Incidence Of Human Leptospirosis Research Articles

Clinical epidemiological characterization of leptospirosis during the period 2001-2022 in the Santa Clara municipality, Cuba

The objective of the study was to characterize clinically and epidemiologically human leptospirosis in the Santa Clara municipality, between 2001 and 2022. An observational, descriptive and cross-sectional study was carried out. In the affected human population, the incidence, trend, seasonality and endemic channel were determined in a 21-year time series. The occurrence of outbreaks by year, morbidity, lethality, mortality, cases by area, seasonality, were found. The incidence of human leptospirosis in the municipality of Santa Clara is high, and the most affected were the “Captain Roberto Fleites” and “Marta Abreu” health areas. The age group with the highest number of cases was emphasized in patients with age comprehend between 15 and 59 years old, with a predominance of males. Human leptospirosis manifests a seasonal behavior with a tendency to persist. The most frequent symptoms in affected humans were headache, pyrexia, myalgia and jaundice and afebrile cases in pediatric age are described as contributions to the epidemiology in the territory.

Risk of human leptospirosis in Colombia: spatiotemporal analysis and related hydroclimatic factors.

Leptospirosis is an endemic zoonosis in tropical areas that is mainly related to rural activities; nevertheless, human leptospirosis (HL) outbreaks differ among regions. In Colombia, HL notifications are mandatory. Our objective was to determine the spatiotemporal distribution of HL in Colombia during 2007-2018 and its relationship with the main hydroclimatic variables. We determined the estimated incidence and lethality of HL according to department and year. The Bayesian spatiotemporal analysis of an autoregressive model (STAR) model included HL cases and hydroclimatic factors (average temperature, rainfall and relative humidity) for quarterly periods. During the study period, 10 586 HL cases were registered (estimated incidence: 1.75 cases x 105) and 243 deaths by HL (lethality 2.3%). The STAR model found association of HL risk with temperature (RR:6.80; 95% CI 3.57 to 12.48) and space. Quindío and three other Amazonian departments (Guainía, Guaviare and Putumayo) had a positive relationship with a significant number of HL cases, adjusted for quarterly precipitation and humidity. Spatial analysis showed a high risk of HL in departments of the western Andean Colombian regions. By contrast, in the spatiotemporal model, a higher HL risk was associated with temperature and departments of the North Colombian Amazon regions and Quindío in the Colombian Andean region.

Clinical manifestations of human leptospirosis: bacteria matter.

A high incidence of human leptospirosis is recorded on Mayotte, an oceanic island located in southwestern Indian Ocean, but the severity of the disease appears relatively mild in terms of mortality rate and admission to the intensive care unit. It has been proposed that mild leptospirosis may result from a limited virulence of some of the occurring Leptospira species to which the population is exposed. Clinical and biological data of patients admitted to the Centre Hospitalier de Mayotte were collected and the infecting Leptospira species were determined through molecular typing. Leptospira interrogans was detected in the minority of admitted patients but most of these patients suffered from severe forms, with 50% admitted to intensive care unit and suffering from organ failures. Nineteen percent of patients infected with Leptospira borgpetersenii were admitted to the intensive care, with 13% displaying organ failures, and one patient died. Leptospira mayottensis was found in 28% of the patients and not a single severe case was observed. The distribution of Leptospira species in patients was not different from that reported 10-15 years ago and bacterial genotypes were very closely related to those previously reported. These results highlight the importance of the diversity of pathogenic Leptospira circulating on Mayotte island and are in keeping with distinct outcome of the disease depending on the infecting Leptospira. Altogether, presented data support that the infecting Leptospira species is an important driver of disease severity in humans.

Epizootological and epidemiological aspects of leptospirosis in Ukraine for the period 2003–2022

Zoonotic leptospirosis is an infectious disease caused by pathogenic Leptospira bacteria that can be transmitted from animals to humans. Animals, especially wild and domestic mammals, are reservoir hosts that carry and excrete the bacteria in their urine. A retrospective analysis of the incidence of leptospirosis in animals and humans in Ukraine from 2003 to 2022 was conducted based on reports from regional state laboratories of veterinary medicine and the Center for Public Health. GIS mapping was used to analyze and visualize the data. The incidence and prevalence of leptospirosis among different animal species, including farm, domestic and wild animals, were analyzed. These studies included a retrospective analysis of blood serum samples from different animal species for leptospirosis and analysis of the results to determine the level of seropositivity. The study analyzed a total of 6,543,934 samples, with an overall seropositivity rate of 3.3%. Among cattle, 4.1% of the samples were positive. For pigs, 2.1% were positive. Horses had a seropositivity rate of 7.9%, while dogs and cats had seropositivity rates of 17.5% and 13.1% respectively. Wild boars showed a positivity rate of 2.2%. The number of seropositive animals of different species in Ukraine showed different dynamics from 2003 to 2022. The highest number of positive cases was found among cattle, pigs and horses. However, the number of positive cases decreased significantly after 2015, which coincides with a significant reduction in the number of farm animals. Trends of increasing seropositivity among dogs and cats in the period 2007–2015 indicate that these species are also active carriers of Leptospira, as are the leading agricultural species. Wildlife species with stable seropositivity serve as both sources and reservoirs of Leptospira. Wild pigs are becoming the main bacterial carriers in all regions of Ukraine. There is a marked disproportion between the number of positive cases among farm animals and wildlife, indicating that seropositivity in these populations exists largely autonomously. A total of 7,937 people were infected in Ukraine between 2003 and 2022. Certain regions, such as Lviv, Kherson, Kyiv, Mykolaiv, and Vinnytsia, account for a larger share of the total number of cases, ranging from 4.8% to 7.3%. The incidence of human leptospirosis has fluctuated over the years, peaking at 473 cases in 2014, followed by a decline: 301 cases in 2015, 323 cases in 2016 and 330 cases in 2017, and in subsequent years the number of cases remained relatively stable, ranging from 142 to 295 cases per year. The study emphasizes the need to improve preventive measures and raise public awareness of the disease, especially in rural areas. It is important to adopt a comprehensive interdisciplinary approach involving collaboration between veterinary medicine, public health and environmental authorities to better understand and address the complexities of leptospirosis transmission and reduce its impact on animal and human health.

A predictive risk map for human leptospirosis guiding further investigations in brown rats and surface water

ABSTRACT Leptospirosis is a zoonosis caused by the spirochete Leptospira spp. It is often not clear why certain areas appear to be hotspots for human leptospirosis. Therefore, a predictive risk map for the Netherlands was developed and assessed, based on a random forest model for human leptospirosis incidence levels with various environmental factors and rat density as variables. Next, it was tested whether misclassifications of the risk map could be explained by the prevalence of Leptospira spp. in brown rats. Three recreational areas were chosen, and rats (≥25/location) were tested for Leptospira spp. Concurrently, it was investigated whether Leptospira spp. prevalence in brown rats was associated with Leptospira DNA concentration in surface water, to explore the usability of this parameter in future studies. Approximately 1 L of surface water sample was collected from 10 sites and was tested for Leptospira spp. Although the model predicted the locations of patients relatively well, this study showed that the prevalence of Leptospira spp. infection in rats may be an explaining variable that could improve the predictive model performance. Surface water samples were all negative, even if they had been taken at sites with a high Leptospira spp. prevalence in rats.

Incidence and distribution of human leptospirosis in the Western Cape Province, South Africa (2010-2019): a retrospective study.

leptospirosis is an emerging zoonosis of global importance. In South Africa, the infection is an underreported public health concern, with limited information on its incidence and distribution. This study investigated the incidence of human leptospirosis in Western Cape Province (WCP) between 2010 and 2019, and compared the incidence based on seasonal and demographic factors. a retrospective study was conducted with data on leptospirosis diagnoses in WCP obtained from the National Health Laboratory Services. With the provincial population sizes as the denominator, incidence of leptospirosis was estimated and expressed as cases per 100,000 population. Negative binomial regression was used to estimate the effect of sex, season, and year on the incidence of leptospirosis. two hundred and fifty-four (254) cases of leptospirosis were reported between 2010 and 2019, with the highest number of cases being in 2015 and the annual incidence ranged between 0.15 and 0.66/100,000 population. Males had a higher incidence compared to females (0.55 vs. 0.25/ 100,000 population; incidence rate ratio (IRR) 2.2, 95% CI: 1.66,3.03). The 18-44 age cohort had the highest average incidence (0.56/100,000 population), while the ≤17 age cohort had the lowest incidence (0.07/100,000 population). The 18-44 (IRR 8.0, 95% CI: 4.65,15.15) and ≥45 (IRR 7.4, 95% CI: 4.17,14.17) age cohorts were more at risk of infection compared to ≤17 age cohort. leptospirosis is an important zoonosis in WCP disproportionately affecting males and the productive age demographic groups. These findings should enhance targeted prevention and provoke further investigation on the importance of environmental and socioeconomic factors on leptospirosis burden.

Incidence of Human Leptospirosis among Scrub Typhus and Chikungunya Negative Children in West Bengal, India, 2022

Leptospirosis caused by the bacterium Leptospira, has been classified by the World Health Organisation (WHO) as a neglected tropical disease with worldwide significance. Leptospirosis in endemic places affects adults more frequently and severely than it affects children. There is a lack of data specifically focusing on children, and it is yet unknown why this discrepancy exists. As the majority of human leptospiral infections are mild or asymptomatic in endemic areas, goal of our study was to describe the prevalence of the Leptospira disease spectrum and the variations in clinical manifestations among patients admitted for febrile illness in a tertiary care facility.

Agro-Environmental Determinants of Leptospirosis: A Retrospective Spatiotemporal Analysis (2004-2014) in Mahasarakham Province (Thailand).

Leptospirosis has been recognized as a major public health concern in Thailand following dramatic outbreaks. We analyzed human leptospirosis incidence between 2004 and 2014 in Mahasarakham province, Northeastern Thailand, in order to identify the agronomical and environmental factors likely to explain incidence at the level of 133 sub-districts and 1982 villages of the province. We performed general additive modeling (GAM) in order to take the spatial-temporal epidemiological dynamics into account. The results of GAM analyses showed that the average slope, population size, pig density, cow density and flood cover were significantly associated with leptospirosis occurrence in a district. Our results stress the importance of livestock favoring leptospirosis transmission to humans and suggest that prevention and control of leptospirosis need strong intersectoral collaboration between the public health, the livestock department and local communities. More specifically, such collaboration should integrate leptospirosis surveillance in both public and animal health for a better control of diseases in livestock while promoting public health prevention as encouraged by the One Health approach.

Leptospirosis Transmission in Ponorogo District of East Java, Indonesia

This study aims to identify Leptospira bacterial infection in livestock owners and their livestock, as well as to examine potential risk factors correlated with the incidence. 50 participants were selected and their blood samples were collected. 50 urine samples were collected from livestock owned by the participants. Polymerase Chain Reaction (PCR) was used to identify the existence of the Leptospira bacteria. The questionnaire instrument was used to obtain information about individual characteristics and hygiene. The Chi-Squared test was adopted to examine the correlation between outcome and explanatory variables. The confirmation PCR test detected the bacterial DNA in 2 out of 50 blood samples examined (4%) and 3 out of 50 urine samples examined (6%). Human leptospirosis incidence is significantly correlated with occupation type (p=0.035), personal protective equipment (PPE) use (p=0.044), water puddle contact (p=0.044), cage sanitation (p=0.044) and Leptospira bacteria presence in livestock urine (p=0.007). Insignificant correlation was showed in owners’ age variable. The presence of Leptospira bacteria both in livestock and the owners indicates the real threat of animal to human transmission. Further study with larger sample size and wider range variables and meticulous examination technique is required to comprehend the investigation.

Leptospirosis Transmission in Ponorogo District of East Java, Indonesia

This study aims to identify Leptospira bacterial infection in livestock owners and their livestock, as well as to examine potential risk factors correlated with the incidence. 50 participants were selected and their blood samples were collected. 50 urine samples were collected from livestock owned by the participants. Polymerase Chain Reaction (PCR) was used to identify the existence of the Leptospira bacteria. The questionnaire instrument was used to obtain information about individual characteristics and hygiene. The Chi-Squared test was adopted to examine the correlation between outcome and explanatory variables. The confirmation PCR test detected the bacterial DNA in 2 out of 50 blood samples examined (4%) and 3 out of 50 urine samples examined (6%). Human leptospirosis incidence is significantly correlated with occupation type (p=0.035), personal protective equipment (PPE) use (p=0.044), water puddle contact (p=0.044), cage sanitation (p=0.044) and Leptospira bacteria presence in livestock urine (p=0.007). Insignificant correlation was showed in owners’ age variable. The presence of Leptospira bacteria both in livestock and the owners indicates the real threat of animal to human transmission. Further study with larger sample size and wider range variables and meticulous examination technique is required to comprehend the investigation.

Leptospirosis in the Republic of Tatarstan. Epidemiological Features

The study presents a characteristic of the current epidemiological situation on leptospirosis in the Republic of Tatarstan, investigation of the circulation of leptospirosis agents among the population of small mammals, and the species composition of Leptospira that caused diseases in humans.Materials and methods. The paper contains the data on the incidence of leptospirosis among the population in the Russian Federation (RF) for the period between 2000 and 2018, in the Republic of Tatarstan – since 1998, submitted by the Rospotrebnadzor Administrations in the constituent entities of the Russian Federation, materials of the Center for Hygiene and Epidemiology in the Republic of Tatarstan and the Main Veterinary Administration of the Republic of Tatarstan.Results and discussion. We have carried out the analysis of the epidemiological situation in the Republic of Tatarstan for the period of 1998–2018, by the administrative territories of the republic. The incidence of human leptospirosis caused by various leptospira serogroups has been assessed. In total, 112 people got infected with leptospirosis during the analyzed period. Also the data of epizootiological survey of small mammals inhabiting the natural foci of leptospirosis in the republic are presented. Laboratory tests of 1565 samples from mouse-like rodents for the presence of leptospirosis pathogens have been performed. 1.9 % of the tests gave a positive result. Dominant in the Republic of Tatarstan are the serogroups of Leptospira – Leptospira grippotyphosa and L. hebdomadis. The results of laboratory studies on the carriage of leptospira among small mammals and contamination of environmental objects indicate the circulation of pathogens of leptospirosis in the population of small mammals, habitant in forest shrub, near-water and meadow field stations of the republic. The red vole prevails in this community, the average index of its dominance is 66.7 %. Epizootiological monitoring point to a latent epizootic process in the community of mouse-like rodents.

Leptospirosis Transmission in Ponorogo District of East Java, Indonesia: A Cross-Sectional Study

This study aims to identify Leptospira bacterial infection in livestock owners and their livestock, as wellas to examine potential risk factors correlated with the incidence. 50 participants were selected and theirblood samples were collected. 50 urine samples were collected from livestock owned by the participants.Polymerase Chain Reaction (PCR) was used to identify the existence of the Leptospira bacteria. Thequestionnaire instrument was used to obtain information about individual characteristics and hygiene. TheChi-Squared test was adopted to examine the correlation between outcome and explanatory variables. Theconfirmation PCR test detected the bacterial DNA in 2 out of 50 blood samples examined (4%) and 3 out of50 urine samples examined (6%). Human leptospirosis incidence is significantly correlated with occupationtype (p=0.035), personal protective equipment (PPE) use (p=0.044), water puddle contact (p=0.044), cagesanitation (p=0.044) and Leptospira bacteria presence in livestock urine (p=0.007). Insignificant correlationwas showed in owners’ age variable. The presence of Leptospira bacteria both in livestock and the ownersindicates the real threat of animal to human transmission. Further study with larger sample size and widerrange variables and meticulous examination technique is required to comprehend the investigation.

Pathogenic Leptospira species in rodents from Corsica (France).

Leptospirosis is a worldwide emerging zoonotic disease caused by Leptospira species, that in some patients develop severe forms with high mortality. In France, Corsica is the area where the highest incidences have been reported. The present study was focused on the analysis of pathogenic Leptospira species in rodents of Corsica, as these micromammals are the main natural reservoirs of the bacteria, in order to identify the circulating species and to locate possible risk focuses of transmission, as no previous study on the presence of Leptospira species has been carried out in the island. Rattus rattus, Rattus norvegicus, Apodemus sylvaticus and Mus musculus domesticus were captured in the proximity of water sources along Corsica, the detection of pathogenic Leptospira species was carried out by amplification of the LipL32 gene. The bacteria were found in all the rodent species analyzed and widely. The general prevalence was 10.4%, reaching the maximum value in Bastia (45%). Leptospira interrogans and Leptospira borgpetersenii were identified by phylogenetic analysis, but also two sequences which corresponded to an unnamed Leptospira species, only previously found in rodents of New Caledonia. The high incidence of human leptospirosis in Corsica could be partially explained by the wide distribution of pathogenic Leptospira species identified in this study. Also, the presence of an unknown pathogenic species of Leptospira in an area with high prevalence, may be involved in the higher incidence of Leptospirosis in this island, however, the zoonotic capacity of this species remains unknown. The results obtained are interesting for public health since all positive samples were found near water sources and one of the routes of transmission of leptospirosis is contact with contaminated water. This information could help the competent entities to take preventive measures, reducing the incidence of human leptospirosis in Corsica.

Estimating acute human leptospirosis incidence in northern Tanzania using sentinel site and community behavioural surveillance.

Many infectious diseases lack robust estimates of incidence from endemic areas, and extrapolating incidence when there are few locations with data remains a major challenge in burden of disease estimation. We sought to combine sentinel surveillance with community behavioural surveillance to estimate leptospirosis incidence. We administered a questionnaire gathering responses on established locally relevant leptospirosis risk factors and recent fever to livestock‐owning community members across six districts in northern Tanzania and applied a logistic regression model predicting leptospirosis risk on the basis of behavioural factors that had been previously developed among patients with fever in Moshi Municipal and Moshi Rural Districts. We aggregated probability of leptospirosis by district and estimated incidence in each district by standardizing probabilities to those previously estimated for Moshi Districts. We recruited 286 community participants: Hai District (n = 11), Longido District (59), Monduli District (56), Moshi Municipal District (103), Moshi Rural District (44) and Rombo District (13). The mean predicted probability of leptospirosis by district was Hai 0.029 (0.005, 0.095), Longido 0.071 (0.009, 0.235), Monduli 0.055 (0.009, 0.206), Moshi Rural 0.014 (0.002, 0.049), Moshi Municipal 0.015 (0.004, 0.048) and Rombo 0.031 (0.006, 0.121). We estimated the annual incidence (upper and lower bounds of estimate) per 100,000 people of human leptospirosis among livestock owners by district as Hai 35 (6, 114), Longido 85 (11, 282), Monduli 66 (11, 247), Moshi Rural 17 (2, 59), Moshi Municipal 18 (5, 58) and Rombo 47 (7, 145). Use of community behavioural surveillance may be a useful tool for extrapolating disease incidence beyond sentinel surveillance sites.

Spatial distribution of leptospirosis incidence in the Upper Yangtze and Pearl River Basin, China: Tools to support intervention and elimination

BackgroundSince 2011 human leptospirosis incidence in China has remained steadily low with persistent pockets of notifications reported in communities within the Upper Yangtze River Basin (UYRB) and Pearl River Basin (PRB). To help guide health authorities within these residual areas to identify communities where interventions should be targeted, this study quantified the local effect of socioeconomic and environmental factors on the spatial distribution of leptospirosis incidence and developed predictive maps of leptospirosis incidence for UYRB and PRB. MethodsData on all human leptospirosis cases reported during 2005–2016 across the UYRB and PRB regions were geolocated at the county-level and included in the analysis. Bayesian conditional autoregressive (CAR) models with zero-inflated Poisson link for leptospirosis incidence were developed after adjustment of environmental and socioeconomic factors such as precipitation, normalized difference vegetation index (NDVI), modified normalized difference water index (MNDWI), land surface temperature (LST), elevation, slope, land cover, crop production, livestock density, gross domestic product and population density. ResultsThe relationship of environmental and socioeconomic variables with human leptospirosis incidence varied between both regions. While across UYRB incidence of human leptospirosis was associated with MNDWI and elevation, in PRB human leptospirosis incidence was significantly associated with NDVI, livestock density and land cover. Precipitation was significantly and positively associated with the spatial variation of incidence of leptospirosis in both regions. After accounting for the effect of environmental and socioeconomic factors, the predicted distribution of residual high-incidence county is potentially more widespread both in the UYRB and PRB compared to the observed distribution. In the UYRB, the highest predicted incidence was found along the border of Chongqing and Guizhou towards Sichuan basin and northwest Yunnan. The highest predicted incidence was also identified in counties in the central and lower reaches of the PRB. ConclusionsThis study demonstrated significant geographical heterogeneity in leptospirosis incidence within UYRB and PRB, providing an evidence base for prioritising targeted interventions in counties identified with the highest predicted incidence. Furthermore, environmental drivers of leptospirosis incidence were highly specific to each of the regions, emphasizing the importance of localized control measures. The findings also suggested the need to expand interventional coverage and to support surveillance and diagnostic capacity on the predicted high-risk areas.

Identification of Leptospira spp. from environmental sources in areas with high human leptospirosis incidence in the Philippines

ABSTRACTLeptospira is the causative agent of leptospirosis, which is considered an emerging major threat to public health due to its increasing frequency reported worldwide. In the Philippines, the prevalence of the disease continuously rises, particularly in urban areas. Because leptospirosis is commonly transmitted through contact with contaminated environment, water and soil samples were collected in regions in the Philippines where high incidence of human leptospirosis cases was reported recently. Of the 54 samples screened for the presence of Leptospira, 35% were found positive through 23S rRNA gene PCR-based detection. None were found positive when primers targeting lipL32, lipL41, and ompL1 genes were used. Most of these isolates were collected from rural areas. However, 16S rRNA gene sequencing identified all isolates to be L. yanagawae and L. meyeri, which are nonpathogenic. Despite the lack of evidence of the presence of pathogenic species in the environmental sources, the results still suggest that leptospires persist in these areas. These data are crucial for environmental monitoring and identification of contaminated areas where humans may be at risk of infection.

Influence of Specific Leptospirosis Prevention to Epidemic Process

Aim of the study was to investigate the features of vaccine prevention of leptospirosis and its influence on morbidity.Materials and methods. The incidence of human leptospirosis in the Russian Federation in 1956–2016, 41 cases of disease in Siberia and the Far East in 2012–2016, official Rossel'khoznadzor data, volumes of laboratory studies and vaccination of animals in Primorsk Territory and Irkutsk Region were analyzed. Blood sera from 7315 humans, 2189 dogs, 481 bovine animals and 50 small cattle, 115 pigs, 88 horses were investigated to pathogenic Leptospira antibodies.Results. Essential significance of vaccinal leptospiroses prevention in farm animals and dogs to decrease the epizootic and epidemic process activities is demonstrated. Currently, the epidemic process in Siberia and at the Far East includes only sporadic cases, the immune stratum of the population is 3,7 ± 0,2%. Postvaccinal antibody titres in dogs, pigs and small cattle rarely exceed 1:100 while in bovine animals and horses it can reach 1:800 without disease signs.Conclusion. Human immunization in the antropurgic foci is impractical at effective specific prophylaxis for animals. The standard base for leptospiroses requires improvement. The concept of absolute and relative diagnostic antibody titer in microagglutination test is offered to use in clinical diagnostics. In veterinary the correction of diagnostic titer depending on the animal species and vaccination time is necessary.

Assessment of animal hosts of pathogenic Leptospira in northern Tanzania.

Leptospirosis is a zoonotic bacterial disease that affects more than one million people worldwide each year. Human infection is acquired through direct or indirect contact with the urine of an infected animal. A wide range of animals including rodents and livestock may shed Leptospira bacteria and act as a source of infection for people. In the Kilimanjaro Region of northern Tanzania, leptospirosis is an important cause of acute febrile illness, yet relatively little is known about animal hosts of Leptospira infection in this area. The roles of rodents and ruminant livestock in the epidemiology of leptospirosis were evaluated through two linked studies. A cross-sectional study of peri-domestic rodents performed in two districts with a high reported incidence of human leptospirosis found no evidence of Leptospira infection among rodent species trapped in and around randomly selected households. In contrast, pathogenic Leptospira infection was detected in 7.08% cattle (n = 452 [5.1–9.8%]), 1.20% goats (n = 167 [0.3–4.3%]) and 1.12% sheep (n = 89 [0.1–60.0%]) sampled in local slaughterhouses. Four Leptospira genotypes were detected in livestock. Two distinct clades of L. borgpetersenii were identified in cattle as well as a clade of novel secY sequences that showed only 95% identity to known Leptospira sequences. Identical L. kirschneri sequences were obtained from qPCR-positive kidney samples from cattle, sheep and goats. These results indicate that ruminant livestock are important hosts of Leptospira in northern Tanzania. Infected livestock may act as a source of Leptospira infection for people. Additional work is needed to understand the role of livestock in the maintenance and transmission of Leptospira infection in this region and to examine linkages between human and livestock infections.

Epidemiological and clinical features of leptospirosis in a highly endemic area over three time periods.

To present the features of human leptospirosis over three time periods (1970-1975; 2000-2005; 2010-2015), to compare the collected data and to determine whether the incidence, seasonal and spatial distribution, prevalence of presumptive infective serogroups and clinical features have changed over the last 50 years. Epidemiological and clinical data obtained from patients hospitalised and treated in a well-known endemic focus of leptospirosis, Koprivnica-Križevci County in Croatia, were analysed. We observed a steady decline in the overall incidence of leptospirosis and a change in the patient age distribution, with the age ratio changing in favour of middle-aged and older patients. Although leptospirosis was most frequently diagnosed in August in all time periods, the number of cases increased in autumn. The most prevalent serogroup during the first and the second time period was Icterohaemorrhagiae, while in the third time period, the serogroup Australis prevailed. We also noted an increase in the number of severe clinical manifestations. This retrospective research demonstrates a continuous decline in the incidence of human leptospirosis in Croatia. The pattern of disease has changed from predominantly mild clinical forms observed in children to more severe clinical forms observed in middle-aged to older patients, especially those working in agriculture. Additional epidemiological changes included an increase in the number of cases during the autumn months and changes in prevailing serogroups. Statistical analysis revealed a significant relationship between the severity of the clinical picture, patient age and presumed sources of infection.

A cross-sectional epidemiological study of domestic animals related to human leptospirosis cases in Nicaragua

Leptospirosis is one of the most extended zoonosis worldwide and humans become infected most commonly through contact with the urine of carrier animals, either directly or via contaminated water or soil. The aim in this study was to analyse the epidemiological behaviour of Leptospira spp., from domestic animals around the sites of human leptospirosis cases in Nicaragua, from 2007 through 2013. We report the results of a cross-sectional epidemiological study with a non-probability sampling of blood (n=3050) and urine (n=299) from Domestic Animals (DA) around the sites of human leptospirosis cases in Nicaragua. We analysed data obtained through Microscopic Agglutination Test (MAT), in-vitro culture, real time PCR and sequencing of lfb1 locus. Frequencies of 30.31% (95% CI: 28.66–31.95) and 15.38% (95% CI: 11.12–19.64) were obtained from serological test and from in-vitro culture, respectively. Although similar frequencies from serology test (P≥0.05) were found in DA species, in-vitro culture frequencies were significantly higher from bovine, equine and sheep (P<0.05) in comparison with swine and canine species. Ten serogroups of pathogenic Leptospira spp. were encountered, with the highest presence of Icterohaemorrhagiae serogroup 34.65% (95% CI: 29.35–39.94). We identified 7 samples homologous to L. interrogans species Pyrogenes serovar and 3 samples as L. noguchii Louisiana or Panama serovars by analysis of lfb1 sequences. We were able to establish a temporal and spatial correlation from DA and cumulative incidence of human cases. Therefore an effective epidemiological surveillance should be implemented with a specific control program toward DA in order to reduce human leptospirosis incidence.