A short review on leptospirosis: Clinical manifestations, diagnosis and treatment

Leptospirosis: a clinical and diagnostic challenge

We present the case of a man in his early 50s who presented with a history of fever, malaise and jaundice. Initial investigations showed liver and renal dysfunction with no discernible cause for the septic process. On starting intravenous antibiotics, the patient developed a septic-shock-like reaction requiring transfer to intensive care. A diagnosis of leptospirosis was eventually established through an extensive and thorough history leading to a stepwise approach to investigations. Treatment targeting leptospirosis was delivered with noticeable clinical improvement.

Accuracy of rapid lateral flow immunoassays for human leptospirosis diagnosis: A systematic review and meta-analysis

BACKGROUND

In the last two decades, several rapid lateral flow immunoassays (LFIs) for the diagnosis of human leptospirosis were developed and commercialized. However, the accuracy and reliability of these LFIs are not well understood. In this study, we aimed to evaluate the accuracy of leptospirosis LFIs as well as the factors affecting the test efficiency using systematic review and meta-analysis.

METHODS AND RESULTS

Original articles reporting the accuracy of human leptospirosis LFIs against microagglutination tests (MAT) or immunofluorescent assays (IFA) were searched from PubMed, Embase, and Scopus, and selected as per pre-set inclusion and exclusion criteria. A total of 49 data entries extracted from 24 eligible records published between 2003 and 2023 were included for meta-analysis. A meta-analysis was performed using STATA. The quality of the included studies was assessed according to the revised QUADAS-2. Only nine studies (32.1%) were considered to have a low risk of bias and no concern for applicability. Pooled sensitivity and specificity were calculated to be 68% (95% confidence interval, CI: 57-78) and 93% (95% CI: 90-95), respectively. However, the ranges of sensitivity (3.6 - 100%) and specificity (53.5 - 100%) of individual entries are dramatically broad, possibly due to the heterogeneity found in both study designs and LFIs themselves. Subgroup analysis demonstrated that IgM detection has better sensitivity than detection of IgG alone. Moreover, the test performance seems to be unaffected by samples from different phases of infection.

CONCLUSIONS

The pooled specificity of LFIs observed is somewhat acceptable, but the pooled sensitivity is low. These results, however, must be interpreted with caution because of substantial heterogeneity. Further evaluations of the LFIs with well-standardized design and reference test will be needed for a greater understanding of the test performance. Additionally, IgM detection type should be employed when leptospirosis LFIs are developed in the future.

Current treatment options for leptospirosis: a mini-review

Leptospirosis, one of the most common global zoonotic infections, significantly impacts global human health, infecting more than a million people and causing approximately 60,000 deaths annually. This mini-review explores effective treatment strategies for leptospirosis, considering its epidemiology, clinical manifestations, and current therapeutic approaches. Emphasis is placed on antibiotic therapy, including recommendations for mild and severe cases, as well as the role of probiotics in modulating the gut microbiota. Furthermore, novel treatment options, such as bacteriophages and newly synthesized/natural compounds, are discussed, and the findings are expected to provide insights into promising approaches for combating leptospirosis.

Unmasking the Enigma of Weil's Disease: A Case Report

We present the case of a 37-year-old male with Weil's disease, a severe form of leptospirosis, who presented without typical ecological risk factors. Initially manifesting as weakness, muscle aches, and fever, the patient rapidly deteriorated, necessitating ICU admission due to septic shock and respiratory failure. Despite initial diagnostic challenges, including normal initial imaging and inconclusive laboratory findings, a presumptive diagnosis of leptospirosis was made using Modified Faine's criteria. Empirical antibiotic treatment with doxycycline led to significant clinical improvement, highlighting the importance of early recognition and treatment in severe cases of leptospirosis. This case underscores the need for heightened clinical suspicion and the use of diagnostic scoring systems, even in atypical presentations, to facilitate timely intervention and improve patient outcomes.

Spatio-Temporal Analysis of Leptospirosis Hotspot Areas and Its Association With Hydroclimatic Factors in Selangor, Malaysia: Protocol for an Ecological Cross-sectional Study

BACKGROUND

Leptospirosis is considered a neglected zoonotic disease in temperate regions but an endemic disease in countries with tropical climates such as South America, Southern Asia, and Southeast Asia. There has been an increase in leptospirosis incidence in Malaysia from 1.45 to 25.94 cases per 100,000 population between 2005 and 2014. With increasing incidence in Selangor, Malaysia, and frequent climate change dynamics, a study on the disease hotspot areas and their association with the hydroclimatic factors would further enhance disease surveillance and public health interventions.

OBJECTIVE

This study aims to examine the association between the spatio-temporal distribution of leptospirosis hotspot areas from 2011 to 2019 with the hydroclimatic factors in Selangor using the geographical information system and remote sensing techniques to develop a leptospirosis hotspot predictive model.

METHODS

This will be an ecological cross-sectional study with geographical information system and remote sensing mapping and analysis concerning leptospirosis using secondary data. Leptospirosis cases in Selangor from January 2011 to December 2019 shall be obtained from the Selangor State Health Department. Laboratory-confirmed cases with data on the possible source of infection would be identified and georeferenced according to their longitude and latitudes. Topographic data consisting of subdistrict boundaries and the distribution of rivers in Selangor will be obtained from the Department of Survey and Mapping. The ArcGIS Pro software will be used to evaluate the clustering of the cases and mapped using the Getis-Ord Gi* tool. The satellite images for rainfall and land surface temperature will be acquired from the Giovanni National Aeronautics and Space Administration EarthData website and processed to obtain the average monthly values in millimeters and degrees Celsius. Meanwhile, the average monthly river hydrometric levels will be obtained from the Department of Drainage and Irrigation. Data are then inputted as thematic layers and in the ArcGIS software for further analysis. The artificial neural network analysis in artificial intelligence Phyton software will then be used to obtain the leptospirosis hotspot predictive model.

RESULTS

This research was funded as of November 2022. Data collection, processing, and analysis commenced in December 2022, and the results of the study are expected to be published by the end of 2024. The leptospirosis distribution and clusters may be significantly associated with the hydroclimatic factors of rainfall, land surface temperature, and the river hydrometric level.

CONCLUSIONS

This study will explore the associations of leptospirosis hotspot areas with the hydroclimatic factors in Selangor and subsequently the development of a leptospirosis predictive model. The constructed predictive model could potentially be used to design and enhance public health initiatives for disease prevention.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/43712.

In Silico Approaches for the Identification of Aptamer Binding Interactions to Leptospira spp. Cell Surface Proteins

Aptamers are nucleic acids that can bind with high affinity and specificity to a range of target molecules. However, their functionality relies on their secondary and tertiary structures such that the combination of nucleotides determines their three-dimensional conformation. In this study, the binding mechanisms of candidate aptamers and their interactions with selected target proteins found in the cell surface of Leptospira were predicted to select high-affinity aptamers. Four aptamers were evaluated through molecular modeling and docking using available software and web-based tools, following the workflow previously designed for in silico evaluation of DNA aptamers. The most predominant and highly conserved surface-exposed proteins among pathogenic Leptospira species were used as aptamer targets. The highest number of interactions was seen in aptamers AP5 and AP1. Hydrogen bonds, along with a few hydrophobic interactions, occur in most aptamer-protein complexes. Further analysis revealed serine, threonine, glutamine, and lysine as main protein residues. H-bond interactions occur mostly with polar amino acids, as reflected in the predicted interaction profiles of aptamer-protein complexes. In silico strategies allowed the identification of key residues crucial in aptamer-target interaction during aptamer screening. Such information can be used in aptamer modification for improved binding affinity and accuracy for diagnostics application.

Severe Leptospirosis: A Case Report

Leptospirosis is an infection caused by Leptospira. Leptospirosis causes disease in humans mainly in developing countries and also in countries with poor housing and sanitation, due to animals (mainly rats) that are potential sources of contamination. The clinical manifestations and the severity of leptospirosis are highly variable. We present the case of a 56-year-old female that was admitted to the emergency department with a three-week history of fever (38.4ºC), headache, dyspnea, and cough. There was a worsening of the patient's clinical status with respiratory failure and the necessity of admission to the intensive care unit for respiratory support with mechanical ventilation. The treatment was initiated with piperacillin and tazobactam, azithromycin, and steroids. There was a favorable evolution, and the patient was transferred to the internal medicine ward after 12 days with a suspected diagnosis of small vessel vasculitis and pneumonia. In the medical ward, after a careful anamnesis, leptospirosis was suspected and confirmed. The aim of this case report is to highlight the importance of a good anamnesis and the fact that an elaborate clinical history helps to consider new diagnostic hypotheses. Also intends to alert to the existence of leptospirosis in developed countries, a disease underdiagnosed in these countries.

A Patient With Fever, Loose Motions and Jaundice: Hickam’s Dictum or Occam's Razor

Infectious diseases like malaria, typhoid, leptospirosis, and dengue fever are the leading causes of morbidity and mortality in developing countries like Pakistan. Although rare, it is possible to have coinfection with organisms that are endemic in a region, causing diagnostic and therapeutic dilemmas.

Leptospirosis is caused by Gram-negative spirochetes. Leptospira are widely distributed and are transmitted by contamination of water and food by the urine of infected animals like rodents. Leptospirosis is characterized by fever, body aches, abdominal pain, and hepatic and renal involvement. Laboratory abnormalities include cytopenia, elevated bilirubin, alanine aminotransferase, and abnormal renal function tests.

Typhoid fever is caused by Salmonella typhi (S. typhi), which is transmitted by fecal contamination of drinking water and food items. The clinical manifestations of typhoid fever include fever, abdominal pain, and diarrhea. Laboratory abnormalities include cytopenia and mildly deranged liver function tests. A strain of S. typhi resistant to all antibiotics except azithromycin and carbapenems was isolated in 2016 in Pakistan.

Most of the clinical manifestations and laboratory abnormalities of leptospirosis and typhoid fever overlap. There have been case reports of coinfection of S. typhi and Leptospira, but there is no report of coinfection of extensively drug-resistant (XDR) S. typhi and Leptospira. We present a case of a 20-year-old man with fever, loose motions, and jaundice from Peshawar, Pakistan who had coinfection of Leptospira and XDR S. typhi. The attending physicians should adopt Hickam’s dictum instead of Occam's razor approach.

Leptospirosis and Coinfection: Should We Be Concerned?

Pathogenic Leptospira is the causative agent of leptospirosis, an emerging zoonotic disease affecting animals and humans worldwide. The risk of host infection following interaction with environmental sources depends on the ability of Leptospira to persist, survive, and infect the new host to continue the transmission chain. Leptospira may coexist with other pathogens, thus providing a suitable condition for the development of other pathogens, resulting in multi-pathogen infection in humans. Therefore, it is important to better understand the dynamics of transmission by these pathogens. We conducted Boolean searches of several databases, including Google Scholar, PubMed, SciELO, and ScienceDirect, to identify relevant published data on Leptospira and coinfection with other pathogenic bacteria. We review the role of the host-microbiota in determining the synanthropic interaction of Leptospira sp. with other bacteria, thus creating a suitable condition for the leptospira to survive and persist successfully. We also discuss the biotic and abiotic factors that amplify the viability of Leptospira in the environment. The coinfection of leptospira with pathogenic bacteria has rarely been reported, potentially contributing to a lack of awareness. Therefore, the occurrence of leptospirosis coinfection may complicate diagnosis, long-lasting examination, and mistreatment that could lead to mortality. Identifying the presence of leptospirosis with other bacteria through metagenomic analysis could reveal possible coinfection. In conclusion, the occurrence of leptospirosis with other diseases should be of concern and may depend on the success of the transmission and severity of individual infections. Medical practitioners may misdiagnose the presence of multiple infections and should be made aware of and receive adequate training on appropriate treatment for leptospirosis patients. Physicians could undertake a more targeted approach for leptospirosis diagnosis by considering other symptoms caused by the coinfected bacteria; thus, more specific treatment could be given.