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PLoS Negl Trop Dis ; 14(4): e0008253, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32324738


BACKGROUND: In the Mediterranean basin, Leishmania infantum is the causative agent of visceral leishmaniasis (VL), a zoonosis in which the dog is the primary domestic reservoir, although wildlife may have a leading role in the sylvatic cycle of the disease in some areas. Infections without disease are very frequent. There is limited information regarding the role that VL patients and asymptomatic infected individuals could be playing in the transmission of L. infantum. Xenodiagnosis of leishmaniasis has been used in this descriptive study to explore the role of symptomatic and asymptomatic infected individuals as reservoirs in a recent focus of leishmaniasis in southwestern Madrid, Spain. METHODOLOGY AND MAIN FINDINGS: Asymptomatic blood donors (n = 24), immunocompetent patients who were untreated (n = 12) or treated (n = 11) for visceral leishmaniasis (VL), and immunocompromised patients with VL (n = 3) were enrolled in the study. Their infectivity to Phlebotomus perniciosus was studied by indirect xenodiagnosis on peripheral blood samples. Quantitative polymerase chain reaction of blood samples from immunocompetent patients untreated for VL and immunocompromised untreated, treated and under secondary prophylaxis for VL was performed. Antibodies against Leishmania were studied by indirect fluorescent antibody and rK39-immunochromatographic tests. A lymphoproliferative assay with a soluble Leishmania antigen was used to screen for leishmaniasis infection in the healthy population. Sixty-two xenodiagnostic tests were carried out and 5,080 sand flies were dissected. Positive xenodiagnosis was recorded in four patients, with different sand fly infection rates: 1 immunosuppressed HIV / L. infantum coinfected asymptomatic patient, 1 immunosuppressed patient with multiple myeloma and symptomatic active VL, and 2 immunocompetent patients with untreated active VL. All blood donors were negative for both xenodiagnosis and conventional PCR. CONCLUSIONS / SIGNIFICANCE: There is no consensus amongst authors on the definition of an 'asymptomatic case' nor on the tools for screening; we, therefore, have adopted one for the sake of clarity. Immunocompetent subjects, both infected asymptomatics and those treated for VL, are limited in number and appear to have no epidemiological relevance. The impact is limited for immunocompetent patients with untreated active VL, whilst immunosuppressed individuals undergoing immunosuppressive therapy and immunosuppressed individuals HIV / L. infantum coinfected were the most infectious towards sand flies. It is noteworthy that the HIV / L. infantum coinfected patient with asymptomatic leishmaniasis was easily infectious to sand flies for a long time, despite being under continuous prophylaxis for leishmaniasis. Accordingly, screening for latent Leishmania infection in HIV-infected patients is recommended in scenarios where transmission occurs. In addition, screening for VL in HIV-infected patients who have spent time in VL-endemic areas should also be implemented in non-endemic areas. More research is needed to better understand if some asymptomatic coinfected individuals contribute to transmission as 'super-spreaders'.

Reservatórios de Doenças , Transmissão de Doença Infecciosa , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/transmissão , Adulto , Animais , Anticorpos Antiprotozoários/sangue , Doenças Assintomáticas/epidemiologia , DNA de Protozoário/sangue , Feminino , Humanos , Leucócitos Mononucleares/imunologia , Masculino , Pessoa de Meia-Idade , Psychodidae/parasitologia , Espanha/epidemiologia
PLoS Negl Trop Dis ; 13(6): e0007461, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31158223


Concomitant infection with human immunodeficiency virus (HIV) and the Leishmania parasite is a growing public health problem, the result of the former spreading to areas where the latter is endemic. Leishmania infection is usually asymptomatic in immunocompetent individuals, but the proportion of HIV+ individuals in contact with the parasite who remain asymptomatic is not known. The aim of the present work was to examine the use of cytokine release assays in the detection of asymptomatic immune responders to Leishmania among HIV+ patients with no previous leishmaniasis or current symptomatology. Eighty two HIV+ patients (all from Fuenlabrada, Madrid, Spain, where a leishmaniasis outbreak occurred in 2009) were examined for Leishmania infantum infection using molecular and humoral response-based methods. None returned a positive molecular or serological result for the parasite. Thirteen subjects showed a positive lymphoproliferative response to soluble Leishmania antigen (SLA), although the mean CD4+ T lymphocyte counts of these patients was below the normal range. Stimulation of peripheral blood mononuclear cells (PBMC) or whole blood with SLA (the lymphoproliferative assay and whole blood assay respectively), led to the production of specific cytokines and chemokines. Thus, despite being immunocompromised, HIV+ patients can maintain a Th1-type cellular response to Leishmania. In addition, cytokine release assays would appear to be useful tools for detecting these individuals via the identification of IFN-γ in the supernatants of SLA-stimulated PBMC, and of IFN-γ, MIG and IL-2 in SLA-stimulated whole blood. These biomarkers appear to be 100% reliable for detecting asymptomatic immune responders to Leishmania among HIV+ patients.

Doenças Assintomáticas/epidemiologia , Infecções por HIV/complicações , Leishmania infantum/imunologia , Leishmaniose Visceral/epidemiologia , Adulto , Idoso , Proliferação de Células , Citocinas/metabolismo , Feminino , HIV , Humanos , Leucócitos Mononucleares/imunologia , Masculino , Pessoa de Meia-Idade , Espanha/epidemiologia , Adulto Jovem
PLoS Negl Trop Dis ; 9(10): e0004179, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26496365


Spain has one of the world's largest pools of organ donors and is a global leader in terms of the number of transplants it performs. The current outbreak of leishmaniasis in Fuenlabrada (in the southwest of the region of Madrid, Spain) has involved 600 clinical cases since late 2009 (prevalence 0.2%). It may therefore be wise to monitor the town's transplanted population for Leishmania infantum; its members are immunosuppressed and at greater risk of infection and relapse following treatment. The present work examines the use of cytokine release assays to determine the prevalence of Leishmania infection in this population, and to confirm recovery following treatment for visceral leishmaniasis (VL). The humoral and cellular immune responses to L. infantum were characterized in 63 solid organ transplant (SOT) recipients from Fuenlabrada, 57 of whom reported no previous episode of VL (NVL subjects), and six of whom had been cured of VL (CVL subjects). Seventeen subjects (12 NVL and 5 CVL) showed a patent lymphoproliferative response to soluble Leishmania antigen (SLA). Stimulation of peripheral blood mononuclear cell cultures and of whole blood with SLA led to the production of different combinations of cytokines that might serve to confirm Leishmania infection or recovery from VL and help prevent cured patients from relapsing into this serious condition.

Técnicas de Laboratório Clínico/métodos , Citocinas/metabolismo , Monitoramento de Medicamentos/métodos , Leishmania infantum/imunologia , Leishmaniose/diagnóstico , Leucócitos Mononucleares/imunologia , Transplantes , Anticorpos Antiprotozoários/sangue , Proliferação de Células , Humanos , Hospedeiro Imunocomprometido , Leishmaniose/epidemiologia , Espanha/epidemiologia , Transplantados
PLoS Negl Trop Dis ; 9(3): e0003594, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25756785


In Spain, Leishmania infantum is endemic, human visceral and cutaneous leishmaniasis cases occurring both in the Peninsula, as well as in the Balearic Islands. We aimed to describe the clinical characteristics of leishmaniasis patients and the changes in the disease evolution after the introduction of antiretroviral therapy in 1997. In this descriptive study, we used Spanish Centralized Hospital Discharge Database for the hospitalized leishmaniasis cases between 1997 and 2011. We included in the analysis only the records having leishmaniasis as the first registered diagnosis and calculated the hospitalization rates. Disease trend was described taking into account the HIV status. Adjusted odds-ratio was used to estimate the association between clinical and socio-demographic factors and HIV co-infection. Of the total 8010 Leishmaniasis hospitalizations records, 3442 had leishmaniasis as first diagnosis; 2545/3442 (75.6%) were males and 2240/3442 (65.1%) aged between 14-65 years. Regarding disease forms, 2844/3442 (82.6%) of hospitalizations were due to visceral leishmaniasis (VL), while 118/3442 (3.4%) hospitalizations were cutaneous leishmaniasis (CL). Overall, 1737/2844 of VL (61.1%) were HIV negatives. An overall increasing trend was observed for the records with leishmaniasis as first diagnosis (p=0.113). Non-HIV leishmaniasis increased during this time period (p=0.021) while leishmaniasis-HIV co-infection hospitalization revealed a slight descending trend (p=0.717). Leishmaniasis-HIV co-infection was significantly associated with male sex (aOR=1.6; 95% CI: 1.25-2.04), 16-64 years age group (aOR=17.4; 95%CI: 2.1-143.3), visceral leishmaniasis aOR=6.1 (95%CI: 3.27-11.28) and solid neoplasms 4.5 (95% CI: 1.65-12.04). The absence of HIV co-infection was associated with lymph/hematopoietic neoplasms (aOR=0.3; 95%CI:0.14-0.57), other immunodeficiency (aOR=0.04; 95% CI:0.01-0.32) and transplant (aOR=0.01; 95%CI:0.00-0.07). Our findings suggest a significant increase of hospitalization in the absence of HIV co-infection, with a predomination of VL. We consider that clinicians in Spain should be aware of leishmaniasis not only in the HIV population but also in non HIV patients, especially for those having immunosuppression as an associate condition.

Leishmaniose/epidemiologia , Adolescente , Adulto , Idoso , Coinfecção/epidemiologia , Feminino , Infecções por HIV/epidemiologia , Hospitalização/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Espanha/epidemiologia , Fatores de Tempo