Control Of Leptospirosis Research Articles

Immunoinformatic approaches for ErpY-LemA chimeric protein design for use in leptospirosis control.

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. 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 35kDa. 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. 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.

Epidemiological characteristics of leptospirosis in China from 2010 to 2022

To analyze the epidemiological characteristics of leptospirosis in China from 2010 to 2022, so as to provide insights into formulation of the leptospirosis control strategy. All data pertaining to clinically diagnosed cases and confirmed cases of leptospirosis reported in China from January 1, 2010 to December 31, 2022 was collected from Chinese Disease Prevention and Control Information Management System. The spatial, temporal and population distributions, and report and diagnosis institutions of leptospirosis cases were analyzed using a descriptive epidemiological method. A total of 4 559 leptospirosis cases were reported in China from 2010 to 2022, with an annual average number of 351 cases, and the number of reported leptospirosis cases reduced from 679 cases in 2010 to 158 cases in 2018. A total of 4 276 leptospirosis cases were reported in Sichuan Province, Yunnan Province, Guangdong Province, Hunan Province, Fujian Province, Zhejiang Province, Guangxi Zhuang Autonomous Region, Anhui Province, Jiangxi Province and Guizhou Province, accounting for 93.79% of the total number of leptospirosis cases in China. The number of leptospirosis cases had recently appeared a remarkable decline in Yunnan Province, while a significant rise was seen in the number of leptospirosis cases in two provinces of Zhejiang and Guangdong. No leptospirosis cases were reported in Henan Province from 2010 to 2020; however, there were 5 cases and 2 cases reported in 2021 and 2022, respectively. There was only one leptospirosis case reported in Shaanxi Province from 2010 to 2017; however, leptospirosis cases were reported in the province for 5 consecutive years since 2018. Leptospirosis cases were reported throughout the year in China from 2010 to 2022, with the peak of incidence found during the period between August and October, and the peak of leptospirosis incidence varied in provinces. A higher number of leptospirosis cases was seen among men than among women, with a male to female ratio of 2.3:1, and the median age of leptospirosis cases was 50 years (interquartile range, 23 years), with the highest proportion of leptospirosis cases reported at ages of 51 to 60 years (23.21%). Among all reported leptospirosis cases, 53.28% were confirmed cases, and the proportion of confirmed cases increased from 35.05% in 2010 to 61.66% in 2022. In addition, there were 67.22% of leptospirosis cases (2 937 cases) reported by comprehensive hospitals, 20.44% (893 cases) by disease control and prevention institutions, 7.23% (316 cases) by grassroots healthcare institutions and 5.10% (223 cases) by other healthcare and medical institutions, and the mortality of reported leptospirosis cases was 1.07% in China from 2010 to 2022, with a higher mortality seen among men than among women (1.39% vs. 0.36%; χ2 = 9.52, P = 0.002). The incidence of leptospirosis remained at a low level in China from 2010 to 2022, and southern China was still the main endemic area for leptospirosis. The epidemiological characteristics of leptospirosis cases varied in endemic provinces, and leptospirosis cases had been continued to be reported in Shaanxi and Henan provinces, which should be paid much attention to. Intensified surveillance of leptospirosis, improved diagnosis and treatment capability of leptospirosis cases and leptospirosis control with adaptations to local circumstance are recommended.

The Influencing Factors of The Leptospirosis Prevalence in the Working Area of the Kebonagung Public Health Center

Leptospirosis is an infectious disease in the world caused by the bacterium Leptospira sp. The Kebonagung Public Health Center reported 34 cases of leptospirosis in 2023. The purpose of the study is to determine the factors influencing the leptospirosis prevalence in the Working Area of the Kebonagung Public Health Center. The type of this research was quantitative using a case control study design. The number of samples obtained were 22 cases and 22 controls. The sampling technique used were non probability sampling with purposive sampling. Univariate data analysis construed the frequency distribution, bivariate analysis with Chi-square test, and multivariate analysis with logistic regression test. The results of the bivariate analysis shows that there is an influence between education (p-value=0,018), occupation (p-value=0,037), and past injury (p-value=0,003) on the prevalence of leptospirosis in the working area of the Kebonagung Public Health Center. There is no influence between income (p-value 0,280) and personal hygiene (p-value=0,203) on the leptospirosis prevalence in the working area of the Kebonagung Public Health Cente,. The results of multivariate analysis shows that the factor that most influenced the prevalence of leptospirosis in the working area of the Kebonagung Public Health Center, is past injuries with (p-value=0,006). It is hoped that the public will adopt clean and healthy living habits, especially in caring for wounds and with Increasing leptospirosis surveillance, cross-sectoral coordination, and also familiarization of leptospirosis prevention and control need to be conducted as soon as possible to prevent the prevalence of leptospirosis.

Cross-sectional serosurvey of Leptospira species among slaughter pigs, goats, and sheep in Uganda.

Leptospira are a group of bacteria, including pathogenic types that cause leptospirosis. In Uganda, Leptospira exposure has been reported in humans, with domesticated animals being speculated as the source. However, comparable evidence of Leptospira prevalence and circulating serovars/serogroups in animals is only documented for cattle, and dogs. Our study determined Leptospira seroprevalence, associated risk factors and serogroups circulating among slaughtered pigs, goats, and sheep in Uganda. During an 11-month cross-sectional survey in selected slaughter facilities in three regions of Uganda, we collected blood from 926 pigs, 347 goats, and 116 sheep. The age, sex, breed, and origin of each sampled animal were noted. The samples were tested for anti-Leptospira antibodies using the microscopic agglutination test, based on a panel of 12 serovars belonging to 12 serogroups. Leptospira seroprevalence was 26.67% (247/926, 95%CI 23.92-29.61) among pigs, and 21.81% (101/463, 95%CI 18.29-25.80) in goats and sheep (small ruminants). L. interrogans Australis and L. kirschneri Grippotyphosa were the commonest serovars among pigs, as was L. borgpetersenii Tarassovi in small ruminants. Pigs sourced from the Eastern (Odds Ratio [OR] = 2.82, 95%CI 1.84-4.30) and Northern (OR = 3.56, 95%CI 2.52-5.02) regions were more likely to be seropositive, compared to those from the Central region. For small ruminants, being female (OR 2.74, 95% CI 1.69-4.57) and adult (OR 4.47, 95% CI 1.57-18.80) was significantly more associated with Leptospira seropositivity. Conclusion/significance: Detection of a moderate seroprevalence, and several Leptospira serogroups among pigs, sheep, and goats from all regions of Uganda, supports existing reports in cattle and dogs, and implies widespread Leptospira exposure in domestic animals in Uganda. These findings may inform future programs for the control of leptospirosis in livestock in Uganda.

Evaluation of protective efficacy, serological responses, and cytokine modulation induced by polyvalent Leptospira vaccines in hamsters

Whole-cell inactivated vaccines (bacterins) are the only licensed vaccines available for leptospirosis prevention and control, especially in domestic and farm animals. However, despite their widespread use, inconsistencies in their efficacy have been reported. Because immunity induced by bacterins is mainly mediated by antibodies against leptospiral lipopolysaccharides, the involvement of cellular responses is not well-known. The aim of this study was to investigate the efficacy and characterize the humoral and cellular immune responses induced by whole-cell inactivated leptospirosis bacterin formulations containing serovars Bratislava, Canicola, Copenhageni, Grippotyphosa, Hardjoprajitno, and Pomona. For the potency test, hamsters were immunized with one dose of polyvalent bacterins (either commercial or experimental) and then challenged with a virulent Pomona strain. Serological (MAT and IgM and IgG-ELISA) and cellular (cytokine transcription in blood evaluated by RT-qPCR) analyses were performed. The results revealed that vaccination with either bacterin formulation was able to protect 90–100% of the hamsters infected with the Pomona serovar, although most of the surviving animals remained as renal carriers. Specific agglutinating antibodies and significant levels of IgM, IgG, and IgG2 (P < 0.05) that were able to react with the six serovars present in the vaccine formulations were produced, indicating that the vaccines can potentially provide immunity against all strains. The protective immunity of these vaccines was mainly mediated by balanced a Th1/Th2 response, characterized by increased IFN-γ, IL-10 and IL-α transcription. These data support the importance of characterizing immunological responses involved in bacterin efficacy and investing in the improvement of these vaccine formulations.

Proteomic profiles of Leptospira borgpetersenii serovar Hardjo strains JB197 and HB203 cultured at different temperatures

Leptospirosis is a global zoonotic disease affecting humans, domestic, and wild animals. Leptospira are typically shed in the urine of reservoir hosts which persist in suitable environments where incidental host transmission occurs after direct contact with infected urine or contaminated environments. Interestingly, serologically identical L. borgpetersenii serovar Hardjo strains JB197 and HB203 show divergent disease severity in the hamster model; JB197 causes severe acute infection while HB203 causes persistent chronic infection. Historically, serovar Hardjo was limited to culture at 29 °C, but utilization of HAN media allows propagation from host tissues at 37 °C. Here, the proteome of strains JB197 and HB203 were characterized after culture from experimentally challenged hamsters at 29 °C and 37 °C. Comparative analyses of JB197 and HB203 samples cultured at 29 °C yielded 425 significantly differentially expressed (DE) proteins, while strains at 37 °C yielded 613 DE proteins including prominent outer membrane proteins and known virulence factors. In agreement, membrane protein GO terms were identified by STRING network analyses along with numerous metabolic KEGG pathways consistent with condition differences. Within strain, JB197 cultured at 29 °C vs 37 °C identified 529 DE proteins, while HB203 identified 524 DE proteins. Investigating differential protein profiles provide insights into strain specific behaviors with implications for better understanding host-pathogen interactions, disease transmission, and response to environmental conditions which can contribute to vaccine development, diagnostic improvement, and ultimately leptospirosis control. SignificanceLeptospirosis is a devastating zoonotic disease affecting humans, wild and domestic animals around the globe. Different species and serovars of Leptospira can affect various animal host species differently; for instance, a serovar that is asymptomatic in the rat may cause severe disease in a dog or human. These differences in host response are not only found at the species and serovar level for Leptospira, but also at the strain level. A prime example comes from strains JB197 and HB203, both species L. borgpetersenii, both serovar Hardjo. Interestingly, JB197 causes a severe acute infection in the hamster while HB203 causes an asymptomatic chronic infection. Understanding these unique relationships between pathogen and host species is important, especially in the context of prevention technologies such as vaccine design, where the strain of Leptospira used as a bacterin might have different efficiencies in different hosts. In this study, proteomic profiles of strains JB197 and HB203 were analyzed, and results revealed diverse protein expression profiles of outer membrane proteins, as well as proteins functioning in motility and growth.

Seroprevalence of Leptospirosis in Cattle in Smallholder Livestock Production Systems in Bungoma County, Kenya

Leptospirosis is an important re-emerging bacterial zoonosis of public health importance in Kenya. It is transmitted through contact with contaminated soil, water, or urine of infected animals. The disease is associated with high economic losses which include high cost of diagnosis and treatment, disruption of international trade in animals and animal products and loss of milk production following mastitis among others. In this study, the sero-prevalence of bovine leptospirosis in Kimilili and Mt Elgon Sub-Counties of Bungoma County in Kenya was estimated. A cross-sectional study was conducted between April to July, 2017 where blood serum samples from 200 head of cattle from five wards and one slaughter house using systematic random sampling technique. The samples were then subjected to the Enzyme Linked Immunorsorbent Assay (ELISA) test. The findings show an overall sero-prevalence for leptospirosis in cattle in the study area to be 16%. The sero-prevalence of leptospirosis in the study area by wards is as follows; 10.7% in Kibingei, 12.5% in Kimilili, 17.6 in Maeni, 16.7% in Kamukuywa and 15.6% in Kaptama. The study also reveals that the sero-prevalence was relatively higher in Kimilili Slaughterhouse which recorded 21.0%. The study therefore demonstrates that there is a high sero-prevalence of leptospirosis in cattle in Kimilili and Mt Elgon Sub-Counties, Bungoma County. This study therefore provides critical public health information which is necessary in guiding leptospirosis prevention and control in Bungoma County. It is therefore recommended that strategies for surveillance and laboratory diagnosis of leptospirosis should be initiated in Bungoma County. This will help in providing better estimates of leptospirosis burden in the county.

KNOWLEDGE AND AWARENESS OF LEPTOSPIROSIS AMONG MALAYSIAN POPULATION: A PILOT STUDY

Leptospirosis is a zoonotic disease that poses a significant public health concern, particularly in tropical regions. Knowledge, awareness, and preventive practices (KAP) towards leptospirosis play a crucial role in safeguarding human health and mitigating the spread of the disease. To gain insights into the knowledge gaps and behavioural patterns towards leptospirosis among the Malaysian population, an online survey was conducted and randomly distributed through social media platforms. A total of 200 respondents participated in this study, where the majority belonged to young Malay adults (58.5%), and most resided in Selangor, Kuala Lumpur, and Kelantan. Data from the survey found that 59% of the total respondents had limited specific knowledge and awareness of leptospirosis, while 44% demonstrated poor practices in preventing the transmission of leptospirosis. While this input generally reflects the knowledge and awareness of a certain age group of the respondents, there is a need to enhance their knowledge and awareness through effective strategies that will lead to a better understanding and practices towards the management and control of leptospirosis.

Análise espacial da soroprevalência de leptospirose e toxoplasmose no população canina em área de vulnerabilidade socioeconômica e ambiental

ABSTRACT Leptospirosis and toxoplasmosis are zoonoses of occupational character that are spread worldwide, mainly in tropical and socioeconomically vulnerable areas. Both diseases have vertebrate hosts, which spread the infectious agent to the environment and are potentially infectious to humans and can progress to fatal cases. The present study reinforces the importance of One Health for the control and prophylaxis of leptospirosis and toxoplasmosis using sentinel animals in areas of socioeconomic vulnerability based on a serological study. A total of 336 blood samples were obtained from the canine population of the urban district, which has high rates of poverty and sanitation. The results were analyzed based on seroreactivity animals and georeferencing by kernel spatial mapping. A total of 43.3% (52/120) of the animals were seroreagents for anti-Leptospira spp., with a predominance of Canicola (35/52 = 67.3%) and Pyrogenes (5/52 = 9.6%), while 52.97% (178/336) of the dogs were seroreactive for anti-Toxoplasma gondii. The presence of seroreagent dogs for both zoonosis alert to the inadequate hygienic-sanitary conditions of the studied region, and highlight the importance of a survey of the social, economic and environmental structure to identify factors related to the links in the epidemiological chain of pathogen transmission and necessary corrective actions.

Characteristics of leptospirosis cases, prevention and control managements 1955–2020, Guangzhou, China

BackgroundLeptospirosis, which is an easily overlooked zoonotic disease, was once widespread in Guangzhou, China. However, due to the implementation of control measures, the number of cases is decreasing. Based on the characteristics of leptospirosis cases in Guangzhou, China, between 1955 and 2020, we describe the changes and achievements in prevention and control management strategies over that period. MethodsThe development of the leptospirosis control system in Guangzhou occurred over three periods: Period I: 1955–1978; Period II: 1979–2000; and Period III: 2001–2020. Data about leptospirosis cases were obtained from the Guangzhou Center for Disease Control and Prevention (CDC) and national health departments. The demographic characteristics of leptospirosis patients were analyzed using descriptive statistics. ResultsDuring Period I, only the Guangzhou CDC and medical institutions at every level participated in the leptospirosis control system. During Period II, additional types of organizations, including local CDCs, countryside committees, community committees, and the Patriotic Health Movement Commission, were involved in the control system. Additionally, strong links were established between different organizations. After entering Period III, an increasing number of departments joined the cooperation, and the management of human patients was expanded to include the management of host animals, and thus, the prevalence of leptospirosis was monitored and controlled in various ways. The leptospirosis control system in Guangzhou has been further improved. From 1955 to 2020, a total of 2501 leptospirosis cases were recorded in Guangzhou, and the number of cases decreased significantly over time, from 1608 (Period I) to 744 (Period II) and then to 149 (Period III). ConclusionThe improvements of the leptospirosis control system in Guangzhou that occurred over decades were associated with a marked decrease in the number of leptospirosis cases. Guangzhou's experience can provide guidance for other countries or cities around the world facing similar challenges.

Epidemiology of Human Leptospirosis in Bantul District, Yogyakarta Province, Indonesia

Bantul District has the highest number of leptospirosis cases in Yogyakarta Province. Transmission of leptospirosis occurs primarily through exposure to water and soil contaminated with the urine of infected animals. This study aims to describe the epidemiological characteristics of leptospirosis in Bantul District, Yogyakarta. This is cross-sectional research. Leptospirosis cases were collected from active and passive detections. Selected positive cases underwent home visits for interviews about epidemiological data. Rat surveys were carried out to find out the existing rat species and successful traps in the study area. The most leptospirosis cases were found at Kasihan public health center. There were 74 suspect cases, 4 probable cases, and 15 cases positively confirmed. The cases increased from January to April and from November - December. Cases in males were more related to his work as a farmer. Fever, headache and muscle aches are the most common symptoms felt by leptospirosis sufferers. The most caught rats was Rattus tanezumi. Leptospirosis epidemiological information can be used as a basis or reference for Bantul District Health Office in prevention and control of leptospirosis in priority areas

Pathogenic Leptospira Infections in Hubei Province, Central China.

Leptospirosis is an important zoonosis that is caused by pathogenic Leptospira, which is considered to be a re-emerging infectious disease in many countries. Rodents are the most important reservoirs for both human and animal infection. An epidemiological survey of pathogenic Leptospira in rodents is important for the prevention and control of leptospirosis. In this study, a total of 964 rodents were captured from six cities in Hubei Province, and two pathogenic Leptospira species (L. interrogans and L. borgpetersenii) were detected using nested PCR with an overall prevalence of 4.8%. L. interrogans was distributed in five sampling sites, which may be the dominant species of pathogenic Leptospira in Hubei Province. In addition, Rattus norvegicus showed a relatively high infection rate, which may play an important role in the transmission and infection of pathogenic Leptospira. This study reveals the prevalence of pathogenic Leptospira in wild rodents in Hubei Province, suggesting that the risk of leptospirosis infection in Hubei Province still exists.

One Health: An Effective and Ethical Approach to Leptospirosis Control in Australia.

The increasing concerns over emerging infectious diseases and potential pandemics led to the formation of One Health, a collaborative, multidisciplinary approach to address the risks from human-animal-ecosystem interactions. This multi-sectoral approach is specifically important in Australia, a biodiverse country with unique flora, fauna, and many infectious diseases, including leptospirosis. Leptospirosis is a relatively rare but potentially fatal zoonosis, with an attributed mortality of around 60,000 deaths per year worldwide. In recent years, sporadic cases and alarming outbreaks of leptospirosis have been notified in many states and territories of Australia, noteworthily in 2018 and 2019. The sudden outbreaks in these two years have raised a question about the possibility of a more severe menace or a potential threat to both humans and animals. Amid the fight against leptospirosis, One Health has been shown to be an excellent and ideal framework, especially in Australia, the country that has taken the lead in zoonosis control using this approach. In this review, the focus will be put on the effectiveness and ethics of One Health in leptospirosis control under the Australian setting to further advocate the implementation of this framework for many other infectious diseases.

Investigating Leptospira dynamics in a multi-host community using an agent-based modelling approach.

Leptospirosis, a neglected bacterial zoonosis, is a global public health issue disproportionately affecting impoverished communities such as urban slums in the developing world. A variety of animal species, including peridomestic rodents and dogs, can be infected with different strains of leptospirosis. Humans contract leptospirosis via exposure to water or soil contaminated with the urine of infected animals. Due to the unavailability of safe and effective vaccines, preventive strategies mainly focus on minimizing human exposure to contaminated environment. In marginalized communities, this approach is ineffective due to infrastructure deficiencies and the difficulties in implementing sanitation and hygiene practices. Moreover, continuing the expansion of urban slums worldwide will likely contribute to the increase in outbreaks of leptospirosis. Effective prevention of leptospirosis outbreaks will therefore require a thorough understanding of Leptospira transmission dynamics in impoverished, high-density settings. We developed the agent-based model MHMSLeptoDy to investigate Leptospira dynamics in a realistic, in silico high-density community of rodents, dogs and human hosts, and two host-adapted Leptospira strains. Virtual explorations using MHMSLeptoDy were undertaken to evaluate alternate interventions and to assess the zoonotic transmission risk of leptospirosis. A key finding from model explorations is that rodents are the main contributors of rodent-adapted as well as dog-adapted strains in the environment, whereas dogs play an important role in distributing the rodent-adapted strain. Alternate leptospirosis control strategies can be evaluated using the open-source, customizable agent-based model, MHMSLeptoDy. This modelling approach provides a sophisticated mechanism to quantitatively evaluate nuanced intervention strategies and inform the design of rational, locally relevant leptospirosis control programmes.

Seroprevalence and Molecular Characterization of Leptospira spp. in Rats Captured near Pig Farms in Colombia.

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.

ErpY-like protein, a promising antigen to leptospirosis control: characterization of antigenic and immunogenic potential

ErpY-like protein (LIC11966) is an antigen from Leptospira spp., which is possibly involved in the infection process and, consequently, can be a promising solution for the development of new diagnostic tests and vaccines. Here, the presence of the erpY-like gene was evaluated in several Leptospira serovars by polymerase chain reaction (PCR), and the ErpY-like recombinant protein was produced and characterized in terms of antigenicity and immunogenicity in vivo. The erpY-like gene was detected by PCR in all Leptospira pathogenic serovars tested (n = 8) and was absent in the saprophytic ones. The rErpY-like protein was recognized by antibodies present in the sera of humans and animals (swine and canine) naturally infected, suggesting ErpY-like expression during natural infection. The rErpY-like protein used to immunize mice with Freund’s adjuvant stimulated a mixed Th1/Th2 response, an important protective immunity against leptospirosis

Leptospirosis: Morbidity, mortality, and spatial distribution of hospitalized cases in Ecuador. A nationwide study 2000-2020.

BackgroundIn Ecuador, leptospirosis surveillance involves a mandatory notification of all cases and a hospitalization for severe illness. Morbidity and mortality are, nevertheless, underestimated and contribute directly to the status of leptospirosis as a neglected disease. Leptospira spp. is zoonotic in Ecuador with established endemic transmission in the Tropics. Here, we review retrospective national data within the country to aid in control strategies.Methodology/Principal findingsIn a population-based nationwide study, we analysed morbidity, mortality, and spatial distribution on confirmed hospital-discharged leptospirosis cases from 2000–2020 from a publicly accesible National Database, including males and females of all ages. We computed data for the 24 provinces across the four-geoclimatic regions of Ecuador based on seasonal and monthly variations and calculated rates according to age and sex. The spatial distribution was estimated at the level of ecoregions, provinces, and cantons. A total of 2,584 hospitalizations were recorded over all three continental regions in 22 provinces, except Carchi province and the Galapagos Islands. The annual incidence varied from 0.27 to 2.45 cases per 100,000 inhabitants with ages ranging from 1 to 98 years-old and an overall male/female ratio of 1.92:1. Most hospitalizations and deaths occurred in males ages 25–34 years. We registered 79 fatalities (3.06%); the highest mortality rate was 0.05 per 100,000 inhabitants. More cases clustered in the tropical cantons of central and north of the Coast and in the southern Amazon when compared to the Andes.Conclusions and significanceOur findings evidence leptospirosis endemicity and pinpoint the highest incidence within resource-poor tropical settings. The highest incidence occurred in males of adult age, with those also exhibiting the highest mortality. The national incidence rate was stable, but peaks occurred intermittently during the rainy seasons. Thus, strategies aimed at leptospirosis monitoring and control involving the application of preventive measures should consider this season and the aforementioned high-risk groups.

Pathogenic Leptospira Species Are Widely Disseminated among Wild Rodents in Urban Areas of Guangzhou, Southern China.

Leptospirosis is a neglected zoonotic disease with global importance caused by pathogenic Leptospira. Rodents are considered the most significant reservoirs for both human and animal infection. Historically, Guangzhou has been an endemic region of human leptospirosis. Although the incidence in humans has significantly decreased in the past decades in China, the epidemiology of pathogenic Leptospira in wild rodents is of great significance for the prevention and control of human leptospirosis. In this study, a total of 296 wild rodents were trapped in urban areas of Guangzhou, in southern China, in 2020. Three pathogenic Leptospira species, i.e., Leptospira interrogans, L. borgpetersenii, and L. kirschneri, were detected by nested PCR in this wild rodent population with an overall prevalence of 9.5%. Additionally, L. interrogans was detected in three of the four captured rodent species, and the relative high prevalence suggests that L. interrogans probably represents the preponderant species of the pathogenic Leptospira circulating in Guangzhou. Taken together, this study reveals a high genetic diversity of pathogenic Leptospira disseminated among wild rodents in the urban areas of Guangzhou and emphasizes that the risk for the occurrence of human leptospirosis in Guangzhou remains high.

Incidence of leptospirosis in Fujian province, 2015-2020

Objective: To analyze the incidence of leptospirosis in Fujian province from 2015 to 2020 and provide the scientific evidences for the risk assessment, prevention and control of leptospirosis. Methods: The incidence data of leptospirosis in Fujian during 2015-2020 were collected from China Information System for Disease Control and Prevention for a descriptive analysis, and software ArcGIS 10.3.1 was used for spatial autocorrelation analysis, and rats were captured in 17 surveillance areas during the same period, and the rat organs were collected for pathogen culture, the level of Leptospira antibody was detected in serum samples of rats, healthy population and the serum samples of patients sent by the hospitals. The infection status of Leptospira in human and rats were analyzed. Results: The incidence of leptospirosis in Fujian showed a downward trend from 2015 to 2020. A total of 176 cases of leptospirosis were reported. There were obvious seasonality and bimodal distribution. The majority of cases were farmers, accounting for 49.43% (87/176). Most cases were aged 30-69 years (85.80%, 151/176). The male to female ratio of the cases was 3.51∶1 (137∶39). Spatial autocorrelation analysis showed that leptospirosis had high or low clustering areas. From 2015 to 2020, the average capture rate of rats in 17 surveillance areas was 6.96% (1 519/21 838), Rattus losea, Rattus flavipectus and Niviventer fulvescens were the main species. The average positive rate of Leptospira antibody in rats was 28.64% (252/880). Java and Autumnalis were the predominant serogroups, accounting for 56.75% (143/252) and 17.46% (44/252), respectively. The average positive rate of Leptospira antibody in healthy population was 16.13% (254/1 575), and Autumnalis and Australis were the predominant serogroups, accounting for 71.65% (182/254). The confirmation rate of leptospirosis in patient serum samples sent by the hospitals was 2.23% (188/8 431), Autumnalis (56.38%, 106/188) and Hebdomadis (19.68%, 37/188) were the major serogroups. Conclusions: The incidence of leptospirosis in Fujian showed a downward trend from 2015 to 2020, there were obvious area clustering and seasonality. The high clustering areas were mainly distributed in northern, western and central Fujian. Java and Autumnalis were the predominant serogroups in rats. The infection rate in healthy population decreased year by year. Autumnalis and Hebdomadis were the main serogroups in population in Fujian.

Role of Diagnostics in Epidemiology, Management, Surveillance, and Control of Leptospirosis.

A One Health approach to the epidemiology, management, surveillance, and control of leptospirosis relies on accessible and accurate diagnostics that can be applied to humans and companion animals and livestock. Diagnosis should be multifaceted and take into account exposure risk, clinical presentation, and multiple direct and/or indirect diagnostic approaches. Methods of direct detection of Leptospira spp. include culture, histopathology and immunostaining of tissues or clinical specimens, and nucleic acid amplification tests (NAATs). Indirect serologic methods to detect leptospiral antibodies include the microscopic agglutination test (MAT), the enzyme-linked immunosorbent assay (ELISA), and lateral flow methods. Rapid diagnostics that can be applied at the point-of-care; NAAT and lateral flow serologic tests are essential for management of acute infection and control of outbreaks. Culture is essential to an understanding of regional knowledge of circulating strains, and we discuss recent improvements in methods for cultivation, genomic sequencing, and serotyping. We review the limitations of NAATs, MAT, and other diagnostic approaches in the context of our expanding understanding of the diversity of pathogenic Leptospira spp. Novel approaches are needed, such as loop mediated isothermal amplification (LAMP) and clustered regularly interspaced short palindromic repeats (CRISPR)-based approaches to leptospiral nucleic acid detection.