Summary: To date, most Leishmania and human immunodeficiency virus (HIV) coinfection cases reported to WHO come from Southern Europe. Up to the year 2001, nearly 2,000 cases of coinfection were identified, of which 90% were from Spain, Italy, France, and Portugal. However, these figures are misleading because they do not account for the large proportion of cases in many African and Asian countries that are missed due to a lack of diagnostic facilities and poor reporting systems. Most cases of coinfection in the Americas are reported in Brazil, where the incidence of leishmaniasis has spread in recent years due to overlap with major areas of HIV transmission. In some areas of Africa, the number of coinfection cases has increased dramatically due to social phenomena such as mass migration and wars. In northwest Ethiopia, up to 30% of all visceral leishmaniasis patients are also infected with HIV. In Asia, coinfections are increasingly being reported in India, which also has the highest global burden of leishmaniasis and a high rate of resistance to antimonial drugs. Based on the previous experience of 20 years of coinfection in Europe, this review focuses on the management of Leishmania-HIV-coinfected patients in low-income countries where leishmaniasis is endemic.

https://www.who.int/leishmaniasis/burden/hiv_coinfection/Clinical_Microbiology_Reviews_2008.pdf

The Relationship between Leishmaniasis and AIDS: the Second 10 Years

PCR diagnosis and characterization of Leishmania in local and imported clinical samples.

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.

The group of diseases known as the leishmaniases are caused by obligate intracellular protozoa of the genus Leishmania ([39][1]). Natural transmission of leishmania is carried out by a certain species of sandfly of the genus Phlebotomus (Old World) or Lutzomyia (New World). These are present in

Laboratory Diagnosis of Visceral Leishmaniasis

Tegumentary leishmaniasis, comprising the cutaneous and mucocutaneous forms, is caused by at least 13 dermotropic species of protozoa of the genus Leishmania, most of which are prevalent in the New World. Although diseases in the Old and New Worlds share similar characteristics, the ultimate manifestations and severity are quite different, with more severe forms associated with mucosal lesions observed in the New World. For the diagnosis and treatment of leishmaniasis, differences based on clinical features, usefulness/sensitivity of diagnostic methods and therapeutic responses are mainly emphasized. We present a critical review of the diagnostic methods, their contribution and the necessity for their improvement/development, particularly in molecular diagnosis aimed at detection and species identification, as well as serodiagnosis. In addition to a review of the drugs currently utilized, we describe differences in their effectiveness in Old and New World leishmaniasis. HIV/Leishmania coinfection is also presented in the context of diagnosis and treatment.

https://www.tandfonline.com/doi/pdf/10.1586/eri.10.19

Current diagnosis and treatment of cutaneous and mucocutaneous leishmaniasis

A PCR assay amplifying a repeated sequence from the Leishmania infantum genome was compared with direct examination of bone marrow aspirate, myeloculture, and serology for the diagnosis of visceral leishmaniasis in immunocompromised patients. Of 73 patients living in an area endemic for leishmaniasis and where visceral leishmaniasis was suspected by physicians, only 10 had an indisputable diagnosis of visceral leishmaniasis. None of the diagnostic tests performed in the study achieved 100% sensitivity for diagnosing visceral leishmaniasis. PCR exhibited superior sensitivity (82%) in comparison with bone marrow aspirate examination (55%) and myeloculture (55%). Our PCR assay also showed good specificity (97%), negative predictive value (97%), and positive predictive value (82%) even when all unconfirmed PCR results were scored as false positives. Serology exhibited good sensitivity (80%) and excellent specificity (100%), negative predictive value (98%), and positive predictive value (100%) in diagnosing new cases of visceral leishmaniasis but failed to diagnose relapses. We also observed consistent negative serological results using several different immunological detection methods for 2 of the 10 patients with confirmed cases of visceral leishmaniasis. This lack of serological reactivity persisted throughout the course of their infections. These results demonstrate the importance of using PCR as an aid in the diagnosis of visceral leishmaniasis in immunocompromised patients.

Comparison of PCR with direct examination of bone marrow aspiration, myeloculture, and serology for diagnosis of visceral Leishmaniasis in immunocompromised patients.

When infected with Leishmania species, patients develop specific antibodies that constitute the basis of serodiagnosis. Using Western blot analysis, we studied the specificity of anti-L. infantum antibodies in patients with visceral leishmaniasis (including patients with acquired immunodeficiency syndrome [AIDS]) and in healthy subjects living in an endemic area. Sera from patients with visceral leishmaniasis recognized numerous antigens that had a molecular mass range of 12-120 kD. The 14-, 16-, 28-30-, 46-, and 68-kD antigens were recognized by 92%, 95%, 63%, 80%, 69%, and 89% of the patients' sera, respectively. The 14-16-kD antigens had the greatest specificity for leishmaniasis. The same pattern was found with sera from AIDS patients with proven leishmaniasis, but the 14-kD band was not present in some cases; recognition of the 16-kD band was constant. In these patients, Western blotting characterized specific antibodies even when the results of classic serologic tests (indirect immunofluorescent antibody test and enzyme-linked immunosorbent assay) were negative. Western blotting was found to be more sensitive than the IFA and ELISA, and it was used to detect antibodies to the 14-, 16-, 22-, and 24-kD antigens in subjects living in an endemic area. The detection of antibodies for the 14-kD and 16-kD Leishmania antigens would be a valuable tool both in the diagnosis of visceral leishmaniasis and in epidemiologic studies.

Western blot analysis of antibodies to Leishmania infantum antigens: potential of the 14-kD and 16-kD antigens for diagnosis and epidemiologic purposes.

To construct a DNA probe specific for protozoa that cause visceral leishmaniasis, we cloned Pst I fragments of Leishmania infantum genomic DNA into a Bluescript II SK® vector. A clone of 4.3 kb that contained a highly repetitive sequence was isolated and cut with three restriction enzymes: Hae III, Rsa I, and Sau 3A. After a new molecular cloning step, we isolated and sequenced a 140-basepair (bp) fragment. Two oligonucleotides were synthesized to be used as primers for a polymerase chain reaction. Using this probe, we detected an amount of DNA equivalent to one promastigote of L. infantum. This probe showed a high specificity; all protozoa tested that cause visceral leishmaniasis and L. major (one of the causative agents of Old World cutaneous leishmaniasis) showed a 100-bp amplified sequence, whereas other Leishmania strains showed a signal of a different size or else no signal. Moreover, no amplified sequence was obtained with other pathogenic parasites tested (Trypanosoma brucei, T. cruzi, Plasmodium falciparum, Pneumocystis carinii, and Toxoplasma gondii).

Isolation and Characterization of a Repetitive DNA Sequence from Leishmania infantum: Development of a Visceral Leishmaniasis Polymerase Chain Reaction

Phylogenetic relationships between Old World Leishmania strains revealed by analysis of a repetitive DNA sequence

Complications of visceral leishmaniasis are explained in part by immune complex pathology, particularly nephritis. Using the polyethylene glycol precipitation method, we identified among these complexes a Leishmania infantum circulating antigen by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. Monoclonal antibodies were produced to specifically detect this antigen. This protein (molecular weight 51 kD) is a cytoplasmic antigen of L. infantum and its synthesis by promastigotes is related to stationary-phase culture. It was present in sera from dogs whose leishmaniasis was associated with nephritis, and it was found in the sera of 30% of human patients with visceral leishmaniasis. It was also detected in the sera of patients with cutaneous leishmaniasis, and it persists in the sera of clinically cured subjects.

M. Quilici

Papers

Comparison of PCR with direct examination of bone marrow aspiration, myeloculture, and serology for diagnosis of visceral Leishmaniasis in immunocompromised patients.

Western blot analysis of antibodies to Leishmania infantum antigens: potential of the 14-kD and 16-kD antigens for diagnosis and epidemiologic purposes.

Isolation and Characterization of a Repetitive DNA Sequence from Leishmania infantum: Development of a Visceral Leishmaniasis Polymerase Chain Reaction

Phylogenetic relationships between Old World Leishmania strains revealed by analysis of a repetitive DNA sequence

Characterization of a circulating antigen involved in immune complexes in visceral leishmaniasis patients