Disseminated cutaneous leishmaniasis due to Leishmania(Leishmania) amazonensis in human immunodeficiency virus(HIV)-infected patients: A report of two cases

Rationale: Co-infection of human immunodeficiency virus(HIV) and Leishmania spp. has impact on clinical and therapeutic outcomes of leishmaniases. Most studies do not present the identification of Leishmania species causing American tegumentary leishmaniasis in co-infections. In the Americas, Leishmania(L.) Viannia(V.) braziliensis and L.(V.) guyanensis have been identified. Patient concerns: In this study, two cases of American tegumentary leishmaniasis in patients infected with HIV are described. Patients presented several lesions with rapid dissemination and mucosal involvement. Diagnosis: Disseminated cutaneous leishmaniasis caused by L. amazonensis was identified by molecular test. Interventions: The patients were treated with conventional therapies for HIV infection and American tegumentary leishmaniasis. Outcomes: In co-infection, the clinical manifestations are atypical and the treatment response can be impaired. Lessons: These cases show that HIV infection impacts L. amazonensis infection and point to the relevance of identifying Leishmania species, which can lead to a better patient management.     

First occurrence of an autochthonous canine case of Leishmania (Leishmania) infantum chagasi in the municipality of Campinas, State of São Paulo, Brazil

An autochthonous case of visceral leishmaniasis is reported in a dog (Canis familiaris) as an apparently natural infection in a non-endemic area. DNA obtained from spleen and liver samples produced the expected fragment in a Leishmania-specific rDNA-based nested-PCR assay. The PCR product, a 490 bp fragment, was sequenced and the nucleotide sequence was identical to that of Leishmania (Leishmania) infantum chagasi. These results are surprising since no autochthonous human or canine cases of visceral leishmaniasis have ever been reported in this municipality. This case suggests that natural transmission of this disease is occurring in this area.     

Importance of cats in zoonotic leishmaniasis in Portugal

Leishmaniasis, caused by Leishmania infantum, is an endemic zoonosis in the Mediterranean basin. Dogs are considered the major host for these parasites, as well as the main reservoir for human visceral infection. In recent years, asymptomatic infection or clinical disease caused by L. infantum in cats has been reported in several countries where zoonotic leishmaniasis is present. The aim of the present study was to perform a leishmaniasis survey in cats from an endemic focus. Twenty-three adult stray cats were surveyed by clinical examination, and peripheral blood samples for serological and molecular analysis were collected. In 7 of the 23 cats (30.4%) Leishmania DNA was detected in blood. A low level of fluorescent antibodies was detected in four serum samples. All the animals were asymptomatic. Taking into account the high rate of asymptomatic feline leishmaniasis in this survey, it can be suggested that cats may act as a habitual reservoir host of L. infantum infection in endemic areas. Furthermore, it will be important in the future to add this parasitosis to the differential diagnosis of feline infections from leishmaniasis foci in cats. Feline leishmaniasis diagnosis should be accessed by molecular tools.     

Visceral leishmaniasis. Persistence of parasites in lymph nodes after clinical cure

Visceral leishmaniasis (VL) is generally associated with severe immunodeficiency (AIDS; renal, liver, and heart transplantations; haemopoietic malignancies). More rarely it can be related to an immunotolerence status such as pregnancy. Various observations report the development of leishmaniasis several months or even years after exposure to the parasite. Relapses occur rarely in patients not known to be immunocompromised, but are common after incomplete treatment. They are frequent in patients with Leishmania/HIV co-infection. Asymptomatic phases and relapses suggest that parasite can exist in the tissues for a long time before and/or after clinical onset of the disease.The mechanisms of onset of clinical leishmaniasis following exposure and infestation are highly relevant to understanding the pathology of the disease. The survival of Leishmania parasite between infection and disease or after cure is a very important issue for clinicians and epidemiologists. We describe two cases of VL occurring in a patient with lymphoma and in a pregnant woman. In both cases, parasites remained present in the lymph nodes after clinical cure.     

Pancreatic involvement in co-infection visceral leishmaniasis and HIV: histological and ultrastructural aspects

The involvement of the gastrointestinal tract in the co-infection of HIV and Leishmania is rarely reported. We report the case of an HIV-infected adult man co-infected with a disseminated form of leishmaniasis involving the liver, lymph nodes, spleen and, as a feature reported for the first time in the English literature, the pancreas. Light microscopy showed amastigote forms of Leishmania in pancreatic macrophages and immunohistochemical staining revealed antigens for Leishmania and also for HIV p24. Microscopic and ultrastructural analysis revealed severe acinar atrophy, decreased zymogen granules in the acinar cytoplasm and also nuclear abnormalities such as pyknosis, hyperchromatism and thickened chromatin. These findings might correspond to the histologic pattern of protein-energy malnutrition in the pancreas as shown in our previous study in pancreas with AIDS and no Leishmania. In this particular case, the protein-energy malnutrition may be due to cirrhosis, or, Leishmania or HIV infection or all mixed. We believe that this case represents the morphologic substratum of the protein energy malnutrition in pancreas induced by the HIV infection. Further studies are needed to elucidate these issues.     

Kala-azar in a high transmission focus: an ethnic and geographic dimension

In 1994-1996, we studied a group of 58 game wardens stationed in an area known to be highly endemic for visceral leishmaniasis (kala-azar) for evidence of infection with Leishmania donovani. Leishmania DNA was detected by the polymerase chain reaction in the peripheral blood of cases of active kala-azar, former patients with visceral leishmaniasis, patients, and asymptomatic subjects. Using the cloned antigen rk39, antibodies were detected in 44.2% of the game wardens while leishmanin skin test result was positive in 77% of our sample. It was shown that certain tribes from northern Sudan were more likely to develop subclinical infections, while those of the Baria tribe from southern Sudan and those of the Nuba tribe from western Sudan were more likely to develop visceral leishmaniasis. Whether this is due to genetic factors or previous exposure to Leishmania parasites remains to be elucidated.     

Oral miltefosine treatment in children with visceral leishmaniasis: a brief review.

Visceral leishmaniasis (VL) or kala-azar is an infection disease caused by hemiflagellate protozoan parasites (Leishmania donovani) and transmitted to humans by the phlebotomine sandfly. Leishmaniasis is distributed worldwide and 13 million people are estimated to be infected, with about 1.8 million new cases each year. All antileishmanial drugs are toxic and most have to be used parenterally for prolonged period. The therapy has been further complicated by large number of infected children and declining effectiveness of pentavalent antimonial compounds. Although the lipid formulations of amphotericin B are an important advance in therapy, their high cost precludes their use. Miltefosine, a phosphocholine analogue originally developed as antimalignant drug, has been found to be highly active against Leishmania in vitro and in animal model. Based on these experiences this drug was tried against human visceral leishmaniasis and found to be highly effective in children. The aim of this review is to evidence the pharmacodymamic and pharmacokinetic characteristics and the safety, tolerance and efficacy of this drug for treatment of visceral leishmaniasis in children.     

Leishmania and HIV co-infection: dermatological manifestations

Leishmania species can cause a wide spectrum of cutaneous disease in HIV-positive patients: asymptomatic, localized cutaneous, mucosal, muco-cutaneous, diffuse cutaneous or post-kala-azar leishmaniasis. In such cases, which are usually severely immunocompromised, the leishmanial parasites reach the skin of the human host by dissemination after either a new infection (resulting from the bite of infected sandfly or, probably, the sharing of contaminated syringes by intravenous-drug users) or the re-activation of a latent infection. Recent experience and past observations on the dermatology of leishmaniasis in those with Leishmania/HIV co-infection are reviewed here.     

洛阳市1起输入性皮肤利什曼病疫情流行病学 筛查报告

目的　了解中国石油天然气第一建设公司乌兹别克斯坦务工归国员工中利什曼原虫感染情况，并及时采取相关防控措施，防止疫情扩大。方法　设计调查问卷采集筛查对象相关信息，由内科医生触诊肝、脾及浅表淋巴结，皮肤科医生检查皮肤经常暴露处皮肤损害情况，对筛查对象行B超检查肝脾大小，采集筛查对象血清，应用内脏利什曼病快速检测试纸条（rK39）检测，对于筛查中发现的有皮肤损害者，采集皮损处组织镜检利什曼原虫，病原学检测阳性组织用分子生物学方法鉴定虫种。结果　共181人接受筛查，内科检查中6人颈部可触及肿大淋巴结，皮肤科检查中12人有皮肤损害表现，B超检查提示5人肝脾肿大，rK39试纸条检测血清显示3人结果呈阳性。共采集2人份典型皮损处组织，其中1份组织病原学检测发现利什曼原虫；提取前鞭毛体DNA，用利什曼原虫属特异性引物K13A/K13B和L5.8S/LITSR分别扩增出120 bp和350 bp的片段，片段序列与硕大利什曼原虫相应序列（GenBank登录号：EU370906.1、FN677342.1）同源性分别为90%和98%。结论　筛查发现6例皮肤利什曼病患者，其中2例尚未痊愈。1例未痊愈者确诊为由硕大利什曼原虫感染引起的输入性皮肤利什曼病。     

洛阳市1起输入性皮肤利什曼病疫情流行病学 筛查报告

目的　了解中国石油天然气第一建设公司乌兹别克斯坦务工归国员工中利什曼原虫感染情况,并及时采取相关防控措施,防止疫情扩大。方法　设计调查问卷采集筛查对象相关信息,由内科医生触诊肝、脾及浅表淋巴结,皮肤科医生检查皮肤经常暴露处皮肤损害情况,对筛查对象行B超检查肝脾大小,采集筛查对象血清,应用内脏利什曼病快速检测试纸条（rK39）检测,对于筛查中发现的有皮肤损害者,采集皮损处组织镜检利什曼原虫,病原学检测阳性组织用分子生物学方法鉴定虫种。结果　共181人接受筛查,内科检查中6人颈部可触及肿大淋巴结,皮肤科检查中12人有皮肤损害表现,B超检查提示5人肝脾肿大,rK39试纸条检测血清显示3人结果呈阳性。共采集2人份典型皮损处组织,其中1份组织病原学检测发现利什曼原虫;提取前鞭毛体DNA,用利什曼原虫属特异性引物K13A/K13B和L5.8S/LITSR分别扩增出120 bp和350 bp的片段,片段序列与硕大利什曼原虫相应序列（GenBank登录号：EU370906.1、FN677342.1）同源性分别为90%和98%。结论　筛查发现6例皮肤利什曼病患者,其中2例尚未痊愈。1例未痊愈者确诊为由硕大利什曼原虫感染引起的输入性皮肤利什曼病。     

Leishmaniasis in Bahia, Brazil: evidence that Leishmania amazonensis produces a wide spectrum of clinical disease

One hundred fourteen Leishmania isolates from patients with different clinical forms of leishmaniasis in the State of Bahia, Brazil, were characterized by indirect radioimmune binding assay using specific monoclonal antibodies (serodeme analysis). Seventy-five of these isolates were also analyzed by enzyme electrophoresis, based on 11 enzyme loci; parasite species were compared, according to their characteristic zymodemes, to those of WHO Leishmania reference strains. All isolates could be classified into one of three species: Leishmania amazonensis (n = 40), L. braziliensis (n = 39) or L. chagasi (n = 35). The most interesting information obtained from this study is the realization that L. amazonensis is capable of producing a wide spectrum of disease in humans. Infection with this parasite was associated with many different clinical presentations, including cutaneous leishmaniasis [CL] (20/49 cases), mucocutaneous leishmaniasis [MCL] (5/13 cases) and, of special note, visceral leishmaniasis [VL] (11/46 cases), as well as four cases of post kalaazar dermal leishmaniasis [PKDL]. In situ tissue parasite characterization, by immunoperoxidase assay and employing anti-L. amazonensis amastigote monoclonal antibodies, confirmed the infection with this species in two cases of CL, one case of DCL, one case of MCL and one case of PKDL. Our results also demonstrate the difficulty of parasite differentiation based on clinical grounds, since at least L. amazonensis infection can be associated with all types of leishmanial diseases, and different Leishmania species may be associated with indistinguishable clinical presentations. Since leishmanial parasites may vary in their biological behavior or in their response to treatment, it is important that their identification be made by reliable methods.     

Persistence of leishmania parasites in scars after clinical cure of American cutaneous leishmaniasis: is there a sterile cure?

BACKGROUND: It is uncertain whether Leishmania parasites ever disappear after clinical cure of American cutaneous leishmaniasis (ACL). Recently, sensitive molecular techniques have allowed the identification of Leishmania parasites directly in specimens from patients' scars. METHODS: Scars of 32 patients from northeastern Brazil who were treated and clinically cured of ACL were analyzed by use of polymerase chain reaction (PCR), culture, and histopathologic examination. RESULTS: DNA specific for Leishmania (Viannia) was detected in scars of 30 (93.7%) of 32 patients. In specimens from 3 of the scars, Leishmania parasites could be isolated by culture; PCR results also were positive for those 3 specimens. No parasites were found by histopathologic examination, and fibrotic alterations were present in all cases, with slight inflammatory foci observed in 4 of the cases studied. CONCLUSIONS: The results suggest that clinical cure of ACL is rarely associated with sterile cure. The implications of persistence of parasites for the clinical evolution, relapse, and transmission of leishmaniasis deserves further studies, particularly with the increasing incidence of coinfection with leishmaniasis and acquired immunodeficiency syndrome.     

Natural infection of Lutzomyia tortura with Leishmania (Viannia) naiffi in an Amazonian area of Ecuador

Natural infection of sand flies with Leishmania parasites was surveyed in an Amazonian area in Ecuador where leishmaniasis is endemic. Seventy-one female sand flies were dissected and one was positive for Leishmania protozoa. The species of this sand fly was identified as Lutzomyia (Lu.) tortura on the basis of morphologic characteristics. Analysis of the cytochrome b gene sequence identified the parasite as L. (Viannia) naiffi. We report the distribution of L. (V.) naiffi in Ecuador and detection of a naturally infected sand fly in the Ecuadorian Amazon and natural infection of Lu. tortura with Leishmania parasites in the New World.     

Influence of the inoculation route in BALB/c mice infected by Leishmania infantum

Mice of the BALB/c strain are frequently used, due to their high susceptibility to Leishmania infection. Most of the studies in visceral leishmaniasis use the endovenous or the intraperitoneal routes to inoculate the parasites. In this study, the development of experimental visceral leishmaniasis infection was evaluated in BALB/c mice inoculated with Leishmania infantum parasites by endovenous (EV group) or intraperitoneal (IP group) routes. The results shows that both inoculation routes were able to produce progressive infection in mice. However, a higher dispersion of the values of parasite density was detected among the animals of the EV group than the IP group. Our results indicate that the intraperitoneal inoculation results in a higher homogeneity of infections, so we suggest that this route should be preferentially used in experimental infections in the mice model, particularly when pools of samples are required for immune cellular studies.     

Experimental leishmaniasis in humans: review

Experimental infection of humans with Leishmania parasites has contributed significantly to the understanding of the etiology, transmission, and pathogenesis of leishmaniasis and the immunity associated with it. Leishmania organisms recovered from human and animal tissue, insect vectors, and in vitro cultures have all produced cutaneous or visceral leishmaniasis in human subjects who were voluntarily inoculated with them. Volunteers bitten by infected Phlebotomine sandflies also developed cutaneous or visceral disease. In these experiments, it appeared that the parasite must undergo certain developmental changes within the sandfly for it to become infective and that the parasites in sandflies were far more efficient in causing full-blown infection than were cultured Leishmania organisms. The clinical manifestations of these experimental infections did not differ from infections that were acquired naturally. Natural or experimental infections appeared to confer resistance to subsequent leishmanial infection. This immunity was best documented to be a species-specific phenomenon; however, a small number of studies have demonstrated cross protection between some Leishmania species. In this review article, data from human experimental infections are summarized and discussed in light of recent advances in the field.     

Pathophysiology of experimental leishmaniasis: the role of parasite physiology in the development of metastatic disease

This paper addresses the issue of how physiological properties of Leishmania determine the pattern of development of disseminated leishmaniasis in the mammalian host. It presents direct experimental evidence from in vivo studies that species of Leishmania differ in their capacity to multiply in cutaneous and visceral sites which results in differences in the pattern and rate of development of leishmaniasis. It was found that Leishmania mexicana amazonensis begins to multiply in the cutaneous site of inoculation within 7 days. Parasites, detected in the liver and spleen at 4 weeks, increased 100-fold during the next 4 months. However, the slow multiplication of L. mexicana amazonensis in the liver and spleen was more apparent than real. Parasites implanted in those organs of athymic nude mice by an intravenous injection were rapidly eliminated with a half-time of 16 hr. Thus, the parasites found in small numbers in the liver during the development of disseminated cutaneous disease in mice are most likely those which have been recently removed from the blood. Those few parasites that are not removed from the blood can establish metastatic foci in distant cutaneous sites, and replicate progressively once there.     

First report of natural infection of least weasel (Mustela nivalis Linnaeus, 1776) with Leishmania major in Tunisia

Zoonotic cutaneous leishmaniasis, caused by Leishmania major (L. major), is endemic in Tunisia. Several rodents have been identified as reservoir hosts of parasites. This study reports, for the first time, the natural infection with L. major zymodeme MON-25 in a specimen of least weasel: Mustela nivalis Linnaeus, 1776 (M. nivalis) collected in Sidi Bouzid. This finding justifies further research on larger samples of this animal to verify its role as a potential reservoir host for cutaneous leishmaniasis in Tunisia.     

Atypical cutaneous leishmaniasis cases display elevated antigen-induced interleukin-10

In humans, Leishmania chagasi parasites can produce subclinical infections, atypical cutaneous leishmaniasis (ACL) and visceral leshmaniasis that is potentially fatal if not treated in a timely fashion. L. chagasi parasites that cause both ACL and visceral disease appear to be genetically similar, which suggests that host factors such as the immune response play an important role in controlling infection. We evaluated the immunologic response in ACL using peripheral blood mononuclear cells (PBMCs) of 37 subjects divided into three groups: (i) active ACL cases, (ii) asymptomatic cases and (iii) persons with no history of Leishmania infection. The supernatants of stimulated PBMCs were analysed for production of IL-10, IFN-gamma and IL-2. Robust production of IL-10 in response to Leishmania stimulation was observed in active ACL cases, compared to low levels in asymptomatic cases and negative controls. Serum IgE levels, measured by ELISA, were not significantly different among the three groups. In addition, ACL cases displayed depressed levels of all cytokines in response to mitogen. Thus, this first characterization of the immune response in ACL suggests a role for IL-10 as well as partial immunosuppression.     

Microscopy and polymerase chain reaction detection of Leishmania chagasi in the pleural and ascitic fluid of a patient with AIDS: Case report and review of diagnosis and therapy of visceral leishmaniasis.

Atypical visceral leishmaniasis is increasingly reported in immunocompromised patients, including patients with AIDS. A case of visceral leishmaniasis in an HIV-infected Brazilian patient with pulmonary and peritoneal involvement is reported. Histological evaluation of pleural fluid and ascites aspirate revealed macrophages with intracellular Leishmania. Polymerase chain reaction analysis was positive for Leishmania in the pleural and ascitic fluid with use of primers specific for Leishmania chagasi. In addition to classical methods for diagnosing leishmaniasis, such as microscopy and culture, polymerase chain reaction detection and identification of Leishmania species in pleural effusions and ascites are important diagnostic tools that should be considered by clinicians evaluating HIV-infected patients from endemic areas of visceral leishmaniasis. The authors review the clinical manifestations, diagnostic and therapeutic aspects of visceral leishmaniasis in immunocompetent and HIV-infected patients.     

Evidence for leishmania (viannia) parasites in the skin and blood of patients before and after treatment

BACKGROUND: American cutaneous leishmaniasis is considered to be a zoonotic disease transmitted by sand flies that feed on infected sylvatic mammals. However, the "domestication" of transmission and the increase in treatment failure with antimonial drugs have raised the suspicion of anthroponotic transmission of American cutaneous leishmaniasis. METHODS: The objective of the present study was to explore the potential of humans as a source of infection for sand flies. Biological (xenodiagnosis and culture) and molecular (polymerase chain reaction/Southern blot) detection methods were used to evaluate peripheral-blood monocytes and tissue fluids from sites accessible to sand flies from 59 adult patients with parasitologically confirmed American cutaneous leishmaniasis. RESULTS: Overall, 44.1% of patients (26/59) presented biological and/or molecular evidence of Leishmania parasites in normal skin, peripheral-blood monocytes, lesion scars, or lesion border (by xenodiagnosis) before (18/59 [30.5%]) or after (10/27 [37.0%]) treatment. Leishmania parasites were cultured from the unaffected skin of 2 (3.6%) of 55 patients, and xenodiagnosis gave positive results for 5 (8.8%) of 57 patients before treatment. CONCLUSIONS: The presence of Leishmania parasites in the unaffected skin and peripheral-blood monocytes of a high proportion of patients even after treatment and the acquisition of infection by sand flies support the plausibility of anthroponotic transmission of American cutaneous leishmaniasis.