Leptospirosis trends in China, 2007-2018: A retrospective observational study

Prevalence and Characteristics of Novel Pathogenic Leptospira Species in Bats in Yunnan Province, China

Leptospirosis has been identified as a zoonotic disease caused by pathogenic spirochetes of the bacterial genus Leptospira. Rodents are considered the primary hosts of these bacteria, whereas many recent studies suggest that bats may serve as potential natural reservoirs. However, studies on pathogenic spirochetes hosted by bat populations still need to be completed in China. In this study, a total of 276 bats belonging to five genera collected in Yunnan Province (Southwest China) from 2017 to 2021 were included in the screening. Pathogenic spirochetes were detected by PCR amplification and sequencing targeting four genes (rrs, secY, flaB, and LipL32), resulting in 17 positive samples. Phylogenetic analysis based on multi-loci concatenated sequences, inferred by MLST approach, identified the strains as two novel Leptospira species within the pathogenic group. Of note, only Rousettus leschenaultii was found to harbor these spirochetes, suggesting it may be one of the potential natural reservoirs in circulating leptospires in this region. Nevertheless, the pathogenesis and transmission dynamics still need to be fully understood, requiring in-depth studies on other animals and the surrounding population.

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.

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.

The diagnosis of leptospirosis complicated by pulmonary tuberculosis complemented by metagenomic next-generation sequencing: A case report

Leptospirosis is a zoonotic infection caused by the pathogenic Leptospira. Leptospirosis is transmitted mainly through contact with contaminated rivers, lakes, or animals carrying Leptospira. Human leptospirosis has a wide range of non-specific clinical manifestations ranging from fever, hypotension, and myalgia to multi-organ dysfunction, which severely hampers the timely clinical diagnosis and treatment of leptospirosis. Therefore, there is an urgent clinical need for an efficient strategy/method that can be used for the accurate diagnosis of leptospirosis, especially in critically ill patients. Here, we report a case of a 75-year-old male patient with clinical presentation of fever, cough, and diarrhea. Initial laboratory tests and a computed tomography (CT) scan of the chest suggested only tuberculosis. The patient was finally diagnosed with pulmonary tuberculosis (PTB) combined with leptospirosis by sputum Xpert MTB RIF, epidemiological investigations, and delayed serological testing. Furthermore, through metagenomic next-generation sequencing (mNGS) of clinical samples of cerebrospinal fluid (CSF), urine, plasma and sputum, the causative pathogens were identified as Mycobacterium tuberculosis complex and Leptospira spp. With specific treatment for both leptospirosis and tuberculosis, and associated supportive care (e.g., hemodialysis), the patient showed a good prognosis. This case report suggests that mNGS can generate a useful complement to conventional pathogenic diagnostic methods through more detailed etiological screening (i.e., at the level of species or species complex).

Prevalence of Leptospira in murine in China: A systematic review and meta-analysis

Leptospirosis is an acute infectious disease caused by pathogenic bacteria from the genus Leptospira. The disease is widely distributed throughout China, causing harm to human and animal health. Murine may naturally carry a variety of pathogenic Leptospira, thus being important sources of infection by humans and livestock. The aim of this study was to assess and analyse the prevalence of Leptospira and its risk factors in murine. We collected 46 publications published between inception and 2022 through China Knowledge Network (CNKI), VIP Chinese Journal Database, Wanfang Database, PubMed, and ScienceDirect. In these studies, a total of 54,051 murine in 5 regions of China were investigated, and the prevalence of leptospirosis ranged from 1.11 to 35.29%. The prevalence of murine leptospirosis in south China was the highest, at 20.13%, and the lowest in northeast China, at 1.11% (P < 0.05). The prevalence of leptospirosis in male murine was 21.38%, which was significantly higher than that in females (17.07%; P < 0.05). Results according to detection method subgroup showed that the prevalence from serological testing was 15.94%, which was significantly higher than that of etiology and molecular biology methods (P < 0.01). In the sample subgroup, the positive rate of serum samples was 15.30%, which was significantly higher than that of tissue samples, at 7.97%. In addition, the influence of different geographical factors on prevalence was analyzed, indicating that the Yangtze River Basin was a high-incidence area for leptospirosis. The study showed that Leptospira were ubiquitous throughout the country, and factors such as environment, temperature and landform affect the murine distribution and their bacteria carrying rate. We suggest strengthening the continuous monitoring of leptospirosis and taking effective and comprehensive measures such as reducing water contact, vaccinating in high-incidence seasons, and avoiding human contamination caused by water pollution and contact with infected murine.

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.

Human leptospirosis in the municipality of São Paulo, SP, Brazil: distribution and trend according to sociodemographic factors, 2007-2016

OBJECTIVES

This study aimed to describe the incidence and proportional lethality of human leptospirosis in the municipality of São Paulo, between 2007 and 2016, according to sociodemographic factors and characteristics of the disease, and to assess the temporal trends of incidence, according to age group and region of residence.

METHODS

Proportional distributions of leptospirosis cases of residents in the municipality were built and regression models with a Binomial Negative response were adjusted.

RESULTS

2,201 cases of leptospirosis were registered, most of them being males (82%), aged between 20 to 59 years (64.6%), white (39%) or brown (32.8%), residing in the South (27.8%), East (23.8%) and North (18.5%) regions. The overall lethality was 15.1%. The risk was higher in the 20 to 59 age group. There was a downward trend in incidence in all age groups and regions, estimated at 5.6% per year.

CONCLUSIONS

Despite the downward trend in incidence, leptospirosis is a serious disease with high lethality, affecting mainly male individuals in the age groups considered economically active and living in the peripheral regions of the municipality.