• Parasites, Hosts and Diseases
• /
• v.55 no.1
• /
• pp.1-7
• /
• 2017

Cutaneous leishmaniasis (CL) caused by Leishmania donovani is an endemic vector-borne disease in Sri Lanka. Over 2,500 cases have been reported since 2000 and the number of CL cases has dramatically increased annually. Total 57 clinically suspected CL patients attending the dermatology clinic in Anuradhapura Teaching Hospital were recruited from January to June 2015. Slit skin smears and skin biopsies were taken from each of the subjects. Clinical and epidemiological data were obtained using interviewer administered questionnaire. Forty-three (75.4%) patients among 57 were confirmed positive for L. donovani. The majority (77%) of infected patients was males, and the most affected age group was 21-40 years. Soldiers in security forces, farmers, and housewives were identified as high risk groups. The presence of scrub jungles around the residence or places of occupation (P=0.003), the presence of sandflies (P=0.021), and working outsides more than 6 hr per day (P=0.001) were significantly associated with CL. The number of lesions ranged from 1-3, and the majority (76%) of the patients had a single lesion. Upper and lower extremities were the prominent places of lesions, while the wet type of lesions were more prevalent in females (P=0.022). A nodular-ulcerative type lesion was common in both sexes. The presence of sandflies, scrub jungles, and outdoor activities contributed to spread of Leishmania parasites in an endemic pattern. Implementation of vector control programs together with health education with regard to transmission and prevention of CL are necessary to control the spread of this infection.

• Parasites, Hosts and Diseases
• /
• v.56 no.1
• /
• pp.21-24
• /
• 2018

Cutaneous leishmaniasis (CL) can be seen in 2 forms, zoonotic and anthroponotic, in Iran. In this study, epidemiological aspects of CL were studied during an 8-year period (2009-2016) in city of Kashan, central Iran. The demographic and epidemiological data, including age, sex, occupation, number and site of the lesions, treatment regimen, past history of CL, and season of all patients were gathered from the health centers. Descriptive statistics were used to describe features of the study data. Total 2,676 people with CL were identified. The highest annual incidence was estimated to be 182 per 100,000 population in 2009 and the least was in 2016 (47 per 100,000 population). The highest frequency affected age groups were observed in 20-29 year-old patients (20.9%). More than 51% of the patients were under 30 years old. The maximum frequency of the disease, 1,134 (43.3%), was seen in autumn. The most common location of lesions was hands (61.4%). Most of the patients (81.6%) were treated by systemic glucantime regimen. In the city of Kashan, the incidence rate of the CL disease is significantly higher than many other regions of Iran. To reduce the risk of disease, control of reservoir hosts and vectors of disease, and education of individual protection are strongly recommended.

• Parasites, Hosts and Diseases
• /
• v.54 no.6
• /
• pp.797-801
• /
• 2016

Heishui county, located in northwest Sichuan province, southwestern China, is an endemic area of zoonotic visceral leishmaniasis (VL) and is the most intractable area. VL is never destroyed in it. Asymptomatic dogs (Leishmania parasites have been diagnosed but clinically healthy) are considered to be a potential reservoir host in zoonotic VL area, and most can lead to infection of individuals, that is a new challenge for controlling VL in humans. The present study aimed to assess the Leishmania infection rate of asymptomatic dogs in Heishui county. Total 105 asymptomatic domestic dogs were gathered from 4 districts in Heishui county to investigate the infection rate with serological and molecular methods based on ELISA and kinetoplast minicircle DNA(kDNA) PCR, respectively. Out of 105 dogs, 44 (41.9%) were positive by more than 1 method; 21 (20.0%) were positive by ELISA, and 30 (28.6%) were positive by kDNA-PCR. Our study showed that Leishmania infection of domestic dogs which is clinically healthy is prevalent in the studied district, and the asymptomatic dogs infected by Leishmania may be the primary reason for the prevalence of visceral leishmaniasis in the area.

• Parasites, Hosts and Diseases
• /
• v.56 no.3
• /
• pp.229-236
• /
• 2018

Cutaneous leishmaniasis (CL) has been one of the most common parasitic diseases in Saudi Arabia. This study exhibits the clinical features, diagnosis, cytokine profile and treatment of CL patients in Al-Taif province. Ninety CL suspects at a tertiary care general hospital were enrolled in one-year study. Patients were interviewed, clinically-examined, and subjected to laboratory tests: skin scraping smear microscopy, OligoC-TesT commercial PCR (Coris BioConcept) and kinetoplast DNA (kDNA) PCR for Leishmania diagnosis. Interferon-gamma (RayBio; Human $IFN-{\gamma}$ ) and nitric oxide (NO) levels in patients' sera were evaluated before treatment with sodium stibogluconate (pentostam) with 20-day intramuscular drug regimen. Positive rates of microscopy, commercial PCR and kDNA PCR were 74.4%, 95.5% and 100%, respectively. Patients came to hospital mostly in winter (45.0%). CL was frequently exhibited in Saudi patients (78.8%), male gender (70.7%), age <20 years (50.0%), rural-dwellers (75.5%) and patients with travel history (86.6%). Lesion was mostly single ulcer (93.3%), occurred in the face (67.7%). Upon pentostam treatment, 85.1% of ulcers showed rapid healing signs. Levels of $IFN-{\gamma}$ and NO were significantly higher in the healing than the non-healing cases (P<0.001). The kDNA PCR proved more sensitive than microscopy and OligoC-TesT commercial PCR. Our results open perspectives for $IFN-{\gamma}$ use as a biomarker predicting treatment response.

• Parasites, Hosts and Diseases
• /
• v.51 no.1
• /
• pp.75-84
• /
• 2013

Cutaneous leishmaniasis (CL) is an endemic parasitic infection in the Mediterranean region, including Libya and its Al-jabal Al-gharbi province. We aimed at studying the occupational relevance as well as other epidemiological aspects of CL. We investigated 140 CL cases who attended at Gharyan outpatient polyclinic during a period of 6 months in 2009. CL infection was clinically diagnosed and confirmed by demonstration of Leishmania parasites on smears from lesions. Our findings showed that males were more affected than females (P=0.04), and people above 10-years were more affected than younger ones (P=0.0001). A significant percent of CL cases belonged to Al-Kawasem subprovince (P=0.0001). Farm-related activities were the most frequent occupations among CL cases (P=0.04). In addition to farm workers, housewives and students are at risk groups since they are engaged at farm activities. Moreover, those who have occupations that require staying outdoors for a part of night, e.g., policemen, are also at risk. Compared to children, adult CL patients had multiple lesions (P=0.001) that were more prevalent in their upper and lower extremities than the face (P=0.0001). We conclude that CL is a major health problem in Al-jabal Al-gharbi province of Libya. The presence of rodents and sandflies makes it a suitable environment for Leishmania to spread in an endemic epidemiological pattern. Being engaged in farming activities or outdoor occupations increases the risk of infection. Various clinical patterns of CL suggest the presence of more than 1 species of Leishmania at Al-jabal Al-gharbi province. We propose that the 2 species responsible for CL in this area are L. major and L. tropica. Further investigations to identify the leishmanial species responsible for CL at Al-jabal Al-gharbi together with adoption of preventive and control programs are needed.

• IMMUNE NETWORK
• /
• v.24 no.2
• /
• pp.14.1-14.26
• /
• 2024

The inflammatory response during cutaneous leishmaniasis (CL) involves immune and non-immune cell cooperation to contain and eliminate Leishmania parasites. The orchestration of these responses is coordinated primarily by CD4⁺ T cells; however, the disease outcome depends on the Th cell predominant phenotype. Although Th1 and Th2 phenotypes are the most addressed as steers for the resolution or perpetuation of the disease, Th17 cell activities, especially IL-17 release, are recognized to be vital during CL development. Th17 cells perform vital functions during both acute and chronic phases of CL. Overall, Th17 cells induce the migration of phagocytes (neutrophils, macrophages) to the infection site and CD8⁺ T cells and NK cell activation. They also provoke granzyme and perforin secretion from CD8⁺ T cells, macrophage differentiation towards an M2 phenotype, and expansion of B and Treg cells. Likewise, immune cells from the inflammatory infiltrate have modulatory activities over Th17 cells involving their differentiation from naive CD4⁺ T cells and further expansion by generating a microenvironment rich in optimal cytokines such as IL-1β, TGF-β, IL-6, and IL-21. Th17 cell activities and synergies are crucial for the resistance of the infection during the early and acute stages; however, if unchecked, Th17 cells might lead to a chronic stage. This review discusses the synergies between Th17 cells and the inflammatory infiltrate and how these interactions might destine the course of CL.

• Parasites, Hosts and Diseases
• /
• v.44 no.1 s.137
• /
• pp.55-61
• /
• 2006

For treating Leishmania major infection in BALB/c mice, we used thalidomide in conjunction with glucantime. Groups of mice were challenged with $5{\time}10^3$ metacyclic promastigotes of L. major subcutaneously. A week after the challenge, drug treatment was started and continued for 12 days. Thalidomide was orally administrated 30 mg/kg/day and glucantime was administrated intraperitoneally (200 mg/kg/day). It was shown that the combined therapy is more effective than single therapies with each one of the drugs since the foot pad swelling in the group of mice received thalidomide and glucantime was significantly decreased (0.9 :t 0.2 mm) compared to mice treated with either glucantime, thalidomide, or carrier alone (1.2 :t 0.25, 1.4 :t 0.3, and 1.7 :t 0.27 mm, respectively). Cytokine study showed that the effect of thalidomide was not dependent on IL-12; however, it up-regulated IFN-yand down-regulated IL-10 production. Conclusively, thalidomide seems promising as a conjunctive therapy with antimony in murine model of visceral leishmaniasis.

• Parasites, Hosts and Diseases
• /
• v.44 no.1 s.137
• /
• pp.43-48
• /
• 2006

Experimental murine models with high, intermediate and low levels of genetically based susceptibility to Leishmania major infection reproduce almost entire spectrum of clinical manifestations of the human disease. There are increasing non-comparative studies on immune responses against isolated antigens of L. major in different murine strains. The aim of the present study was to find out whether there is an antigen that can induce protective immune response in resistant and susceptible murine strains. To do that, crude antigenic extract of procyclic and metacyclic promastigotes of L. major was prepared and subjected to SDS-PAGE electrophoresis. Western-blotting was used to search for antigen(s) capable of raising high antibody level of IgG2a versus IgG1 in the sera of both infected resistant and susceptible strains. Two novel antigens from metacyclic promastigotes of L. major (140 and 152 kDa) were potentially able to induce specific dominant IgG2a responses in BALB/c and C57BU6 mice. The 2 antigens also reacted with IgG antibody of cutaneous leishmaniasis patients. We confirm that 140 and 152 kDa proteins of L. major promastigotes are inducing IgG production in mice and humans.

• Parasites, Hosts and Diseases
• /
• v.45 no.2 s.142
• /
• pp.103-109
• /
• 2007

Leishmania tropica and L. major are etiologic agents of human cutaneous leishmaniasis. Delayed type hypersensitivity (DTH) is an immunologic response that has been frequently used as a correlate for protection against or sensitization to leishmania antigen. In BALB/c mice, L. tropica infection results in non-ulcerating disease, whereas L. major infection results in destructive lesions. In order to clarify the immunologic mechanisms of these 2 different outcomes, we compared the ability of these 2 leishmania species in induction of DTH response in this murine model. BALB/c mice were infected with L. major or L. tropica, and disease evolution and DTH responses were determined. The results show that the primary L. major infection can exacerbate the secondary L. major infection and is associated with DTH response. Higher doses of the primary L. major infection result in more disease exacerbation of the secondary L. major infection as well as higher DTH response. L. tropica infection induces lower DTH responses than L. major. We have previously reported that the primary L. tropica infection induces partial protection against the secondary L. major infection in BALB/c mice. Induction of lower DTH response by L. tropica suggests that the protection induced against L. major by prior L. tropica infection may be due to suppression of DTH response.

• Parasites, Hosts and Diseases
• /
• v.45 no.4
• /
• pp.287-293
• /
• 2007

The identification and characterization of antigens that elicit human T cell responses is an important step toward understanding of Leishmania major infection and ultimately in the development of a vaccine. Micropreparative SDS-PAGE followed by electro transfer to a PVDF membrane and elution of proteins from the PVDF, was used to separate 2 novel proteins from L. major promastigotes, which can induce antibodies of the IgG2a isotype in mice and also are recognized by antisera of recovered human cutaneous leishmaniasis subjects. Fractionation of the crude extract of L. major revealed that all detectable proteins of interest were present within the soluble Leishmania antigens (SLA). Quantitation of these proteins showed that their expression in promastigotes is relatively very low. Considering the molecular weight, immunoreactivity, chromatographic and electrophoretic behavior in reducing and non-reducing conditions, these proteins are probably 2 isoforms of a single protein. A digest of these proteins was resolved on Tricine-SDS-PAGE and immunoreactive fragments were identified by human sera. Two immunoreactive fragments (36.4 and 34.8 kDa) were only generated by endoproteinase Glu-C treatment. These immunoreactive fragments or their parent molecules may be ideal candidates for incorporation in a cocktail vaccine against cutaneous leishmaniasis.