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1.
Braz. j. biol ; 84: e257402, 2024. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1355856

RESUMO

Abstract Visceral leishmaniasis (VL) is an infectious disease predominant in countries located in the tropics. The prediction of occurrence of infectious diseases through epidemiologic modeling has revealed to be an important tool in the understanding of its occurrence dynamic. The objective of this study was to develop a forecasting model for the incidence of VL in Maranhão using the Seasonal Autoregressive Integrated Moving Average model (SARIMA). We collected monthly data regarding VL cases from the National Disease Notification System (SINAN) corresponding to the period between 2001 and 2018. The Box-Jenkins method was applied in order to adjust a SARIMA prediction model for VL general incidence and by sex (male or female) for the period between January 2019 and December 2013. For 216 months of this time series, 10,431 cases of VL were notified in Maranhão, with an average of 579 cases per year. With regard to age range, there was a higher incidence among the pediatric public (0 to 14 years of age). There was a predominance in male cases, 6437 (61.71%). The Box-Pierce test figures for overall, male and female genders supported by the results of the Ljung-Box test suggest that the autocorrelations of residual values act as white noise. Regarding monthly occurrences in general and by gender, the SARIMA models (2,0,0) (2,0,0), (0,1,1) (0,1,1) and (0,1,1) (2, 0, 0) were the ones that mostly adjusted to the data respectively. The model SARIMA has proven to be an adequate tool for predicting and analyzing the trends in VL incidence in Maranhão. The time variation determination and its prediction are decisive in providing guidance in health measure intervention.


Resumo A leishmaniose visceral (LV) é uma doença de natureza infecciosa, predominante em países de zonas tropicais. A predição de ocorrência de doenças infecciosas através da modelagem epidemiológica tem se revelado uma importante ferramenta no entendimento de sua dinâmica de ocorrência. O objetivo deste estudo foi desenvolver um modelo de previsão da incidência da LV no Maranhão usando o modelo de Média Móvel Integrada Autocorrelacionada Sazonal (SARIMA). Foram coletados os dados mensais de casos de LV através do Sistema de Informação de Agravos de Notificação (SINAN) correspondentes ao período de 2001 a 2018. O método de Box-Jenkins foi aplicado para ajustar um modelo de predição SARIMA para incidência geral e por sexo (masculino e feminino) de LV para o período de janeiro de 2019 a dezembro de 2023. Durante o período de 216 meses dessa série temporal, foram registrados 10.431 casos de LV no Maranhão, com uma média de 579 casos por ano. Em relação à faixa etária, houve maior registro no público pediátrico (0 a 14 anos). Houve predominância do sexo masculino, com 6437 casos (61,71%). Os valores do teste de Box-Pierce para incidência geral, sexo masculino e feminino reforçados pelos resultados do teste Ljung-Box sugerem que as autocorrelações de resíduos apresentam um comportamento de ruído branco. Para incidência mensal geral e por sexo masculino e feminino, os modelos SARIMA (2,0,0) (2,0,0), (0,1,1) (0,1,1) e (0,1,1) (2, 0, 0) foram os que mais se ajustaram aos dados, respectivamente. O modelo SARIMA se mostrou uma ferramenta adequada de previsão e análise da tendência de incidência da LV no Maranhão. A determinação da variação temporal e sua predição são determinantes no norteamento de medidas de intervenção em saúde.


Assuntos
Humanos , Masculino , Feminino , Recém-Nascido , Lactente , Pré-Escolar , Criança , Adolescente , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/epidemiologia , Estações do Ano , Brasil/epidemiologia , Incidência , Modelos Estatísticos
2.
Turkiye Parazitol Derg ; 46(3): 242-245, 2022 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-36094128

RESUMO

At the end of 2019, the newly detected severe acute respiratory syndrome-coronavirus (COVID)-2 in China spread rapidly and caused a global epidemic. It has been observed that the virus, which is the cause of COVID-2019 and can cause severe acute respiratory failure, later causes a hyperinflammatory picture and causes a clinical picture similar to Kawasaki disease. Fever, cardiac involvement and rash are the most common findings in this picture, which is called multisystem inflammatory syndrome (MIS-C). Although its pathophysiology is not fully known yet, the most common cause is thought to be post-infection immune dysregulation. Visceral leishmaniasis (VL) is a zoonosis in which Leishmania infantum and rarely Leishmania donovani are the agents and can cause a similar clinical picture. In this text; we discussed a patient who was followed up with a diagnosis of COVID-associated MIS-C, but without an adequate response in his clinic with MIS-C treatment, and was diagnosed with VL with further examinations. To our knowledge, this is the first MIS-C and VL co-occurence in the literature.


Assuntos
COVID-19 , Leishmania infantum , Leishmaniose Visceral , COVID-19/complicações , COVID-19/diagnóstico , Criança , Humanos , Leishmaniose Visceral/complicações , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/epidemiologia , SARS-CoV-2 , Síndrome de Resposta Inflamatória Sistêmica
3.
Artigo em Inglês | MEDLINE | ID: mdl-36074447

RESUMO

Human Visceral Leishmaniasis (HVL) presents a subacute clinical evolution with systemic involvement, which can result in high case fatality, especially among untreated individuals or those with low socioeconomic status. This study aimed to identify epidemiological and clinical factors associated with HVL case fatality in the Ceara State, from 2007 to 2018. This is an analytical cross-sectional study. The bivariate analysis was performed by Stata 15.1 using Pearson's Chi-square or Fisher's exact test; and Poisson regression for age-controlled multivariate analysis. From 2007 to 2018, there were 4,863 new confirmed cases and 343 deaths from HVL (case fatality rate=7.05%). The risk factors associated with case fatalities were: age group (RR=8.69; 95%CI:3.56-21.20); black population (RR=2.21; 95%CI:1.45-3.35); jaundice symptoms (RR=1.72; 95%CI:1.38-2.14); edema (RR=2.62; 95%CI:2.10-3.26) and hemorrhagic phenomena (RR=1.63; 95%CI:1.26-2.10); and no prescription drug intake (RR=4.03; 95%CI:2.98-5.46). Treatment with pentavalent antimonial was a protective factor (RR=0.35; 95%CI:0.27-0.45). The number of deaths increased among the elderly, illiterate, urban residents, and black skin color individuals. The drugs pentavalent antimonial and amphotericin B showed an association with death, but were not considered causal factors. Treatment failure led to a high risk of death. In multivariate analysis, the risk factors for fatal cases were age group, black skin, symptoms of jaundice, edema and hemorrhagic phenomena; and failure to take the prescription drugs. Treatment with pentavalent antimonial was shown to be a protective factor. Knowing the factors associated with the fatality of VL-HIV cases may help to improve public policies, in order to refine the epidemiological surveillance program and, consequently, prevent deaths related to the disease in Ceara.


Assuntos
Icterícia , Leishmaniose Visceral , Idoso , Brasil/epidemiologia , Estudos Transversais , Edema , Humanos , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/epidemiologia
4.
PLoS Negl Trop Dis ; 16(8): e0010718, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36040931

RESUMO

People living with HIV (PLHIV) have an increased risk of developing visceral leishmaniasis (VL) and poor outcomes compared to HIV negative individuals. Here, we aim to establish the prevalence and determinants of asymptomatic Leishmania infection (ALI) in a cohort of PLHIV in Bihar, India. We hoped to evaluate optimal diagnostic algorithms to detect ALI in PLHIV. We conducted a cross-sectional survey of PLHIV ≥18 years of age with no history or current diagnosis of VL or post kala-azar dermal leishmaniasis (PKDL) at anti-retroviral therapy centres within VL endemic districts of Bihar. ALI was defined as a positive rK39 enzyme-linked immunosorbent assay (ELISA), rK39 rapid diagnostic test (RDT) and/or quantitative polymerase chain reaction (qPCR). Additionally, the urinary Leishmania antigen ELISA was evaluated. Determinants for ALI were established using logistic regression and agreement between diagnostic tests calculated using Cohen's Kappa. A total of 1,296 PLHIV enrolled in HIV care, 694 (53.6%) of whom were female and a median age of 39 years (interquartile range 33-46), were included in the analysis. Baseline prevalence of ALI was 7.4% (n = 96). All 96 individuals were positive by rK39 ELISA, while 0.5% (n = 6) and 0.4% (n = 5) were positive by qPCR and rK39 RDT, respectively. Negligible or weak agreement was seen between assays. Independent risk factors for ALI were CD4 counts <100 (OR 3.1; 95% CI 1.2-7.6) and CD4 counts 100-199 (OR = 2.1;95% CI:1.1-4.0) compared to CD4 counts ≥300, and a household size ≥5 (OR = 1.9;95% CI:1.1-3.1). A total of 2.2% (n = 28) participants were positive by Leishmania antigen ELISA, detecting 20 additional participants to the asymptomatic cohort. Prevalence of ALI in PLHIV in VL endemic villages in Bihar was relatively high. Using the Leishmania antigen ELISA, prevalence increased to 9.0%. Patients with low CD4 counts and larger household size were found to have significantly higher risk of ALI. Trial Registration: Clinical Trial Registration CTRI/2017/03/008120.


Assuntos
Infecções por HIV , Leishmania donovani , Leishmania , Leishmaniose Visceral , Leishmaniose , Adulto , Infecções Assintomáticas/epidemiologia , Estudos Transversais , Ensaio de Imunoadsorção Enzimática , Feminino , Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Humanos , Índia/epidemiologia , Leishmaniose Visceral/complicações , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência
5.
Acta Trop ; 235: 106626, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35981601

RESUMO

Previous studies demonstrated that insecticide collars are highly effective in reducing canine visceral leishmaniasis (CVL); however, it is unclear if the efficacy differs by socioeconomic conditions across diverse communities. This study aimed fourfold: (i) to evaluate the protection of 4% impregnated deltamethrin collared (DMC) dogs in different areas of an endemic city for visceral leishmaniasis (VL); (ii) to analyze socioeconomic variables with the seroconversion rates; (iii) to analyze the indirect effect of DMC on untreated dogs in areas of intervention; and, (iv) to evaluate the potential transmission to other dogs in the same household when one positive dog is present. The study employed the municipality of Bauru, São Paulo, Brazil, as the area of interest and used Geographic Information System tools to fit binary logistic regression models.  Dogs were divided into three cohort studies: intervention with DMC (I), indirect effect of DMC (IE), and control (C). Pre-intervention, lower mean income was associated with higher rates of CVL and a 142% increase in the odds of transmission (OR = 1.42, p-value = 0.001, CI 1.14,1.77). Post-intervention, lower-income areas depicted greater efficacy (76%) than higher-income areas (45%). The overall efficacy of DMC in preventing CVL was 63%; however, seroconversion rates were higher for IE (6.02%) than C (3.78%), revealing the failure of the indirect protection of DMC to manage the spread of the disease among the general non-wearing DMC canine population living in the same area. The protected dogs may repel the vectors, and non-protected dogs attract them, creating a higher transmission rate for non-protected dogs. Greater seroconversion was observed for living with an infected dog (10.20% in IE and 8.75% in C) than for the indirect effect of DMC, demonstrating the social burden of CVL. Overall, uncollared dogs have three times higher odds of being infected with CVL than DMC dogs (p < 0.005), and uncollared dogs living with (an) infected dog(s) in the same household can reach 3.5 times higher odds than those living with negative ones (p < 0.005). The results may assist in enhancing public policies and minimizing inequality in low and middle-income countries that suffer from neglected diseases such as VL.


Assuntos
Doenças do Cão , Inseticidas , Leishmania infantum , Leishmaniose Visceral , Piretrinas , Animais , Brasil/epidemiologia , Doenças do Cão/epidemiologia , Doenças do Cão/prevenção & controle , Cães , Humanos , Inseticidas/farmacologia , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/prevenção & controle , Leishmaniose Visceral/veterinária , Nitrilas/farmacologia , Piretrinas/farmacologia
6.
PLoS Negl Trop Dis ; 16(8): e0010676, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35969605

RESUMO

BACKGROUND: Most people infected with Leishmania remain asymptomatic, which is a common element that may promote the resurgence of clinically evident leishmaniasis in individuals with impaired cell-mediated immune responses. Unfortunately, there is no universally accepted assay to identify asymptomatic infection. This cross-sectional study focuses on the employment of three methods targeting different features of the parasitic infection to be used in combination for the screening of latent leishmaniasis in a newly endemic area of northeastern Italy. METHODOLOGY/PRINCIPAL FINDINGS: The selected methods included highly sensitive Real-Time PCR for detection of parasitic kinetoplast (k)DNA in peripheral blood, Western Blot (WB) for detection of specific IgG, and Whole Blood stimulation Assay (WBA) to evaluate the anti-leishmanial T-cell response by quantifying the production of IL-2 after stimulation of patients' blood with Leishmania specific antigens. Among 145 individuals living in a municipality of the Bologna province, northeastern Italy, recruited and screened for Leishmania infection, 23 subjects tested positive (15.9%) to one or more tests. Positive serology was the most common marker of latent leishmaniasis (15/145, 10%), followed by the detection of specific cell-mediated response (12/145, 8%), while only few individuals (6/145, 4%) harbored parasitic DNA in the blood. CONCLUSIONS/SIGNIFICANCE: Combining different tests substantially increased the yield of positivity in detecting latent Leishmania infection. The test combination that we employed in this study appears to be effective to accurately identify latent leishmaniasis in an endemic area.


Assuntos
Doenças do Cão , Leishmania infantum , Leishmaniose Visceral , Leishmaniose , Animais , Estudos Transversais , Doenças do Cão/epidemiologia , Cães , Humanos , Leishmania infantum/genética , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/parasitologia
7.
Mikrobiyol Bul ; 56(3): 377-386, 2022 Jul.
Artigo em Turco | MEDLINE | ID: mdl-35960232

RESUMO

Leishmaniasis is an infectious disease caused by Leishmania parasites, transmitted by sand flies and common in the Mediterranean region. Cyprus is located in the east of Mediterranean Sea and is considered endemic for Leishmaniasis. In our study, it was aimed to investigate Leishmania infantum IgG seropositivity in healthy volunteers living in different regions of Northern Cyprus and to determine the risk factors for Leishmaniasis and measure the level of public knowledge about the disease. A total of 300 healthy volunteers (farmer/livestock: 100, hunter: 100, control group: 100) from five different regions of Northern Cyprus were included in the study, including Nicosia, Kyrenia, Famagusta, Morphou/Lefka, and Trikomo/Karpasia. The participants' blood was drawn and prepared questionnaire forms were filled out. Collected blood was centrifuged and the serum samples were separated and stored at -80ºC until the day of the test. All serum samples were tested for L.infantum IgG specific antibodies using the ELISA method (NovaTec, Immundiagnostica GmbH, Germany) in accordance with the manufacturer's recommendations. L.infantum IgG positivity was found to be 4.7% (14/300). The mean ages of L.infantum IgG positive and negative participants were 43.64 ± 11.74 and 42.17 ± 14.32 respectively. There was no statistically significant relationship between seropositivity and age (p= 0.706). The positivity rate was found to be significantly higher in hunters and farmers/livestocks compared with the control group (p= 0.020). In addition, it was determined that having a dog and the number of dogs owned were significantly associated with Leishmaniasis (p= 0.017, p= 0.020, respectively). On the other hand, 77% (231/300) of the volunteers included in our study had no prior knowledge about the disease. When compared to the other study groups, it was determined that hunters had the most knowledge of the Leishmaniasis infection (p= 0.001). Moreover, it was observed that as the education level of the participants increased, the level of knowledge about the disease also increased in parallel (p≤ 0.001). According to the results in our study, L.infantum IgG seropositivity was undeniably high in the healthy population living in Northern Cyprus. It is clear that outdoor activities such as hunting or dealing with farming/livestock are risk factors for the disease. In this context, it is apparent that more clear results will be obtained about the prevalence of the disease with the conduction of large-scale epidemiological studies. As a result, we concluded that especially risk groups should be informed about the current status of Leishmaniasis infection and necessary precautions should be taken.


Assuntos
Leishmania infantum , Leishmaniose Visceral , Leishmaniose , Psychodidae , Animais , Chipre/epidemiologia , Cães , Humanos , Imunoglobulina G , Leishmaniose/epidemiologia , Leishmaniose/parasitologia , Leishmaniose/veterinária , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/parasitologia , Psychodidae/parasitologia
8.
PLoS Negl Trop Dis ; 16(8): e0010696, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35981057

RESUMO

BACKGROUND: Visceral Leishmaniasis (VL) is endemic in South Sudan, manifesting periodically in major outbreaks. Provision of treatment during endemic periods and as an emergency response is impeded by instability and conflict. Médecins Sans Frontières (MSF) has provided health care in South Sudan since the late 1980's, including treatment for 67,000 VL patients. In recent years, MSF monitoring data have indicated increasing numbers of VL relapse cases. A retrospective analysis of these data was performed in order to provide insight into the possible causes of this increase. METHODOLOGY/PRINCIPAL FINDINGS: Programme monitoring data from the MSF hospital in Lankien, Jonglei State, South Sudan, for the period 2001-2018 were analysed to detect trends in VL relapse as a proportion of all VL cases presenting to MSF treatment centres. Routinely collected patient-level data from relapse and primary VL cases treated at all MSF sites in South Sudan over the same period were analysed to describe patient characteristics and treatments received. VL relapse as a proportion of all VL cases increased by 6.5% per annum (95% CI 0.3% to 13.0%, p = 0.04), from 5.2% during 2001-2003 to 14.4% during 2016-2018. Primary VL and VL relapse patients had similar age, sex and anthropometric characteristics, the latter indicating high indices of undernutrition which were relatively constant over time. Clinical factors (Hb, spleen size, and VL severity score) also did not vary substantially over time. SSG/PM was the main treatment regimen from 2001-2018, used in 68.7% of primary and 70.9% of relapse VL cases; AmBisome was introduced in 2013, received by 22.5% of primary VL and 32.6% of VL relapse cases from 2013-2018. CONCLUSION: Increasing incidence of VL relapse in South Sudan does not appear to be explained by changes in patient characteristics or other factors. Our data are concerning and may indicate an emergence of treatment-resistant parasite strains, decreasing the effectiveness of treatment regimens. This warrants further investigation as a causal factor. New chemical entities that will enable safe and highly effective short-course oral treatments for VL are urgently needed.


Assuntos
Leishmaniose Visceral , Doença Crônica , Humanos , Incidência , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/epidemiologia , Recidiva , Estudos Retrospectivos , Sudão do Sul/epidemiologia
9.
J Nepal Health Res Counc ; 20(1): 194-201, 2022 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-35945875

RESUMO

BACKGROUND: Visceral leishmaniasis is transmitted to humans by Leishmania donovani infected Phlebotomus argentipes sandflies. Nepal has successfully met the elimination target of less than 1 case per 10,000, although recently this threshold has been surpassed demonstrating ongoing transmission. The main objective of the present study was to investigate transmission of visceral leishmaniasis in 4 visceral leishmaniasis endemic districts of Nepal including Palpa, Morang, Saptari and Sarlahi. METHODS: Human blood samples (331), domestic animals blood samples [goats (n =67), dogs (n =1), cows (n = 6), buffaloes (n = 16), and ox (n = 10)] and sandflies samples (3976 from 142 households) were collected from the villages of these 4 districts. Human blood samples were tested for VL antibodies using the rK39 rapid diagnostic test (InBios International, Seattle, WA). kDNA of L.donovani was amplified by PCR from DNA extracted from human blood, animal blood and sandfly samples. RESULTS: Out of 331 screened across 4 districts,32 were positive on rK39 serology and 16 were positive by PCR amplification of kDNA from L. donovani. The majority of the positive serology and PCR tests were from the Ishworpur village in the Sarlahi district where there was an outbreak of 18 cases of VL. This study also revealed the presence of L. donovani DNA in female P. argentipes sandflies collected from the Ishworpur village of Sarlahi, 6 villages in the Saptari,10 villages in the Palpa, and from 9 villages in the Morang. Blood samples from domestic animals in the same villages were negative for kDNA detection by PCR. CONCLUSIONS: The results of human and sandfly findings strongly point towards local transmission of visceral leishmaniasis in these 4 districts of Nepal. Notably, there is a significant level of transmission in the Ishworpur village in the Sarlahi district. The observations from this study suggest that domestic animals are not a reservoir host for L. donovani in these districts in Nepal. Ongoing surveillance is needed to identify new outbreaks such as in the Sarlahi district.


Assuntos
Leishmania donovani , Leishmaniose Visceral , Phlebotomus , Animais , Bovinos , DNA de Cinetoplasto , Cães , Feminino , Humanos , Leishmania donovani/genética , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/veterinária , Nepal/epidemiologia , Phlebotomus/genética
10.
Infect Genet Evol ; 103: 105327, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35811035

RESUMO

Canine leishmaniasis is increasingly reported worldwide and represent a threat to both animal and human health. In a previous pilot study conducted in Bobo-Dioulasso, the second town of Burkina Faso, we reported five cases of canine leishmaniasis. With the perspective of a One Health action plan, and in the context of increasing urbanization, this study aimed to provide new information on Leishmania spp in dogs in this city. A cross-sectional survey was carried out from May to August 2018 in six districts of the city in order to record clinical and biological data from domestic dogs randomly selected per district. Blood samples were collected into EDTA tubes (4-5 mL), treated and stored at -20 °C until further analyses. The infection status of the dogs was performed by serological tests using plasma, and real time-PCR (RT-PCR) to detect Leishmania parasites using buffy coats. Nested PCR was used for typing the Leishmania species in dogs which were found to be RT-PCR positive. A total of 147 dogs were examined clinically and sampled for blood collection, including 53.7% females and 46.3% of males with a median age of 3 years. The seroincidence of Leishmania parasites within this dog population was 4.76% (95% CI:2.26-9.72). The incidence of Leishmania was 10.88% (95% CI: 6.73-17.11) by RT-PCR which was significantly more sensitive (p = 0,047) and a fair concordance was observed between both tests (Kappa = 0.39, p < 0.001). The characterization of Leishmania species revealed that L. major was circulating in this domestic dog population. Our results confirmed the persistence of zoonotic circulation of Leishmania parasites such as L. major currently in Bobo-Dioulasso city and highlight the need for targeted interventions in order to control transmission of leishmaniasis in this region.


Assuntos
Doenças do Cão , Leishmania , Leishmaniose Visceral , Leishmaniose , Animais , Burkina Faso/epidemiologia , Pré-Escolar , Estudos Transversais , Doenças do Cão/parasitologia , Cães , Feminino , Humanos , Leishmania/genética , Leishmaniose/epidemiologia , Leishmaniose/veterinária , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/veterinária , Masculino , Projetos Piloto , Reação em Cadeia da Polimerase em Tempo Real
11.
Tunis Med ; 100(1): 13-26, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35822327

RESUMO

Visceral leishmaniasis (VL) is a severe life threatening parasitosis requiring early management of cases. It is an emerging disease in the Mediterranean region with a spread of endemic areas and an increase in case incidence. The patient profile has also evolved with more affected adults, presenting generally non-specific symptoms. Hence the interest of a systematic biological confirmation. The microscopic detection of Leishmania amastigotes in bone marrow aspirates (BMA) smears is the gold standard diagnostic technique. However, it requires invasive sampling. Serological tests searching for specific antibodies remain highly contributory, but their interpretation must always take into account the epidemiological context and the patient's clinical and biological features. Currently, the Western-Blot represents the most specific serological technique for diagnostic confirmation. VL diagnosis has greatly improved by the introduction of both rapid diagnostic tests (RDTs) and molecular biological techniques. RDTs using recombinant rk39 antigen are easy to perform and deliver results in less than 30 minutes. Real-time PCR (Polymerase Chain Reaction) is currently retained as the best technique for VL diagnosis. It is efficient on simple blood samples, allowing to avoid invasive BMA needed for microscopy. In addition, real time PCR estimates parasite load which is helpful for the post-treatment follow-up. In any case, the choice of techniques to be used should be strategic and adapted to the local epidemiology as well as to the means available.


Assuntos
Leishmaniose Visceral , Adulto , Humanos , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/epidemiologia , Grupos Raciais , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade , Testes Sorológicos
12.
Front Cell Infect Microbiol ; 12: 900084, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35811682

RESUMO

Visceral leishmaniasis is an important global health problem with an estimated of 50,000 to 90,000 new cases per year. VL is the most serious form of leishmaniasis as it can be fatal in 95% of the cases if it remains untreated. VL is a particularly acute problem in Brazil which contributed with 97% of all cases reported in 2020 in the Americas. In this country, VL affects mainly the poorest people in both urban and rural areas and continues to have a high mortality rate estimated around 8.15%. Here, we performed a temporal parasite population study using whole genome sequence data from a set of 34 canine isolates sampled in 2008, 2012 and 2015 from a re-emergent focus in Southeastern Brazil. Our study found the presence of two distinct sexual subpopulations that corresponded to two isolation periods. These subpopulations diverged hundreds of years ago with no apparent gene flow between them suggesting a process of rapid replacement during a two-year period. Sequence comparisons and analysis of nucleotide diversity also showed evidence of balancing selection acting on transport-related genes and antigenic families. To our knowledge this is the first population genomic study showing a turn-over of parasite populations in an endemic region for leishmaniasis. The complexity and rapid adaptability of these parasites pose new challenges to control activities and demand more integrated approaches to understand this disease in New World foci.


Assuntos
Doenças do Cão , Leishmania infantum , Leishmaniose Visceral , Leishmaniose , Animais , Brasil/epidemiologia , Doenças do Cão/epidemiologia , Doenças do Cão/parasitologia , Cães , Humanos , Leishmania infantum/genética , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/parasitologia , Leishmaniose Visceral/veterinária
13.
Parasitol Res ; 121(9): 2683-2695, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35802163

RESUMO

The parasitic protozoa Leishmania (Leishmania) infantum is the etiological agent of human visceral leishmaniasis and canine leishmaniasis in South America, where Brazil is the most affected country. This zoonotic disease is transmitted by the bite of an infected phlebotomine sand fly and dogs constitute the main domestic reservoir of the parasite. In this study, we screened 2348 dogs of the municipality of Embu das Artes, Brazil, for antibodies against the parasite. Prevalence for canine leishmaniasis seropositivity was 2.81%, as assessed using a Dual-Path Platform rapid test for canine leishmaniasis. Twenty-five seropositive dogs were euthanized for parasite isolation and 14 isolates were successful obtained. Nucleotide sequencing of the internal transcribed spacer confirmed the isolates to be L. (L.) infantum, and very low sequence variability was observed among them. The in vitro susceptibility to miltefosine and paromomycin was assessed and moderate variation in paromomycin susceptibility was found among the isolates in the promastigote and intracellular amastigote stages. On the other hand, in vitro susceptibility to miltefosine of these isolates was homogenous, particularly in the amastigote stage (EC50 values from 0.69 to 2.07 µM). In addition, the miltefosine sensitivity locus was deleted in all the isolates, which does not corroborate the hypothesis that the absence of this locus is correlated with a low in vitro susceptibility. Our findings confirm that the municipality of Embu das Artes is endemic for canine leishmaniasis and that isolates from this region are susceptible to paromomycin and miltefosine, indicating the potential of these drugs to be clinically evaluated in the treatment of human visceral leishmaniasis in Brazil.


Assuntos
Doenças do Cão , Leishmania infantum , Leishmaniose Visceral , Animais , Brasil/epidemiologia , Doenças do Cão/parasitologia , Cães , Humanos , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/veterinária , Paromomicina/uso terapêutico
14.
PLoS Negl Trop Dis ; 16(7): e0010304, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35834563

RESUMO

BACKGROUND: Visceral leishmaniasis (VL) is targeted for elimination as a public health problem in Nepal by 2023. For nearly three decades, the core vector control intervention in Nepal has been indoor residual spraying (IRS) with pyrethroids. Considering the long-term use of pyrethroids and the possible development of resistance in the vector Phlebotomus argentipes sand flies, we monitored the susceptibility status of their field populations to the insecticides of different classes, in villages with and without IRS activities in recent years. METHODOLOGY/PRINCIPAL FINDINGS: Sand flies were collected from villages with and without IRS in five VL endemic districts from August 2019 to November 2020. The WHO susceptibility test procedure was adopted using filter papers impregnated at the discriminating concentrations of insecticides of the following classes: pyrethroids (alpha-cypermethrin 0.05%, deltamethrin 0.05%, and lambda-cyhalothrin 0.05%), carbamates (bendiocarb 0.1%) and organophosphates (malathion 5%). Pyrethroid resistance intensity bioassays with papers impregnated with 5× of the discriminating concentrations, piperonyl butoxide (PBO) synergist-pyrethroid bioassays, and DDT cross-resistance bioassays were also performed. In the IRS villages, the vector sand flies were resistant (mortality rate <90%) to alpha-cypermethrin and possibly resistant (mortality rate 90-97%) to deltamethrin and lambda-cyhalothrin, while susceptibility to these insecticides was variable in the non-IRS villages. The vector was fully susceptible to bendiocarb and malathion in all villages. A delayed knockdown time (KDT50) with pyrethroids was observed in all villages. The pyrethroid resistance intensity was low, and the susceptibility improved at 5× of the discriminating concentrations. Enhanced pyrethroid susceptibility after pre-exposure to PBO and the DDT-pyrethroid cross-resistance were evident. CONCLUSIONS/SIGNIFICANCE: Our investigation showed that P. argentipes sand flies have emerged with pyrethroid resistance, suggesting the need to switch to alternative classes of insecticides such as organophosphates for IRS. We strongly recommend the regular and systematic monitoring of insecticide resistance in sand flies to optimize the efficiency of vector control interventions to sustain VL elimination efforts in Nepal.


Assuntos
Inseticidas , Leishmaniose Visceral , Phlebotomus , Psychodidae , Piretrinas , Animais , DDT , Resistência a Inseticidas , Inseticidas/farmacologia , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/prevenção & controle , Malation , Nepal/epidemiologia , Piretrinas/farmacologia
15.
PLoS Negl Trop Dis ; 16(7): e0010609, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35853080

RESUMO

The development of Leishmania parasites within sand fly vectors occurs entirely in the insect gut lumen, in the presence of symbiotic and commensal bacteria. The impacts of host species and environment on the gut microbiome are currently poorly understood. We employed MiSeq sequencing of the V3-16S rRNA gene amplicons to characterize and compare the gut microbiota of field-collected populations of Phlebotomus kandelakii, P. perfiliewi, P. alexandri, and P. major, the primary or secondary vectors of zoonotic visceral leishmaniasis (ZVL) in three distinct regions of Iran where ZVL is endemic. In total, 160,550 quality-filtered reads of the V3 region yielded a total of 72 operational taxonomic units (OTUs), belonging to 23 phyla, 47 classes, 91 orders, 131 families, and 335 genera. More than 50% of the bacteria identified were Proteobacteria, followed by Firmicutes (22%), Deinococcus-Thermus (9%), Actinobacteria (6%), and Bacteroidetes (5%). The core microbiome was dominated by eight genera: Acinetobacter, Streptococcus, Enterococcus, Staphylococcus, Bacillus, Propionibacterium, Kocuria, and Corynebacterium. Wolbachia were found in P. alexandri and P. perfiliewi, while Asaia sp. was reported in P. perfiliewi. Substantial variations in the gut bacterial composition were found between geographically distinct populations of the same sand fly species, as well as between different species at the same location, suggesting that sand fly gut microbiota is shaped by both the host species and geographical location. Phlebotomus kandelakii and P. perfiliewi in the northwest, and P. alexandri in the south, the major ZVL vectors, harbor the highest bacterial diversity, suggesting a possible relationship between microbiome diversity and the capacity for parasite transmission. In addition, large numbers of gram-positive human or animal pathogens were found, suggesting that sand fly vectors of ZVL could pose a potential additional threat to livestock and humans in the region studied. The presence of Bacillus subtilis, Enterobacter cloacae, and Asaia sp suggests that these bacteria could be promising candidates for a paratransgenesis approach to the fight against Leishmaniasis.


Assuntos
Microbioma Gastrointestinal , Leishmaniose Visceral , Phlebotomus , Psychodidae , Animais , Bactérias/genética , Humanos , Irã (Geográfico)/epidemiologia , Leishmaniose Visceral/epidemiologia , Phlebotomus/parasitologia , Psychodidae/parasitologia , RNA Ribossômico 16S/genética
16.
Parasit Vectors ; 15(1): 215, 2022 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-35715844

RESUMO

BACKGROUND: Query ID="Q1" Text="Graphical abstract: As per journal requirements, graphical abstract is necessary. Kindly check and provide the same."The magnitude of the health problems caused by leishmaniasis has been a major driving factor behind the development and implementation of leishmaniasis control programs by the national authorities in Iran, with a priority for health and environmental management. Such programs are not achievable unless all of the factors leading to the infection, including the parasite's life-cycle, vectors and reservoirs, are recognized. So far in Iran, humans and rodents have been considered the principal reservoirs of Leishmania tropica and Leishmania major, respectively, both associated with cutaneous leishmaniasis (CL), with domestic dogs considered to be the main reservoir for Leishmania infantum, associated with visceral leishmaniasis (VL). The role of other mammals in maintaining the Leishmania parasite has remained unclear. This study aimed to investigate Leishmania infection among livestock in endemic areas of VL and CL in Fars province, southern Iran, using serological and molecular methods. METHODS: Blood samples from 181 clinically healthy livestock, including 49 sheep, 114 goats, 16 cattle and two donkeys, were screened to detect Leishmania DNA and anti-Leishmania antibodies using qPCR (quantitative PCR) and the direct agglutination test (DAT), respectively. Four qPCR-positive samples were amplified using the internal transcribed spacer one (ITS1) primers in conventional PCR and sent for directional sequencing. RESULTS: Of the 181 livestock tested, 51 (28.2%) were infected with Leishmania, using serological and molecular methods. Anti-Leishmania antibodies were detected in 70 (38.7%) (95% confidence interval [CI]: 31.5-46.2) and Leishmania DNA in 93 (51.4%) (95% CI: 43.9-58.9) livestock. The identified Leishmania spp. were L. infantum and L. major. CONCLUSIONS: The findings of the present study show a relatively high prevalence of Leishmania infection among livestock in endemic areas of the disease, in Fars province, southern Iran. Given the large population of this group of animals and the fact that they live in the vicinity of the main reservoirs of the disease and vectors, it seems that sand flies regularly bite these animals. Further studies are needed to determine the role of livestock in the parasite's life-cycle and the epidemiology of Leishmania infection.


Assuntos
Leishmania infantum , Leishmaniose Cutânea , Leishmaniose Visceral , Animais , Bovinos , Cães , Irã (Geográfico)/epidemiologia , Leishmania infantum/genética , Leishmaniose Cutânea/diagnóstico , Leishmaniose Cutânea/epidemiologia , Leishmaniose Cutânea/veterinária , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/veterinária , Gado , Mamíferos/genética , Reação em Cadeia da Polimerase em Tempo Real , Ovinos/genética
17.
Parasit Vectors ; 15(1): 202, 2022 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-35698163

RESUMO

BACKGROUND: Zoonotic leishmaniosis caused by Leishmania infantum is endemic in several countries of the Mediterranean Basin, Latin America, and Asia. Dogs are the main hosts and reservoirs of human infection. Thus, from a One Health perspective, early diagnosis of Leishmania infection in dogs is essential to control the dissemination of the parasite among other dogs and to humans. The aim of this study was to estimate the diagnosis accuracy of three serological tests to detect antibodies to Leishmania in dogs from two endemic settings using Bayesian latent class models (BLCM). METHODS: A total of 378 dogs from two Portuguese and Brazilian endemic areas of leishmaniosis (194 animals from Portugal and 184 from Brazil) were screened. Detection of anti-Leishmania antibodies was performed using two commercial ELISA (L. infantum IgG-ELISA® and EIE-LVC®) and a rapid immunochromatographic test (DPP-LVC®). Bayesian latent class models were used to estimate Leishmania infection prevalence, together with sensitivities and specificities of the three diagnostic tests, in the two dog populations simultaneously. Predictive values were also calculated. Credibility intervals (CI) were obtained, considering different types of prior information. RESULTS: A posterior median Leishmania seroprevalence of 13.4% (95% CI 9.0-18.7) and of 21.6% (15.0-28.3) was estimated to the Portuguese and Brazilian dog subpopulations, respectively. The Bayesian analysis indicated that all tests were highly specific (specificity above 90%), and that the DPP-LVC® was more sensitive (96.6%; 83.1-99.9) than both ELISAs in the Portuguese subpopulation, while in the Brazilian subpopulation, EIE-LVC® and L. infantum IgG-ELISA®, had the highest sensitivity (88.2%; 73.7-97.0) and specificity (98.7%; 95.1-99.9), respectively. CONCLUSIONS: In general, the levels of diagnosis accuracy of the three serological tests to detect Leishmania antibodies assessed by BLCM indicate their utility in canine epidemiological studies. The same approach should be used to assess the performance of these techniques in the clinical management of infected and sick dogs using representative samples from the wide spectrum of clinical situations, namely from subclinical infection to manifest disease. The low positive predictive value of the serological tests used in the current protocol of the Brazilian Ministry of Health suggests that they should not be used individually and may not be sufficient to target reservoir-based control interventions.


Assuntos
Doenças do Cão , Leishmania infantum , Leishmaniose Visceral , Leishmaniose , Animais , Anticorpos Antiprotozoários , Teorema de Bayes , Brasil/epidemiologia , Doenças do Cão/diagnóstico , Doenças do Cão/epidemiologia , Doenças do Cão/parasitologia , Cães , Ensaio de Imunoadsorção Enzimática/métodos , Imunoglobulina G , Análise de Classes Latentes , Leishmaniose/diagnóstico , Leishmaniose/epidemiologia , Leishmaniose/veterinária , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/veterinária , Portugal/epidemiologia , Estudos Soroepidemiológicos , Testes Sorológicos/métodos
18.
Sci Rep ; 12(1): 10426, 2022 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-35729270

RESUMO

Mediterranean type of visceral leishmaniasis (VL) is a zoonotic parasitic infection. Some provinces of Iran are endemic for VL while other parts are considered as sporadic areas. This study aimed to assess a combination of recombinant K26 and rK39 antigens as well as crude antigen (CA), derived from an Iranian strain of L. infantum, compared to direct agglutination test (DAT) for the detection of VL in humans and domestic dogs as animal reservoir hosts of the disease. A combination of rK26 and rK39 antigens and also CA was evaluated using indirect ELISA on serum samples of 171 VL confirmed humans (n = 84) and domestic dogs (n = 87) as well as 176 healthy humans (n = 86) and domestic dogs (n = 90). Moreover, 36 serum samples of humans (n = 20) and canines (n = 16) with other potentially infectious diseases were collected and tested for finding cross- reactivity. The results of ELISA were compared to DAT, currently considered as gold standard for the serodiagnosis of VL. The sensitivity and specificity, positive predictive and negative predictive values were calculated compared to DAT. The positive sera had previously shown a positive DAT titer ≥ 1:800 for humans and ≥ 1:80 for dogs. Analysis was done by MedCalc and SPSS softwares. Using the combination of rK26 and rK39 in ELISA, a sensitivity of 95.2% and a specificity of 93.0% % were found in human sera at a 1:800 (cut-off) titer when DAT-confirmed cases were compared with healthy controls; a sensitivity of 98.9% and specificity of 96.7%% were found at a 1:80 (cut-off) titer compared with DAT. A good degree of agreement was found between the combined rK39 and rK26-ELISA with DAT in human (0.882) and dog serum samples (0.955) by kappa analysis (p < 0.05). The ELISA using the CA test showed 75% sensitivity in human and 93.1% in dog serum samples as well as 53.5% specificity in human and 83.3% in dog,s sera, respectively. The combination of rK26 and rK39 recombinant antigen prepared from Iranian strain of Leishmania infantum showed high accuracy for the serodiagnosis of VL in human and domestic dogs. Further extended field trial with a larger sample size is recommended.


Assuntos
Doenças do Cão , Leishmania infantum , Leishmaniose Visceral , Testes de Aglutinação/métodos , Animais , Anticorpos Antiprotozoários , Antígenos de Protozoários/genética , Doenças do Cão/diagnóstico , Doenças do Cão/parasitologia , Cães , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , Irã (Geográfico)/epidemiologia , Leishmania infantum/genética , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/veterinária , Sensibilidade e Especificidade , Zoonoses
19.
Vet Parasitol Reg Stud Reports ; 32: 100740, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35725103

RESUMO

Bats are parasitized by a wide spectrum of ecto and endoparasites, but their role as a reservoir for some zoonoses is not fully understood. The objective of this work was to evaluate the presence of Leishmania DNA in the blood of bats from 30 municipalities in the state of Minas Gerais, Brazil. We analyzed samples of 120 bats, covering 29 species. The blood samples were used for DNA extraction and submitted to conventional PCR analysis with primers directed to the Leishmania ITS-1 region of the rRNA. In total, 1.67% (2/120 samples) were positive for Leishmania spp., detected in animals from the metropolitan region of Belo Horizonte, the state capital. Sequencing of the positive samples revealed that both bats were infected with Leishmania (Leishmania) infantum. Considering the adaptability of some bats species to synanthropic environments, the results of the present work can contribute to a better comprehension of the leishmaniasis cycle and epidemiology.


Assuntos
Quirópteros , Leishmania infantum , Leishmaniose Visceral , Leishmaniose , Animais , Brasil/epidemiologia , Leishmania infantum/genética , Leishmaniose/epidemiologia , Leishmaniose/veterinária , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/parasitologia , Leishmaniose Visceral/veterinária
20.
Vet Parasitol Reg Stud Reports ; 32: 100745, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35725108

RESUMO

According to the last leishmaniasis report from the Pan American Health Organization (2021) so far Panama is considered free of visceral leishmaniasis (VL). Although the presence of potential vectors and reservoirs involved in the VL transmission cycle have been described in some rural regions of the country, no cases have been reported in humans and domestic or wild animals. Dogs play an important role in the urban transmission of VL; therefore, it is important to detect possible cases of canine visceral leishmaniasis (CVL) in the country. In this sense,this study reports for the first time the Leishmania (Leishmania) infantum infection in imported dogs in Panama. Eleven dogs with clinical suspicion of CVL were evaluated by parasitological (bone marrow aspirate smear), serological (indirect immunofluorescence and/or reference immunochromatographic rapid test) and molecular tests (conventional PCR). The dogs included in this study were analyzed during the period from 2013 to 2020. All dogs presented clinical manifestations compatible with CVL. The samples were initially evaluated by smears and/or rapid serological tests by private practice veterinarians, and later confirmed by serological and/or molecular tests at the national reference laboratory for Leishmania diagnosis. The diagnosis was confirmed in 5/11 dogs by serological, parasitological and/or conventionals PCR targeting kDNA minicircle and Hsp70 gene. Leishmania (L.) infantum species was identified in 3/5 dogs by PCR-RFLP and by sequencing Hsp70-PCR products. This study evidenced the need to increase awareness of private practitioners as well as public health veterinarians on visceral leishmaniasis (VL), and to consider this parasitosis in the differential diagnosis of dogs with clinical and epidemiological characteristics compatible with the disease.


Assuntos
Doenças do Cão , Leishmania infantum , Leishmaniose Visceral , Leishmaniose , Animais , Doenças do Cão/diagnóstico , Doenças do Cão/epidemiologia , Cães , Leishmania infantum/genética , Leishmaniose/veterinária , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/veterinária , Saúde Pública
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