Over 850 Leishmania-human immunodeficiency virus (HIV) coinfection cases have been recorded, the majority in Europe, where 7 to 17% of HIV-positive individuals with fever have amastigotes, suggesting that Leishmania-infected individuals without symptoms will express symptoms of leishmaniasis if they become immunosuppressed. However, there are indirect reasons and statistical data demonstrating that intravenous drug addiction plays a specific role in Leishmania infantum transmission: an anthroponotic cycle complementary to the zoonotic one has been suggested. Due to anergy in patients with coinfection, L. infantum dermotropic zymodemes are isolated from patient viscera and a higher L. infantum phenotypic variability is seen. Moreover, insect trypanosomatids that are currently considered nonpathogenic have been isolated from coinfected patients. HIV infection and Leishmania infection each induce important analogous immunological changes whose effects are multiplied if they occur concomitantly, such as a Th1-to-Th2 response switch; however, the consequences of the viral infection predominate. In fact, a large proportion of coinfected patients have no detectable anti-Leishmania antibodies. The microorganisms share target cells, and it has been demonstrated in vitro how L. infantum induces the expression of latent HIV-1. Bone marrow culture is the most useful diagnostic technique, but it is invasive. Blood smears and culture are good alternatives. PCR, xenodiagnosis, and circulating-antigen detection are available only in specialized laboratories. The relationship with low levels of CD4+ cells conditions the clinical presentation and evolution of disease. Most patients have visceral leishmaniasis, but asymptomatic, cutaneous, mucocutaneous, diffuse cutaneous, and post-kala-azar dermal leishmaniasis can be produced by L. infantum. The digestive and respiratory tracts are frequently parasitized. The course of coinfection is marked by a high relapse rate. There is a lack of randomized prospective treatment trials; therefore, coinfected patients are treated by conventional regimens. Prophylactic therapy is suggested to be helpful in preventing relapses.

Leishmania and human immunodeficiency virus coinfection: the first 10 years.

Visceral leishmaniasis in human immunodeficiency virus (HIV)-infected and non-HIV-infected patients. A comparative study.

Protozoa are among the most important pathogens that can cause infections in immunocompromised hosts. These microorganisms particularly infect individuals with impaired cellular immunity, such as those with hematological neoplasias, renal or heart transplant patients, patients using high doses of corticosteroids, and patients with acquired immunodeficiency syndrome. The protozoa that most frequently cause disease in immunocompromised patients are Toxoplasma gondii, Trypanosoma cruzi, different Leishmania species, and Cryptosporidium parvum; the first two species cause severe acute meningoencephalitis and acute myocarditis, Leishmania sp. causes mucocutaneous or visceral disease, and Cryptosporidium can lead to chronic diarrhea with hepatobiliary involvement. Various serological, parasitological, histological and molecular methods for the diagnosis of these infections are currently available and early institution of specific therapy for each of these organisms is a basic measure to reduce the morbidity and mortality associated with these infections.

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Some Aspects of Protozoan Infections in Immunocompromised Patients: A Review

Leishmania-HIV co-infection has been globally controlled in Southern Europe since 1997 because of highly active anti retroviral therapy (HAART), but it appears to be an increasing problem in other countries such as Ethopia, Sudan, Brazil or India where both infections are becoming more and more prevalent. Most of the scientific background on Leishmania/HIV co-infection has been dropped from the Mediterranean experience and although the situations among countries are not fully comparable, it is of high importance to take advantage of this knowledge. In this review several aspects of the Leishmania/HIV co-infection are emphasized viz., epidemiological features, new ways of transmission, pathogenesis, clinical outcome, diagnosis, treatment and secondary prohylaxis. An extensive review of the literature on Leishmania/HIV co-infection has allowed the inclusion of a comprehensive and updated list of bibliographical references.

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Leishmania/HIV co-infections in the second decade.

A PCR assay for the diagnosis of leishmaniosis was developed by using primers that were selected from the sequence of the small-subunit rRNA gene. The assay was optimized for routine diagnostic use. Processing of the clinical samples is rapid and simple (lysis of erythrocytes in Tris-EDTA buffer, digestion with proteinase K directly in PCR buffer, and no further purification steps). Furthermore, an internal control is included in every specimen in order to detect the presence of PCR inhibitors. The PCR was compared with diagnostic in vitro cultivation of promastigote stages for the detection of Leishmania spp. in clinical specimens from humans and dogs with a tentative diagnosis of leishmaniosis. PCR and cultivation gave identical results with all but 1 of the 95 specimens from humans. The PCR result in this case was false negative, possibly because of unequal apportionment of this sample. With 10 skin biopsies from six patients with cutaneous leishmaniosis, the sensitivity was 60%. For six human immunodeficiency virus-positive patients with visceral leishmaniosis, all bone marrow biopsies and 7 of 11 whole blood samples (after isolation of leukocytes by Ficoll-Paque) were positive in both tests. PCR detected one more case with the use of 500 microliters of whole blood with direct lysis of the erythrocytes in Tris-EDTA buffer. With dog lymph node aspirates, the sensitivity was 100% (16 of 16 samples) for both methods; furthermore, PCR was positive for 5 of 13 whole blood samples from dogs with leishmaniosis. The specificity of the PCR was 100% (70 specimens from patients without leishmaniosis). This PCR assay proved to be feasible as a routine diagnostic test, being reliable and faster than in vitro cultivation.

https://jcm.asm.org/content/jcm/33/5/1145.full.pdf

PCR and in vitro cultivation for detection of Leishmania spp. in diagnostic samples from humans and dogs.

Physicians examined the records of 47 adults with visceral leishmaniasis (VL) and HIV-1 infection who were patients at 3 urban teaching hospitals in the Andalucia region in southern Spain between January 1986 and November 1991. They wanted to identify the clinical biological and epidemiological features of VL in HIV-1 positive patients. 96% of the cases were diagnosed with both infections during the last 2 years of the study period and 79% between January and November 1991. All the patients had risk factors for HIV infection (65.9% IV drug use 21.3% sexual contact and 12.8% blood transfusion). 70% exhibited the classic symptoms of VL (fever enlarged liver and spleen and depressed counts of blood cells). Most patients were already very immunocompromised when VL was diagnosed. 87% had a total lymphocyte count of less than 1000 x 1 million/1 and a CD4 lymphocyte count of less than 200 x 1 million/1. In fact 66% had full blown AIDS prior to diagnosis of VL. VL was the first severe infection in 10 cases. 68% also suffered from opportunistic infections especially candidiasis extrapulmonary tuberculosis and Pneumocystis carinii pneumonia. Microscopic examination of Leishmania amastiogotes in tissue samples led to a diagnosis in 94% of cases isolation of motile amastigotes in culture of bone marrow aspirate in 2% and microscopic and culture in 4%. Just 46% completed a full course of treatment (pentavalent antimony allopurinol and/or pentamidine). Only 38% had a microbiological response. Immunofluorescence detected sizeable titers (>1:40) of antileishmanial antibodies in just 31% of cases. 17% experienced clear clinical improvement. Physicians in endemic areas should consider VL in every HIV-1 infected patient with fever hepatosplenomegaly or hematological abnormalities to avoid underdiagnosis of leishmaniasis.

Jiménez E

Papers

Visceral leishmaniasis in HIV-1-infected individuals: a common opportunistic infection in Spain?