Visceral leishmaniasis

About: Visceral leishmaniasis is a research topic. Over the lifetime, 7486 publications have been published within this topic receiving 184865 citations. The topic is also known as: Kala-Azar & viscus leishmaniasis.

Chronic exposure to arsenic in drinking water can lead to resistance to antimonial drugs in a mouse model of visceral leishmaniasis

Abstract: The Indian subcontinent is the only region where arsenic contamination of drinking water coexists with widespread resistance to antimonial drugs that are used to treat the parasitic disease visceral leishmaniasis. We have previously proposed that selection for parasite resistance within visceral leishmaniasis patients who have been exposed to trivalent arsenic results in cross-resistance to the related metalloid antimony, present in the pentavalent state as a complex in drugs such as sodium stibogluconate (Pentostam) and meglumine antimonate (Glucantime). To test this hypothesis, Leishmania donovani was serially passaged in mice exposed to arsenic in drinking water at environmentally relevant levels (10 or 100 ppm). Arsenic accumulation in organs and other tissues was proportional to the level of exposure and similar to that previously reported in human liver biopsies. After five monthly passages in mice exposed to arsenic, isolated parasites were found to be completely refractory to 500 μg⋅mL−1 Pentostam compared with the control passage group (38.5 μg⋅mL−1) cultured in vitro in mouse peritoneal macrophages. Reassessment of resistant parasites following further passage for 4 mo in mice without arsenic exposure showed that resistance was stable. Treatment of infected mice with Pentostam confirmed that resistance observed in vitro also occurred in vivo. We conclude that arsenic contamination may have played a significant role in the development of Leishmania antimonial resistance in Bihar because inadequate treatment with antimonial drugs is not exclusive to India, whereas widespread antimonial resistance is.

Clinical and laboratory alterations in dogs naturally infected by Leishmania chagasi

Abstract: INTRODUCTION: Canine visceral leishmaniasis (CVL) is a zoonotic disease with different clinical manifestations. Parasitism often occurs in bone marrow, but changes have been observed in peripheral blood and serum biochemical parameters. The aim of this study was to evaluate the hematological and biochemical parameters in dogs naturally infected by Leishmania chagasi. METHODS: Eighty-five adult dogs of both sexes and various weights and ages from the Zoonosis Control Center of Fortaleza (CCZ) were used, selected by immunofluorescence assay (IFA) and considered positive with IFA titers greater than 1:40 and by visualizing amastigotes of Leishmania chagasi in smears obtained by bone marrow aspiration. The dogs (n = 85) were grouped according to clinical signs: negative (CN = 7), subclinical (CS = 10), and clinical (CC = 68). Blood samples were collected for determination of hematological and biochemical serum values. The experimental protocol was approved by the CEUA/UECE. RESULTS: The most frequent clinical signs were cachexia (77.9%), keratitis (61.8%), and lymphadenopathy (55.9%), and 86.8% of the animals showed more than one clinical sign characteristic of CVL. In CC were observed reductions in red blood cells (63%), hematocrit (72%), and hemoglobin (62%), as well as leukocytosis (33%), neutropenia (28%), thrombocytopenia (50%), uremia (45%), hyperproteinemia (53%, p<0.05), hypergammaglobulinemia (62%, p<0.01), and hypoalbuminemia (58%). CONCLUSIONS: Animals with the clinical form of the disease demonstrate hematological and biochemical changes consistent with anemia, uremia, hyperproteinemia, and hyperglobulinemia, which present themselves as strong clinical markers of visceral leishmaniasis associated with the signs previously reported.

[Feline leishmaniasis: what's the epidemiological role of the cat?].

Abstract: Feline leishmaniasis (FL) is a quite uncommon feature Clinical disease has been described in cats since nineties begin More than 40 reports in world literature have been referred, but the clinical cases have been only recently well defined Most of the reports focus on infected cats living in endemic areas, even if, more recently FL due to Leishmania infantum was found in Sao Paulo State, in Brazil where autochthonous human or canine leishmaniasis cases have never reported In Europe clinical cases of FL have been described from Portugal, France, Spain and Italy from 1996 to 2002 When a typing of the etiological agent was performed L infantum was identified in all reported cases In some endemic areas serological surveys have also been carried out in cats, using IHAT in Egypt, Western blot in France or IFAT in Italy Sixty Egyptian cats had low serological antibody titers, from 1/32 to 1/128, in the endemic focus of canine leishmaniasis of Alpes Maritimes 12 out of 97 (125%) cats showed antibodies versus antigens 14 and/or 18 kDa of L infantum A previous survey by means of IFAT in Liguria and Toscana on 110 and 158 feline sera respectively reports a seroprevalence of 09% with low titer, while sera from Sicily seem to be positive at higher dilutions Animals living in an endemic area can develop specific antibodies against leishmania and, in our experience, they can be evidentiated by means of IFAT The antibody titers appear to be lower in affected cats than in dogs, even if the number of clinical cases is very scanty PCR tests on feline blood samples are in progress, but preliminary results confirm the presence of leishmania DNA in such specimens Cutaneous leishmaniasis is the more frequent form in cats and it was reported from several countries Typical signs include nodular to ulcer or crusty lesions on the nose, lips, ears, eyelids, alopecia: clinical signs of cutaneous FL are unspecific and in endemic area this infection must be taken into account Visceral leishmaniasis is not common in cats: this form shows visceral involvement: liver and spleen are interested, with lymph nodes and kidney The cat probably has to considerate to play an active role in the disease, in contrast to goats, calves and horses who could act as accidental reservoirs of leishmania, while sheep appears to be not susceptible to experimental infection In endemic foci for kala-azar in Sudan cows, goats and donkeys had a high prevalence of specific antibodies Recently in Europe sporadic cases of equine leishmaniasis have been reported: L infantum was the causative agent Equine leishmaniasis appears as a self-healing skin-dwelling disease, with a massive accumulation of parasites The animals do not often show detectable specific antibodies and recover without any chemotherapy Untreated affected cats can frequently die and we also observed lymph nodes and blood involvement indicating a spread of leishmania in feline hosts The epidemiological role of the cat has never been clarified due also to lack of xenodiagnosis trials This species is believed to have a high degree of natural resistance, as observed following experimental infection Some of the affected cats were FIV and/or FeLV positive and these viroses such as stress may induce an impaired cellular immune response, even if leishmania infected cat was not submitted to CD4+, CD8+ lymphocyte counts nor other immunological test However the resistance of the cat to leishmania infection probably depends on genetic factors, not strictly related to cell mediated immunity, taking into account the high seroprevalence of FIV infections (30%) in our country versus the number of clinical cases

Leishmania-HIV Co-infection: Clinical Presentation and Outcomes in an Urban Area in Brazil

Abstract: Background Visceral leishmaniasis (VL) is an emerging condition affecting HIV-infected patients living in Latin America, particularly in Brazil. Leishmania-HIV coinfection represents a challenging diagnosis because the clinical picture of VL is similar to that of other disseminated opportunistic diseases. Additionally, coinfection is related to treatment failure, relapse and high mortality.

The emergence of Leishmania major and Leishmania donovani in southern Turkey.

Abstract: Background: In southern Turkey, Leishmania tropica and L. infantum are both the causative agents of cutaneous leishmaniasis (CL) and visceral leishmaniasis (VL), respectively. However, L. majorand L. donovani were known to exist after the influx of Syrian refugees. Methods: Between the years of July 2003 and July 2013, a total of 167 smears and 113 bone marrow samples weretakenfromCLandVL-suspectedcases,respectively.Sampleswereanalysedthroughreal-timePCRandITS1 DNA sequencing. Results: One hundred and seven 64% (107/167) smears and 56% (63/113) bone marrow samples were positive for leishmaniasis according to the real-time PCR. Three different Leishmania species were found in the 107 CL cases by real-time PCR: 42% (45/107) L. tropica, 36.5% (39/107) L. infantum and 21.5% (23/107) L. major .I n addition, three different Leishmania species were identified in the 63 VL cases: 60.3% (38/63) L. infantum, 30.2% (19/63) L. donovani and 9.5% (6/63) L. tropica using real-time PCR. The results of real-time PCR were confirmed with Leishmania ITS1 DNA sequencing. Conclusions: This study revealed that in southern Turkey, L. majorand L. donovani were the aetiological agents of CL and VL, respectively. It was assumed that emergence of L. major and L. donovani was due to influx of Syrian refugees, as well as the effects of global warming.