lesions. Likewise, there was no association between helminth burden and response to treatment after 90 days. Considering quantification of parasite DNA in CL lesions, participants who were cured at 90 days had a median of 0.017 ng/mg gDNA, and participants who failed therapy had a median of 0.091 ng/mg gDNA (P = 0.03). The results indicate that cutaneous Leishmania load may influence therapeutic response in CL.

Efficacy and safety of pentamidine isethionate for tegumentary and visceral human leishmaniasis: a systematic review.

We performed a systematic review of the literature to investigate the efficacy and safety of pentamidine isethionate for the treatment of human tegumentary and visceral leishmaniasis. A total of 616 papers were evaluated, and 88 studies reporting data on 3108 cases of leishmaniasis (2082 patients with tegumentary leishmaniasis and 1026 with visceral leishmaniasis) were finally included. The majority of available studies were on New World cutaneous leishmaniasis and visceral leishmaniasis caused by Leishmania donovani. At the same time, few data are available for Old World cutaneous leishmaniasis, mucosal leishmaniasis, and visceral leishmaniasis caused by L. infantum. Pooled cure rate for tegumentary leishmaniasis was 78.8% (CI 95%, 76.9-80.6%) and 92.7% (CI 95%, 88.3-97.1%) according to controlled randomized trial and observational studies and case report and case series respectively. Pooled cure rate for visceral leishmaniasis was 84.8% (CI 95%, 82.6-87.1%) and 90.7% (CI 95%, 84.1-97.3%) according to controlled randomized trial and observational studies and case report and case series, respectively. Comparable cure rate was observed in recurrent and refractory cases of visceral leishmaniasis. Concerning the safety profile, among about 2000 treated subjects with some available information, the most relevant side effects were six cases of arrhythmia (including four cases of fatal ventricular fibrillation), 20 cases of irreversible diabetes, 26 cases of muscular aseptic abscess following intramuscular administration. Pentamidine isethionate is associated with a similar cure rate of the first-line anti-leishmanial drugs. Severe and irreversible adverse effect appear to be rare. The drug may still have a role in the treatment of any form of human leishmaniasis when the first-line option has failed or in patients who cannot tolerate other drugs also in the setting of travel medicine. In difficult cases, the drug can also be considered as a component of a combination treatment regimen.

Therapeutic advances in the topical treatment of cutaneous leishmaniasis: A review

Cutaneous leishmaniasis has been endemic since decades. Millions of cases are reported worldwide specially in developing and underdeveloped countries. There are 2 major types of cutaneous leishmaniasis based on the causating species found in different regions of the world. These include New and Old World cutaneous leishmaniasis, which are self-healing, but if not treated, these may cause severe scars and many other complications like mucosal involvement. The conventional gold standard treatment for both types is mainly intralesional or parenteral administration of antimonial. Lately, a great deal of research has been done on development of topical treatment based on single agent or combination therapy. This review summarizes the current state of literature regarding therapeutic outcome of topical treatment against cutaneous leishmaniasis caused by different species in different regions.

Effect of Adjunctive Topical Liposomal Azithromycin on Systemic Azithromycin on Old World Cutaneous Leishmaniasis: A Pilot Clinical Study.

The treatment of Cutaneous Leishmaniasis (CL) is complex, and the search for safer, more efficient, and cost-effective treatments is ongoing. This study aimed to evaluate the efficacy of the combination of liposomal and oral azithromycin as the first clinical study against CL. This assessor-blind, randomized clinical trial was conducted in out-patients Leishmaniasis clinic of Skin Diseases and Leishmaniasis. The cutaneous lesions of eligible participants were randomized to receive either oral azithromycin or the combined oral and topical liposomal azithromycin. All participants received 250 mg of azithromycin twice daily or 8 mg/per kg for 4 weeks. In the combination group, a topical liposomal formulation of 0.04 mmol/mL of azithromycin was administered as 0.2-0.5 cc twice daily according to the lesion size in order to make a thin layer of the drug on the surface of the lesion. The size and induration changes from baseline to the end of the study were analyzed. Twenty-one lesions of 13 patients in the combination group and 20 lesions of 14 patients in the oral group were recruited. The mean ± SD of improvement was significantly different between two groups after 12 weeks (3.89 ± 0.46 vs. 3.15 ± 1.23 P = 0.02 combination group vs. oral group respectively). The patients did not experience any systemic adverse effects related to azithromycin and the only adverse effects related to topical treatment were mild pruritus in 2 cases. In conclusion, the combination of oral and topical liposomal formulation of azithromycin is safe and effective to treat CL.

766. Everything Old is New Again-A Case Series of New World Leishmaniasis in African Children in Portland, Maine

BackgroundLeishmaniasis has many clinical manifestations and treatment regimens, dependent on species and host. Old world leishmaniasis is found primarily in Africa and Asia, and is associated with visceral disease, while new world disease, seen primarily in Latin America, is more commonly mucocutaneous. We present a case series of pediatric African patients with New World cutaneous leishmaniasis (NWCL).MethodsData extraction was performed via chart review, analyzing travel history, clinical presentation, diagnosis, and management in children with cutaneous leishmaniasis presenting to the pediatric infectious diseases clinic in Portland, ME. Biopsy specimens were sent to the federal CDC for identification by PCR and culture.ResultsFive cases of NWCL were diagnosed in pediatric patients in Maine from November 2018 through February 2020. Median age of patients was 10 years (range 1.5-15 years). Four cases (80%) occurred in children from Angola or Democratic Republic of Congo, arriving in Maine via Central/South America, with one case in a child from Rwanda who arrived in Maine via Texas. Three patients had multiple skin lesions and two had isolated facial lesions. Leishmaniasis was not initially suspected resulting in median time to diagnosis of 5 months (range 1-7 months). Four patients were initially treated with antibacterials for cellulitis and one was treated with griseofulvin. After no improvement, patients underwent biopsy with 2 patients diagnosed with L panamensis, 1 with L braziliensis, 1 with mixed infection (L panamensis and L mexicana), and 1 with Leishmania species only. One patient was managed with surgical excision, 3 with ketoconazole, and 1 was observed off therapy. Four patients were referred to otolaryngology. All continue to be followed in infectious disease clinic.ConclusionWe present five cases of new world cutaneous leishmaniasis in African pediatric patients arriving to Maine through Latin America or Texas. Patients were diagnosed with cellulitis, tinea corporis or atopic dermatitis initially, underscoring importance of high index of suspicion in migrant patients. Detailed travel history and epidemiologic knowledge is essential to diagnosis, as patients may present with illness not congruent with country of origin. Optimal therapy remains unclear.Disclosures All Authors: No reported disclosures

The Potential of Systemic Control of Sand Flies Using Fipronil in the Novel Leishmania major (Kinetoplastida: Trypanosomatidae) Reservoirs Meriones tristrami (Rodentia: Muridea) and Meriones crassus (Rodentia: Muridea).

Leishmania major (Yakimoff & Schokhor, 1914), an important causative agent of Old World Cutaneous Leishmaniasis (CL), is transmitted by sand flies among a limited number of gerbilline reservoir-species. We can take advantage of this strong dependency to break the pathogen transmission cycle by using systemic insecticides that render the host toxic to the blood-feeding vector. We evaluated the potential of this approach with two novel reservoir species, incriminated for CL expansion in several sites in the Middle East. Specifically, we evaluated: 1) the residuality of the systemic insecticide fipronil in Meriones tristrami (Thomas, 1892) fed on fipronil-treated baits and 2) the treatments' adulticide effect on sand flies that blood fed on treated and untreated M. tristrami and M. crassus (Sundevall, 1842). We fed M. tristrami with food pellets containing 0.1 g/kg fipronil and used gas chromatograph-mass spectrometery analysis and bioassays to examine its residual toxicity to blood-feeding female sand flies. In M. tristrami, fipronil was rapidly metabolized to fipronil sulfone, found in the blood, urine, and feces for ≥31 d after fipronil admission. The survival of sand flies that blood fed on fipronil-treated M. tristrami and M. crassus was significantly reduced for at least 15 and 9 d respectively, after fipronil admission. These results hold promise for the potential contribution of systemic control approaches to CL integrated management strategies against novel CL (due to L. major) outbreaks in Israel and elsewhere.

Cutaneous leishmaniasis in refugees from Syria: complex cases in Berlin 2015-2020.

The Syrian conflict has led to a dramatic increase of Old World cutaneous leishmaniasis (CL), triggered by continuous population displacements, disrupted control programmes, poor shelter and sanitation. A retrospective patient record study was conducted at the Institute of Tropical Medicine and International Health in Berlin. Records of all refugees from Syria treated for CL between January 2015 and March 2020 were reviewed. Twenty refugees from Syria were treated. Seventeen refugees (85%) had complex lesions, mainly due to previous therapy failure or localization on the face. A long disease duration (50% > 1year), pronounced facial scarring (20%), recurrences (20%), or worsening of existing lesions (20%) were observed. Nine patients (45%) had been pretreated in Syria. Complete remission was achieved in 10 of 16 patients (63%) treated with perilesional antimony. Eight patients (40%) required systemic treatment, thereof four (20%) repeated systemic treatment. Eight patients (40%) reported a delay of therapy ≥3months in Germany, thereof one patient with a delay of 12months and one patient with a delay of 32months. Between 2015 and 2020, Syrian refugees presented with severe morbidities of CL frequently requiring systemic and even consecutive systemic treatments. We assume a combination of socioeconomic and environmental factors associated with the ongoing Syrian conflict and migration to be responsible for the complex clinical presentations in this case series. More attention should be drawn to the situation of Syrian refugees with CL in countries where they are displaced to.

Performance of a universal PCR assay to identify different Leishmania species causative of Old World cutaneous leishmaniasis

BackgroundThe characterization of Leishmania species is important for clinical management of the diseases and the epidemiological control of the parasite distribution. Most of the published polymerase chain reaction (PCR) amplification methods lack the ability to identify all species complexes, have low performance and usually need post-PCR procedures. There is a need for improving the diagnosis of CL by development of an accurate affordable PCR method to identify all Leishmania species in clinical specimens.MethodsWe designed an optimized a PCR amplifying the internal transcribed spacer 2 sequence of the ribosomal RNA gene (ITS2) aligned from different strains of CL-causing Leishmania species in the Old World. The performance of the method was evaluated on lesion samples from several CL suspected patients and the limit of detection (LOD) was determined on DNA of promastigotes from reference strains.ResultsThe universal PCR enabled simultaneous discrimination of L. major, L. tropica and L. infantum using one primer pair in one reaction. Stained smear microscopy and Novy-MacNeal-Nicolle (NNN) medium culture alone detected 77.27% (17/22) and 72.73% (16/22) of the positive CL samples, respectively. The PCR assay showed 100% sensitivity (22/22) (95% CI: 84.56–100%) and 100% specificity (3/3) (95% CI: 29.24–100%) for species identification on isolates from lesion scraping/exudate and 100% sensitivity (13/13) (95% CI: 75.29–100%) and 100% specificity (11/11) (95% CI: 71.51–100%) for species identification on biopsy samples of CL patients, while being capable to successfully amplify as little as 0.01–0.1 pg of Leishmania DNA from cultured promastigotes.ConclusionsWe present a validated easy-to-use affordable universal PCR assay to identify the most common Old World Leishmania species causing CL. This PCR assay could be used as a sensitive/specific technique to diagnose CL-causing Leishmania species in clinical samples with high accuracy.

Nutritional Intake and Chronicity Associated with the Old World Cutaneous Leishmaniasis: Role of Vitamin A

Old world cutaneous leishmaniasis (CL) is known as a self-healing cutaneous parasitic infection. Host immunity has a fundamental role in the course of this infection. This study was designed to investigate the relationship between nutritional status and vitamin A intake with the clinical course of CL. Overall, 250 patients with CL attending a dermatology clinic in Imam Reza Hospital Mashhad, Iran, were enrolled from Apr 2011 to Aug 2012. For data gathering, a semi-quantitative 302-item food frequency questionnaire was utilized. They received routine treatment protocols for leishmaniasis and 1 year of follow-up. As for the 149 patients who completed the study, a deficiency of macro and micronutrients, particularly vitamin A, was significantly related to a chronic clinical disease course. Imbalanced or insufficient nutritional intake including vitamin A deficiency, may influence the clinical course of CL.

The egg and larval pheromone dodecanoic acid mediates density-dependent oviposition of Phlebotomus papatasi

BackgroundGravid females assess the conditions of oviposition sites to secure the growth and survival of their offspring. Conspecific-occupied sites may signal suitable oviposition sites but may also impose risk due to competition or cannibalism at high population density or heterogeneous larval stage structure, respectively. Chemicals in the habitat, including chemicals emitted from other organisms, serve as cues for females to assess habitat conditions. Here, we investigated the attraction and oviposition preference of the Old World cutaneous leishmaniasis vector, Phlebotomus papatasi, to young and old conspecific stages, including eggs and evaluated the effect of a semiochemical associated with eggs and neonate larvae.MethodsAttraction and oviposition preference of Ph. papatasi to each of various life stages (eggs, first-, second-, third-, fourth-instar larvae, pupae and male and female adults) was investigated using cage and oviposition jar behavioral assays. Identification of organic chemical compounds extracted from eggs was performed using GC-MS and chemicals were tested in the same behavioral assays in a dose-response manner. Behavioral responses were statistically analyzed using logistic models.ResultsGravid Ph. papatasi females were significantly attracted to and preferred to oviposit on medium containing young life stages (eggs and first instars). This preference decreased towards older life stages. Dose effect of eggs indicated a hump-shaped response with respect to attraction but a concave-up pattern with respect to oviposition. Chemical analysis of semiochemicals from eggs and first-instar larvae revealed the presence of dodecanoic acid (DA) and isovaleric acid. Sand flies were attracted to and laid more eggs at the lowest DA dose tested followed by a negative dose-response.ConclusionsFindings corroborated our hypothesis that gravid sand flies should prefer early colonized oviposition sites as indicators of site suitability but avoid sites containing older stages as indicators of potential competition. Findings also supported the predictions of our hump-shaped oviposition regulation (HSR) model, with attraction to conspecific eggs at low-medium densities and switching to repellence at high egg densities. This oviposition behavior is mediated by DA that was identified from surface extracts of both eggs and first-instar larvae. Isovaleric acid was also found in extracts of both stages.