Leptospirosis: an emerging global public health problem

Epidemiological analysis of leptospirosis, dengue, and Co-infection rates among febrile illness cases in Dakshina Kannada, Karnataka

INTRODUCTION

Leptospirosis and dengue are two significant public health concerns in tropical and subtropical regions, often resulting in severe forms of disease and fatality. This study addresses the pressing public health issues of leptospirosis and dengue in the Dakshina Kannada district of Karnataka, India. Both diseases pose significant health risks and are relatively understudied in this region, making it essential to investigate their prevalence and clinical presentations for targeted healthcare planning.

AIM

The primary aim is to determine the frequency of leptospirosis and dengue among febrile illness cases to understand the epidemiological patterns and assess co-infection rates in Dakshina Kannada.

METHOD

Between 2020 and 2021, serum samples suspected of leptospirosis were tested using IgM ELISA (n = 1629) and the Microscopic Agglutination Test (MAT) (n = 92) for leptospirosis, while dengue was tested using NS1Ag and IgM antibodies ELISA (n = 1415). Data were collected through medical records and patient interviews. Seasonal trends, gender, and age distributions were analyzed.

RESULT

The study found a significant prevalence of leptospirosis (21 %) and dengue (10 %) among febrile illness cases in the study area, with a 1.3 % co-infection rate. Clinically, fever was common to both diseases, but leptospirosis also frequently exhibited symptoms such as abdominal pain, myalgia, and jaundice. MAT screening revealed a predominance of anti-leptospiral antibodies against the Djasiman, Pyrogenes, Hurstbridge, Hebdomadis, and Grippotyphosa serogroups in Dakshina Kannada.

CONCLUSION

The study highlights the urgent need for focused public health interventions, improved diagnostic tools, and targeted epidemiological studies to manage these diseases. The findings underscore the necessity of enhancing diagnostic capabilities and public health awareness, particularly considering the significant health risks posed by leptospirosis and dengue in the region.

Leptospirosis in India: insights on circulating serovars, research lacunae and proposed strategies to control through one health approach

Leptospirosis is one of the most neglected zoonotic infections of public health concern worldwide and a remerging infection in tropical countries such as India. The infection least explored disease and the epidemiological and other critical data are scarce for the disease rate reported and to control the infection. Leptospirosis as sapronosis is as underrated as the infection itself, and this article aims to explore the significance of this aspect of the disease. The research review aimed at the epidemiological understanding of the infection to control the negative impact of the disease. A mixed review and analysis were carried out to understand the knowledge published on the critical and understudied areas like epidemiology, transmission, diagnosis, treatment, and control of infection. A systematic analysis was carried out to extract information about the reported circulating strains, and research lacunae in India with the published data available in PubMed. The article elaborately discusses crucial inference areas of infection transmission and addresses lacunae in critically unacclaimed areas of infection to control the spread of infection using one health approach (OHA), and strategies to control leptospiral infection are proposed. The article also reviewed how and why Leptospirosis can be best studied and controlled by "One health approach" in India.

Spatiotemporal assessment of pathogenic Leptospira in subtropical coastal watersheds

The World Health Organization classifies leptospirosis as a significant public health concern, predominantly affecting impoverished and unsanitary regions. By using the Pensacola Bay System as a case study, this study examines the underappreciated susceptibility of developed subtropical coastal ecosystems such as the Pensacola Bay System to neglected zoonotic pathogens such as Leptospira. We analyzed 132 water samples collected over 12 months from 44 distinct locations with high levels of Escherichia coli (>410 most probable number/100 mL). Fecal indicator bacteria (FIB) concentrations were assessed using IDEXX Colilert-18 and Enterolert-18, and an analysis of water physiochemical characteristics and rainfall intensity was conducted. The LipL32 gene was used as a quantitative polymerase chain reaction (qPCR) indicator to identify the distribution of Leptospira interrogans. The results revealed 12 instances of the presence of L. interrogans at sites with high FIB over various land cover and aquatic ecosystem types. Independent of specific rainfall events, a seasonal relationship between precipitation and elevated rates of fecal bacteria and leptospirosis was found. These findings highlight qPCR's utility in identifying pathogens in aquatic environments and the widespread conditions where it can be found in natural and developed areas.

Prevalence, genetic diversity and eco-epidemiology of pathogenic Leptospira species in small mammal communities in urban parks Lyon city, France

Rodents are recognized as the main reservoirs of Leptospira spp. Rats, in particular, serve as hosts for the widely predominant Leptospira interrogans serovar Icterohaemorrhagiae, found worldwide. Several studies have shown the importance of other reservoirs, such as mice or hedgehogs, which harbor other leptospires' serovars. Nevertheless, our knowledge of circulating Leptospira spp. in reservoirs other than rats remains limited. In this context, we proposed an eco-health approach to assess the health hazard associated with leptospires in urban green spaces, where contacts between human/small mammals and domestic animals are likely. We studied the prevalence, the diversity of circulating strains, and epidemiology of pathogenic Leptospira species in small terrestrial mammal communities (rodents and shrews), between 2020-2022, in two parks in Lyon metropolis, France. Our study showed a significant carriage of Leptospira spp. in small terrestrial mammals in these parks and unveiled a global prevalence rate of 11.4%. Significant variations of prevalence were observed among the small mammal species (from 0 to 26.1%), with Rattus norvegicus exhibiting the highest infection levels (26.1%). We also observed strong spatio-temporal variations in Leptospira spp. circulation in its reservoirs. Prevalence seems to be higher in the peri-urban park and in autumn in 2021 and 2022. This is potentially due to differences in landscape, abiotic conditions and small mammal communities' composition. Our study suggests an important public health relevance of rats and in a lesser extent of other rodents (Apodemus spp., Clethrionomys glareolus and Mus musculus) as reservoirs of L. interrogans, with rodent species carrying specific serogroups/serovars. We also emphasize the potential hazard associated between the shrew Crocidura russula and L. kirschneri. Altogether, these results improve our knowledge about the prevalence of leptospirosis in an urban environment, which is an essential prerequisite for the implementation of prevention of associated risks.

Domestic dogs in indigenous Amazonian communities: Key players in Leptospira cycling and transmission?

BACKGROUND

Leptospirosis is the world's most common zoonotic disease. Mitigation and control rely on pathogen identification and understanding the roles of potential reservoirs in cycling and transmission. Underreporting and misdiagnosis obscure the magnitude of the problem and confound efforts to understand key epidemiological components. Difficulties in culturing hamper the use of serological diagnostics and delay the development of DNA detection methods. As a result, especially in complex ecosystems, we know very little about the importance of different mammalian host species in cycling and transmission to humans.

METHODOLOGY/PRINCIPAL FINDINGS

We sampled dogs from five indigenous Kichwa communities living in the Yasuní National Park in the Ecuadorian Amazon basin. Blood and urine samples from domestic dogs were collected to assess the exposure of these animals to Leptospira and to identify the circulating species. Microscopic Agglutination Tests with a panel of 22 different serovars showed anti-leptospira antibodies in 36 sampled dogs (75%), and 7 serogroups were detected. Two DNA-based detection assays revealed pathogenic Leptospira DNA in 18 of 19 dog urine samples (94.7%). Amplicon sequencing and phylogenetic analysis of 16S rRNA and SecY genes from 15 urine samples revealed genetic diversity within two of three different Leptospira species: noguchii (n = 7), santarosai (n = 7), and interrogans (n = 1).

CONCLUSIONS/SIGNIFICANCE

The high prevalence of antibodies and Leptospira DNA provides strong evidence for high rates of past and current infections. Such high prevalence has not been previously reported for dogs. These dogs live in the peridomestic environment in close contact with humans, yet they are free-ranging animals that interact with wildlife. This complex web of interactions may explain the diverse types of pathogenic Leptospira observed in this study. Our results suggest that domestic dogs are likely to play an important role in the cycling and transmission of Leptospira. Future studies in areas with complex ecoepidemiology will enable better parsing of the significance of genotypic, environmental, and host characteristics.

Seroprevalence and Risk Factors Associated with Leptospirosis in High-Risk Occupational Groups in the State of Gujarat as Determined by IgM ELISA and MAT Test: A Cross-Sectional Study

Background

Leptospirosis is a reemerging zoonosis affecting humans and animals worldwide in tropical and subtropical countries. The study was conducted to estimate the seroprevalence of leptospirosis in high-risk occupational groups (cattle farm workers, poultry farm workers, and slaughterhouse workers) in the state of Gujarat and to determine related risk factors for leptospirosis.

Methods

Using an interview-guided questionnaire, a cross-sectional study was conducted involving 123 people in high-risk occupational groups (namely, cattle farm workers, poultry farm workers, and slaughterhouse workers) from five districts of the state of Gujarat, India. The participants' serum samples were screened for antileptospiral antibodies by using Immunoglobulin G (IgG) and Immunoglobulin M (IgM) enzyme-linked immunosorbent assays (ELISAs) followed by a microscopic agglutination test (MAT). The Chi-square (χ2) test and odds ratio were calculated using IBM SPSS Statistics for Windows, version 22 (IBM Corp., Armonk, N.Y., USA) to ascertain the associated risk factors.

Results

Regarding demographic information, this study included 104 men and 19 women in high-risk occupational groups. The overall seroprevalence of antileptospiral antibodies in these high-risk workers was 46.3%. The seroprevalence was the highest among poultry farm workers (56.6%), followed by cattle farm workers (54.5%) and slaughterhouse workers (25.6%). The MAT in combination with IgM is adequate for the serological diagnosis of leptospirosis, but we have also employed IgG ELISA to understand the chronic infection in these high-risk occupational groups as exposure was both past and present. Tests were conducted for antibodies against various Leptospira serovars in the major serogroups; frequent serovars included Hurstbridge, Panama, Javanica, Tarassovi, Copenhageni, Pomona, and Weaveri, among others. The significant (P < 0.05) risk factors associated with leptospirosis in these high-risk occupations reported to be living in field areas, the presence of livestock in the neighborhood, working in slaughterhouses, drinking water from natural water resources, contact with animals such as dogs or livestock, and wounds during occupational practice.

Conclusion

Considering the high seroprevalence of leptospirosis, high-risk occupational groups should be regularly screened for potential development of the fatal disease. Hurstbridge was found to be the most prevalent serovar in the studied population, followed by Panama, Javanica, and Tarassovi.

Antibiotic prophylaxis for leptospirosis

BACKGROUND

Leptospirosis is a global zoonotic and waterborne disease caused by pathogenic Leptospira species. Antibiotics are used as a strategy for prevention of leptospirosis, in particular in travellers and high-risk groups. However, the clinical benefits are unknown, especially when considering possible treatment-associated adverse effects. This review assesses the use of antibiotic prophylaxis in leptospirosis and is an update of a previously published review in the Cochrane Library (2009, Issue 3).

OBJECTIVES

To evaluate the benefits and harms of antibiotic prophylaxis for human leptospirosis.

SEARCH METHODS

We identified randomised clinical trials through electronic searches of the Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE, Embase, LILACS, Science Citation Index Expanded, and other resources. We searched online clinical trial registries to identify unpublished or ongoing trials. We checked reference lists of the retrieved studies for further trials. The last date of search was 17 April 2023.

SELECTION CRITERIA

We included ⁠⁠randomised clinical trials of any trial design, assessing antibiotics for prevention of leptospirosis, and with no restrictions on age, sex, occupation, or comorbidity of trial participants. We looked for trials assessing antibiotics irrespective of route of administration, dosage, and schedule versus placebo or no intervention. We also included trials assessing antibiotics versus other antibiotics using these criteria, or the same antibiotic but with another dose or schedule.

DATA COLLECTION AND ANALYSIS

We followed Cochrane methodology. The primary outcomes were all-cause mortality, laboratory-confirmed leptospirosis regardless of the presence of an identified clinical syndrome (inclusive of asymptomatic cases), clinical diagnosis of leptospirosis regardless of the presence of laboratory confirmation, clinical diagnosis of leptospirosis confirmed by laboratory diagnosis (exclusive of asymptomatic cases), and serious adverse events. The secondary outcomes were quality of life and the proportion of people with non-serious adverse events. We assessed the risk of bias of the included trials using the RoB 2 tool and the certainty of evidence using GRADE. We presented dichotomous outcomes as risk ratios (RR) and continuous outcomes as mean difference (MD), with their 95% confidence intervals (CI). We used a random-effects model for our main analyses and the fixed-effect model for sensitivity analyses. Our primary outcome analyses included trial data at the longest follow-up.

MAIN RESULTS

We identified five randomised clinical trials comprising 2593 participants that compared antibiotics (doxycycline, azithromycin, or penicillin) with placebo, or one antibiotic compared with another. Four trials assessed doxycycline with different durations, one trial assessed azithromycin, and one trial assessed penicillin. One trial had three intervention groups: doxycycline, azithromycin, and placebo. Three trials assessed pre-exposure prophylaxis, one trial assessed postexposure prophylaxis, and one did not report this clearly. Four trials recruited residents in endemic areas, and one trial recruited soldiers who experienced limited time exposure. The participants' ages in the included trials were 10 to 80 years. Follow-up ranged from one to three months. Antibiotics versus placebo Doxycycline compared with placebo may result in little to no difference in all-cause mortality (RR 0.15, 95% CI 0.01 to 2.83; 1 trial, 782 participants; low-certainty evidence). Prophylactic antibiotics may have little to no effect on laboratory-confirmed leptospirosis, but the evidence is very uncertain (RR 0.56, 95% CI 0.25 to 1.26; 5 trials, 2593 participants; very low-certainty evidence). Antibiotics may result in little to no difference in the clinical diagnosis of leptospirosis regardless of laboratory confirmation (RR 0.76, 95% CI 0.53 to 1.08; 4 trials, 1653 participants; low-certainty evidence) and the clinical diagnosis of leptospirosis with laboratory confirmation (RR 0.57, 95% CI 0.26 to 1.26; 4 trials, 1653 participants; low-certainty evidence). Antibiotics compared with placebo may increase non-serious adverse events, but the evidence is very uncertain (RR 10.13, 95% CI 2.40 to 42.71; 3 trials, 1909 participants; very low-certainty evidence). One antibiotic versus another antibiotic One trial assessed doxycycline versus azithromycin but did not report mortality. Compared to azithromycin, doxycycline may have little to no effect on laboratory-confirmed leptospirosis regardless of the presence of an identified clinical syndrome (RR 1.49, 95% CI 0.51 to 4.32; 1 trial, 137 participants), on the clinical diagnosis of leptospirosis regardless of the presence of laboratory confirmation (RR 4.18, 95% CI 0.94 to 18.66; 1 trial, 137 participants), on the clinical diagnosis of leptospirosis confirmed by laboratory diagnosis (RR 4.18, 95% CI 0.94 to 18.66; 1 trial, 137 participants), and on non-serious adverse events (RR 1.12, 95% CI 0.36 to 3.48; 1 trial, 137 participants), but the evidence is very uncertain. The certainty of evidence for all the outcomes was very low. None of the five included trials reported serious adverse events or assessed quality of life. One study is awaiting classification. Funding Four of the five trials included statements disclosing their funding/supporting sources, and the remaining trial did not include this. Three of the four trials that disclosed their supporting sources received the supply of trial drugs directly from the same pharmaceutical company, and the remaining trial received financial support from a governmental source.

AUTHORS' CONCLUSIONS

We do not know if antibiotics versus placebo or another antibiotic has little or have no effect on all-cause mortality or leptospirosis infection because the certainty of evidence is low or very low. We do not know if antibiotics versus placebo may increase the overall risk of non-serious adverse events because of very low-certainty evidence. We lack definitive rigorous data from randomised trials to support the use of antibiotics for the prophylaxis of leptospirosis infection. We lack trials reporting data on clinically relevant outcomes.

First isolation and genotyping of pathogenic Leptospira spp. from Austria

Leptospirosis is a globally distributed zoonotic disease. The standard serological test, known as Microscopic Agglutination Test (MAT), requires the use of live Leptospira strains. To enhance its sensitivity and specificity, the usage of locally circulating strains is recommended. However, to date, no local strain is available from Austria. This study aimed to isolate circulating Leptospira strains from cattle in Austria to enhance the performances of the routine serological test for both humans and animals. We used a statistical approach combined with a comprehensive literature search to profile cattle with greater risk of leptospirosis infection and implemented a targeted sampling between November 2021 and October 2022. Urine and/or kidney tissue were sampled from 410 cattle considered at higher risk of infection. Samples were inoculated into EMJH-STAFF culture media within 2-6 h and a real-time PCR targeting the lipL32 gene was used to confirm the presence/absence of pathogenic Leptospira in each sample. Isolates were further characterised by core genome multilocus sequence typing (cgMLST). Nine out of 429 samples tested positive by PCR, from which three isolates were successfully cultured and identified as Leptospira borgpetersenii serogroup Sejroe serovar Hardjobovis, cgMLST cluster 40. This is the first report on the isolation and genotyping of local zoonotic Leptospira in Austria, which holds the potential for a significant improvement in diagnostic performance in the country. Although the local strain was identified as a cattle-adapted serovar, it possesses significant zoonotic implications. Furthermore, this study contributes to a better understanding of the epidemiology of leptospirosis in Europe.

Human leptospirosis: In search for a better vaccine

Leptospirosis is a neglected disease caused by bacteria of the genus Leptospira and is more prevalent in tropical and subtropical countries. This pathogen infects humans and other animals, responsible for the most widespread zoonosis in the world, estimated to be responsible for 60 000 deaths and 1 million cases per year. To date, commercial vaccines against human leptospirosis are available only in some countries such as Japan, China, Cuba and France. These vaccines prepared with inactivated Leptospira (bacterins) induce a short-term and serovar-specific immune response, with strong adverse side effects. To circumvent these limitations, several research groups are investigating new experimental vaccines in order to ensure that they are safe, efficient, and protect against several pathogenic Leptospira serovars, inducing sterilizing immunity. Most of these protocols use attenuated cultures, preparations after LPS removal, recombinant proteins or DNA from pathogenic Leptospira spp. The aim of this review was to highlight several promising vaccine candidates, considering their immunogenicity, presence in different pathogenic Leptospira serovars, their role in virulence or immune evasion and other factors.

Identifying risk factors and disease severity in leptospirosis: A meta-analysis of clinical predictors

Leptospirosis is a bacterial zoonosis with a wide spectrum of clinical presentations. In order to identify potential risk factors and predictors of disease severity, a meta-analysis of the clinical features of severe and non-severe leptospirosis patients was conducted. PubMed was searched to collect studies on the difference in clinical characteristics of severe and nonsevere patients, and data were analyzed using Comprehensive Meta-Analysis V3 software. Results showed that patients with severe outcomes were more likely to have dyspnoea, oliguria, and hemorrhagic symptoms than nonsevere patients. Determining these predictors in the early stages of the disease could thus significantly reduce the development of severe cases and related mortality.

Domestic dogs in indigenous Amazonian communities: key players in Leptospira cycling and transmission?

Background

Leptospirosis is the world's most common zoonotic disease. Mitigation and control rely on pathogen identification and understanding the roles of potential reservoirs in cycling and transmission. Underreporting and misdiagnosis obscure the magnitude of the problem and confound efforts to understand key epidemiological components. Difficulties in culturing hamper the use of serological diagnostics and delay the development of DNA detection methods. As a result, especially in complex ecosystems, we know very little about the importance of different mammalian host species in cycling and transmission to humans.

Methodology/Principal Findings

We sampled five indigenous Kichwa communities living in the Yasuní National Park in the Ecuadorian Amazon basin. Blood and urine samples from domestic dogs were collected to assess the exposure of these animals to Leptospira, and to identify the circulating species. Microscopic Agglutination Tests with a panel of 22 different serovars showed anti-leptospira antibodies in 36 sampled dogs (75%), and 10 serotypes were detected. Two DNA-based detection assays revealed pathogenic Leptospira DNA in 18 of 19 dog urine samples (94.7%). Amplicon sequencing and phylogenetic analysis of 16s rDNA and SecY genes from 15 urine samples revealed genetic diversity within two of three different Leptospira species: noguchii (n=7), santarosai (n=7), and interrogans (n=1).

Conclusions/Significance

The high prevalence of antibodies and Leptospira DNA provides strong evidence for high rates of past and current infections. Such high prevalence has not been previously reported for dogs. These dogs live in the peridomestic environment in close contact with humans, yet they are free-ranging animals that interact with wildlife. This complex web of interactions may explain the diverse types of pathogenic Leptospira observed in this study. Our results suggest that domestic dogs are likely to play an important role in the cycling and transmission of Leptospira. Future studies in areas with complex ecoepidemiology will enable better parsing of the significance of genotypic, environmental, and host characteristics.

Clinical characteristics and outcomes of patients with leptospirosis complicated with acute pancreatitis: a systematic review

OBJECTIVES

Acute pancreatitis (AP) is a severe complication of leptospirosis. This review focuses on the current evidence of AP in patients with leptospirosis.

METHODS

Data on clinical characteristics, biochemical parameters, diagnosis, complications, critical care, fluid management, operative management, and outcomes were analyzed. This study was registered in PROSPERO (CRD42022360802).

RESULTS

We included 35 individual case reports and 4 case series involving 79 patients. Sex was reported for 48 (60.7%) patients; 38 (48.1%) were male and 10 (12.6%) were female. The patients' mean age was 45.13 (15-83 years). Acute kidney injury, thrombocytopenia, hypotension, and liver injury were the most common complications reported. Complete recovery was reported for 36 (45.5%) patients. Biochemical and radiological recovery was reported for 10 (12.6%) and 9 (11.3%) patients, respectively. Death was reported in 18 (22.7%) patients.

CONCLUSION

A high degree of clinical suspicion and different modalities of investigations are essential in the diagnosis of AP in leptospirosis. AP can be easily missed in leptospirosis because both conditions share similar clinical presentations and complications. Because of the high prevalence of acute kidney injury, judicious fluid management and close monitoring are mandatory.

Diffuse Myocardial Calcifications Caused by Leptospirosis

Severe leptospirosis is defined by multiple organ failure. Cardiac involvement is an uncommon complication in patients with leptospirosis, and the pathophysiology of it is not well understood. Diffuse myocardial calcifications connected with sepsis are infrequent, and their effect on heart function is hard to predict. They can lead to conduction disorders and arrhythmias, thereby causing sudden death. Myocardial calcifications are usually revealed incidentally by radiological investigations such as computed tomography (CT) scan in patients with or after sepsis and are commonly unidentified in practice because most cases progress gradually. This case report involves a 51-year-old male who presented to the emergency department with sepsis. The patient was diagnosed with leptospirosis, causing septic cardiomyopathy and diffuse calcifications of the myocardium of the left ventricle. This case highlights the importance of multimodality imaging and a multidisciplinary approach to diagnoses since early recognition and treatment are essential. Follow-up of such patients is necessary to monitor the systolic function of the left ventricle and cardiac arrhythmia.

Aptamer-based assay for rapid detection, surveillance, and screening of pathogenic Leptospira in water samples

Leptospirosis is a potentially fatal waterborne infection caused by Leptospira interrogans, impacting both humans and animals in tropical regions. However, current diagnostic methods for detecting pathogenic Leptospira have sensitivity, cost, and time limitations. Therefore, there is a critical need for a rapid, sensitive, and cost-effective detection method. This study presents the development of an aptamer-based assay for pathogenic Leptospira detection. Aptamers targeting Leptospira were generated using the SELEX method and screened for binding affinity with major Leptospiral outer membrane proteins through in silico analysis. The aptamer with the highest binding affinity was selected for further evaluation. To enable visual detection, the aptamer was conjugated to gold nanoparticles (AuNPs), resulting in a colorimetric response in the presence of L. interrogans. The aptamer-AuNP-based colorimetric assay exhibited a detection limit of 57 CFU/mL and demonstrated high specificity and reproducibility in detecting pathogenic Leptospira in water samples. This aptamer-based assay represents a significant advancement in leptospirosis diagnostics, offering a rapid, sensitive, and cost-effective approach for detecting pathogenic Leptospira. Its potential for epidemiological applications, such as outbreak source identification and improved prevention, diagnosis, and treatment, particularly in resource-limited settings, highlights its importance in addressing the challenges associated with leptospirosis.

Isolation and molecular characterization of pathogenic Leptospira species from cattle in Zaria and its environs, Kaduna State, Nigeria

Leptospirosis is a zoonotic disease caused by pathogenic serovars of Leptospira spp. The paucity of information on the status of leptospirosis in cattle in the study area led to this study. A cross-sectional study was carried out with a total of 130 kidney samples from cattle which were cultured using Ellinghausen Mc-Cullough Johnson Harris enrichment and examined on dark field microscope after 8 weeks of culture. DNA was extracted directly from 6 kidney tissues to confirm the presence of pathogenic Leptospira spp. and further sequenced to determine the species of Leptospira spp. Result of the culture indicated that the overall occurrence of Leptospira spp.was 32.30 %. Phylogenetic analysis of lipL32 sequences showed Leptospira interrogans isolates from cattle nucleotide homology ranging from 99.40 % to 99.73 % with a query cover of 100 % when compared with sequence from gene bank. In conclusion, this study established that cattle may act as a significant reservoir of leptospirosis in the study area and pose a potential risk to abattoir workers, veterinarians and local communities.

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

Background

Leptospirosis, 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.

Methods

The 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.

Results

During 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).

Conclusion

The 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.

Leptospirosis and characterization of Leptospira isolates from patients in Koprivnica-Križevci County, Croatia from 2000-2004

Introduction

Leptospirosis, caused by spirochetes of the genus Leptospira , is present in the Koprivnica-Križevci County area, Croatia. Clinical manifestation can range from asymptomatic, short-term mild, non-specific febrile disease, to severe forms with high mortality rates.

Aim

The aim of the study was to valuate culture in front of microscopic agglutination test (MAT) for diagnosis of infection, and to evaluate clinical and laboratory features of the disease. Moreover, we want to characterize Leptospira strains involved in infection in Koprivnica-Križevci County, Croatia.

Methods

We included 68 patients with clinical presentation consistent with leptospirosis collected in a 5-year period (2000-2004). Clinical samples (blood, urine and cerebrospinal fluid, CSF) were inoculated in Kolthoff's medium; species of isolated Leptospira strains was determined with Tm of real-time PCR, serogroup/serovar with MAT and NotI-RFLP analysis. Demonstration of specific antibodies in patients' sera was done using microscopic agglutination test.

Results

Leptospira was isolated from the blood of 14/51(27.5 %) patients and the most often identified serogroup/serovar was Icterohaemorrhagiae (8/10, 80%) followed by Grippotyphosa (10%). Regarding to species level, 8/10 isolated belonged to L. interrogans sensu stricto and one to L. kirschneri species. MAT was carried out on 51 patients with suspected leptospirosis, and was positive in 11/51(21.5 %) patients. Most of our patients presented with moderate severe symptoms, were hospitalized from August to October, and were infected mainly during the work or recreation in our county. The frequency of particular clinical features and pathological laboratory findings correlated with the severity of the clinical condition.

Conclusions

Leptospirosis can be confirmed microbiologically, culture and MAT contributed almost equally to the diagnosis of infection. Serovar Icterohaemorrhagiae was found as the dominant one, and L. interrogans sensu stricto as dominant species in our county. Epidemiological data shown that leptospirosis occurs seasonally, affects the rural population, and most commonly is presented with moderate severe clinical course.

Diagnostic accuracy of an immunomagnetic separation-PCR assay to detect pathogenic Leptospira spp. in urine from dairy cattle, using a Bayesian latent class model

Leptospirosis is a zoonotic disease that has spread worldwide and causes significant economic losses in the dairy industry. The causal agents of this infectious disease are members of the genus Leptospira, known as pathogenic Leptospira spp. Specific clinical signs of the infection are difficult to detect. Therefore, the disease is normally under-diagnosed, mostly due to the lack of a cost-effective technique for diagnosing animals with a low bacterial load in their urine. The aim of this study was to assess the diagnostic accuracy of a qPCR coupled with a previous Immunomagnetic separation (IMS) step (IMS-qPCR) against a qPCR without using IMS, using a Bayesian latent class model (2 tests, 3 populations) to determine the leptospirosis infectious status in naturally infected dairy cattle. The results revealed that IMS qPCR had a sensitivity (Se) of 95.7% (95% Probability Interval (PI) = 85.0; 99.4%) and a specificity (Sp) of 98% (95% PI = 96.1; 99.4%), indicating that it is more sensitive than conventional qPCR (Se = 69.7% (95% PI = 59.2; 79.0%); median difference = 25.2% (Monte Carlo Error = 10.2%); and the Sp = 98.8% (95% PI = 97.6; 99.5%), median difference = 0.8% (Monte Carlo Error = 2.1%). Therefore, results shows that IMS-qPCR is a more useful diagnostic tool in terms of accuracy for detecting infectious animals with pathogenic Leptospira in their urine.

Effect of Cattle-Specific Diseases on Carcass Inspection and Meat Quality

There are severe cattle-specific viral (foot and mouth, vesicular stomatitis, rinderpest, rift valley fever, malignant catarrhal fever, lumpy skin, rabies, bovine leukosis, bovine viral diarrhea, and bovine spongiform encephalopathy), bacterial (tuberculosis, black quarter, botulism, malignant oedema, leptospirosis, brucellosis, anthrax, hemogenic septicemia, actinomycosis, actinobacillosis, mastitis, and metritis), parasitic (lungworm, fasciolosis, cysticercosis, hydatid disease, and onchocercosis), and protozoal (trypanosomiasis, theileriosis, anaplasmosis, babesiosis, and sarcosporidiosis) diseases that affect the carcass judgment and meat quality. These diseases adversely affect cattle health, welfare, and red meat production. This chapter aims to describe the etiology, mode of transmission, ante-mortem and post-mortem findings, carcass and meat quality judgment, and differential diagnosis of these diseases.

Occupational health surveillance and detection of emerging occupational diseases among Taiwan farmers, through analysis of national-based farmers' and medico-administrative databases

OBJECTIVES

The purpose of this study was to identify occupational injuries and diseases associated with agriculture in Asia, to provide a reference for prevention and hypotheses for future research.

METHODS

We matched data on agricultural workers (n = 963,124) enrolled in Taiwan's national Farmers Health Insurance since its inception in 1989, to general population controls of the same age, gender, and township. The study population was linked to the National Health Insurance Research Database from 2001 to 2016 for inpatient cases. Logistic regression was used to assess odds ratios for outcomes.

RESULTS

Farmers had 2.76 times the risk of mycotic corneal ulcer (95% CI: 1.96-3.87) and 1.65 times the risk of typhus fever infections (95% CI: 1.47-1.85) compared to the general population. The odds ratio for poisonous animal bites was 2.22 (95% CI: 2.07-2.38), for falling into a storm drain or manhole was 2.04 (95% CI: 1.30-3.20), and for toxic effects from pesticides was 2.01 (95% CI: 1.92-2.11). The toxic effects of organophosphate and carbamate insecticides were correlated with the cultivation of rice, fruit trees, and flowers. Q fever and motorcycle accidents were associated with fruit tree cultivation.

CONCLUSIONS

The study identifies agricultural occupational injuries and diseases that may inform occupational health policy and the development of prevention priorities to prevent occupational hazards for farmers.

Seroprevalence of human leptospirosis in a rural community from Tandil, Argentina. Assessment of risk factors and spatial analysis

Leptospirosis is a neglected zoonosis that is widely distributed in the world. Although it is endemic in Argentina, prevalence remains unknown. The aims of the study were: (i) to determine the prevalence of leptospirosis in humans from a rural community in Tandil Argentina, (ii) to identify infecting Leptospira spp. serogroups, (iii) to identify factors associated with the infection, (iv) to estimate the population attributable fraction (PAF) of the risk factors and (v) to determine the spatial patterns of disease presentation and related risk factors. Blood samples from 202 participants were collected. A survey was conducted to obtain clinical and epidemiological data. Serological testing was performed by the microscopic agglutination test (MAT). Univariate and multivariate methods were applied to evaluate associations. Spatial clusters were investigated for seroprevalence and risk factors. Antibodies were found in 32.2% of participants (95% CI: 25.8-39.1). The most prevalent serogroup was Hebdomadis followed by Sejroe; Icterohaemorrhagiae; Tarassovi and Canicola. Living at lower altitudes (OR: 13.04; 95% CI: 2.60-65.32); not having access to water supply network (OR: 2.95; 95% CI: 1.30-6.69); living close to flooded streets (OR: 2.94; 95% CI: 1.14-7.69) and practicing water sports (OR: 3.12; 95% CI: 1.12-8.33) were associated with seropositivity. Factors related with housing characteristics, services and infrastructure had the higher PAF (from 17% to 81%). A spatial cluster with higher rates of positivity and of the main risk factors was determined. This work contributes useful data for specific preventive measures that should be implemented for the control of the disease.

An Overview of Anthropogenic Actions as Drivers for Emerging and Re-Emerging Zoonotic Diseases

Population growth and industrialization have led to a race for greater food and supply productivity. As a result, the occupation and population of forest areas, contact with wildlife and their respective parasites and vectors, the trafficking and consumption of wildlife, the pollution of water sources, and the accumulation of waste occur more frequently. Concurrently, the agricultural and livestock production for human consumption has accelerated, often in a disorderly way, leading to the deforestation of areas that are essential for the planet's climatic and ecological balance. The effects of human actions on other ecosystems such as the marine ecosystem cause equally serious damage, such as the pollution of this habitat, and the reduction of the supply of fish and other animals, causing the coastal population to move to the continent. The sum of these factors leads to an increase in the demands such as housing, basic sanitation, and medical assistance, making these populations underserved and vulnerable to the effects of global warming and to the emergence of emerging and re-emerging diseases. In this article, we discuss the anthropic actions such as climate changes, urbanization, deforestation, the trafficking and eating of wild animals, as well as unsustainable agricultural intensification which are drivers for emerging and re-emerging of zoonotic pathogens such as viral (Ebola virus, hantaviruses, Hendravirus, Nipah virus, rabies, and severe acute respiratory syndrome coronavirus disease-2), bacterial (leptospirosis, Lyme borreliosis, and tuberculosis), parasitic (leishmaniasis) and fungal pathogens, which pose a substantial threat to the global community. Finally, we shed light on the urgent demand for the implementation of the One Health concept as a collaborative global approach to raise awareness and educate people about the science behind and the battle against zoonotic pathogens to mitigate the threat for both humans and animals.

Clinical characteristics and prognosis of patient with leptospirosis: A multicenter retrospective analysis in south of China

Purpose

Leptospirosis is a zoonotic disease caused by pathogenic spirochetes of the genus Leptospira. However, there is currently no consensual definition or diagnostic criteria for severe and different forms of leptospirosis. Therefore, more insight on clinical manifestations, risk factors, and outcomes of leptospirosis is warranted. The identification of leptospirosis with distinct clinical manifestations and prognosis in our population.

Methods

Multiple correspondence analysis and hierarchical classification on principal components were presented to identify different clinical types of leptospirosis. The outcomes were clinical phenotypes, laboratory and imaging findings, and prognosis.

Results

The 95 enrolled patients had median values of 54.0 years (39.0-65.0) for age, 9.0 (7.0-14.0) for total hospital stay lengths, of whom 86.3% was male and 40.0% was transferred to ICU. Three clinical types were distinguished: mild leptospirosis (n=43, 45.3%) with less organ dysfunction and shorter hospital stays; respiratory leptospirosis (n=28, 29.5%) with hemoptysis, and respiratory and circulatory failure; and hepato-renal leptospirosis (n=24, 25.3%) with worst liver and kidney dysfunction. Total hospital mortality was 15.8% and was associated with dyspnea and high levels of neutrophil counts.

Conclusions

The identification of leptospirosis with distinct clinical manifestations and prognosis in our population may assist clinicians to distinguish leptospirosis-like disease. Moreover, dyspnea and neutrophil count were found to be independent risk factors for severe leptospirosis progression.

Seroprevalence of pathogenic Leptospira spp. in domestic dogs from southern Chile and risk factors associated with different environments

Leptospirosis is a neglected and severe zoonotic bacterial disease that affects canine populations worldwide, and it is present in animals from different settings, such as urban and rural environments. Therefore, a cross-sectional study was conducted on owned domestic dogs from urban and rural origins in southern Chile. The study aimed: 1) to estimate the true prevalence of pathogenic Leptospira in dogs from urban and rural environments in southern Chile, 2) to determine the serovars circulating in an endemic area of Chile, 3) to assess potential risk factors associated with seropositivity in dogs from urban and rural environments. Blood samples from 706 canines were collected, and the serum was tested with Micro-Agglutination-Test (MAT), using a panel of 13 serovars. A Bayesian approach was applied to estimate True prevalence (TP). In addition, dog owners answered a questionnaire that had prompts regarding dog characteristics and potential risk factors. The effect of these factors on the risk of being infected was analysed using a logistic regression model. The TP for urban dogs was 9.4% and 9.1% for rural animals. However, seroprevalence was higher in dogs with different individual, lifestyle, and habitat characteristics regarding their origin. For example, in urban animals, those living in places with rodents roaming near houses and dogs with rodent hunting habits had decreased risk for the seropositivity in MAT. On the other hand, in rural dogs, those of a recognized breed, with contact with cattle and sheep, living with more than one cat at home and living in places close to natural water sources have more risk to seropositivity in MAT. The presence of anti-Leptospira antibodies is widespread in pet dogs in urban and rural environments in southern Chile, and individual, lifestyle and habitat characteristics of the animals, according to the origin, are associated with the seropositivity in MAT. Therefore, the adoption of preventive measures is urgent, in addition to increase the awareness either in public health institutions, practitioners and companion animals' owners, considering the zoonotic potential of Leptospira infection and the close contact between people and their pets.

Prevalence of leptospirosis among patients attending renal and general outpatient clinics in Mulago Hospital, Kampala, Uganda

In this study, we sought to establish the prevalence of leptospirosis among renal patients and general outpatients attending Mulago National Referral Hospital, Uganda. A total of 254 patients were recruited, their blood samples collected and interviewer-administered semi-structured questionnaires provided between July and October 2018. These questionnaires captured data on sociodemographic characteristics and symptoms of leptospirosis disease. An individual with an average body temperature of 37.3 ± 1.1 °C was considered to be having fever. The blood samples were analyzed using the standard Microscopic Agglutination Test (MAT) with a panel of 14 Leptospira-serovars belonging to 11 serogroups. Prevalence was reported with confidence intervals while questionnaire data was analyzed using logistic regression analysis. We present an overall prevalence of leptospirosis at 4.70% (95% CI = 2.60-8.30) after analysis of samples from recruited patients. This seropositivity (12/254) was classified into 7 serovars, among which, Canicola and Djasiman presented with titers between ≥ 200 and ≥ 400 in samples of both renal patients and outpatients, indicative of the active disease. Djasiman was the highest contributor to the reported prevalence. Overall, most examined participants presented with common symptoms of abdominal pain (AOR = 24.4, 95% CI (2.42-267.89), p = 0.02) and dehydration (AOR = 0.1, 95% CI (0.01-0.69), p = 0.05). Our study suggests that these symptoms and previous history of abdominal pain may be caused by Leptospira infections among the studied participants. We therefore recommend inclusion of leptospirosis in the differential diagnosis for renal and febrile illnesses. Indeed, abdominal pain and dehydration should be further studied with a bigger sample size and for other related febrile illnesses.

A lethal model of Leptospira infection in hamster nasal mucosa

Leptospirosis is a fatal zoonosis caused by contact between skin or a mucosal surface and contaminated soil or water. Hamsters were infected by intraperitoneal injection fto establish experimental leptospirosis, which is not a natural route of infection. There are no reports of nasal mucosal infection in hamsters. In this study, infection of the nasal mucosa was performed to establish a model of natural infection. Both methods of infection can cause lethal models with similar symptoms in the later stages of infection, such as weight loss, blood concentration, increased neutrophils (GRAN), and decreased lymphocytes (LYM) in the blood, severe organ damage and liver function obstruction. The burden of Leptospira in the organs and blood was lower in the mucosal inoculation groups at 1 day after infection. However, mucosal infection induced a higher Leptospira burden in urine than intraperitoneal infection in the late stages of infection. After nasal mucosal infection, antibody levels were higher and lasted longer. These results indicated that the route of nasal mucosal infection is a good choice for studying leptospirosis in hamsters.

The establishment of a leptospirosis experimental model is still key to elucidating the pathogenesis of leptospirosis. Hamsters were infected by intraperitoneal injection to establish experimental leptospirosis, although this is not a natural route of infection. The transmission characteristics of Leptospira and the disease progression in hamsters infected by a natural transmission route (e.g. through mucosal surfaces) had not been explored. In this study, we compared the dynamics of Leptospira infection in hamsters inoculated via the nasal mucosa or by intraperitoneal inoculation, and compared the burden of Leptospira and the level of antibodies produced with disease progression, such as body weight, serology, haematological changes and histopathological changes. Our data suggested that there are significant differences in the dynamics of infection between intraperitoneal and mucosal infection pathways. Although the result was the same in the later stage of infection, the course of mucosal infection was slower, which may better recapitulate the natural history of the disease, assist in studying kidney disease caused by Leptospira, and provide an animal model for the study of leptospirosis mucosal immunity.

Next Generation Sequencing for Diagnosis of Leptospirosis Combined With Multiple Organ Failure: A Case Report and Literature Review

Introduction

Leptospirosis poses a major threat to human life. The disease spectrum ranges from a nearly undetectable presentation to severe multi-organ dysfunction and death. Leptospirosis is difficult to diagnose by traditional antibody and culture tests. We here present a case of multiple organ failure associated with leptospirosis.

Material and Methods

A 64-year-old woman presented with fatigue and arthralgia, which developed rapidly into multiple organ injuries, and she eventually died of cerebral hemorrhage. Serum antibody test and cultures of blood, sputum, urine, and feces samples were all negative. The patient was diagnosed with leptospirosis by the next-generation sequencing (NGS).

Conclusion

We conclude that leptospirosis is a neglected zoonosis caused by pathogenic Leptospira species. New techniques such as NGS are highlighted for early diagnosis. Surveillance for pathogens during diagnosis can provide guidance for clinical treatment and improves prognosis.

A core and pan gene map of Leptospira genus and its interactions with human host

Leptospira species are the etiological agent of an emerging zoonotic disease known as "Leptospirosis" that substantially affects both human health and economy across the globe. Despite the global importance of the disease, pathogenetic features, host-adaptation and proper diagnosis of this bacteria remains lacking. To accomplish these gaps, pan-genome of Leptospira genus was explored in the present study. The pan-genome of Leptospira genus was comprised of core (692) and accessory parts (softcore:1804, shell:6432, cloud:16,600). The functional analysis revealed the abundancy of "Translation, ribosomal structure and biogenesis" COG class in core-genes; whereas in accessory parts, genes involved in signal transduction was the most abundant. Furthermore, pathogen-host interaction (PHI) analysis of core and accessory proteins with human proteins showed the presence of a total of 599 and 510 interactions, respectively. There were eight hubs in core PHI network and five hubs in PHI network of accessory proteins. The human's proteins involved in these interactions were found functionally enriched in metabolic processes, responses to stimulus and immune system processes. Further, pan-genome based phylogeny separated the Leptospira genus in three major clades (belonging to P1, P2 and S) which relates with their pathogenicity level. Additionally, pathogenic and saprophytic clade specific genes of Leptospira have also been identified and functionally annotated for COG, KEGG and virulence factors. The results revealed the presence of 102 pathogenic and 215 saprophytic group specific gene clusters. The COG functional annotation of pathogen specific genes showed that defence mechanism followed by signal transduction mechanisms category were most significantly enriched COG categories; whereas in saprophytic group, signal transduction mechanisms was the most abundant COG, suggesting their role in adaptation and hence important for microbe's evolution and survival. In conclusion, this study provides a new insight of genomic features of Leptospira genus which may further be implemented for development of better control actions of the disease.

Prevalence of anti-leptospiral antibodies and frequency distribution of Leptospira serovars in small ruminants in enzootic South Peninsular India

Background and Aim:

For understanding the epidemiology of leptospirosis, the confined abundance of several species of pathogenic leptospires and knowledge on the serovar(s) prevalent in the reservoir and carrier hosts may be a useful indicator of transmission to incidental/accidental hosts in a geographical niche. The present study was carried out to ascertain the frequency distribution of Leptospira serovars and the prevalence of anti-leptospiral antibodies in small ruminants (sheep and goats) in the epidemiological units (villages) in the coastal districts of enzootic regions in South Peninsular India.

Materials and Methods:

A total of 1167 serum samples (sheep n=299 and goats n=868) from apparently healthy animals, randomly collected from various epidemiological units were tested in microscopic agglutination test (MAT) using 18 reference Leptospira serovars antigens.

Results:

The overall seroprevalence of 40% (at 95% confidence intervals [CI]: 36.82-42.43) in small ruminants (44% [95% CI: 40.49-52.26] in sheep and 38% [95% CI: 34.96-41.41] in goats) was observed with the predominance of Icterohaemorrhagiae, Javanica, Australis, Hurstbridge, and Pyrogenes serogroup anti-leptospiral antibodies in the studied region. The Chi-squared test revealed that the presence of anti-leptospiral antibodies is significantly not independent (associated) across the administrative division (Chi-square=105.80, p<0.05) as well as for sheep (Chi-square=34.67, p<0.01) and goats (Chi-square=68.78, p<0.01). Among seropositive samples (n=462 reactors), the MAT was positive for more than one serovar in 73% of sheep (95/131) and 53% of goats (177/331), representing an overall 59% cross-reactive prevalence in small ruminants. The determined frequency distribution (varied among small ruminants) of the employed serovars representing major reactive serogroup was Icterohaemorrhagiae (29.87), Javanica (20.78), Australis (20.35), Hurstbridge (16.23), Pyrogenes (15.8), Djasmin (15.58), Bataviae (15.37), Autumnalis (14.5), Canicola (14.5), Hebdomadis (14.07), Shermani (13.64), Panama (13.42), Sejroe (12.77), etc.

Conclusion:

This study indicates alarmingly high seroprevalence of leptospirosis in small ruminants with existing endemicity in the studied region in South Peninsular India. Further, these prevalent serovars in the administrative division may be of use in the reference panels of antigens in the MAT in both humans and animal disease diagnostic laboratories for effective and timely diagnosis of leptospirosis and to combat the challenges in public health.

Herpes Infections in Suspected Cases of Yellow Fever in the Democratic Republic of the Congo

In the battle to quickly identify potential yellow fever arbovirus outbreaks in the Democratic Republic of the Congo, active syndromic surveillance of acute febrile jaundice patients across the country is a powerful tool. However, patients who test negative for yellow fever virus infection are too often left without a diagnosis. By retroactively screening samples for other potential viral infections, we can both try to find sources of patient disease and gain information on how commonly they may occur and co-occur. Several human arboviruses have previously been identified, but there remain many other viral families that could be responsible for acute febrile jaundice. Here, we assessed the prevalence of human herpes viruses (HHVs) in these acute febrile jaundice disease samples. Total viral DNA was extracted from serum of 451 patients with acute febrile jaundice. We used real-time quantitative PCR to test all specimens for cytomegalovirus (CMV), herpes simplex virus (HSV), human herpes virus type 6 (HHV-6) and varicella-zoster virus (VZV). We found 21.3% had active HHV replication (13.1%, 2.4%, 6.2% and 2.4% were positive for CMV, HSV, HHV-6 and VZV, respectively), and that nearly half (45.8%) of these infections were characterized by co-infection either among HHVs or between HHVs and other viral infection, sometimes associated with acute febrile jaundice previously identified. Our results show that the role of HHV primary infection or reactivation in contributing to acute febrile jaundice disease identified through the yellow fever surveillance program should be routinely considered in diagnosing these patients.

Both Full-Length and Protease-Cleaved Products of Osteopontin Are Elevated in Infectious Diseases

Circulating full-length osteopontin (FL-OPN) is elevated in plasma from patients with various infectious diseases, such as adult T-cell leukemia, Mycobacterium tuberculosis (TB), hepatitis virus infection, leptospirosis, acquired immune deficiency syndrome (AIDS), AIDS/TB, and coronavirus disease 2019 (COVID-19). Proteolysis of OPN by thrombin, matrix metalloproteases, caspase 8/3, cathepsin D, plasmin, and enterokinase generates various cleaved OPNs with a variety of bioactivities by binding to different target cells. Moreover, OPN is susceptible to gradual proteolysis. During inflammation, one of the cleaved fragments, N-terminal thrombin-cleaved OPN (trOPN or OPN-Arg¹⁶⁸ [OPN-R]), induces dendritic cell (DC) adhesion. Further cleavage by carboxypeptidase B2 or carboxypeptidase N removes Arg¹⁶⁸ from OPN-R to OPN-Leu¹⁶⁷ (OPN-L). Consequently, OPN-L decreases DC adhesion. In particular, the differences in plasma level over time are observed between FL-OPN and its cleaved OPNs during inflammation. We found that the undefined OPN levels (mixture of FL-OPN and cleaved OPN) were elevated in plasma and reflected the pathology of TB and COVID-19 rather than FL-OPN. These infections are associated with elevated levels of various proteases. Inhibition of the cleavage or the activities of cleaved products may improve the outcome of the therapy. Research on the metabolism of OPN is expected to create new therapies against infectious diseases.

Clinical Features and Severity of Leptospirosis Cases Reported in the Hawke's Bay Region of New Zealand

AIMS

To record demographics, symptoms, signs, and laboratory features of confirmed leptospirosis cases in the Hawke's Bay area of New Zealand to aid clinicians in diagnosis and recognition of severity.

METHODS

Review of suspected leptospirosis cases referred to the reference laboratory from hospitals in the Hawke's Bay region between March 2003 and March 2012. Inclusion criteria were IgM positivity and diagnosis confirmed with either polymerase chain reaction (PCR) or microscopic agglutination test (MAT). A retrospective systematic review of case notes was completed for demographic and laboratory data.

RESULTS

Forty-three cases were included. Most common presenting symptoms were pyrexia (93%), myalgia, and headache (both 86%). 93% of patients worked in the farming or meat industries. The most common biochemical abnormalities were elevated CRP (100%) and abnormal urinalysis (93%). There was no difference in disease severity between icteric and anicteric patients. Compared to other studies, patients in New Zealand have less severe disease.

CONCLUSION

Contrary to popular understanding, this study has not found icteric leptospirosis to be related to more severe disease. Anicteric leptospirosis should be a differential diagnosis in patients presenting with pyrexia, myalgia, and headache who have elevated CRP and abnormal urinalysis.

Climate influence the human leptospirosis cases in Brazil, 2007-2019: a time series analysis

BACKGROUND

Human leptospirosis is responsible for great losses and deaths, especially in developing countries, which can be mitigated by knowing the correct health indicators and climate influence on the disease.

METHODS

Leptospirosis cases and deaths, population and precipitation were recovered from different databases (2007-2019). Annual incidence, mortality and case fatality rates (CFRs) of human leptospirosis and average precipitation were calculated for Brazil and its regions. Time series analysis using an moving average with external variable (ARMAX) model was used to analyse the monthly contribution and precipitation influence over leptospirosis cases for each Brazilian region and for the whole country. A forecast model to predict cases for 2020 was created for Brazil.

RESULTS

Human leptospirosis exhibited heterogeneous distribution among Brazilian regions, with most cases occurring during the rainy season and precipitation influenced the disease occurrence in all regions but the South. The forecast model predicted 3276.99 cases for 2020 (mean absolute percentage error 14.680 and root mean square error 53.013). Considering the annual average for the period, the leptospirosis incidence was 1913 cases per 100 000 inhabitants, mortality was 0.168 deaths per 100 000 inhabitants and the CFR was 8.83%.

CONCLUSIONS

The models built can be useful for planning leptospirosis surveillance and control actions for the whole country and its regions and, together with the health indicators, revealed no uniform epidemiological situation of leptospirosis in Brazil.

Existence of Similar Leptospira Serovars among Dog Keepers and Their Respective Dogs in Mwanza, Tanzania, the Need for a One Health Approach to Control Measures

This study investigated seroepidemiology of Leptospira serovars among the dog keepers and their dogs in the city of Mwanza, Tanzania. A total of 205 dog keepers and 414 dogs were tested for Leptospira antibodies using a microscopic agglutination test (MAT). The median age of the dog keepers was 26 (inter quartile range (IQR): 17-40) years and median duration of keeping dogs was 36 (IQR: 24-120) months. The seropositivity of Leptospira antibodies was (33/205 (16.1%, 95% CI: 11.0-21.1) among dog keepers and (66/414 (15.9%, 95% CI: 12.4-19.4) among dogs, p = 0.4745. Among the serovars tested (Sokoine, Grippotyphosa, Kenya, Pomona and Hebdomadis), the most prevalent serovar was Sokoine in both dog keepers and their dogs (93.9% (31/33) vs. and 65.1% (43/66), p = 0.009). Thirty-one out of thirty-three seropositive dog keepers (93.9%) had dogs positive for Leptospira antibodies with 28 (84.9%) having similar serovars with their respective seropositive dogs. Having tertiary education (AOR: 0.24, 95% CI: 0.07-0.84, p = 0.026) independently protected individuals from being Leptospira seropositive. More than three quarters of dog keepers had similar serovars as their dogs, necessitating one health approach to control measures in endemic areas.

Leptospira interrogans Serovar Hardjo Seroprevalence and Farming Practices on Small-Scale Dairy Farms in North Eastern India; Insights Gained from a Cross-Sectional Study

Leptospirosis is a zoonotic disease of major public health concern in India. Bovines play an important role in maintaining and transmitting this disease and proximity between dairy cows and humans makes the dairy cow-human nexus a transmission route of public health interest, yet one currently under-examined in North Eastern India. We report a cross-sectional survey carried out on small-scale dairy farms in the states of Assam and Bihar in North Eastern India investigating seroprevalence for Leptospira interrogans serovar Hardjo, the most common pathogenic serovar reported in cattle worldwide. Higher seroprevalence was reported on dairy farms in Bihar 4.5% (95% CI 2.6–7.5%) than in Assam 1.2% (95% CI 0.42–3.6%), but overall seroprevalence levels were low. The study is the first indication of leptospirosis circulating in small-scale dairy farms in these states. To correlate farming practices with zoonotic risk, we combined results from a dairy farmer questionnaire with cow seroprevalence. However, low seroprevalence levels found in this study made the identification of risk factors difficult. Nevertheless, poor farming practices around hygiene and biosecurity on dairy farms have been highlighted. Implementing simple measures could mitigate environmental contamination, and therefore, reduce the risk of Leptospira interrogans, and other zoonoses transmission, at the animal-environment-human interface.

Development of in-house ELISAs as an alternative method for the serodiagnosis of leptospirosis

BACKGROUND

Leptospirosis is most often diagnosed clinically, and a laboratory test with high diagnostic accuracy is required.

METHODS

IgM and IgG ELISAs using Leptospira antigens were established and evaluated in relation to the microscopic agglutination test (MAT). Antigen preparation consisted of saprophytic Leptospira biflexa to detect genus-specific antibodies (genus-specific ELISA) and a pool of the five most prevalent Leptospira interrogans serovars in Sri Lanka to detect serovar-specific antibodies (serovar-specific ELISA). IgM and IgG immune responses were studied in severe and mild leptospirosis patients (n = 100 in each group).

RESULTS

The ELISAs showed high repeatability and reproducibility. The serovar-specific IgM-ELISA showed a sensitivity of 80.2% and specificity of 89%; the genus-specific IgM-ELISA showed a sensitivity of 83.3% and specificity of 91%. The serovar- and genus-specific IgG-ELISAs showed sensitivities of 73.3% and 81.7%, respectively, and specificities of 83.3% and 83.3%, respectively. The commercial IgM-ELISA showed a sensitivity of 79.2% and specificity of 93%. The commercial IgG-ELISA showed a sensitivity of 50% and specificity of 96.7%. IgM levels observed in mild and severe leptospirosis patients were significantly higher than in the healthy control group, with mean absorbance values of 0.770, 0.778, and 0.163, respectively. Severe leptospirosis patients had significantly higher mean anti-leptospiral IgG levels compared to both mild leptospirosis patients and healthy control group subjects (0.643, 0.358, and 0.116, respectively; ANOVA, p < 0.001). The presence of anti-leptospiral IgG above an optical density of 0.643 at 1:100 could predict a high risk of severe disease.

CONCLUSION

The serovar-specific in-house ELISA could be used for the laboratory diagnosis of leptospirosis in endemic settings. The high levels of anti-leptospiral IgG observed suggest its value as a predictor of disease severity.

Evaluation of recombinant leptospiral surface antigen (Lsa27) lipoprotein for serodiagnosis of human leptospirosis by latex agglutination test

PURPOSE

Leptospirosis has wide clinical presentations often mimicking other illnesses, thus rapid and simple diagnostics will have facilitated the initial patient management and therapy compared to other inaccessible and laborious tests/assays.

METHOD

In this study, the sensitized latex beads coated with purified recombinant outer membrane (OM)-leptospiral surface antigen (Lsa27) lipoprotein of pathogenic Leptospira was evaluated as a diagnostic antigen in latex agglutination test (LAT) for the detection of anti-leptospiral antibodies in the human sera. The prepared rLsa27 latex beads were evaluated with the confirmed microscopic agglutination test (MAT) reactive (at 1:50) Leptospira-specific positive (n = 42) and non-reactive negative (n = 80) sera from human cases suspected of leptospirosis with the history of pyrexia of unknown origin.

RESULT

The results revealed the relative diagnostic sensitivity of 90.48 % (confidence interval (CI) at 95 % : 77.4-97.3 %) and diagnostic specificity of 91.35 % (CI at 95 %: 82.8-96.4 %), with an accuracy of 90.98 % (CI at 95 %: 84.44-95.41 %), and the kappa value of 0.8036 ± 0.056 SE (CI at 95 %: 0.69-0.91) with a substantial agreement against gold standard serological MAT.

CONCLUSION

The findings suggest that the rLsa27 protein-based LAT can be useful as a simple rapid screening diagnostic test for the detection of anti-leptospiral antibodies in the sera of humans. This rapid test can be complemented by other confirmatory diagnostics for the early detection of Leptospira antibodies which may in turn help in the prompt treatment and mitigates the public health problem at primary health care level.

Human leptospirosis in the Marche region: Over 10 years of surveillance

We conducted a 10 years' retrospective study in 347 symptomatic individuals to assess the regional distribution of leptospirosis. A total of 173 individuals were diagnosed positive (49.8%): 11.5% were found positive to Leptospira by microscopic agglutination test positive, whereas 38.3% were found positive by microscopy analysis. The maximum peak of leptospirosis was reached in 2017 (n = 32). The most common serovars were Icterohaemorrhagiae and Poi.

Insight into the Epidemiology of Leptospirosis: A Review of Leptospira Isolations from "Unconventional" Hosts

Leptospirosis is a re-emerging worldwide zoonotic disease. Even though the primary serological test for diagnosis and surveying is the microscopic agglutination test (MAT), isolation remains the gold-standard test to detect Leptospira infections. The leptospirosis transmission is linked to maintenance and accidental hosts. In the epidemiology of Leptospira some serovar are strictly related to specific maintenance hosts; however, in recent years, the bacterium was isolated from an even wider spectrum of species. The aim of this review is to report the isolation of Leptospira strains in animals which could be recognized as "unconventional" hosts, analyzing studies from 1960 to 2020 that highlighted the Leptospira isolation. This scientific literature aimed to provide evidence of infection in several animal species including of the Carnivora, Didelphimorphia, Rodentia, Cetacea, Cingulata, Afrosoricida, Chiroptera and Primate orders, as well as in Reptilia and Amphibia classes. In conclusion, the spreading of Leptospira is attention-worthy because the infection could occur in all the animal species ranging in a specific area. Further screening and isolations are needed to collect all necessary data to gain a complete understanding of leptospirosis epidemiology and its modifications.

Renal Replacement Therapy in a Patient Diagnosed With Pancreatitis Secondary to Severe Leptospirosis

In areas where the zoonotic disease leptospirosis is endemic, reduced morbidity and mortality is strongly linked to quick initiation of renal replacement therapy.

Molecular Detection of Microorganisms Associated with Small Mammals and Their Ectoparasites in Mali

Small mammals are the natural reservoirs for many zoonotic pathogens. Using molecular tools, we assessed the prevalence of bacteria and protozoans in small mammals and their ectoparasites in Faladjè, Bougouni, and Bamoko, Mali. A total of 130 small mammals belonging to 10 different species were captured, of which 74 (56.9%) were infested by ectoparasites, including Laelaps echidnina, Xenopsylla cheopis, Amblyomma variegatum, Rhipicephalus sanguineus sensu lato, and Haemaphysalis spp. nymphs. DNA of Bartonella was found in 14/75 (18.7%), 6/48 (12.5%), and 3/7 (42.8%) small mammals from Faladjè, Bougouni, and Bamako, respectively. In Faladjè, Bartonella DNA was detected in 31/68 (45.6%) of L. echidnina and 14/22 (63.6%) of X. cheopis. In Bougouni, it was found in 2/26 (7.7%) of L. echidnina and 10/42 (23.8%) of X. cheopis. The sequences of Bartonella obtained from small mammals were close to those of Bartonella mastomydis, Bartonella elizabethae, and uncultured Bartonella spp. In Faladjè, Coxiella burnetii DNA was detected in 64.4% (29/45) of Haemaphysalis spp. ticks, 4.5% (2/44) of Mastomys erythroleucus, 12.5% (1/8) of Praomys daltoni, and 1.5% (1/68) of L. echidnina. We found DNA of Wolbachia in X. cheopis from Faladjè and DNA of Rickettsia africae and Ehrlichia ruminantium in Am. variegatum from Bougouni. The results of our study show that several small mammal species harbor and may serve as potential reservoirs of Bartonella spp., likely to play a major role in the maintenance, circulation, and potential transmission of bacteria in Mali. The pathogenicity of these bacteria for humans or animals remains to be demonstrated.

Vulnerabilities for Exposure to Emerging Infectious Disease at Urban Settlements in Nepal

In Nepal, rapid urbanization and rural-to-urban migration especially due to internal civil conflict have catalyzed the development of temporary settlements, often along rivers on undeveloped land. This study conducted surveillance for viruses in small mammals and assessed potential risks for virus transmission to people in urban settlements along rivers in Kathmandu, Nepal. We collected samples from 411 small mammals (100 rodents and 311 shrews) at four riverside settlement sites and detected six viruses from four virus families including Thottapalayam virus; a strain of murine coronavirus; two new paramyxoviruses; and two new rhabdoviruses. Additionally, we conducted surveys of 264 residents to characterize animal-human contact. Forty-eight percent of individuals reported contact with wildlife, primarily with rodents and shrews (91%). Our findings confirm that rodents and shrews should be considered a health threat for residents of temporary settlements, and that assessment of disease transmission risk coupled with targeted surveillance for emerging pathogens could lead to improved disease control and health security for urban populations. Additionally, interventions focused on disease prevention should consider the unique urban ecology and social dynamics in temporary settlements, along with the importance of community engagement for identifying solutions that address specific multi-dimensional challenges that life on the urban river margins presents.

Canine vaccination in Germany: A survey of owner attitudes and compliance

BACKGROUND

Vaccination is the most important preventive measure for protection against infectious diseases in humans and companion animals. Nevertheless, scepticism about the safety and importance of vaccines is increasing in human and in veterinary medicine. Although owner attitudes towards vaccination have been investigated in cats, there are no similar studies in dogs. The goals of this study were therefore to investigate the vaccination status of dogs in Germany, to determine owner compliance with vaccination and to identify factors that play a role in owners' decisions to have their dogs vaccinated.

METHODS

Data were collected from August 2018 to February 2019 using an online survey targeting dog owners in Germany. A total of 3,881 questionnaires were evaluated, and factors associated with the vaccination status of dogs were determined by a linear logistic regression model using Akaike information criterion. Cohen's kappa statistic was used to evaluate agreement between questionnaire and 340 vaccination passports submitted voluntarily by owners.

RESULTS

A total of 46.8% (n = 1,818/3,881) of dogs were vaccinated with core vaccines according to current guidelines with the lowest vaccination rate for leptospirosis (50.1%; n = 1,941/3,874). Dog's age (16 weeks to 15 months) (odds ratio (OR): 3.08; 95% CI: 2.05-4.68), type (working dog) (OR: 2.06; 95% CI: 1.22-3.53) and travelling abroad within previous 36 months (OR: 1.82; 95% CI: 1.12-2.96) had the strongest 'positive' association with the vaccination status. Recommendation from a veterinarian not to vaccinate against leptospirosis had the strongest 'negative' association (OR: 0.08; 95% CI: 0.04-0.18).

CONCLUSION

The study revealed a need for improvement in vaccination compliance because of inadequate vaccination coverage, especially for leptospirosis, in dogs. Factors influencing owner compliance were numerous. Vaccination recommendations made by the veterinarian had a strong association with the vaccination status and should be used to increase canine vaccination rates.