RESUMEN

Rats are major reservoirs for pathogenic Leptospira, the bacteria causing leptospirosis, particularly in urban informal settlements. However, the impact of variation in rat abundance and pathogen shedding rates on spillover transmission to humans remains unclear. This study aimed to investigate how spatial variation in reservoir abundance and pathogen pressure affect Leptospira spillover transmission to humans in a Brazilian urban informal settlement. A longitudinal eco-epidemiological study was conducted from 2013 to 2014 to characterize the spatial distribution of rat abundance and Leptospira shedding rates in rats and determine the association with human infection risk in a cohort of 2,206 community residents. Tracking plates and live-trapping were used to measure rat abundance and quantify rat shedding status and load. In parallel, four sequential biannual serosurveys were used to identify human Leptospira infections. To evaluate the role of shedding on human risk, we built three statistical models for: (1) the relative abundance of rats, (2) the shedding rate by individual rats, and (3) human Leptospira infection, in which "total shedding", obtained by multiplying the predictions from those two models, was used as a risk factor. We found that Leptospira shedding was associated with older and sexually mature rats and varied spatially and temporally-higher at valley bottoms and with seasonal rainfall (December to March). The point estimate for "total shedding" by rat populations was positive, i.e., Leptospira infection risk increased with total shedding, but the association was not significant [odds ratio (OR) = 1.1; 95% confidence interval (CI): 0.9, 1.4]. This positive trend was mainly driven by rat abundance, rather than individual rat shedding (OR = 1.8; 95% CI: 0.6, 5.4 vs. OR = 1.0; 95% CI: 0.7, 1.4]. Infection risk was higher in areas with more vegetative land cover (OR = 2.4; 95% CI: 1.2, 4.8), and when floodwater entered the house (OR = 2.4; 95% CI: 1.6, 3.4). Our findings indicate that environmental and hydrological factors play a more significant role in Leptospira spillover than rat associated factors. Furthermore, we developed a novel approach combining several models to elucidate complex links between animal reservoir abundance, pathogen shedding and environmental factors on zoonotic spillover in humans that can be extended to other environmentally transmitted diseases.

Asunto(s)

Reservorios de Enfermedades , Leptospira , Leptospirosis , Zoonosis , Animales , Humanos , Leptospirosis/epidemiología , Leptospirosis/microbiología , Leptospirosis/transmisión , Leptospira/aislamiento & purificación , Reservorios de Enfermedades/microbiología , Brasil/epidemiología , Ratas , Zoonosis/microbiología , Masculino , Femenino , Adulto , Derrame de Bacterias , Estudios Longitudinales , Persona de Mediana Edad , Factores de Riesgo , Población Urbana/estadística & datos numéricos , Adolescente , Adulto Joven

RESUMEN

BACKGROUND: Leptospirosis is responsible for various clinical syndromes, classically linked with fever and acute kidney injury. METHODOLOGY/PRINCIPAL FINDINGS: A prospective multicenter observational study was conducted in six health institutions in the region of Urabá, Colombia. Enrollment was based on leptospirosis-compatible clinical syndrome and a positive preliminary serological test, with PCR used to confirm the disease. Clinical data were collected using a standard questionnaire at enrollment, complemented with a review of clinical records. A total of 100 patients were enrolled, 37% (95% CI 27.0-46.9%) had a positive PCR result confirming acute leptospirosis. The most frequent symptoms in patients with a positive PCR test were headache (91.9%; 34/37), chills and sweating (80.6%; 29/37), nausea (75%; 27/37), dizziness (74.3%; 26/37), vomiting (61.1%; 22/37), congestion (56.8%; 21/37), and conjunctival suffusion (51.4%; 19/37). The frequency of clinical signs classically described in leptospirosis was low: jaundice (8.3%; 3/36) and anuria/oliguria (21.6%; 8/37). An increased neutrophile percentage was reported in 60.6% (20/33) of patients. The presence of complications was 21.6% (8/37), with pulmonary complications being the most frequent (75.0% 6/8). One confirmed case died resulting in a fatality of 2.7% (95% CI 0.5-13.8). CONCLUSIONS/SIGNIFICANCE: Leptospirosis should be considered within the differential diagnoses of an undifferentiated acute febrile syndrome. Leptospirosis presents diagnostic challenges due to limitations in both clinical and laboratory diagnosis thus it is important to improve understanding of disease presentation and identify signs and symptoms that might help differentiate it from other causes of febrile illness.

Asunto(s)

Fiebre , Leptospirosis , Humanos , Leptospirosis/diagnóstico , Leptospirosis/complicaciones , Leptospirosis/epidemiología , Colombia/epidemiología , Masculino , Femenino , Adulto , Estudios Prospectivos , Fiebre/etiología , Persona de Mediana Edad , Adulto Joven , Adolescente , Anciano , Niño , Leptospira/aislamiento & purificación , Leptospira/genética , Reacción en Cadena de la Polimerasa

RESUMEN

Leptospirosis and toxoplasmosis are re-emerging zoonosis caused by infection with pathogenic spirochaetes of Leptospira and the protozoa Toxoplasma gondii, respectively. Wild boars (Sus scrofa), an exotic invasive species in Brazil, could play a role in the diseases' epidemiological cycles, but this issue is still unexplored. This study aimed to evaluate the Leptospira spp. and T. gondii seropositivity in wild boars in Rio Grande do Sul state, south Brazil. Of evaluated animals, 16% (13/80) and 85% (52/61) had antibodies to T. gondii and Leptospira spp., respectively. Sex, weight, age, hunt location and season of hunt were evaluated by their association with seropositivity for both pathogens, but none of them had statistical significance. This study revealed that wild boars should be considered as a potential source of Leptospira spp. and T. gondii dissemination for humans and animal species in shared environments in Rio Grande do Sul state.

Asunto(s)

Anticuerpos Antiprotozoarios , Leptospira , Leptospirosis , Sus scrofa , Enfermedades de los Porcinos , Toxoplasma , Toxoplasmosis Animal , Animales , Leptospirosis/epidemiología , Leptospirosis/veterinaria , Brasil/epidemiología , Toxoplasmosis Animal/epidemiología , Toxoplasmosis Animal/inmunología , Toxoplasma/inmunología , Leptospira/inmunología , Sus scrofa/parasitología , Porcinos , Enfermedades de los Porcinos/epidemiología , Enfermedades de los Porcinos/parasitología , Enfermedades de los Porcinos/microbiología , Anticuerpos Antiprotozoarios/sangre , Masculino , Femenino , Estudios Seroepidemiológicos , Anticuerpos Antibacterianos/sangre , Zoonosis/epidemiología , Zoonosis/parasitología , Humanos , Salud Pública

RESUMEN

Leptospirosis, an acute bacterial zoonotic disease, is endemic in Puerto Rico. Infection in approximately 10%-15% of patients with clinical disease progresses to severe, potentially fatal illness. Increased incidence has been associated with flooding in endemic areas around the world. In 2022, Hurricane Fiona, a Category 1 hurricane, made landfall and inundated Puerto Rico with heavy rainfall and severe flooding, increasing the risk for a leptospirosis outbreak. In response, the Puerto Rico Department of Health (PRDH) changed guidelines to make leptospirosis cases reportable within 24 hours, centralized the case investigation management system, and provided training and messaging to health care providers. To evaluate changes in risk for leptospirosis after Hurricane Fiona to that before the storm, the increase in cases was quantified, and patient characteristics and geographic distribution were compared. During the 15 weeks after Hurricane Fiona, 156 patients experienced signs and symptoms of leptospirosis and had a specimen with a positive laboratory result reported to PRDH. The mean weekly number of cases during this period was 10.4, which is 3.6 as high as the weekly number of cases during the previous 37 weeks (2.9). After Hurricane Fiona, the proportion of cases indicating exposure to potentially contaminated water increased from 11% to 35%, and the number of persons receiving testing increased; these factors likely led to the resulting overall surge in reported cases. Robust surveillance combined with outreach to health care providers after flooding events can improve leptospirosis case identification, inform clinicians considering early initiation of treatment, and guide public messaging to avoid wading, swimming, or any contact with potentially contaminated floodwaters.

Asunto(s)

Tormentas Ciclónicas , Brotes de Enfermedades , Leptospirosis , Puerto Rico/epidemiología , Leptospirosis/epidemiología , Humanos , Masculino , Adulto , Femenino , Persona de Mediana Edad , Adolescente , Adulto Joven , Niño , Anciano , Preescolar , Desastres

RESUMEN

Bovine Genital Leptospirosis (BGL) is a chronic reproductive syndrome characterized by genital infection by Leptospira spp. An accurate diagnosis of BGL is crucial to implementing proper control measures in field conditions. This study aimed to evaluate the reliability of serology by Microscopic Agglutination Test (MAT) for diagnosing leptospirosis in subfertile cows with genital infection. Of three herds, 93 non-pregnant cows with reproductive failures were submitted to the blood sampling (serology by MAT) and genital samples (lipL32-PCR). A total of 62/93 (66.6%) cows presented seroreactive to cutoff 100, while 45/93 (48.4%) cows were positive to cutoff 200, mainly against the Sejroe serogroup. In PCR analysis, 55/93 (59.1%) were positive. MAT results were compared with PCR (considered the standard), and test parameters and Cohen's kappa (ƙ) were calculated for the cut-offs 100 and 200. A ROC curve was performed for each cut-off of titers 100 to 1,600. The sensitivity and specificity of MAT100 were calculated at 66.6% and 33.3%, while for MAT200 the sensitivity was estimated as 35% and specificity as 54.5%. The accuracy of MAT was poor, being 54.8% in MAT100 and 42% in MAT200. Furthermore, the area under the curve of ROC analysis was low for all titers, and the correlation was poor for MAT100 and MAT200 (ƙ < 0). The results demonstrated that MAT is a limited technique to diagnose bovine genital carriers individually, and if only MAT is applied, genital carriers may pass undetected, impairing the control programs.

Asunto(s)

Pruebas de Aglutinación , Enfermedades de los Bovinos , Leptospirosis , Sensibilidad y Especificidad , Animales , Leptospirosis/veterinaria , Leptospirosis/diagnóstico , Bovinos , Pruebas de Aglutinación/veterinaria , Femenino , Enfermedades de los Bovinos/diagnóstico , Enfermedades de los Bovinos/microbiología , Enfermedades de los Genitales Femeninos/veterinaria , Enfermedades de los Genitales Femeninos/diagnóstico , Enfermedades de los Genitales Femeninos/microbiología , Leptospira/aislamiento & purificación , Reproducibilidad de los Resultados

RESUMEN

Leptospirosis is a zoonotic disease whose transmission is linked to multiple factors involving the interface between animals, humans, and the environment. This disease is of great importance for public health, as it profoundly affects the health aspects of the population and animals. Considering the importance of non-human primates in this epidemiological chain, the objective of this research was to conduct a systematic literature review with meta-analysis, providing information on leptospirosis in non-human primates (NHPs) and an update on the infection situation in Brazil and other countries. Thus, a search was performed in five databases, initially finding 3332 studies, of which 32 met the eligibility criteria and were used for the systematic review. According to them, the most prevalent serogroup in non-human primates was Icterohaemorrhagiae, which is adapted to rodents as primary hosts. A wide distribution of the infection was found in the regions of both wild and captive animals. Through meta-analysis, the seroprevalence rate of leptospirosis in non-human primates was 27.21% (CI 17.97-38.95%). Cochran's Q test (p < 0.01) identified heterogeneity between studies, classified as high by the Higgins and Thompson test (I2 = 92.4%). Therefore, seroepidemiological and Leptospira isolation studies in non-human primates are important to investigate and monitor the suspected impact of these species as maintainers or transmitters of the pathogen to humans and other wild and domestic animals, in addition to demonstrating the need for standardization related to control and prevention measures.

Asunto(s)

Leptospirosis , Primates , Animales , Leptospira/inmunología , Leptospira/aislamiento & purificación , Leptospirosis/sangre , Leptospirosis/epidemiología , Leptospirosis/microbiología , Leptospirosis/veterinaria , Enfermedades de los Monos/sangre , Enfermedades de los Monos/epidemiología , Enfermedades de los Monos/microbiología , Enfermedades de los Monos/transmisión , Primates/microbiología , Estudios Seroepidemiológicos , Zoonosis/sangre , Zoonosis/epidemiología , Zoonosis/microbiología , Zoonosis/transmisión , Humanos

RESUMEN

PURPOSE: The current diagnostic methods for leptospirosis diagnosis are technically complex and expensive, with limited applicability to specialized laboratories. Furthermore, they lack diagnostic accuracy in the acute stage of the disease, which coincides with a period when antibiotics are highly effective. New simple and accurate tests are mandatory to decentralize and improve diagnosis. Here, we introduced a new lateral flow immunoassay (Lepto-LF) for human leptospirosis. METHODS: We conducted a double-blinded assay using 104 serum samples from patients with confirmed or discarded diagnosis for leptospirosis. The diagnostic performance of Lepto-LF was estimated across different ranges of days from onset of symptoms (dpo), considering the diagnostic algorithm as reference standard. Additionally, it was compared with the screening methods enzyme-linked immunosorbent assay (IgM-ELISA) and the slide agglutination test using temperature-resistant antigen (SATR). RESULTS: Lepto-LF exhibited perfect diagnostic performance with a Youden´s index J = 1 from 6 dpo in the acute phase. IgM-ELISA gave slightly lower accuracy with J = 0.91 and 95.5% of both sensitivity and specificity; while SATR showed a markedly inferior yield (J = 0.41, sensitivity = 95.5%, specificity = 45.5%). The performances remained consistent in the convalescence phase of the disease (> 10 dpo). CONCLUSION: Lepto-LF was found to be a reliable test for simple, rapid and early diagnosis of leptospirosis, resulting a promising tool for decentralizing leptospirosis diagnosis and enabling timely treatment of patients. In addition, Lepto-LF may be employed as confirmatory test, especially in remote areas and vulnerable contexts where the standard MAT is not available.

Asunto(s)

Anticuerpos Antibacterianos , Ensayo de Inmunoadsorción Enzimática , Leptospirosis , Sensibilidad y Especificidad , Humanos , Leptospirosis/diagnóstico , Leptospirosis/sangre , Anticuerpos Antibacterianos/sangre , Ensayo de Inmunoadsorción Enzimática/métodos , Inmunoensayo/métodos , Inmunoensayo/normas , Leptospira/inmunología , Leptospira/aislamiento & purificación , Inmunoglobulina M/sangre , Masculino , Femenino , Adulto , Persona de Mediana Edad , Método Doble Ciego , Pruebas de Aglutinación/métodos , Adulto Joven

RESUMEN

Leptospirosis is a zoonotic disease with significant global impact and a challenging diagnosis. The utilization of adequately validated rapid tests is relevant for the opportune identification of the disease and for reduction in fatality rates. The present study analyzes the accuracy and reliability of the Dual Path Platform (DPP) assay -produced in Brazil by the Oswaldo Cruz Foundation (Fiocruz)- for diagnosing leptospirosis. Firstly, a serological panel was constructed in the Brazilian Reference Laboratory for Leptospirosis using samples routinely handled by reference laboratories of six Brazilian states. It consisted of 150 positive (according to MAT and IgM-ELISA) and 250 negative samples for leptospirosis. Subsequently, the panel samples were distributed to the reference laboratories for the performance of DPP assays in triplicate. Different measures were used in the assessment of diagnostic quality. Predictive values were estimated for different pre-test probability settings. Sensitivities varied between 67.33 % and 74.00 % and specificities between 93.20 % and 98.40 % in the states, and there were adequate agreements between them. Accuracies were lower for the samples of patients with less than 7 days of symptoms. In contexts of prevalence values up to around 25 %, positive and negative predictive values were around 90 %. However, in situations of high pre-test probabilities, NPVs were low. This study improves understanding of the use of DPP in diagnosing leptospirosis, particularly its application in healthcare settings. As long as the time of symptoms onset and clinical and epidemiological contexts are adequately considered for the interpretation of results, DPP is a valid option to be used in the leptospirosis diagnostic routine.

Asunto(s)

Anticuerpos Antibacterianos , Leptospirosis , Sensibilidad y Especificidad , Humanos , Anticuerpos Antibacterianos/sangre , Brasil/epidemiología , Ensayo de Inmunoadsorción Enzimática/métodos , Inmunoglobulina M/sangre , Leptospira/aislamiento & purificación , Leptospira/inmunología , Leptospirosis/sangre , Leptospirosis/diagnóstico , Leptospirosis/inmunología , Leptospirosis/microbiología , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Pruebas Serológicas/métodos

RESUMEN

Leptospirosis is an anthropozoonosis of economic and public health importance, caused by bacteria of the genus Leptospira. Horses are deemed important in its transmission chain due to their proximity to humans, and because the species is often asymptomatic, making these animals potential silent reservoirs. In this context, the objectives of this study were to determine the prevalence of seropositive horses for Leptospira spp., and to identify the presence of Leptospira spp. serogroups and antibody titers, the occurrence of areas with higher density of infection cases and demographic characteristics associated with seropositivity in the states of Paraíba (PB), Pernambuco (PE), Rio Grande do Norte (RN) and Ceará (CE), in the Northeast region of Brazil, during rainy (May and June) and dry (October and November) seasons from 2017 to 2019. Using the microscopic agglutination test (MAT), 1152 equine serum samples from 225 municipalities were analyzed. Anti-Leptospira antibodies were detected in 23.9 % (95 % CI= 21.4 - 26.3 %) of the samples in the three-year period, with a frequency of 30.4 % (95 % CI= 26.7 - 34.2 %) during the rainy period (with greater emphasis on the Ballum serogroup) and 17.4 % (95 % CI= 14.3 - 20.5 %) in the dry period (with greater emphasis on the Sejroe serogroup). Age of horses ≥ 6 years (6-10 years, 11-15 years and ≥ 16 years), rainy season, and animal belonging to Pernambuco state were factors with higher seropositivities. Regarding spatial distribution, a higher percentage of seropositive animals was observed in Pernambuco (P < 0.05), in interstate border areas, and large urban centers, with a spatial cluster detected in the dry season of 2018 with relative risk of 2.8 (P = 0.049) times higher in municipalities within the cluster. It is suggested that measures for controlling rodents and contact with wild animals in equine farming, both in rainy and dry periods, combined with care regarding the use of pastures shared with cattle and the adoption of immunoprophylaxis are important in preventing and controlling leptospirosis in horses in the Northeast region of Brazil.

Asunto(s)

Enfermedades de los Caballos , Leptospira , Leptospirosis , Estaciones del Año , Animales , Caballos , Leptospirosis/veterinaria , Leptospirosis/epidemiología , Leptospirosis/microbiología , Brasil/epidemiología , Enfermedades de los Caballos/epidemiología , Enfermedades de los Caballos/microbiología , Leptospira/aislamiento & purificación , Leptospira/inmunología , Estudios Seroepidemiológicos , Prevalencia , Masculino , Femenino , Anticuerpos Antibacterianos/sangre , Análisis Espacial , Serogrupo

RESUMEN

Leptospirosis, a bacterial infection transmitted through contact with infected animals or contaminated water sources, imposes a substantial health burden in Colombia. Since 2007, the National Institute of Health (INS) has mandated the notification and confirmation of all suspected leptospirosis cases. This passive surveillance program employs the microscopic agglutination test (MAT) on serum samples to ascertain confirmed cases of leptospirosis infection. However, the absence of a robust surveillance system has hindered our comprehensive understanding of the morbidity, mortality, geographical distribution, species/serovars, and strains responsible for severe disease. Our study aimed to provide an epidemiological overview of MAT-confirmed human leptospirosis cases reported over 6 years (2015-2020) in Colombia. In addition, we offer insights into the status of leptospirosis in the country, focusing on risk factors and proposing potential improvements for diagnosis and disease management. During the 6-year surveillance period, the laboratory at the INS received 3,535 serum samples from suspected human leptospirosis cases, with 880 (25%) confirmed through MAT. The incidence of leptospirosis was calculated at 1.9 cases per 100,000 people, with a higher prevalence among men (82.1%). Furthermore, 54 (6.1%) deaths were confirmed as leptospirosis, and cases were documented across nearly all regions of Colombia. Our findings emphasize the urgent need to strengthen leptospirosis laboratory surveillance, implement effective prevention measures, and enhance diagnostic capabilities in Colombia. The analysis conducted in this study provides the groundwork for estimating the impact of leptospirosis and raises awareness of its significance in public health.

Asunto(s)

Leptospirosis , Humanos , Leptospirosis/epidemiología , Leptospirosis/diagnóstico , Leptospirosis/sangre , Colombia/epidemiología , Masculino , Femenino , Adulto , Persona de Mediana Edad , Adolescente , Adulto Joven , Niño , Anciano , Pruebas de Aglutinación , Preescolar , Incidencia , Leptospira/aislamiento & purificación , Factores de Riesgo , Prevalencia , Lactante

RESUMEN

OBJECTIVES: To identify distinct phenotypes of critically ill leptospirosis patients upon ICU admission and their potential associations with outcome. DESIGN: Retrospective observational study including all patients with biologically confirmed leptospirosis admitted to the ICU between January 2014 and December 2022. Subgroups of patients with similar clinical profiles were identified by unsupervised clustering (factor analysis for mixed data and hierarchical clustering on principal components). SETTING: All patients admitted to the ICU of the University Hospital of Guadeloupe on the study period. PATIENTS: One hundred thirty critically ill patients with confirmed leptospirosis were included. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: At ICU admission, 34% of the patients had acute respiratory failure, and 26% required invasive mechanical ventilation. Shock was observed in 52% of patients, myocarditis in 41%, and neurological involvement in 20%. Unsupervised clustering identified three clusters-"Weil's Disease" (48%), "neurological leptospirosis" (20%), and "multiple organ failure" (32%)-with different ICU courses and outcomes. Myocarditis and neurological involvement were key components for cluster identification and were significantly associated with death in ICU. Other factors associated with mortality included shock, acute respiratory failure, and requiring renal replacement therapy. CONCLUSIONS AND RELEVANCE: Unsupervised analysis of critically ill patients with leptospirosis revealed three patient clusters with distinct phenotypic characteristics and clinical outcomes. These patients should be carefully screened for neurological involvement and myocarditis at ICU admission.

Asunto(s)

Enfermedad Crítica , Unidades de Cuidados Intensivos , Leptospirosis , Humanos , Masculino , Leptospirosis/mortalidad , Leptospirosis/epidemiología , Femenino , Enfermedad Crítica/mortalidad , Estudios Retrospectivos , Persona de Mediana Edad , Adulto , Insuficiencia Multiorgánica/mortalidad , Guadalupe/epidemiología , Anciano , Análisis por Conglomerados

RESUMEN

Leptospirosis, a neglected zoonotic disease, is caused by pathogenic spirochetes belonging to the genus Leptospira and has one of the highest morbidity and mortality rates worldwide. Vaccination stands out as one of the most effective preventive measures for susceptible populations. Within the outer membrane of Leptospira spp., we find the LIC12287, LIC11711, and LIC13259 lipoproteins. These are of interest due to their surface location and potential immunogenicity. Thorough examination revealed the conservation of these proteins among pathogenic Leptospira spp.; we mapped the distribution of T- and B-cell epitopes along their sequences and assessed the 3D structures of each protein. This information aided in selecting immunodominant regions for the development of a chimeric protein. Through gene synthesis, we successfully constructed a chimeric protein, which was subsequently expressed, purified, and characterized. Hamsters were immunized with the chimeric lipoprotein, formulated with adjuvants aluminum hydroxide, EMULSIGEN®-D, Sigma Adjuvant System®, and Montanide™ ISA206VG. Another group was vaccinated with an inactivated Escherichia coli bacterin expressing the chimeric protein. Following vaccination, hamsters were challenged with a virulent L. interrogans strain. Our evaluation of the humoral immune response revealed the production of IgG antibodies, detectable 28 days after the second dose, in contrast to pre-immune samples and control groups. This demonstrates the potential of the chimeric protein to elicit a robust humoral immune response; however, no protection against challenge was achieved. While this study provides valuable insights into the subject, further research is warranted to identify protective antigens that could be utilized in the development of a leptospirosis vaccine. KEY POINTS: • Several T- and B-cell epitopes were identified in all the three proteins. • Four different adjuvants were used in vaccine formulations. • Immunization stimulated significant levels of IgG2/3 in vaccinated animals.

Asunto(s)

Anticuerpos Antibacterianos , Vacunas Bacterianas , Leptospirosis , Lipoproteínas , Animales , Leptospirosis/prevención & control , Leptospirosis/inmunología , Lipoproteínas/inmunología , Lipoproteínas/genética , Vacunas Bacterianas/inmunología , Vacunas Bacterianas/genética , Anticuerpos Antibacterianos/sangre , Anticuerpos Antibacterianos/inmunología , Cricetinae , Epítopos de Linfocito B/inmunología , Epítopos de Linfocito B/genética , Proteínas Recombinantes de Fusión/inmunología , Proteínas Recombinantes de Fusión/genética , Adyuvantes Inmunológicos/administración & dosificación , Inmunoglobulina G/sangre , Epítopos de Linfocito T/inmunología , Epítopos de Linfocito T/genética , Leptospira interrogans/inmunología , Leptospira interrogans/genética , Proteínas de la Membrana Bacteriana Externa/inmunología , Proteínas de la Membrana Bacteriana Externa/genética , Vacunación , Inmunidad Humoral , Leptospira/inmunología , Leptospira/genética , Inmunogenicidad Vacunal

RESUMEN

Leptospirosis is a common but underdiagnosed zoonosis. We conducted a 1-year prospective study in La Guaira State, Venezuela, analyzing 71 hospitalized patients who had possible leptospirosis and sampling local rodents and dairy cows. Leptospira rrs gene PCR test results were positive in blood or urine samples from 37/71 patients. Leptospira spp. were isolated from cultured blood or urine samples of 36/71 patients; 29 had L. interrogans, 3 L. noguchii, and 4 L. venezuelensis. Conjunctival suffusion was the most distinguishing clinical sign, many patients had liver involvement, and 8/30 patients with L. interrogans infections died. The Leptospira spp. found in humans were also isolated from local rodents; L. interrogans and L. venezuelensis were isolated from cows on a nearby, rodent-infested farm. Phylogenetic clustering of L. venezuelensis isolates suggested a recently expanded outbreak strain spread by rodents. Increased awareness of leptospirosis prevalence and rapid diagnostic tests are needed to improve patient outcomes.

Asunto(s)

Brotes de Enfermedades , Leptospira , Leptospirosis , Filogenia , Roedores , Animales , Leptospirosis/epidemiología , Leptospirosis/veterinaria , Leptospirosis/microbiología , Leptospirosis/diagnóstico , Humanos , Venezuela/epidemiología , Bovinos , Leptospira/genética , Leptospira/aislamiento & purificación , Leptospira/clasificación , Femenino , Roedores/microbiología , Adulto , Masculino , Persona de Mediana Edad , Enfermedades de los Bovinos/microbiología , Enfermedades de los Bovinos/epidemiología , Adolescente , Leptospira interrogans/genética , Leptospira interrogans/aislamiento & purificación , Leptospira interrogans/clasificación , Adulto Joven , Estudios Prospectivos , Niño , Anciano , Enfermedades Endémicas , Zoonosis/epidemiología , Zoonosis/microbiología , Preescolar

RESUMEN

AIMS: Currently, immunoinformatic approaches have shown promise in rapidly and cost-effectively identifying new antigens from the Leptospira proteome. Chimeric multiepitope proteins offer a strategy with significant potential for implementation in diagnosis and vaccines development. METHODS AND RESULTS: In this study, we detail the immunoinformatic analyses and design of a new recombinant chimeric protein constructed with epitopes identified from the sequences of ErpY-like and LemA proteins, previously identified as potential antigens for controlling leptospirosis. We expressed the chimeric protein using Escherichia coli heterologous systems, evaluated its antigenicity using serum from naturally infected patients, and its immunogenicity in mice as an animal model, with Freund as an adjuvant. The resulting recombinant chimeric protein, named rErpY-LemA, was successfully expressed and purified using a prokaryotic system, with an expected mass of 35 kDa. Serologic assays using serum samples from naturally infected patients demonstrated recognition of the chimera protein by antibodies present in sera. Animals immunized with the chimera exhibited a significant IgG antibody response from the 7th day (P < 0.001), persisting until day 49 of experimentation, with a titer of 1:12,800 (P < 0.05). Notably, significant production of IgA, IgM, and IgG subclasses was observed in animals immunized with the chimera. CONCLUSIONS: These results highlight the promising role of immunoinformatics in rapidly identifying antigens and the potential of chimeric multiepitope proteins in developing effective strategies for leptospirosis control.

Asunto(s)

Antígenos Bacterianos , Leptospirosis , Proteínas Recombinantes de Fusión , Leptospirosis/inmunología , Leptospirosis/prevención & control , Animales , Ratones , Antígenos Bacterianos/inmunología , Antígenos Bacterianos/genética , Proteínas Recombinantes de Fusión/inmunología , Proteínas Recombinantes de Fusión/genética , Humanos , Anticuerpos Antibacterianos/sangre , Leptospira/inmunología , Leptospira/genética , Biología Computacional , Epítopos/inmunología , Epítopos/genética , Vacunas Bacterianas/inmunología , Vacunas Bacterianas/genética , Escherichia coli/genética , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/genética , Proteínas Bacterianas/inmunología , Proteínas Bacterianas/genética

RESUMEN

Background and Objectives: Ventilator-associated pneumonia may occur within 48 to 72 hours after endotracheal intubation and mechanical ventilation, being the most frequent infection in intensive care units, linked to increased mortality. This research aims to identify the epidemiological profile of patients with ventilator-associated pneumonia in the intensive care unit of a teaching hospital. Methods: This is a cross-sectional, retrospective, documentary study with a quantitative approach. The data collection was carried out using a semi-structured instrument with data made available by the Hospital Infection Control Commission and in the electronic medical records of patients diagnosed with ventilator-associated pneumonia, from July to December 2022. Data were organized using the Excel software and subsequently analyzed with the program Statistical Package for Social Science for Windows, using descriptive statistics. Results: Most individuals were male (59.6%), aged 60 years or older (53.9%), retired (48.3%), nondrinkers (61.8%), nonsmokers (66.3%), with pre-existing comorbidities (62.9%), hospitalized due to trauma (23.6%), enteral nutrition (97.8%), Klebsiella pneumoniae pathogenic agent (15.7%), using endotracheal tube (91.7%), not requiring reintubation (67.4%), not presenting multidrug resistance (59.6%), and the clinical outcome was death (65.2%). Conclusion: There is still a need for specific interventions and measures for critically ill patients. It is expected that the variables found may contribute to promoting patient safety on mechanical ventilation and help to develop prevention strategies in order to reduce the incidence of ventilator-associated pneumonia.(AU)

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Justificativa e Objetivos: A pneumonia associada à ventilação mecânica (PAV) ocorre a partir de 48 a 72 horas após a intubação endotraqueal e ventilação mecânica, sendo a infecção mais frequente nas unidades de terapia intensiva, vinculada ao aumento da mortalidade. Esta pesquisa tem como objetivo identificar o perfil epidemiológico de pacientes com PAV em Unidades de Terapia Intensiva de um hospital escola. Métodos: Trata-se de um estudo transversal, retrospectivo, documental, com abordagem quantitativa. A coleta foi realizada através de instrumento semiestruturado, com dados disponibilizados pela Comissão de Controle de Infecção Hospitalar e nos prontuários eletrônicos dos pacientes com diagnóstico de PAV, entre julho a dezembro de 2022. Os mesmos foram organizados no software Excel e, posteriormente, analisados através do programa SPSS®, versão 22, mediante estatísticas descritivas. Resultados: A maioria era do sexo masculino (59,6%), faixa de etária de 60 anos ou mais (53,9%), aposentados (48,3%), não etilistas (61,8%), não tabagista (66,3%), com comorbidades preexistentes (62,9%), diagnóstico de internação por trauma (23,6%), nutrição enteral (97,8%), agente patogênico Klebsiella pneumoniae (15,7%), em uso de tubo endotraqueal (91,7%), não precisaram de reintubação (67,4%), não tiveram multirresistência (59,6%), e apresentaram como desfecho clínico óbito (65,2%). Conclusão: O perfil epidemiológico se caracteriza pelo sexo masculino, com idade igual ou superior a 60 anos, com comorbidades, vítima de trauma e com desfecho clínico desfavorável ao óbito. Espera-se que as variáveis encontradas possam contribuir para promover a segurança do paciente em ventilação mecânica e ajudar a desenvolver estratégias de prevenção, a fim de reduzir a incidência de PAV.(AU)

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Justificación y Objetivos: La neumonía asociada a ventilación mecánica (NAVM) ocurre entre 48 y 72 horas después de la intubación endotraqueal y ventilación mecánica, por lo que es la infección más frecuente en las unidades de cuidados intensivos asociada al aumento de la mortalidad. Este estudio tiene como objetivo identificar el perfil epidemiológico de los pacientes con neumonía asociada a ventilación mecánica en la unidad de cuidados intensivos de un hospital universitario. Métodos: Se trata de un estudio transversal, retrospectivo, documental, con enfoque cuantitativo. La recogida de datos se realizó mediante un instrumento semiestructurado con datos facilitados por la Comisión de Control de Infecciones Hospitalarias y en los registros electrónicos de pacientes con diagnóstico de NAVM, en el período de julio a diciembre de 2022. Los datos se pusieron en software Excel para, posteriormente, pasar por un análisis mediante el programa Statistical Package for Social Science para Windows, versión 22, utilizando estadística descriptiva. Resultados: La mayoría de los participantes fueron hombres (59,6%), mayores de 60 años (53,9%), jubilados (48,3%), no bebedores (61,8%), no fumadores (66,3%), con comorbilidades preexistentes (62,9%), diagnóstico de hospitalización por traumatismos (23,6%), nutrición enteral (97,8%), agente patógeno Klebsiella pneumoniae (15,7%), en uso de tubo endotraqueal (91,7%), no requirieron nueva intubación (67,4%), no presentaron multirresistencia (59,6%) y tuvieron como desenlace clínico muerte (65,2%). Conclusión: El perfil epidemiológico se caracterizó por sexo masculino, de 60 años o más, con comorbilidades, víctima de traumatismos y desenlace clínico desfavorable de muerte. Se espera que las variables encontradas puedan contribuir a promover la seguridad del paciente en la ventilación mecánica y ayudar a desarrollar estrategias de prevención para reducir la incidencia de NAVM.(AU)

Asunto(s)

Humanos , Perfil de Salud , Salud Pública , Leptospirosis/epidemiología

RESUMEN

A group of children with clinical suspicion of dengue were assessed to determine if there was an overestimation of dengue compared with that of leptospirosis and leishmaniasis. This descriptive and analytical cross-sectional study, based on the active search of participants with acute febrile illness, was conducted at two pediatric hospitals. The collection of clinical and epidemiological data was performed using questionnaires, and laboratory tests specific for dengue were performed using immunochromatographic, serological, and molecular methods. Dengue-negative samples were assessed for Leptospira and Leishmania spp. using molecular tests. Data were assessed using analysis of variance (ANOVA), the chi-square test, and Fisher's exact test. In total, 86 participants were evaluated, of whom 39 (45%) were positive for dengue fever, 4 (5%) for leptospirosis, and 1 (1%) for leishmaniasis. Forty-two participants (49%) presented dengue-like symptoms. The predominant age range for the virus was 3-10 years. Most clinical manifestations were nonspecific, with frequent concomitant gastrointestinal and respiratory symptoms. Furthermore, we found that the acute febrile syndrome in childhood persists as a challenge for health professionals, especially in the early days of the disease, due to a plurality of diagnostic hypotheses, associated with the difficulty of establishing well-defined symptoms in children, especially in infants. Dengue fever continues to be a frequent pathology with acute febrile infections in childhood; however, there is an overestimation of the disease, especially in endemic regions, when one considers only the clinical epidemiological diagnosis.

Asunto(s)

Dengue , Fiebre , Humanos , Dengue/epidemiología , Dengue/complicaciones , Dengue/diagnóstico , Masculino , Femenino , Estudios Transversales , Preescolar , Niño , Lactante , Leptospirosis/epidemiología , Leptospirosis/diagnóstico , Leptospirosis/complicaciones , Adolescente

RESUMEN

Leptospirosis is a global disease that impacts people worldwide, particularly in humid and tropical regions, and is associated with significant socio-economic deficiencies. Its symptoms are often confused with other syndromes, which can compromise clinical diagnosis and the failure to carry out specific laboratory tests. In this respect, this paper presents a study of three algorithms (Decision Tree, Random Forest and Adaboost) for predicting the outcome (cure or death) of individuals with leptospirosis. Using the records contained in the government National System of Aggressions and Notification (SINAN, in portuguese) from 2007 to 2017, for the state of Pará, Brazil, where the temporal attributes of health care, symptoms (headache, vomiting, jaundice, calf pain) and clinical evolution (renal failure and respiratory changes) were used. In the performance evaluation of the selected models, it was observed that the Random Forest exhibited an accuracy of 90.81% for the training dataset, considering the attributes of experiment 8, and the Decision Tree presented an accuracy of 74.29 for the validation database. So, this result considers the best attributes pointed out by experiment 10: time first symptoms medical attention, time first symptoms ELISA sample collection, medical attention hospital admission time, headache, calf pain, vomiting, jaundice, renal insufficiency, and respiratory alterations. The contribution of this article is the confirmation that artificial intelligence, using the Decision Tree model algorithm, depicting the best choice as the final model to be used in future data for the prediction of human leptospirosis cases, helping in the diagnosis and course of the disease, aiming to avoid the evolution to death.

Asunto(s)

Leptospirosis , Aprendizaje Automático , Leptospirosis/diagnóstico , Humanos , Algoritmos , Árboles de Decisión , Brasil/epidemiología , Evaluación de Resultado en la Atención de Salud/métodos , Masculino , Femenino , Adulto

RESUMEN

OBJETIVE: this study was to determine the relationship between acute febrile illness and bacterial pathogens with zoonotic potential that cause emerging and re-emerging diseases in a central-eastern region of Peru. RESULTS: Out of the 279 samples analyzed, 23 (8.2%) tested positive for infection by Rickettsia spp., while a total of 15 (5.4%) tested positive for Leptospira spp. Women had a higher frequency of infection by Rickettsia spp., with 13 cases (53.3%), while men had a higher frequency of infection by Leptospira spp., with 10 cases (66.7%). The most frequently reported general symptom was headache, with 100.0% (n = 23) of patients with Rickettsia (+) and 86.7% (n = 13) of patients with Leptospira (+) experiencing it. Arthralgia was the second most frequent symptom, reported by 95.6% (n = 22) and 60% (n = 9) of patients with Rickettsia (+) and Leptospira (+), respectively. Myalgia was reported by 91.3% (n = 21) and 66.7% (n = 10) of patients with Rickettsia (+) and Leptospira (+), respectively. Retroocular pain, low back pain, and skin rash were also present, but less frequently. Among the positives, no manifestation of bleeding was recorded, although only one positive case for Leptospira spp. presented a decrease in the number of platelets.

Asunto(s)

Leptospira , Leptospirosis , Infecciones por Rickettsia , Rickettsia , Humanos , Perú/epidemiología , Rickettsia/aislamiento & purificación , Femenino , Masculino , Leptospira/aislamiento & purificación , Leptospira/patogenicidad , Leptospirosis/epidemiología , Leptospirosis/microbiología , Leptospirosis/complicaciones , Leptospirosis/diagnóstico , Infecciones por Rickettsia/epidemiología , Infecciones por Rickettsia/microbiología , Infecciones por Rickettsia/diagnóstico , Adulto , Animales , Fiebre/microbiología , Zoonosis/microbiología , Zoonosis/diagnóstico , Zoonosis/epidemiología , Mialgia/microbiología , Mialgia/epidemiología , Persona de Mediana Edad , Adulto Joven , Adolescente , Cefalea/microbiología , Cefalea/etiología , Cefalea/epidemiología , Artralgia/microbiología , Artralgia/etiología

RESUMEN

This study examines household pets as potential epidemiological links between environments contaminated with pathogenic leptospires and humans in Santa Fe, Argentina. The aims of our study were: (a) to characterize the habits and exposure to environmental sources of leptospirosis in the population of dogs and cats attending to municipal spay and neutering campaigns in Santa Fe, Argentina, (b) to assess the seroprevalence of anti-Leptospira antibodies in asymptomatic dogs and cats, (c) to evaluate factors that could increase seropositivity, and (d) to identify spatial clusters of seropositive dogs and cats in the capital city of Santa Fe. From May to November 2022, a cross-sectional serosurvey was conducted during municipal spaying/neutering campaigns. Eligible household dogs and cats were over 6 months old, apparently healthy, and not vaccinated against leptospirosis in the past 6 months. We used microagglutination test (MAT) to assess anti-Leptospira antibodies using a panel of 10 reference strains. We used generalized linear mixed effects models (GLMM) to examine individual and census tract-level risk factors for seropositivity, and local Moran's I statistic for spatial clusters. Results showed higher leptospiral antibody prevalence in dogs (18.2 %) than cats (3.6 %, p = 0.002). Dogs with street access had higher likelihood of being seropositive (OR: 3.8, 95 % CI: 1.2; 11.9), and areas with chronic poverty showed an elevated risk of presenting seropositive animals (RR: 4.0, 95 % CI: 1.1; 14.4). Spatial analysis didn't reveal significant seropositivity clusters among census tracts. These findings shed light on widespread Leptospira seropositivity in pets in this endemic region. Understanding seroprevalence and risk factors can guide public and veterinary health strategies, emphasizing increased leptospirosis vaccination for dogs in vulnerable areas and promoting responsible pet care.

Asunto(s)

Anticuerpos Antibacterianos , Enfermedades de los Gatos , Enfermedades de los Perros , Leptospira , Leptospirosis , Animales , Perros , Gatos , Leptospirosis/veterinaria , Leptospirosis/epidemiología , Leptospirosis/microbiología , Enfermedades de los Perros/epidemiología , Enfermedades de los Perros/microbiología , Enfermedades de los Perros/inmunología , Estudios Seroepidemiológicos , Argentina/epidemiología , Enfermedades de los Gatos/epidemiología , Enfermedades de los Gatos/microbiología , Leptospira/inmunología , Anticuerpos Antibacterianos/sangre , Estudios Transversales , Masculino , Femenino , Factores de Riesgo , Prevalencia , Enfermedades Endémicas/veterinaria , Ciudades/epidemiología

RESUMEN

Leptospirosis is a globally distributed infectious disease caused by pathogenic spirochetes of the Leptospira genus, often overlooked. It is estimated that the disease affects approximately one million people annually, resulting in more than 58,900 deaths. The gold standard for serodiagnosis of leptospirosis is the Microscopic Agglutination Test (MAT). However, the limitations of this technique necessitate the exploration of alternative diagnostic methods. In this study, we evaluated the ErpY-like recombinant protein (rErpY-like) in the development of a serologic diagnostic assay for human leptospirosis. Eighty-six human sera samples, characterized by MAT, underwent evaluation through indirect IgM-ELISA and IgG-ELISA. The sensitivity and specificity values obtained from IgM-ELISA were 60% and 76%, respectively, while those from IgG-ELISA were 96.4% and 100%, respectively. The use of the rErpY-like protein in both IgM-ELISA and IgG-ELISA proves to be a sensitive and specific method for antibody detection. This could potentially serve as a valuable alternative tool in the diagnosis of human leptospirosis.

Asunto(s)

Anticuerpos Antibacterianos , Ensayo de Inmunoadsorción Enzimática , Inmunoglobulina G , Inmunoglobulina M , Leptospira , Leptospirosis , Sensibilidad y Especificidad , Pruebas Serológicas , Leptospirosis/diagnóstico , Leptospirosis/inmunología , Leptospirosis/microbiología , Leptospirosis/sangre , Humanos , Anticuerpos Antibacterianos/sangre , Inmunoglobulina M/sangre , Ensayo de Inmunoadsorción Enzimática/métodos , Inmunoglobulina G/sangre , Leptospira/inmunología , Pruebas Serológicas/métodos , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/genética , Proteínas Bacterianas/inmunología , Proteínas Bacterianas/genética , Antígenos Bacterianos/inmunología