Demonstration Of Amastigotes Research Articles

Emergence of cutaneous leishmaniasis in Nepal

BackgroundCutaneous leishmaniasis (CL) is endemic in 70 countries worldwide. Nepal is considered non-endemic for CL and hence the control program is targeted to visceral leishmaniasis (VL) only. Here, we report the emergence of CL cases in different parts of Nepal.MethodsWe analyzed the CL and VL cases reported to Epidemiology and Diseases Control Division (EDCD), Ministry of Health and Population, Nepal through District Health Information System 2 (DHIS-2) and Early Warning and Reporting System (EWRS) during the past 4 years (2016–2019). Any laboratory-confirmed case was included in the study. Demographic and clinical details of each patient were transcribed into Excel sheets, verified with the case report forms and analyzed.ResultsVL has been reported in Nepal since 1980, but CL was reported very recently. From 2016 to 2019, 42 CL cases were reported from 26 different hospitals to EDCD which had been diagnosed on the basis of clinical presentation, and laboratory findings (demonstration of amastigotes in Giemsa-stained smears and rK39 test results). Majority of the patients (31.0%, 13/42) visited to the hospital within 1–6 months of onset of lesions. Facial region (38.1%, 16/42) was the common place where lesions were found ompared to other exposed parts of the body. CL was successfully treated with miltefosine for 28 days. The majority of CL patients did not have history of travel outside the endemic areas and there was no report of sandfly from these areas.ConclusionThese evidences highlight that the Government of Nepal need to pay more efforts on CL and include it in differential diagnosis by clinicians, and plan for an active surveillance when the country is targeting leishmaniasis elimination by the year 2025 with the decreasing number of VL cases.

A Clinico-Epidemiological Study of Cutaneous Leishmaniasis in a Non-Endemic Region of South Rajasthan.

Introduction:Cutaneous leishmaniasis (CL) is a vector-borne protozoal infection of the skin with variable clinical manifestations. In Rajasthan, western Thar desert is endemic for this disease.Aim:The present study was aimed to describe clinico-epidemiological features of cutaneous leishmaniasis cases from a non-endemic area of South Rajasthan.Materials and Methods:A hospital-based prospective study was carried out during a period of 3 years (2017-2019). Data regarding clinical profile and treatment outcome were recorded in a predesigned proforma for analysis. Diagnosis of CL was made clinically and confirmed by demonstration of amastigotes in microscopic examination of Giemsa stained tissue smear of lesions.Results:Out of 24 patients, 16 (67%) were females and 8 (33%) were males. The age ranged from 3 months to 68 years (median-25). Face (67%) and extremities (29%) were the common sites affected. The most common morphological form was crusted plaques (54%) followed by nodular lesions (38%). Slit skin smear for Leishmania donovani bodies was positive in all patients (100%).Conclusion:This study highlights a focus of CL in non-endemic areas of South Rajasthan. Of late leishmaniasis is breaking out of its classical boundaries and is increasingly being reported from new geographic locations with a possibility of a novel parasite variant. Therefore, a high clinical suspicion of CL should be kept in non-endemic area.

Visceral leishmaniasis after orthotopic liver transplantation: a rare cause of infection

Visceral leishmaniasis (VL) was known as an opportunistic infection associated with immunosuppression, particularly related to human immunodeficiency virus infection and rarely to solid organ transplant recipients. We report a case of VL, 6 months after liver transplantation, in a patient who presented with febrile pancytopenia. The diagnosis was made by demonstration of amastigotes in smears from bone marrow. VL is a very rare infection in patients who undergo liver transplantation and, to our knowledge, this is the first case diagnosed in Portugal.

Comparative Study of rK39 Leishmania Antigen for Serodiagnosis of Visceral Leishmaniasis: Systematic Review with Meta-Analysis

BackgroundThe rK39 recombinant protein is derived from a specific antigen produced by the Leishmania donovani complex, and has been used in the last two decades for the serodiagnosis of visceral leishmaniasis. We present here a systematic review and meta-analysis of studies evaluating serologic assays to diagnose visceral leishmaniasis to determine the accuracy of rK39 antigen in comparison to the use of other antigen preparations.Methodology/Principal FindingsA systematic review with meta-analysis of the literature was performed to compare the rK39 strip-test and ELISA formats against serological tests using promastigote antigens derived from whole or soluble parasites for Direct Aglutination Test (DAT), Indirect Immunofluorescence test (IFAT) and ELISA with a promastigote antigen preparation (p-ELISA). Gold standard diagnosis was defined by the demonstration of amastigotes on hematological specimens. A database search was performed on Medline, Lilacs, Scopus, Isi Web of Science, and Cochrane Library. Quality of data was assessed using the QUADAS questionnaire. A search of the electronic databases found 352 papers of which only 14 fulfilled the selection criteria. Three evaluated the rK39 ELISA, while 13 evaluated the rK39 immunochromatographic strip test. The summarized sensitivity for the rK39-ELISA was 92% followed by IFAT 88% and p-ELISA 87%. The summarized specificity for the three diagnostic tests was 81%, 90%, and 77%. Studies comparing the rK39 strip test with DAT found a similar sensitivity of 94%, although the DAT had a slightly higher specificity. The rK39 strip test was more sensitive and specific than the IFAT and p-ELISA. We did not detect any difference in the sensitivity and specificity between strips produced by different manufacturers.ConclusionsThe rK39 protein used either in a strip test or in an ELISA, and the DAT are the best choices for implementation of rapid, easy and efficient test for serodiagnosis of VL.

Bacterial infections in children with visceral leishmaniasis: observations made in Kerman province, southern Iran, between 1997 and 2007

Cases of human visceral leishmaniasis (VL) are often found to have bacterial infections. Between 1997 and 2007, 60 cases of VL were admitted to the paediatric ward of the Afzalipour Medical Centre, which forms part of the Kerman University of Medical Sciences, in southern Iran. On admission, the 60 cases (39 boys and 21 girls), each of which was confirmed by the demonstration of amastigotes in a bone-marrow aspirate, had a mean (S.D.) age of 48.8 (44.4) months and a mean (S.D.) erythrocyte sedimentation rate of 53.2 (34.2) mm/h. Twenty-five (42%) of the cases (14 boys and 11 girls) were found to have bacterial infections. Urinary infections (seen in 36% of the cases with bacterial infection) were the most common, followed by blood (28%), respiratory (16%), gastro-intestinal (12%) and skin infections (8%). Despite treatment of all the VL cases with meglumine antimoniate, four (7%) died on the paediatric ward, all four having concurrent bacterial infections. The leucopenia and immunosuppression associated with VL probably facilitate the development of fatal bacterial co-infections. The prompt diagnosis and treatment of both the VL and any bacterial co-infections should therefore reduce mortality among VL cases.

False-positive results of a rapid K39-based strip test and Chagas disease

The definitive diagnosis of visceral leishmaniasis (VL) requires invasive procedures with demonstration of amastigotes in tissue or promastigotes in culture. Unfortunately, these approaches require laboratory materials not available in poor countries where the disease is endemic. The correct diagnosis of VL is important, and made more difficult by the fact that several common tropical diseases such as malaria, disseminated tuberculosis, and enteric fever share the same clinical presentation. Serological tests have been developed to replace parasitological diagnosis in the field. A commercially available K39-based strip test for VL has been developed for this purpose. The endemic area of leishmaniasis in Brazil overlaps the endemic area of Chagas disease, a disease that can cause false-positive serological test results. The aim of this study was to evaluate the incidence of false-positive exams using a rapid test for VL in patients with Chagas disease. A rapid test based on the recombinant K39 antigen of Leishmania was used in: (1) 30 patients with confirmed Chagas disease, (2) 30 patients with a serological diagnosis of Chagas disease by ELISA, indirect immunofluorescence, indirect hemagglutination, and chemiluminescence, (3) 30 healthy patients from a non-endemic area as the control group, (4) 30 patients with confirmed VL, and (5) 20 patients with proved cutaneous leishmaniasis. The sensitivity and specificity of the rapid strip test were 100% when compared with healthy volunteers and those with confirmed Chagas disease. One false-positive result occurred in the group with Chagas disease diagnosed by serological tests (specificity of 96%). The rapid test based on recombinant K39 is a useful diagnostic assay, and a false-positive result rarely occurs in patients with a serological diagnosis of Chagas disease.

Clinical manifestations of cutaneous leishmaniasis in Sri Lanka — possible evidence for genetic susceptibility among the Sinhalese

Human cutaneous leishmaniasis (CL) caused by Leishmania donovani, a pathogen more usually associated with visceral leishmaniasis, is now endemic in Sri Lanka. This report details the characteristics of 200 patients with locally acquired CL, who were recruited prospectively for an ongoing study into the genetic susceptibility to CL in Sri Lanka. In each case, the CL was confirmed by the demonstration of amastigotes in a direct smear and/or promastigotes in a culture. Although only 82% of the Sri Lankan population is Sinhalese, all 200 patients belonged to this ethnic group. The patients had a median age of 32 years (range=4-80 years). Most of them each had a single, non-tender, non-itching and dry lesion which had started as a papule and then gradually enlarged and ulcerated, with changes in the surrounding skin. None of the patients had any signs of systemic disease. Eleven (5.5%) each had at least one other affected family member. Patients with multiple lesions were most likely to be found in families with more than one affected member (P=0.002) but multiple lesions were not associated with diabetes mellitus (P>0.05). Although the results of passive detection under-estimate the true occurrence of a disease, the present data point towards enhanced susceptibility to CL among the Sinhalese and/or certain individuals, possibly determined by genetic factors.

The histological spectrum of non-granulomatous localized mucosal leishmaniasis caused byLeishmania infantum

Although human mucosal leishmaniasis is much more common in Latin America, a few cases that are the result of local transmission occur in Europe. A suspected case of leishmaniasis is usually confirmed by the demonstration of amastigotes in smears, the culture of promastigotes from blood or tissue samples, or the PCR-based demonstration of leishmanial DNA. Biopsies may contain too few parasites to be found positive by microscopy or culture, however, and then a diagnosis may be difficult, especially in regions where human leishmaniasis in general or particular forms of the disease are rarely seen. The aim of the present study was to investigate the histopathological characteristics of three Spanish cases of non-granulomatous mucosal leishmaniasis caused by Leishmania infantum. The hope was that the information collected will help European clinicians diagnose such cases, even when amastigotes cannot be readily demonstrated.

CUTANEOUS LEISHMANIASIS: AN EMERGING INFECTION IN A NON-ENDEMIC AREA AND A BRIEF UPDATE

We report here the emergence of a new focus of cutaneous leishmaniasis (CL) due to Leishmania tropica (L. tropica) in the Ajmer city of Rajasthan, India, a previously non-endemic area. Between January-February 2006, 13 new indigenously acquired cases of CL were diagnosed among the patients attending the Skin and STD department, JLN Hospital, Ajmer. The diagnosis was based on clinical presentation, demonstration of amastigotes (LT bodies) in Giemsa stained smear of the lesion and response to intralesional / local anti-leishmanial drug therapy. In addition, culture of the promastigote forms of L. tropica from the lesion was successfully attempted in four of the smear negatives cases. By retrospective analysis, 23 new indigenous cases of CL have been diagnosed in the same setting during the period January 2004 - December 2005, based on clinical and therapeutic response alone. There was no clear-cut history of sandfly bite and travel outside the district or state to endemic area in any of the cases. However, all of them came from a common residential area (famous dargah of Ajmer) and the peak incidence was seen in January, four months after the famous Urs fair of Ajmer, the location was urban and the lesions were characteristic of L. tropica. Therefore, the disease is suspected to be anthroponotic. These features are suggestive of a common mode of transmission, source and/or vector signalling introduction of this infection into a non-endemic area.

Cutaneous leishmaniasis: An emerging infection in a non-endemic area and a brief update

We report here the emergence of a new focus of cutaneous leishmaniasis (CL) due to Leishmania tropica (L. tropica) in the Ajmer city of Rajasthan, India, a previously non-endemic area. Between January-February 2006, 13 new indigenously acquired cases of CL were diagnosed among the patients attending the Skin and STD department, JLN Hospital, Ajmer. The diagnosis was based on clinical presentation, demonstration of amastigotes (LT bodies) in Giemsa stained smear of the lesion and response to intralesional / local anti-leishmanial drug therapy. In addition, culture of the promastigote forms of L. tropica from the lesion was successfully attempted in four of the smear negatives cases. By retrospective analysis, 23 new indigenous cases of CL have been diagnosed in the same setting during the period January 2004 - December 2005, based on clinical and therapeutic response alone. There was no clear-cut history of sandfly bite and travel outside the district or state to endemic area in any of the cases. However, all of them came from a common residential area (famous dargah of Ajmer) and the peak incidence was seen in January, four months after the famous Urs fair of Ajmer, the location was urban and the lesions were characteristic of L. tropica. Therefore, the disease is suspected to be anthroponotic. These features are suggestive of a common mode of transmission, source and/or vector signalling introduction of this infection into a non-endemic area.

Field adaptable tests for kala-azar

Leishmaniasis is endemic in the tropical and subtropical regions. 12 million cases occur worldwide with 1 to 1.5 million cutaneous and 500,000 visceral leishmaniasis (kala-azar, VL) occuring fresh every year. Leishmania-HIV coinfection is emerging in southern Europe where 25 to 70% of adults with VL have AIDS as well. In the Indian subcontinent, the disease is almost exclusively caused by L donovani. Diagnosis of kala azar (VL) is by demonstration of amastigotes in splenic or bone marrow smears or by culture of leishmania promastigotes from clinical specimen. While the sensitivity of splenic smears could be as high as > 95%, it carries the risk of severe/fatal haemorrhage. Bone marrow aspiration is painful, cumbersome and has a low sensitivity (60-85%). Culture can not be used for routine clinical diagnosis as it requires expensive equipment and expertise [1].

Sero-epidemiological assessment and diagnosis of visceral leishmaniasis in an endemic locality using Fast Agglutination Screening Test (FAST)

The Fast Agglutination Screening Test (FAST) was employed on sera obtained from an endemic area of visceral leishmaniasis in southwestern Ethiopia, in February 2000. The study involved (i) active case detection among 1575 residents of two villages; and (ii) passive case detection in an outpatient clinic. Sera of 1587 individuals, including 143 sera of previously treated VL patients, were tested. Based on the size of agglutination mat, the FAST results were read qualitatively as non-reactive (−), weakly reactive (1+), moderately reactive (2+) and highly reactive (3+). All FAST reactive sera were re-tested with the Direct Agglutination Test (DAT). After clinical screening of 1625 individuals, 61 individuals with signs and symptoms of early or late VL were found; 26 sera were FAST positive. Twenty-two of these suspected VL cases were subjected to parasitological examination using lymph node aspirates. Eighteen (81.8%) were confirmed either by demonstration of amastigotes in smears or promastigotes in NNN cultures. FAST reactive anti-leishmanial antibodies were detected in 4.5% of untreated and 70.6% of previously treated patients. Forty-five sera of 1390 previously untreated asymptomatic individuals (3.2%) were found to be FAST positive. This report demonstrates that FAST is a rapid and cost-effective screening test for the diagnosis and sero-epidemiological surveillance of visceral leishmaniasis.

Studies on the leishmaniases in the Sudan. 3. Clinical and parasitological studies on visceral and mucosal leishmaniasis

The epidemiological, clinical and laboratory findings of 27 patients with visceral leishmaniasis (VL) and six with mucosal leishmaniasis (ML) in Sudan are described. The diagnosis was confirmed by the demonstration of amastigotes in bone-marrow in 20 cases with VL (80%) and impression smears in 2 cases with ML. The enzyme-linked immunosorbent assay and direct agglutination test were positive in all the sera tested. The leishmanin test was positive in all patients with ML, the diameter of the reaction ranging from 18 to 28 mm (mean 23 mm). Only one isolate (from a patient with VL) grew sufficiently well in culture to be typed and this was characterized by isoenzyme electrophoresis as Leishmania donovani zymodeme LON-46. The possibility that the ML isolate could have been L. major zymodeme LON-1 is discussed. The importance of further research to isolate and identify by biochemical procedures a more representative range of isolates of Leishmania from different clinical types in the Sudan, in order to elucidate questions such as the relationship between the vectors and possible animal reservoirs, is emphasized.