Production of leishmanin skin test antigen from Leishmania donovani for future reintroduction in the field.

The leishmanin skin test was used for almost a century to detect exposure and immunity to Leishmania, the causative agent of leishmaniasis, a major neglected tropical disease. Due to a lack of antigen used for the intradermal injection, the leishmanin skin test is no longer available. As leishmaniasis control programs are advancing and new vaccines are entering clinical trials, it is essential to re-introduce the leishmanin skin test. Here we establish a Leishmania donovani strain and describe the production, under Good Laboratory Practice conditions, of leishmanin soluble antigen used to induce the leishmanin skin test in animal models of infection and vaccination. Using a mouse model of cutaneous leishmaniasis and a hamster model of visceral leishmaniasis, soluble antigen induces a leishmanin skin test response following infection and vaccination with live attenuated Leishmania major (LmCen-/-). Both the CD4+ and CD8+ T-cells are necessary for the leishmanin skin test response. This study demonstrates the feasibility of large-scale production of leishmanin antigen addressing a major bottleneck for performing the leishmanin skin test in future surveillance and vaccine clinical trials.

Evaluation of murine OX40L-murine IgG1(MM1) fusion protein on immunogenicity against L. mexicana infection in BALB/c mice.

The majority of OX40L is found on professional antigen-presenting cells (APC), the potency of OX40L to enhance the immunogenicity of potential vaccines against leishmania is not yet fully investigated. There is no report of administration of OX40L on cutaneous leishmaniasis either in therapy or prophylactic immunisation and the present study for the first time reports the effect of OX40L on L. mexicana infection. In this study, B9B8E2 cells were transfected with the murine OX40L and IgG1 plasmids, were used to produce the mOX40-mIgG1 (MM1). The therapeutic effects of MM1(mOX40L-mIgG1) was tested in a challenge experiment using L. mexicana infected BALB/c mice. Mice received two doses of MM1, on day 3 and 7 after the infection. Mice receiving MM1 generated an inflammatory reaction a few days after the injection of the OX40L, which was gradually dampened and finally disappeared 3 weeks later. There was a significant delay in the growth of developing lesions in mice receiving OX40L compared to controls injected with PBS and the size of lesions in the group receiving MM1 was significantly smaller than that of injected with either PBS. 40% of mice given MM1 remained lesion free for two months, when experiments were terminated. The results clearly indicate the high therapeutic effect of mOX40L-mIgG1 fusion protein in L. mexicana infection. The effect of OX40L on the enhancement of immunisation, needs to be further investigated for developing new vaccine strategies.

Cutaneous leishmaniasis situation analysis in the Islamic Republic of Iran in preparation for an elimination plan.

Iran has invariably been under the growing public health threat of cutaneous leishmaniasis (CL), a significant barrier to local development that hinders the prevention and control efforts toward eliminating the disease. So far, no comprehensive and in-depth epidemiological analysis of the CL situation has been carried out nationwide. This study aimed to employ advanced statistical models to analyze the data collected through the Center for Diseases Control and Prevention of Communicable Diseases during 1989-2020. However, we emphasized the current trends, 2013-2020, to study temporal and spatial CL patterns. In the country, the epidemiology of CL is incredibly intricate due to various factors. This fact indicates that the basic infrastructure, the preceding supports, and the implementation plan related to preventive and therapeutic measures need crucial support. The leishmaniasis situation analysis is consistent with desperate requirements for efficient information on the control program in the area. This review provides evidence of temporally regressive and spatially expanding incidence of CL with characteristic geographical patterns and disease hotspots, signifying an urgent need for comprehensive control strategies. This information could be a suitable model and practical experience in the Eastern Mediterranean Region, where over 80% of CL is reported.

Knowledge, attitude, and practice of the rural community about cutaneous leishmaniasis in Wolaita zone, southern Ethiopia.

BACKGROUND: Cutaneous leishmaniasis (CL) is a neglected tropical disease that is caused by a Leishmania parasite and transmitted by the bite of infected female sandflies. Community awareness is an essential component of disease control and prevention. Therefore, this study aimed to assess the community's knowledge, attitude, and practice toward CL in Wolaita zone, southern Ethiopia. METHODS: A community-based cross-sectional study design was employed to include 422 study subjects selected using a systematic sampling technique from two districts, Kindo Didaye and Sodo Zuria. A pretested structured questionnaire was used to collect data from the household heads. Bivariate and multivariate logistic regression analyses were performed to determine the relationship between the participants' knowledge about CL and socio-demographic characteristics. RESULTS: Out of the 422 study participants, only 19% had good knowledge of CL in general. Most (67.1%) of the respondents knew CL by its local name ("bolbo" or "moora") though this knowledge varied highly over the study districts. The majority (86.3%) of respondents did not know how CL is acquired, though they considered CL a health problem. Most (62.8%) respondents believed that CL was an untreatable disease. Most (77%) participants responded that CL patients preferred to go to traditional healers for treatment. Herbal treatment was the most (50.2%) used to treat CL. Knowledge about CL was significantly associated with sex, age, and study districts. CONCLUSION: The overall knowledge, attitude, and practice about CL and its prevention in the study area were low. This emphasizes the need to implement health education and awareness campaign to reduce the risk of CL infection. Policymakers and stakeholders should also give due attention to the prevention and treatment of CL in the study area.

Large scale systemic control short-circuits pathogen transmission by interrupting the sand rat (Psammomys obesus)-to-sand fly (Phlebotomus papatasi) Leishmania major transmission cycle.

Systemic control uses the vertebrate hosts of zoonotic pathogens as "Trojan horses," killing blood-feeding female vectors and short-circuiting host-to-vector pathogen transmission. Previous studies focused only on the effect of systemic control on vector abundance at small spatial scales. None were conducted at a spatial scale relevant for vector control and none on the effect of systemic control on pathogen transmission rates. We tested the application of systemic control, using Fipronil-impregnated rodent baits, in reducing Leishmania major (Kinetoplastida: Trypanosomatidae; Yakimoff & Schokhor, 1914) infection levels within the vector, Phlebotomus papatasi (Diptera: Psychodidae; Scopoli, 1786) population, at the town-scale. We provided Fipronil-impregnated food-baits to all Psammomys obesus (Mammalia:Muridae; Cretzschmar, 1828), the main L. major reservoir, burrows along the southern perimeter of the town of Yeruham, Israel, and compared sand fly abundance and infection levels with a non-treated control area. We found a significant and substantial treatment effect on L. major infection levels in the female sand fly population. Sand fly abundance was not affected. Our results demonstrate, for the first time, the potential of systemic control in reducing pathogen transmission rates at a large, epidemiologically relevant, spatial scale.

Polylactide Nanoparticles as a Biodegradable Vaccine Adjuvant: A Study on Safety, Protective Immunity and Efficacy against Human Leishmaniasis Caused by Leishmania Major.

Leishmaniasis is the 3rd most challenging vector-borne disease after malaria and lymphatic filariasis. Currently, no vaccine candidate is approved or marketed against leishmaniasis due to difficulties in eliciting broad immune responses when using sub-unit vaccines. The aim of this work was the design of a particulate sub-unit vaccine for vaccination against leishmaniasis. The poly (D,L-lactide) nanoparticles (PLA-NPs) were developed in order to efficiently adsorb a recombinant L. major histone H2B (L. major H2B) and to boost its immunogenicity. Firstly, a study was focused on the production of well-formed nanoparticles by the nanoprecipitation method without using a surfactant and on the antigen adsorption process under mild conditions. The set-up preparation method permitted to obtain H2B-adsorbed nanoparticles H2B/PLA (adsorption capacity of about 2.8% (w/w)) with a narrow size distribution (287 nm) and a positive zeta potential (30.9 mV). Secondly, an in vitro release assay performed at 37 °C, pH 7.4, showed a continuous release of the adsorbed H2B for almost 21 days (30%) from day 7. The immune response of H2B/PLA was investigated and compared to H2B + CpG7909 as a standard adjuvant. The humoral response intensity (IgG) was substantially similar between both formulations. Interestingly, when challenged with the standard parasite strain (GLC94) isolated from a human lesion of cutaneous leishmaniasis, mice showed a significant reduction in footpad swelling compared to unvaccinated ones, and no deaths occurred until week 17th. Taken together, these results demonstrate that PLA-NPs represent a stable, cost-effective delivery system adjuvant for use in vaccination against leishmaniasis.

Design and evaluation of two educational media in the form of animation and games to promote the cutaneous leishmaniasis prevention behaviors in adolescent female.

BACKGROUND: Cutaneous leishmaniasis (CL) has social and psychological effects on different groups, especially adolescents and young girls in 98 countries of the world, in addition to the economic burden. Therefore, it is necessary to apply effective methods for CL prevention. In this study, educational messages were designed based on Extended Parallel Process Model in both forms of animation and game, whose effect on the cutaneous leishmaniasis prevention behaviors was evaluated in adolescent female students.  METHODS: This experimental study was carried out from January to September 2021 on 275 adolescent female students in Isfahan province, Iran. Cluster sampling method was used, and then the students were randomly divided into three groups, namely animation education, game education, and control groups. The educational intervention was performed with two new media in the form of animation and games. The data collected before and two months after the education through a valid and reliable researcher-made questionnaire were analyzed in SPSS24 software using statistical tests of ANOVA, Chi-square, paired t and analysis of covariance (ANCOVA). RESULTS: The mean age of the participants was 14.07 ± 0.94. The mean scores of behavior in the animation group (60.60 ± 23.00), the game group (61.70 ± 22.05), and the control group (66.13 ± 24.62) were not significantly different prior to the education. However, after the education, there was a significant difference between the animation (80.66 ± 17.62) and game groups (82.58 ± 19.07) and the control group (69.79 ± 23.29) (P < 0.001). The mean scores of model constructs following the intervention (susceptibility, severity, response efficacy, and perceived self-efficacy) significantly increased in the animation and game groups compared to that in the control group (P < 0.05). CONCLUSION: The results showed that if educational programs contain a combination of threat and efficiency messages, CL-preventive behaviors in adolescents increase. Providing similar educational content with both game and animation methods indicated that both methods had an almost same effect. Although animation production is more costly, it has the advantage of being used in periods and for other adolescents.

Análisis del comportamiento epidemiológico de Leishmaniasis cutánea en Perú 2016-2021 / Analysis of the epidemiological behavior of cutaneous leishmaniasis in Peru 2016-2021

La leishmaniasis cutánea (LC) es una patología cutánea inmunomediada causada principalmente por Leishmania (L.) major, Leishmania tropica, Leishmania braziliensis, L. mexicana y L. amazonensis. La carga de la LC en términos de morbilidad y estigmas sociales se concentra en ciertos países en desarrollo de Asia, África y Sudamérica. Las personas con LC asintomática representan una gran proporción de los individuos infectados en las zonas endémicas que no presentan ninguna lesión y pueden controlar la infección mediante mecanismos aún no del todo conocidos. En la actualidad, no existe ninguna medida profiláctica de control aprobada para la LC. Este reporte epidemiológico reveló que la LC prevalecía en las áreas geográficas de Selva y Sierra de Perú, mientras que departamentos como Ancash y La Libertad, áreas de la Costa, también estuvieron involucradas en el reporte de casos en los últimos años. El patrón de casos de LC reportados en los distintos departamentos del país tuvo un comportamiento muy parecido en el periodo comprendido entre 2016 y 2021, predominando en las primeras 4 o 5 semanas epidemiológicas la mayor frecuencia de pacientes enfermos con lesiones dérmicas compatibles y corroboradas con LC. La enfermedad es endémica en muchas partes del país, por eso se necesitan más esfuerzos y enfoques integrados para combatir esta patología(AU)

Cutaneous leishmaniasis (CL) is an immune-mediated skin pathology caused mainly by Leishmania (L.) major, Leishmania tropica, Leishmania braziliensis, L. mexicana and L. amazonensis. The burden of CL in terms of disease and social stigma is concentrated in certain developing countries in Asia, Africa, and South America. People with asymptomatic CL represent a large proportion of infected individuals in endemic areas who do not have any lesions and can control the infection through mechanisms that are not fully understood. Currently, there is no approved prophylactic control measure for CL. This epidemiological report revealed that CL was prevalent in the Selva and Sierra geographic areas of Peru, while departments such as Ancash and La Libertad, coastal areas, were also involved in the reporting of cases in recent years. The pattern of CL cases reported in the different departments of the country had a very similar behavior in the period between 2016 and 2021, with the highest frequency of sick patients with skin lesions compatible and corroborated with CL predominating in the first 4 or 5 epidemiological weeks. The disease is endemic in many parts of the country, so more efforts and integrated approaches are needed to combat this pathology(AU)

Determinants of anthroponotic cutaneous leishmaniasis by case-control study in Morocco.

Leishmaniasis is endemic in Morocco where both cutaneous and visceral forms coexist. To date, anthroponotic cutaneous leishmaniasis (ACL) determinants remain poorly investigated in Morocco. However, the disease risk factors identification is vital to determine the specific preventive process. In this aim, a case-control study was conducted in the main active ACL foci in central Morocco. Epidemiological data were extracted from bulletins, registers and annual reports of the regional direction of Health offices. The socioeconomic and environmental data were collected from epidemiological surveys, completed by a questionnaire intended for accessible positive population and control people selected from the cases' entourage. The study included 258 cases and 395 controls. Our results showed that many socioeconomic factors were associated with ACL in Morocco such as the rural habitation (OR = 4.163; 95% CI: 2.91-5.96), movement to endemic area (OR = 4.53; 95% CI: 3.03-6.77), provenance from leishmaniasis foci (in Essaouira focus OR = 5.34; 95% CI: 1.19-24.03) and poverty. In addition, environmental factors like proximity of vegetation (OR = 2.45; 95% CI: 1.14-5.25), poor domestic hygiene, particularly the absence of sewage system/waste management (OR = 1.63; 95% CI: 1.35-1.96), and presence of animals (OR = 2.67; 95% CI: 1.14-5.25) increase the risk of ACL in Morocco. Except for Matrimonial status (married people, OR = 4.11; 95% CI: 1.80-9.41), there is however no significant association of the disease with the other socio-demographic factors in the study area (p>0.05). These several risk factors must be taken in consideration to prevent this disease through multidisciplinary collaboration and community participation.

Assessment of knowledge and perceptions on leishmaniasis: An island-wide study in Sri Lanka.

Cutaneous leishmaniasis (CL) is a notifiable disease in Sri Lanka with increasing case numbers reported from every part of the country. In addition to disease treatment and vector control measures, knowledge and perceptions in a community are key contributors to a successful intervention program. An island-wide survey was carried out to assess the knowledge and perceptions regarding CL across the island, with 252 confirmed CL cases and 2,608 controls. Data was collected by trained personnel, using a pre-tested Case Reporting Form (CRF). Although the percentage who referred to CL by its correct name was low (1.4%), majority stated that it is a fly induced skin disease (79.1%). Knowledge on the symptoms, curability and the name of the vector was high in these communities, but specific knowledge on vector breeding places, biting times and preventive methods were poor. The patients were more knowledgeable when compared to the controls. Differences in the level of knowledge could be identified according to the level of education of the participants as well as across the different areas of the country. The main source of information was through the healthcare system, but the involvement of media in educating the communities on the disease was minimal. While this study population was unaccustomed to the use of repellants or sprays, the use of bed nets was high (77.7% of the participants) in this study population. Although misconceptions and incorrect practices are rare in Sri Lankan communities, promoting health education programs which may improve disease awareness and knowledge on vector and its control will further strengthen the control and prevention strategies.

Effectiveness of insecticide thermal fogging in hyrax dens in the control of leishmaniasis vectors in rural Palestine: A prospective study.

BACKGROUND: Zoonotic cutaneous leishmaniasis (ZCL) is endemic in Palestine and transmitted by Phlebotomus sand flies. They inhabit dens of hyraxes, the reservoir animal. Control measures were implemented since 1996 but cases still occur. We estimated the effect of insecticide thermal fogging inside hyrax dens on sand fly density and leishmania infection. METHODOLOGY/PRINCIPAL FINDINGS: During July-September 2019, we conducted a 12-week controlled interrupted time series study in two control and one intervention sites containing three hyrax dens each. We implemented Permethrin thermal fogging in the intervention site at week 6. We measured weekly and 36hrs post-intervention sand fly abundance inside dens using CDC light traps. We performed Next-Generation Sequencing to identify sand fly Leishmania spp. infection. We calculated the abundance reduction (AR) using Mulla's formula and negative binomial regression. Among 11427 collected sand flies, 7339 (64%) were females and 1786 (16%) were Phlebotomus spp. comprising ten species; P. sergenti was the dominant (n = 773, 43%). We report P. arabicus (n = 6) for the first time in Palestine. After fogging, Phlebotomus spp. AR was 93% at 36hrs, 18% and 38% at two and five weeks respectively and 41% during the complete post-intervention period. In the regression models, Phlebotomus spp. density in the intervention site decreased by 74% (IRR: 0.26, 95%CI: 0.11-0.57) at two weeks, 34% (IRR: 0.66, 95%CI: 0.48-0.90) at five weeks and 74% (IRR: 0.26, 95%CI: 0.12-0.59) during the complete period. The density of Leishmania infected sand flies decreased by 65% (IRR: 0.35, 95%CI: 0.26-0.48) at five weeks and 82% (IRR: 0.18, 95%CI: 0.07-0.42) for the complete period (zero infections until week two). Leishmania infection prevalence in the intervention site was 14% pre-intervention and 3.9% post-intervention. CONCLUSIONS/SIGNIFICANCE: Fogging hyrax dens reduced sand fly abundance and leishmania infection during the 5-week post-intervention period and especially the first two weeks suggesting it could be an effective source-reduction measure for ZCL vectors. Future randomized controlled trials are needed to confirm the effectiveness of fogging hyrax dens on decreasing ZCL incidence.

A Community Based Survey of Knowledge, Attitudes, and Practices Concerning Leishmaniasis in Central Morocco.

Leishmaniasis is a major health problem caused by a protozoan of the genus Leishmania, most commonly transmitted by infected female sand flies. Intersectoral collaboration is essential for the implementation of integrated vector management control with community participation. The present study aims to evaluate the knowledge, attitude and practices of the population toward leishmaniasis in central Morocco. A quantitative cross-sectional study was conducted using an administered questionnaire assisted by health professionals, on 750 people in the Marrakech Safi, endemic region of cutaneous leishmaniasis (CL). Of those, 702 agreed to be recruited for our study, of which 63,5% were women, 48,1% were aged between 18 and 40 years, and more than half of the participants (60%) were from rural areas. Overall, the knowledge, attitude and practices (KAPs) for leishmaniasis are too poor for more than 85% of the population in the study area. Basic knowledge and perceptions of leishmaniasis were good for 14,6% of respondents. While, 4,5% of the members had good knowledge of CL, only 0,7% had good level of knowledge about vesciral leishmaniasis (VL). Furthermore 3,7% of those polled have favorable attitudes and preventive practices. No association was found between knowledge and age, province or occupation. However, rural residents were four times more likely than urbain residents to have good basic knowledge (ORA = 4,74; CI95%: 1,04 -22,05). In addition, the female gender also has the chance to possess good basic knowledge and perceptions 3 times more than the men (ORA = 3,18; CI95%: 1,16 -8,69). The low level of KAPs regarding leishmaniasis proves the lack of community participation in the fight against leishmaniasis in central Morocco.

Development and psychometric assessment of cutaneous leishmaniasis prevention behaviors questionnaire in adolescent female students: Application of integration of cultural model and extended parallel process model.

BACKGROUND: Cutaneous Leishmaniasis (CL) is an important public health issue in at least 83 countries, including Iran. Individuals' behavior modification is believed to be one of the best ways for CL prevention. However, no comprehensive questionnaires have been psychoanalyzed for identification of CL prevention behaviors and its numerous associated factors, as well as the impact of educational messages. Thus, the present study was conducted to develop and psychometrically assess CL prevention behaviors questionnaire in female students. METHODS: The present study was performed from October 2020 to May 2021 by developing a preliminary questionnaire based on integration of Cultural Model and Extended Parallel Process Model. The questionnaire was completed online by 460 adolescent female students living in endemic areas of Isfahan, Iran. Exploratory factor analysis was performed using SPSS 24 to ensure the construct validity. Internal reliability was assessed via Cronbach's alpha and external reliability was determined using the test-retest method based on the intraclass correlation coefficient (ICC) index. RESULTS: The first version of the questionnaire contains 110 items, out of which 82 remained according to content validity ratio (CVR) and content validity index (CVI) criteria. Afterwards, 11 items were removed due to low factor load in the construct validity process using the factor analysis technique. Ultimately, a 71-items questionnaire was developed and 12 factors were extracted from it. According to Cronbach's alpha index, the internal reliability for the questionnaire was 0.877 and the ICC index calculated the external reliability as 0.833. CONCLUSIONS: Integration of a Cultural Model with individual model was used for the first time to measure the factors related to CL prevention behaviors in this questionnaire; owing to the strength of the factor structure and appropriate psychometric properties, the questionnaire is applicable in the evaluation process of educational interventions concerning CL prevention, especially in female students.

Leishmania tarentolae as Potential Live Vaccine Co-Expressing Distinct Salivary Gland Proteins Against Experimental Cutaneous Leishmaniasis in BALB/c Mice Model.

Leishmaniasis is a neglected vector-borne disease caused by Leishmania parasites transmitted through the infected sand flies bite. Current treatments are limited, partly due to their high cost and significant adverse effects, and no human vaccine is yet available. Sand flies saliva has been examined for their potential application as an anti-Leishmania vaccine. The salivary protein, PpSP15, was the first protective vaccine candidate against L. major. Additionally, PsSP9 was already introduced as a highly immunogenic salivary protein against L. tropica. Herein, we aimed to develop an effective multivalent live vaccine to control Cutaneous Leishmaniasis induced by two main species, L. major and L. tropica. Hence, the two above-mentioned salivary proteins using T2A linker were incorporated inside the L. tarentolae genome as a safe live vector. Then, the immunogenicity and protective effects of recombinant L. tarentolae co-expressing PpSP15 and PsSP9 were evaluated in pre-treated BALB/c mice with CpG against L. major and L. tropica. Following the cytokine assays, parasite burden and antibody assessment at different time-points at pre and post-infection, promising protective Th1 immunity was obtained in vaccinated mice with recombinant L. tarentolae co-expressing PpSP15 and PsSP9. This is the first study demonstrating the potency of a safe live vaccine based on the combination of different salivary proteins against the infectious challenge with two different species of Leishmania.

Knowledge, attitude, and practices towards cutaneous leishmaniasis in referral cases with cutaneous lesions: A cross-sectional survey in remote districts of southern Khyber Pakhtunkhwa, Pakistan.

BACKGROUND: Cutaneous leishmaniasis is a neglected tropical disease caused by Leishmania spp. and transmitted by female sandflies. Terrorism and counter-insurgency military operations in Federally Administered Tribal Areas (FATA) lead to a large-scale migration of internally displaced persons (IDPs) in Khyber Pakhtunkhwa and thus, new outbreaks of several infectious diseases such as cutaneous leishmaniasis occurred. This study intended to find the prevalence of cutaneous leishmaniasis in people with cutaneous lesions suspected of having cutaneous leishmaniasis in four remote districts of Khyber Pakhtunkhwa and to assess the participant's knowledge, attitude, and practices about the infection and its control. METHODS: A cross-sectional study was carried out in four remote districts of Khyber Pakhtunkhwa including Karak, Lakki Marwat, Tank, and Dera Ismail Khan (D. I. Khan) and a total of 1,674 participants were recruited using a convenience sampling technique. RESULTS: The prevalence of cutaneous leishmaniasis among the participants with cutaneous lesions was 50.4% and the infection was comparatively more prevalent in district Karak. Among participants, 56.8% were male and mostly, 53.8% were under the age of 16 years with 52.8% living in kutcha houses and were from rural areas. Multiple skin lesions were more common, and the face was frequently affected body part. The ratio of participants with lesions older than a month was higher and the majority confronted infections with blood protozoan parasites for the first time. Most participants were unaware of the signs/symptoms of the disease, basic knowledge of the vectors, anthroponotic spread, preventive measures, secondary infections, and reservoir hosts. The use of wood/animal dung as fuel, closeness with reservoir animals, and no use of insect repellents were some of the notable risk factors. CONCLUSION: Cutaneous leishmaniasis is highly prevalent in the study area and a very low level of awareness was reported among the participants. This study necessitates the planning and execution of regulations and preventive programs, public health education, awareness campaigns, and disease management practices to overcome future incidence of cutaneous leishmaniasis.

Evaluation of Household Preparedness and Risk Factors for Cutaneous Leishmaniasis (CL) Using the Community Assessment for Public Health Emergency Response (CASPER) Method in Pakistan.

(1) Background: In endemic areas of Pakistan, local community knowledge and attitudes towards cutaneous leishmaniasis (CL) are critical elements in the effective control and management of the disease. A cross-sectional epidemiologic design was used to assess the disease concern, preparedness, practices, and preventive behavior of the households and to assist the personnel and health care professionals in strengthening their planning efforts and awareness of CL. (2) Methods: A two-stage cluster sampling process, i.e., Community Assessment for Public Health Emergency Response (CASPER) was conducted from September 2020 to March 2021 on present household-level information about community needs and health status regarding CL in a cost-effective, timely, and representative manner. (3) Results: In the current study, 67% of the respondents were aware of CL and its causative agent and showed a low level of pandemic preparedness. The majority (74%) of the respondents mentioned that they did not avoid sandfly exposure areas. The majority (84%) of respondents had unsatisfactory behavior towards using bed nets, sprays, or repellents. (4) Conclusion: In endemic areas of Pakistan, the inadequate concern and low preparedness of the local community toward CL are critical aspects in efficient control and management of the disease.

Identification of Immunodominant Antigens From a First-Generation Vaccine Against Cutaneous Leishmaniasis.

Leishmaniasis is a neglected tropical disease (NTD) caused by parasites belonging to the Leishmania genus for which there is no vaccine available for human use. Thus, the aims of this study are to evaluate the immunoprotective effect of a first-generation vaccine against L. amazonensis and to identify its immunodominant antigens. BALB/c mice were inoculated with phosphate buffer sodium (PBS), total L. amazonensis antigens (TLAs), or TLA with Poly (I:C) and Montanide ISA 763. The humoral and cellular immune response was evaluated before infection. IgG, IgG1, and IgG2a were measured on serum, and IFN-γ, IL-4, and IL-10 cytokines as well as cell proliferation were measured on a splenocyte culture from vaccinated mice. Immunized mice were challenged with 104 infective parasites of L. amazonensis on the footpad. After infection, the protection provided by the vaccine was analyzed by measuring lesion size, splenic index, and parasite load on the footpad and spleen. To identify immunodominant antigens, total proteins of L. amazonensis were separated on 2D electrophoresis gel and transferred to a membrane that was incubated with serum from immunoprotected mice. The antigens recognized by the serum were analyzed through a mass spectrometric assay (LC-MS/MS-IT-TOF) to identify their protein sequence, which was subjected to bioinformatic analysis. The first-generation vaccine induced higher levels of antibodies, cytokines, and cell proliferation than the controls after the second dose. Mice vaccinated with TLA + Poly (I:C) + Montanide ISA 763 showed less footpad swelling, a lower splenic index, and a lower parasite load than the control groups (PBS and TLA). Four immunodominant proteins were identified by mass spectrometry: cytosolic tryparedoxin peroxidase, an uncharacterized protein, a kinetoplast-associated protein-like protein, and a putative heat-shock protein DNAJ. The identified proteins showed high levels of conserved sequence among species belonging to the Leishmania genus and the Trypanosomatidae family. These proteins also proved to be phylogenetically divergent to human and canine proteins. TLA + Poly (I:C) + Montanide ISA 763 could be used as a first-generation vaccine against leishmaniasis. The four proteins identified from the whole-protein vaccine could be good antigen candidates to develop a new-generation vaccine against leishmaniasis.

Immunogenic properties of empty pcDNA3 plasmid against zoonotic cutaneous leishmaniasis in mice.

BACKGROUND: Leishmania (L) parasite, the causative agent of zoonotic cutaneous leishmaniasis (ZCL), effectively stimulates the mammalian cells to mount strong humoral responses by enhancing T-helper-2 (Th2)-associated cytokines for its survival. The best strategy to decrease the intensity of infection in the host is induction of cellular immunity. METHODS: We evaluated the effects of the empty bacterial pcDNA3 plasmid on mice infected with L. major and quantified the immune mediators including IFN-γ, IL-4, IL-10, IgG2a, IgG1, arginase activity and nitric oxide (NO) in the mice. Moreover, the footpad lesion size and parasite load were assessed. RESULTS: We observed that pcDNA3 could modulate the immune responses in favor of host cells and decrease the disease severity. Th2- associated mediators, including arginase, IL-4, and IL-10 are downregulated, while cellular responses are upregulated in line with an increase in the levels of nitric oxide (NO) and interfero-gamma (IFN-γ). Interestingly, pcDNA3 induced specific Th1-associated antibodies, IgG2a isotype; however, it suppressed the production of humoral IgG1. The stimulation of the immune response by the empty pcDNA3 is able to shift the immune function to predominant cellular responses caused by Th1, and it had a positive effect on the treatment of zoonotic cutaneous leishmaniasis (ZCL). CONCLUSIONS: Altogether, we introduced the pcDNA3 as a potential interfering factor in the modulation of the immune system against ZCL. Since this vector has been widely used as a control group in different studies, we suggest that the potential function of the empty vector should be deeply assessed, as it exerts anti-parasitic effects on mice infected with L. major.

Vaccination in Leishmaniasis: A Review Article.

Leishmaniasis is caused by protozoan Leishmania parasites that are transmitted through female sandfly bites. The disease is predominantly endemic to the tropics and semi-tropics and has been reported in more than 98 countries. Due to the side effects of anti-Leishmania drugs and the emergence of drug-resistant isolates, there is currently no encouraging prospect of introducing an effective therapy for the disease. Hence, it seems that the key to disease control management is the introduction of an effective vaccine, particularly against its cutaneous form. Advances in understanding underlying immune mechanisms are feasibale using a variety of candidate antigens, including attenuated live parasites, crude antigens, pure or recombinant Leishmania proteins, Leishmania genes encoding protective proteins, as well as immune system activators from the saliva of parasite vectors. However, there is still no vaccine against different types of human leishmaniasis. In this study, we review the works conducted or being performed in this field.

Prophylactic effect of cutaneous leishmaniasis against COVID-19: a case-control field assessment.

INTRODUCTION: We assessed the potential relationship between COVID-19 and laboratory-confirmed cutaneous leishmaniasis (CL)-registered cases with a history of scarring, compared with volunteer participants without history of CL. METHODS: This case-control retrospective study was conducted in southeastern Iran with a high anthroponotic cutaneous leishmaniasis (ACL) burden. RESULTS: Overall, n=1010 CL cases (n=479 male, n=531 female) were evaluated for infection with SARS-CoV-2. In the CL case group, 2 men and 1 woman (0.3% in total) had a mild form of COVID-19 disease; none were hospitalized or died. In contrast, of n=2020 participants without history of CL, n=57 (2.9%) contracted laboratory-confirmed COVID-19, including mild (66.7%), hospitalized (26.3%), critical (3.5%) and fatal (3.5%). There was a strong negative association between CL infection and COVID-19. The burden of COVID-19 in CL-cured participants significantly reduced the morbidity (odds ratio: 0.12; CI: 0.03-0.30; P <0.001) and mortality (percentile: -4.10, -0.02). CONCLUSION: Participants with a history of CL scar had significantly reduced incidence of COVID-19 morbidity and mortality. The cross-protection mediated by CL may retard COVID-19 in endemic countries. However, further longitudinal studies are needed to explore the potential profile and duration of this protection offered by CL against COVID-19.