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1.
Eur J Med Res ; 27(1): 268, 2022 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-36461021

RESUMO

BACKGROUND: Leptospirosis is an emerging neglected zoonotic disease that presents with nonspecific signs/symptoms and it can be mistaken for other diseases. Owing to limited diagnostic capacity and unawareness, the data on human leptospirosis particularly in neonates are scarce in many sub-Saharan countries. It has been underreported hindering preventive and control measures in place. The study aimed at determining prevalence of leptospirosis as a cause of febrile illness in neonates using IgM ELISA and a quantitative real-time PCR (qPCR). METHODS: This was a descriptive cross-sectional study that included 103 neonatal sepsis cases whose parents/legal guardians gave informed consent. The data on demographic and clinical characteristics were collected using structured data collection form. EDTA whole blood sample was collected from the neonates by trained study nurses. From the samples, IgM ELISA was done using automated analyzers, DNA extracted and qPCR was performed using primers for LipL32, specific for the pathogenic leptospires. RESULTS: The prevalence of anti-leptospiral IgM among the neonates as determined by ELISA was 4.3%, where all of them presented with lethargy and poor feeding. No pathogenic Leptospira species DNA was amplified by qPCR. CONCLUSIONS: Evidence of leptospirosis was demonstrated in neonatal sepsis cases in this study. The findings suggest considerations of leptospirosis in the differential diagnosis of neonates with sepsis. More data are needed on the real epidemiology, clinical features, and burden of leptospirosis in neonates. There is need to include intermediate pathogenic species of Leptospira in the diagnostic qPCR assays.


Assuntos
Leptospira , Leptospirose , Sepse Neonatal , Sepse , Recém-Nascido , Humanos , Leptospira/genética , Sepse Neonatal/diagnóstico , Sepse Neonatal/epidemiologia , Prevalência , Estudos Transversais , Uganda/epidemiologia , Leptospirose/diagnóstico , Leptospirose/epidemiologia , Anticorpos Antibacterianos , Imunoglobulina M , DNA , Sepse/diagnóstico , Sepse/epidemiologia
2.
Geospat Health ; 17(2)2022 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-36468592

RESUMO

Leptospirosis is a serious public health problem in Brazil, which can be observed after flooding events. Using an exploratory mixed clustering method, this ecological study analyzes whether spatial-temporal clustering patterns of leptospirosis occur in Brazil. Data from the Brazilian Unified Health System (SUS) were used to calculate the prevalence of leptospirosis between 2007 and 2017 in all counties of the country. Clustering techniques, including spatial association indicators, were used for analysis and evaluation of disease yearly spatial distribution. Based on Local Indicators of Spatial Association (LISA) with Empirical Bayesian rates detected spatial patterns of leptospirosis ranging from 0.137 (p = 0.001 in 2009) to 0.293 (p = 0.001 in 2008). Over the whole period, the rate was 0.388 (p = 0.001). The main pattern showed permanence of leptospirosis clusters in the South and emergence and permanence of such clusters in northern Brazil. The municipalities with leptospirosis cases and at least one flood occurrence registered in the Brazilian Integrated Disaster Information System were incorporated into the LISA cluster map with Empirical Bayesian rates. These counties were expected to exhibit clustering, not all did. The results of the cluster analysis suggest allocation of health resources in areas with leptospirosis clustering.


Assuntos
Inundações , Leptospirose , Humanos , Brasil/epidemiologia , Teorema de Bayes , Leptospirose/epidemiologia , Análise Espaço-Temporal
3.
PLoS Negl Trop Dis ; 16(11): e0010880, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36378681

RESUMO

BACKGROUND: The first documented human leptospirosis cases in the U.S. Virgin Islands (USVI) occurred following 2017 Hurricanes Irma and Maria. We conducted a representative serosurvey in USVI to estimate the seroprevalence and distribution of human leptospirosis and evaluate local risk factors associated with seropositivity. METHODOLOGY/PRINCIPAL FINDINGS: A stratified, two-stage cluster sampling design was used and consisted of three island strata and random selection of census blocks and then households. All eligible members of selected households were invited to participate (≥5 years old, resided in USVI ≥6 months and ≥6 months/year). Household and individual-level questionnaires were completed, and serum collected from each enrolled individual. Microscopic agglutination test serology was conducted, and bivariate and logistic regression analyses completed to identify risk factors for seropositivity. In March 2019, 1,161 individuals were enrolled from 918 households in St. Croix, St. Thomas, and St. John. The territory-wide weighted seroprevalence was 4.0% (95% CI:2.3-5.7). Characteristics/exposures independently associated with seropositivity using logistic regression included contact with cows (OR: 39.5; 95% CI: 9.0-172.7), seeing rodents/rodent evidence or contact with rodents (OR: 2.6; 95% CI: 1.1-5.9), and increasing age (OR: 1.02; 95% CI: 1.002-1.04); full or partial Caucasian/White race was negatively correlated with seropositivity (OR: 0.02, 95% CI: 0.04-0.7). Bivariate analysis showed self-reported jaundice since the 2017 hurricanes (pRR: 5.7; 95% CI: 1.0-33.4) was associated with seropositivity and using a cover/lid on cisterns/rainwater collection containers (pRR: 0.3; 95% CI: 0.08-0.8) was protective against seropositivity. CONCLUSIONS/SIGNIFICANCE: Leptospirosis seropositivity of 4% across USVI demonstrates an important human disease that was previously unrecognized and emphasizes the importance of continued leptospirosis surveillance and investigation. Local risk factors identified may help guide future human and animal leptospirosis studies in USVI, strengthen leptospirosis public health surveillance and treatment timeliness, and inform targeted education, prevention, and control efforts.


Assuntos
Leptospirose , Feminino , Humanos , Bovinos , Animais , Pré-Escolar , Estudos Soroepidemiológicos , Ilhas Virgens Americanas/epidemiologia , Leptospirose/epidemiologia , Testes de Aglutinação , Fatores de Risco
4.
J Water Health ; 20(2): 356-368, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36366992

RESUMO

Freshwater sports expose practitioners to pathogens in the water environment and may result in infection. In French Brittany, these infections are particularly worrying, especially since 2016 with an increase in the incidence of leptospirosis reaching 1 case per 100,000 inhabitants, which represents the highest incidence observed since 1920. We aimed to estimate the prevalence of infectious diseases related to freshwater sports practice and to identify the factors associated with these infections among freshwater sports licensees in Brittany, France. From March 18, 2019, to May 8, 2019, we interviewed freshwater sports licensees (online study) and club presidents and instructors (phone study) in Brittany. Licensee participants were 18 years old or more and practiced at least one freshwater sport in one of the 79 Brittany clubs. We used logistic regression models to study the association between our variables of interest and potential risk factors. In total, 551 licensees (20.3% of the total number of licensees) and 38 clubs (48.1%) were surveyed. Among the licensees, 29 (5.3%) reported being diagnosed with leptospirosis, of which 12 (41.3%) occurred in the last 5 years. The most reported symptoms were skin irritation/itchy skin (24.3%) and 39 individuals (7.1%) reported at least one hospitalization in their lifetime for a disease related to freshwater sports. The occurrence of leptospirosis was negatively associated with boarding from a pontoon (odds ratio (OR)=0.20, 95% confidence interval (95% CI) 0.06-0.56), practicing for less than 4 years (OR=0.17, 95% CI 0.04-0.56) compared to more than 10 years, and the occurrence of leptospirosis was positively associated with taking a soapy shower after practice (OR=4.38, 95% CI 1.90-10.51). Eskimo roll was positively associated with the occurrence of otitis and conjunctivitis (OR=3.22, 95% CI 1.82-6.03), and skin irritation/itchy skin (OR=1.66, 95% CI 0.99-2.84). Otitis, conjunctivitis, and skin irritation/itchy skin are the most commonly reported freshwater sport-related diseases in French Brittany. Despite a good level of knowledge of prevention measures, their implementation by licensees and clubs remains low. Further studies are needed to identify practices associated with infectious risk in freshwater sports.


Assuntos
Conjuntivite , Leptospirose , Esportes , Humanos , Adolescente , Estudos Transversais , Leptospirose/epidemiologia , Água Doce , França/epidemiologia
5.
Artigo em Inglês | MEDLINE | ID: mdl-36384433

RESUMO

Background: Leptospirosis infection can lead to serious renal and cardiopulmonary complications and can be fatal. Following heavy rainfall and localised flooding in early 2021, Tropical Public Health Services in Cairns were alerted to an increase in leptospirosis cases in the region, with notifications almost three times higher than usual by mid-February. An epidemiological investigation was undertaken. Methods: Leptospirosis notification data were obtained from the Queensland Notifiable Conditions System. Confirmed and probable cases residing in the Cairns region, with an onset date between 1 January and 31 May 2021, were included in the investigation. Case demographics, pathology results, symptoms, hospital stay information and presumed exposure sources were obtained from Queensland Health records; local rainfall data was obtained from the Australian Bureau of Meteorology. Case characteristics and rainfall were compared to the prior ten-year period and the distribution of cases by week of onset, address, exposure source and infecting serovar analysed. Results: A total of 43 leptospirosis cases were notified between January and May 2021, the highest number recorded for the region since 2011. Presumed exposure sources were available for 40 cases (93.0%), with 33 cases (82.5%) exposed occupationally, including 25 cases working on banana farms. Infecting Leptospira serovars were identified for five cases (11.6%), with four infected with serovar Australis and one with serovar Zanoni. Limited information about the specific exposure sites for each case and a low serovar detection rate hampered the ability to confirm the presence or absence of a leptospirosis outbreak. While heavy rainfall is likely to have contributed to the spike in cases, no factors were identified as clearly associated with the increase. Conclusions: A number of pathways are proposed to improve the collection of exposure site data and the identification of infecting serovars, in order to strengthen local leptospirosis surveillance and the ability to detect outbreaks in the Cairns region.


Assuntos
Leptospira , Leptospirose , Humanos , Austrália/epidemiologia , Leptospirose/diagnóstico , Leptospirose/epidemiologia , Estações do Ano , Sorogrupo
6.
PLoS One ; 17(10): e0275447, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36227833

RESUMO

Leptospirosis is considered a neglected tropical disease despite its considerable mortality and morbidity. Lack of prediction remains a major reason for underestimating the disease. Although many models have been developed, most of them focused on the districts situated in the wet zone due to higher case numbers in that region. However, leptospirosis remains a major disease even in the dry zone of Sri Lanka. The objective of this study is to develop a time series model to predict leptospirosis in the Anuradhapura district situated in the dry zone of Sri Lanka. Time series data on monthly leptospirosis incidences from January 2008 to December 2018 and monthly rainfall, rainy days, temperature, and relative humidity were considered in model fitting. The first 72 months (55%) were used to fit the model, and the subsequent 60 months(45%) were used to validate the model. The log-transformed dependent variable was employed for fitting the Univariate seasonal ARIMA model. Based on the stationarity of the mean of the five variables, the ARDL model was selected as the multivariate time series technique. Residuals analysis was performed on normality, heteroskedasticity, and serial correlation to validate the model. The lowest AIC and MAPE were used to select the best model. Univariate models could not be fitted without adjusting the outliers. Adjusting seasonal outliers yielded better results than the models without adjustments. Best fitted Univariate model was ARIMA(1,0,0)(0,1,1)12,(AIC-1.08, MAPE-19.8). Best fitted ARDL model was ARDL(1, 3, 2, 1, 0),(AIC-2.04,MAPE-30.4). The number of patients reported in the previous month, rainfall, rainy days, and temperature showed a positive association, while relative humidity was negatively associated with leptospirosis. Multivariate models fitted better than univariate models for the original data. Best-fitted models indicate the necessity of including other explanatory variables such as patient, host, and epidemiological factors to yield better results.


Assuntos
Leptospirose , Humanos , Incidência , Leptospirose/epidemiologia , Chuva , Sri Lanka/epidemiologia , Temperatura
7.
Curr Opin Ophthalmol ; 33(6): 532-542, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36206109

RESUMO

PURPOSE OF REVIEW: Systemic leptospirosis exists worldwide. But leptospiral uveitis, an important late complication is not identified by ophthalmologists in several countries. RECENT FINDINGS: In the last 18 months numerous publications, especially on epidemiology, surveillances, and novel rapid diagnostic kits to test at the point of care site on leptospirosis have been published from all over the world. However, publications from ophthalmologists are very scarce. Remarkably ophthalmologists should know the global burden of leptospirosis, prevalence of the disease in their country, demographic factors associated, risk factors, and systemic signs to elicit relevant history and travel history. They should be aware of recent advances in investigations to confirm their clinical diagnosis. SUMMARY: It is quite evident from this work that leptospirosis is prevalent worldwide. Ophthalmologists' awareness has to improve to identify the etiological diagnosis. They should have access to simple, less expensive, and less cumbersome laboratory tests.


Assuntos
Infecções Oculares Bacterianas , Leptospirose , Oftalmologistas , Uveíte , Infecções Oculares Bacterianas/diagnóstico , Humanos , Leptospirose/complicações , Leptospirose/diagnóstico , Leptospirose/epidemiologia , Prevalência , Uveíte/diagnóstico
8.
PLoS Negl Trop Dis ; 16(10): e0010589, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36288395

RESUMO

BACKGROUND: Leptospirosis, a life-threatening disease in humans and animals, is one of the most widespread global zoonosis. Contaminated soil and water are the major transmission sources in humans and animals. Clusters of disease outbreaks are common during rainy seasons. METHODOLOGY/PRINCIPAL FINDINGS: In this study, to detect the presence of Leptospira, we applied PCR, direct metagenomic sequencing, and enrichment culture followed by PCR and metagenomic sequencing on water and soil samples. Direct sequencing and enrichment cultures followed by PCR or sequencing effectively detected pathogenic and nonpathogenic Leptospira compared to direct PCR and 16S amplification-based metagenomic sequencing in soil or water samples. Among multiple culture media evaluated, Ellinghausen-McCullough-Johnson-Harris (EMJH) media containing antimicrobial agents was superior in recovering and detecting Leptospira from the environmental samples. Our results show that enrichment culture followed by PCR can be used to confirm the presence of pathogenic Leptospira in environmental samples. Additionally, metagenomic sequencing on enrichment cultures effectively detects the abundance and diversity of Leptospira spp. from environmental samples. CONCLUSIONS/SIGNIFICANCE: The selection of methodology is critical when testing environmental samples for the presence of Leptospira. Selective enrichment culture improves Leptospira detection efficacy by PCR or metagenomic sequencing and can be used successfully to understand the presence and diversity of pathogenic Leptospira during environmental surveillance.


Assuntos
Leptospira , Leptospirose , Animais , Humanos , Leptospira/genética , Água , Leptospirose/diagnóstico , Leptospirose/epidemiologia , Zoonoses , Solo
9.
BMC Vet Res ; 18(1): 376, 2022 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-36273163

RESUMO

BACKGROUND: Leptospirosis is an emerging zoonotic infection worldwide and a cause of life-threatening disease in dogs. Seroprevalence in Swedish dogs is unknown. The aims of the present study were to estimate seroprevalence of pathogenic Leptospira in healthy dogs in Sweden using the microagglutination test (MAT) and a rapid point-of-care enzyme-linked immunosorbent assay (ELISA), and to evaluate risk factors of Leptospira exposure in Swedish dogs. RESULTS: Positive MAT titres (≥ 1:50) were detected in 27/369 (7.3%) of included dogs. Five different serovars were represented of which the Saxkoebing serovar was the most common (64.3%), followed by Copenhagi (14.3%), Bratislava (10.7%), Icterohaemorrhagiae (7.1%), and Canicola (3.6%). The ELISA test (SNAP® Lepto) was positive in 3/316 (0.9%) dogs. Living in urban areas and contact with stagnant water were found to be risk factors for Leptospira seropositivity (p < 0.05) in a multivariable logistic regression model. CONCLUSION: In this first seroprevalence study of Leptospira in Swedish dogs, it was shown that healthy dogs without recent (24 months) travel history and antileptospira vaccination had been exposed to pathogenic Leptospira interrogans serovars. Contact with stagnant water and living in urban areas were independent risk factors for seropositivity.


Assuntos
Doenças do Cão , Leptospira , Leptospirose , Cães , Animais , Estudos Soroepidemiológicos , Suécia/epidemiologia , Proteína Catiônica de Eosinófilo , Anticorpos Antibacterianos , Doenças do Cão/epidemiologia , Leptospirose/epidemiologia , Leptospirose/veterinária , Fatores de Risco , Água
10.
Braz J Microbiol ; 53(4): 2233-2240, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36205841

RESUMO

Leptospirosis is an infectious disease caused by Leptospira spp. and affects animals and humans. Reports of leptospirosis in bats have increased and prompted epidemiological research in Brazil. This study aimed to perform a molecular and epidemiological investigation of pathogenic Leptospira spp. in bat kidneys. The total DNA was extracted from 102 kidney samples from chiropterous of different species and cities in Rio Grande do Sul State (RS), Brazil. The polymerase chain reaction was used to amplify a fragment corresponding to lipL32 gene, which is only present in pathogenic Leptospira spp. lipL32 gene was detected in 22.5% (23/102) of the bat kidney tissues. Phylogenetic analysis showed that L. interrogans is circulating in bats in RS. Most species of the bats collected were insectivores. Pathogenic Leptospira spp. detection in bats demonstrated that these animals participate in the infection chain of leptospirosis and, therefore, may play as reservoirs and disseminators of this microorganism. Thus, it is important to monitor infectious agents, especially with zoonotic potential in bats.


Assuntos
Quirópteros , Leptospira interrogans , Leptospira , Leptospirose , Animais , Humanos , Quirópteros/microbiologia , Filogenia , Leptospira interrogans/genética , Brasil/epidemiologia , Leptospira/genética , Leptospirose/epidemiologia , Leptospirose/veterinária , Leptospirose/microbiologia
11.
Int J Biometeorol ; 66(12): 2529-2540, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36306013

RESUMO

Leptospirosis, the infectious disease caused by a spirochete bacteria, is a major public health problem worldwide. In Argentina, some regions have climatic and geographical characteristics that favor the habitat of bacteria of the Leptospira genus, whose survival strongly depends on climatic factors, enhanced by climate change, which increase the problems associated with people's health. In order to have a method to predict leptospirosis cases, in this paper, five time series forecasting methods are compared: two parametric (autoregressive integrated moving average and an alternative one that allows covariates, ARIMA and ARIMAX, respectively), two nonparametric (Nadaraya-Watson Kernel estimator, one and two kernels versions, NW-1 K and NW-2 K), and one semiparametric (semi-functional partial linear regression, SFPLR) method. For this, the number of cases of leptospirosis registered from 2009 to 2020 in three important cities of northeastern Argentina is used, as well as hydroclimatic covariates related to the presence of cases. According to the obtained results, there is no method that improves considerably the rest and can be recommended as a unique tool for leptospirosis prediction. However, in general, the NW-2 K method gets a better performance. This work, in addition to using a long-term high-quality time series, enriches the area of applications of statistical models to epidemiological leptospirosis data by the incorporation of hydroclimatic variables, and it is recommended directing further efforts in this line of research, under the context of current climate change.


Assuntos
Leptospirose , Humanos , Incidência , Estações do Ano , Leptospirose/epidemiologia , Leptospirose/microbiologia , Modelos Estatísticos , Surtos de Doenças
12.
An Acad Bras Cienc ; 94(3): e20201026, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36074401

RESUMO

Leptospirosis is an important public health problem caused by Leptospira. The objective is to characterize the geographic distribution of pathogenic leptospira serovars in the Americas through a systematic review of the literature between 1930-2017. Searches were conducted in six scientific databases (PubMed, Web of Science, Embase, Lilacs, Scopus and Cochrane). We included studies conducted unambiguously in the Americas, that investigated infection of Leptospira in humans and animals in their natural environments with serovar identification. 283 articles were included, of which 69 were studies in humans, 86 in wild animals, and 182 in domestic animals. Most of them conducted in Brazil (104, 36.7%) and in rural environments (158, 55.8%). Bovines, equines and dogs where the most frequently studied domestic species. However, a large diversity including 80 species of wild animals were studied. Icterohaemorrhgiae, Canicola, Pomona and Grippotyphosa were the most common serovars, described in 46 (16.2%), 38 (13.3%), 32 (11.3%) and 26 (9%) of the articles, respectively. The Results indicate a large concentration of studies in Latin America, with emphasis on Brazil, in wild mammals and three main domestic animal groups. Our results emphasize the need for studies that delve into the relationships of the epidemiological cycle, environment, and health.


Assuntos
Leptospira , Leptospirose , Animais , Animais Selvagens , Anticorpos Antibacterianos , Brasil/epidemiologia , Bovinos , Cães , Equidae , Humanos , Leptospirose/epidemiologia , Leptospirose/veterinária , Sorogrupo
13.
Am J Trop Med Hyg ; 107(5): 1114-1128, 2022 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-36162442

RESUMO

The objective of this study was to determine the etiology of febrile illnesses among patients from October 1, 1993 through September 30, 1999, in the urban community of Iquitos in the Amazon River Basin of Peru. Epidemiological and clinical data as well as blood samples were obtained from consenting patients at hospitals, health clinics and private residences. Samples were tested for arboviruses in cell cultures and for IgM and IgG antibodies by ELISA. Blood smears were examined for malaria, and sera were tested for antibodies to Leptospira spp. by ELISA and microscopic agglutination. Among 6,607 febrile patients studied, dengue viruses caused 14.6% of the cases, and Venezuelan equine encephalitis virus caused 2.5%, Oropouche virus 1.0%, Mayaro virus 0.4%, and other arboviruses caused 0.2% of the cases. Also, 22.9% of 4,844 patients tested were positive for malaria, and of 400 samples tested, 9% had evidence of acute leptospirosis. Although the study was not designed to assess the importance of these pathogens as a cause of human morbidity in the total population, these results indicate that arboviruses, leptospirosis, and malaria were the cause of approximately 50% of the febrile cases. Although the arboviruses that were diagnosed can produce asymptomatic infections, our findings increased the overall understanding of the relative health burden of these infections, as well as baseline knowledge needed for designing and implementing further studies to better assess the health impact and threat of these pathogens in the Amazon Basin of Peru.


Assuntos
Arbovírus , Vírus da Encefalite Equina Venezuelana , Leptospirose , Malária , Humanos , Peru/epidemiologia , Rios , Leptospirose/epidemiologia , Febre/epidemiologia
14.
Elife ; 112022 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-36111781

RESUMO

Background: Zoonotic spillover from animal reservoirs is responsible for a significant global public health burden, but the processes that promote spillover events are poorly understood in complex urban settings. Endemic transmission of Leptospira, the agent of leptospirosis, in marginalised urban communities occurs through human exposure to an environment contaminated by bacteria shed in the urine of the rat reservoir. However, it is unclear to what extent transmission is driven by variation in the distribution of rats or by the dispersal of bacteria in rainwater runoff and overflow from open sewer systems. Methods: We conducted an eco-epidemiological study in a high-risk community in Salvador, Brazil, by prospectively following a cohort of 1401 residents to ascertain serological evidence for leptospiral infections. A concurrent rat ecology study was used to collect information on the fine-scale spatial distribution of 'rattiness', our proxy for rat abundance and exposure of interest. We developed and applied a novel geostatistical framework for joint spatial modelling of multiple indices of disease reservoir abundance and human infection risk. Results: The estimated infection rate was 51.4 (95%CI 40.4, 64.2) infections per 1000 follow-up events. Infection risk increased with age until 30 years of age and was associated with male gender. Rattiness was positively associated with infection risk for residents across the entire study area, but this effect was stronger in higher elevation areas (OR 3.27 95% CI 1.68, 19.07) than in lower elevation areas (OR 1.14 95% CI 1.05, 1.53). Conclusions: These findings suggest that, while frequent flooding events may disperse bacteria in regions of low elevation, environmental risk in higher elevation areas is more localised and directly driven by the distribution of local rat populations. The modelling framework developed may have broad applications in delineating complex animal-environment-human interactions during zoonotic spillover and identifying opportunities for public health intervention. Funding: This work was supported by the Oswaldo Cruz Foundation and Secretariat of Health Surveillance, Brazilian Ministry of Health, the National Institutes of Health of the United States (grant numbers F31 AI114245, R01 AI052473, U01 AI088752, R01 TW009504 and R25 TW009338); the Wellcome Trust (102330/Z/13/Z), and by the Fundação de Amparo à Pesquisa do Estado da Bahia (FAPESB/JCB0020/2016). MTE was supported by a Medical Research UK doctorate studentship. FBS participated in this study under a FAPESB doctorate scholarship.


Assuntos
Leptospirose , Áreas de Pobreza , Adulto , Animais , Brasil/epidemiologia , Estudos de Coortes , Estudos Epidemiológicos , Geografia , Humanos , Leptospirose/epidemiologia , Masculino , Ratos , Zoonoses/epidemiologia
15.
Comput Math Methods Med ; 2022: 1806585, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36164616

RESUMO

This work is aimed at formulating and analyzing a compartmental mathematical model to investigate the impact of rodent-born leptospirosis on the human population by considering a load of pathogenic agents of the disease in an environment and the incidence rate of human infection due to the interaction between infected rodents and the environment. Firstly, the basic properties of the model, the equilibria points, and their stability analysis are studied. We also found the basic reproduction number (R 0) of the model using the next-generation matrix approach. From the stability analysis, we obtained that the disease-free equilibrium (DFE) is globally asymptotically stable if R 0 < 1 and unstable otherwise. The local stability of endemic equilibrium is performed using the phenomenon of the center manifold theory, and the model exhibits forward bifurcation. The most sensitive parameters on the model outcome are also identified using the normalized forward sensitivity index. Finally, numerical simulations of the model are performed to show the stability behavior of endemic equilibrium and the varying effect of the human transmission rates, human recovery rate, and the mortality rate rodents on the model dynamics. The model is simulated using the forward fourth-order Runge-Kutta method, and the results are presented graphically. From graphical stability analysis, we observed that all trajectories of the model solutions evolve towards the unique endemic equilibrium over time when R 0 > 1. Our numerical results revealed that decreasing the transmission rates and increasing the rate of recovery and reduction of the rodent population using appropriate intervention mechanisms have a significant role in reducing the spread of disease infection in the population.


Assuntos
Leptospirose , Modelos Teóricos , Número Básico de Reprodução , Humanos , Incidência , Leptospirose/epidemiologia
16.
PLoS One ; 17(9): e0274362, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36129918

RESUMO

BACKGROUND: Leptospirosis causes significant economic losses and is an occupational risk in the swine industry, especially in developing tropical regions where social and geoclimatic conditions are favorable for the transmission of this disease. Although vaccination can reduce infection risk, efficacy is diminished if local genetic and antigenic variants of the pathogen are not accounted for in the vaccine. Identifying and characterizing strains hosts, and potential mechanisms of transmission is therefore critical for public health mitigation practices. METHODOLOGY/PRINCIPAL FINDINGS: Our study was conducted on a rural breeding farm in Ecuador, where we used a PCR assay that targets lipL32 to detect Leptospira spp. and targeted gene sequencing to identify Leptospira santarosai in the kidneys, testicles, and ejaculate of a vaccinated boar. MAT results showed low titers against serovars found in the vaccine, but the MAT panel did not include serovars of L. santarosai. The boar showed no symptoms of leptospirosis but did show blood in the semen. However, no postmortem histopathological lesions were observed tissue samples. Vaccinated sows that were artificially inseminated with the semen from this boar had reproductive problems, suggesting that transmission had occurred. This is the first documented case of Leptospira santarosai in the reproductive tract of a boar. CONCLUSIONS/SIGNIFICANCE: As L. santarosai is pathogenic in other livestock species and humans, our finding highlights the need to evaluate the prevalence and epidemiological significance of this pathogen in livestock and consider the possibility of venereal transmission. In addition, further studies are needed to identify and characterize local serovars that may impact diagnosis and vaccination programs to better control leptospirosis in livestock and spillover into the human population.


Assuntos
Leptospira , Leptospirose , Animais , Feminino , Leptospira/genética , Leptospirose/epidemiologia , Leptospirose/prevenção & controle , Leptospirose/veterinária , Gado , Masculino , Saúde Pública , Sorogrupo , Suínos
17.
Artigo em Inglês | MEDLINE | ID: mdl-36141812

RESUMO

Gram-negative spirochete Leptospira spp. causes leptospirosis. Leptospirosis is still a neglected disease, even though it can cause potentially fatal infections in a variety of species including humans. The purpose of this study was to determine the seroprevalence of leptospirosis in pig farm captured rodents and characterize the isolated samples. Rats were captured, sampled, and euthanized in the vicinity of pig farms to obtain serum for microagglutination tests (MAT) and kidney tissues for PCR amplification of the 16S rRNA and LipL32 genes. A fraction of the 16S rRNA PCR product was sequenced and phylogenetically analyzed. The results showed a Leptospira seroprevalence of 13.8% (77/555) among the 555 captured rats. PCR positivity for Leptospira spp. reached 31.2% (156/500), and the positivity for pathogenic Leptospira spp. was 4% (22/500). Phylogenetic analysis matched eight samples with L. interrogans serovar icterohaemorrhagiae and two with L. interrogans serovar pyrogenes. Two sequences were located within the pathogenic Leptospira clade but did not match with any specific strain. The seroprevalence found in the rats around swine farms indicates a potential risk of transmission to the pigs. The identification of pathogenic Leptospira outlines the importance of more research as well as updating the current strategies for the diagnosis, control, and prevention of porcine leptospirosis in Colombia.


Assuntos
Leptospira , Leptospirose , Animais , Colômbia/epidemiologia , Fazendas , Humanos , Leptospirose/epidemiologia , Leptospirose/veterinária , Filogenia , RNA Ribossômico 16S/genética , Ratos , Roedores , Estudos Soroepidemiológicos , Suínos
19.
Prev Vet Med ; 208: 105751, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36063662

RESUMO

Goat farming is of great importance for agriculture in Northeast of Brazil, which owns more than 90 % of the national herd, however, most studies on leptospirosis in goats in this region are local surveys with unplanned sampling. Thus, the objective of this study was to determine the factors associated with the seroprevalence of leptospirosis in goats in Northeast region of Brazil. Blood samples were collected from 4121 goats from 222 herds, belonging to the states of Ceará, Paraíba, Piauí , Rio Grande do Norte and Sergipe. Serological diagnosis was carried out using the microscopic agglutination test (MAT). In 82.9 % (95 % CI = 77.3-87.2 %) of the herds there was at least one animal seropositive for at least one of the serogroups of Leptospira sp., and 18.73 % (95 % CI = 17.5-19.9 %) of the animals were seropositive. Antibody titers ranged from 100 to 800 and the most frequent serogroups were Autumnalis (23.06 %) and Australis (20.98 %). According to the robust Poisson regression analysis, four factors were associated with seroprevalence: animal sex (female) (P = 0.040), educational level of the farmer (elementary school) (P < 0.001), contacting institution for technical support (P = 0.040) and presence of irrigation area (P = 0.002). There was a high frequency of Leptospira sp. in goats in the states of Northeast region of Brazil, and it's suggested the need for better technological and preventive assistance of herds.


Assuntos
Doenças das Cabras , Leptospira , Leptospirose , Feminino , Animais , Estudos Soroepidemiológicos , Cabras , Brasil/epidemiologia , Doenças das Cabras/epidemiologia , Anticorpos Antibacterianos , Leptospirose/epidemiologia , Leptospirose/veterinária , Fatores de Risco
20.
Microb Pathog ; 172: 105763, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36116606

RESUMO

Studies related to the prevalence of leptospirosis in the semiarid region showed that even during long periods of drought, the disease has a remarkable frequency in herds in the region. It is a neglected disease and the extent of its effects in the Brazilian semiarid region is not known. The dynamics of this agent is well studied in the urinary tract, however, there are not many studies regarding the genital tract in female goats. Observing this scenario, the present work aimed to diagnose Leptospira spp. in female goats kept in the Brazilian semiarid region by means of serological, molecular and isolation techniques. Blood samples, vaginal fluid, urine and fragments of organs from the genitourinary tract were collected from 40 goats destined for slaughter. Microscopic agglutination test (MAT) was used as a serological technique, with a battery of 24 serovars. The Polymerase Chain Reaction (PCR) of the vaginal fluid, urine and organ fragments was performed, as well as the bacterial growth of these same products in a selective medium. Isolation positive samples were subjected to PCR. It was observed that two (5%) animals were serologically positive for the Pyrogenes serogroup. A total of 29 (72.5%) animals were PCR positive, with DNA present in 51/160 (31.8%) samples from the genital tract and 34/120 (28.3%) from the urinary tract, with no statistical difference. For bacterial growth, 22/40 (55%) animals were positive for growth, with morphology being observed in 19/160 (11.8%) for the genital tract and 16/120 (13.3%) for the urinary tract, with no statistical difference. Two uterus samples showed 99% similarity with L. interrogans after sequencing. Thus, female goats kept under semiarid conditions were positive for Leptospira spp, with positive samples from both the urinary and genital tracts, which possible is an alternative way of adapting and maintaining the agent for severe and adverse conditions.


Assuntos
Leptospira , Leptospirose , Sistema Urinário , Animais , Feminino , Brasil/epidemiologia , Cabras , Leptospirose/diagnóstico , Leptospirose/epidemiologia , Leptospirose/veterinária , Sorogrupo
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