Leptospirosis: Molecular trial path and immunopathogenesis correlated with dengue, malaria and mimetic hemorrhagic infections

Enhancing leptospirosis control with nanosensing technology: A critical analysis

Leptospirosis is a serious health problem in tropical areas; thus, animals shed leptospires in the environment. Humans are accidental hosts infected through exposure to contaminating bacteria in the environment. One health strategy can be applied to protect and eliminate leptospirosis because this cooperates and coordinates activities between doctors, veterinarians, and ecologists. However, conventional methods still have limitations. Therefore, the main challenges of leptospirosis control are the high sensing of detection methods to screen and control the pathogens. Interestingly, nano sensing combined with a leptospirosis detection approach can increase the sensitivity and eliminate some limitations. This article reviews nanomaterial development for an advanced leptospirosis detection method, e.g., latex beads-based agglutination test, magnetic nanoparticles enrichment, and gold-nanoparticles-based immunochromatographic assay. Thus, nanomaterials can be functionalized with biomolecules or sensing molecules utilized in various mechanisms such as biosensors. Over the last decade, many biosensors have been developed for Leptospira spp. pathogen and others. The evolution of biosensors for leptospirosis detection was designed for high efficiency and might be an alternative tool. In addition, the high-sensing fabrications are useful for leptospires screening in very low levels, for example, soil or water from the environment.

Physiological Temperature and Osmotic Changes Drive Dynamic Proteome Alterations in the Leptospiral Outer Membrane and Enhance Protein Export Systems

Leptospirosis, a remerging zoonosis, has no effective vaccine or an unambiguous early diagnostic reagent. Proteins differentially expressed (DE) under pathogenic conditions will be useful candidates for antileptospiral measures. We employed a multipronged approach comprising high-resolution TMT-labeled LC-MS/MS-based proteome analysis coupled with bioinformatics on leptospiral proteins following Triton X-114 subcellular fractionation of leptospires treated under physiological temperature and osmolarity that mimic infection. Although there were significant changes in the DE proteins at the level of the entire cell, there were notable changes in proteins at the subcellular level, particularly on the outer membrane (OM), that show the significance of subcellular proteome analysis. The detergent-enriched proteins, representing outer membrane proteins (OMPs), exhibited a dynamic nature and upregulation under various physiological conditions. It was found that pathogenic proteins showed a higher proportion of upregulation compared to the nonpathogenic proteins in the OM. Further analysis identified 17 virulent proteins exclusively upregulated in the outer membrane during infection that could be useful for vaccine and diagnostic targets. The DE proteins may aid in metabolic adaptation and are enriched in pathways related to signal transduction and antibiotic biosynthesis. Many upregulated proteins belong to protein export systems such as SEC translocase, T2SSs, and T1SSs, indicating their sequential participation in protein transport to the outer leaflet of the OM. Further studies on OM-localized proteins may shed light on the pathogenesis of leptospirosis and serve as the basis for effective countermeasures.

Clinical Presentation and Platelet Profile of Dengue Fever: A Retrospective Study

Background: Dengue fever (DF) is a mosquito-borne viral illness carried worldwide by Aedes aegypti and Aedes albopictus mosquitoes. The aim of the present study was to observe the different clinical presentations of dengue fever and the platelet profile analysis in DF patients.

Methods: This retrospective study was performed on 130 diagnosed patients with dengue fever, aged over 14 years. Data collection included patient age, gender, clinical manifestations, hematocrit, platelet count, and evidence of plasma leakage.

Results: Most of the patients belong to the 21-30 year age group, with a greater number of males compared to females. The common presentation of dengue fever was fever and myalgia, observed in 100% and 95.3% of the patients, respectively. A platelet count of less than 1,00,000 was observed in 77% of patients, whereas decreased total leukocyte count (TLC) and hematocrit were observed in 52.3% and 40% of patients, respectively. About 46.15% of patients had bradycardia on examination. Pleural effusion and ascites were found in 20.7% and 15.3% of patients, respectively.

Conclusion: Patients presenting with fever, hemorrhagic symptoms, or signs of plasma leakage should be promptly suspected, timely diagnosed and managed on the grounds of dengue fever.

Significant Clinical Presentation of Leptospirosis in Relation to Sociodemographic and Risk Factors in a Tertiary Hospital, Malaysia

Introduction: Incidence of leptospirosis has increased within the past few years in many countries. Its clinical presentations were generally nonspecific, making it difficult to assist in the diagnosis. Besides the determination of the common clinical features, the sociodemographic background is essential to identify high-risk populations to assist in prevention. Methods: Data for this study were obtained from electronic medical records among patients clinically diagnosed with leptospirosis at a tertiary hospital in Malaysia from the years 2011 to 2015 and were recorded using standard pro forma. Associations between clinical features and sociodemographics were performed using bivariate analysis and logistic regression. Results: Data were collected from 283 patients. Their mean age was 30.71 years old. Out of 283 patients, 206 (72.8%) were male. Involvement in outdoor events and water activities was the highest risk factor of acquiring leptospirosis in 64 (22.7%) patients followed by 59 (20.8%) patients who were staying in crowded housing areas with poor sanitation. Although fever was the main clinical presentation in 274 (96.8%) patients with leptospirosis, gastrointestinal (GIT) symptoms were the second most frequent in 159 (56.2%) patients followed by pulmonary symptoms, myalgia, headache, and jaundice. From the total number of 283 patients, only 21 (92.6%) presented with severe leptospirosis. GIT symptoms were a significant predictor for leptospirosis severity, while the age group was the significant sociodemographic factor toward GIT presentation in leptospirosis. The relationship between GIT symptoms and crowded housing areas with poor sanitation was also significant. Multivariable logistic regression showed that crowded housing areas with poor sanitation (odds ratio [OR] = 3.570, p < 0.001) and age between 20 and 40 years old (OR = 2.056, p = 0.014) were more likely to have GIT symptoms. Conclusions: Information regarding the clinical features of leptospirosis to the public is necessary, while targeted prevention by educational outreach among 20-40 year olds especially those participating in outdoor water activities are crucial to decrease the incidence and complications of leptospirosis.

Leptospirosis meningitis transmission from a pet mouse: a case report

Background

Leptospirosis is a reemerging zoonosis with a worldwide distribution and a wide range of clinical manifestations. We report a case of leptospirosis meningitis in a previously healthy woman infected by her pet mouse.

Case presentation

A 27-year-old Caucasian woman with pet mice presented to our institute with a 1 week history of fever, headache, myalgia, vomiting, diarrhea, and dark urine. Her admission examination revealed neck stiffness, conjunctivitis, and icteric sclera. Her liver enzymes, bilirubin, white blood cell count, and C-reactive protein were elevated. Her cerebrospinal fluid showed an elevated white blood cell count. Polymerase chain reactions using her cerebrospinal fluid, blood, and urine showed negative results for leptospirosis, but the result of her microagglutination test was positive for Leptospira interrogans serovar sejroe with a more than threefold increase in paired sera. The patient was treated with ceftriaxone for 1 week, and her condition steadily improved.

Conclusions

This case report raises awareness of pet rodents as sources of leptospirosis. Leptospirosis meningitis should be considered in patients with meningeal symptoms and pet rodents.

Prediction mapping of human leptospirosis using ANN, GWR, SVM and GLM approaches

Background

Recent reports of the National Ministry of Health and Treatment of Iran (NMHT) show that Gilan has a higher annual incidence rate of leptospirosis than other provinces across the country. Despite several efforts of the government and NMHT to eradicate leptospirosis, it remains a public health problem in this province. Modelling and Prediction of this disease may play an important role in reduction of the prevalence.

Methods

This study aims to model and predict the spatial distribution of leptospirosis utilizing Geographically Weighted Regression (GWR), Generalized Linear Model (GLM), Support Vector Machine (SVM) and Artificial Neural Network (ANN) as capable approaches. Five environmental parameters of precipitation, temperature, humidity, elevation and vegetation are used for modelling and predicting of the disease. Data of 2009 and 2010 are used for training, and 2011 for testing and evaluating the models.

Results

Results indicate that utilized approaches in this study can model and predict leptospirosis with high significance level. To evaluate the efficiency of the approaches, MSE (GWR = 0.050, SVM = 0.137, GLM = 0.118 and ANN = 0.137), MAE (0.012, 0.063, 0.052 and 0.063), MRE (0.011, 0.018, 0.017 and 0.018) and R² (0.85, 0.80, 0.78 and 0.75) are used.

Conclusion

Results indicate the practical usefulness of approaches for spatial modelling and predicting leptospirosis. The efficiency of models is as follow: GWR > SVM > GLM > ANN. In addition, temperature and humidity are investigated as the most influential parameters. Moreover, the suitable habitat of leptospirosis is mostly within the central rural districts of the province.

Kidney involvement in yellow fever: a review

Yellow fever is one of the most important mosquito-borne diseases, which still affects a significant number of people every year, mainly in tropical countries. Mortality can be high, even with intensive treatment due to multiple organ failure, including acute kidney injury (AKI). This disease can also be a burden on the health care system in developing countries, without mentioning the number of lives that could be spared with an early diagnosis and adequate monitoring and treatment. The pathophysiology of yellow fever-induced acute kidney injury (AKI) is still to be completely understood, and the best clinical approach has not yet been determined. This manuscript presents the most recent scientific evidence of kidney involvement in yellow fever, since AKI plays an important role in the mortality rate. Recent outbreaks have occurred in Brazil and further studies are required to provide a better clinical control for patients with yellow fever.

Monitoring arbovirus in Thailand: Surveillance of dengue, chikungunya and zika virus, with a focus on coinfections

Infections caused by arboviruses such as dengue virus (DENV), chikungunya virus (CHIKV), and Zika virus (ZIKV) frequently occur in tropical and subtropical regions. These three viruses are transmitted by Aedes (Ae.) aegypti and Ae. albopictus. In Thailand, the highest incidence of arbovirus infection and the high circulation of Aedes mosquito mainly occurs in the Southern provinces of the country. Few studies have focused on the incidence of co-infection of arboviruses in this region. In the present study, a cross-sectional study was conducted on a cohort of 182 febrile patients from three hospitals located in Southern Thailand. Surveillance of DENV, CHIKV and ZIKV was conducted from May to October 2016 during the rainy season. The serological analysis and molecular detection of arboviruses were performed by ELISA and multiplex RT-PCR respectively. The results demonstrated that 163 cases out of 182 patients (89.56%) were infected with DENV, with a predominance of DENV-2. Among these DENV positive cases, a co-infection with CHIKV for 6 patients (3.68%) and with ZIKV for 1 patient (0.61%) were found. 19 patients out of 182 were negative for arboviruses. This study provides evidence of co-infection of arboviruses in Southern Thailand and highlight the importance of testing DENV and other medically important arboviruses, such as CHIKV and ZIKV simultaneously.

Managing mosquitoes and ticks in a rapidly changing world - Facts and trends

Vector-borne diseases transmitted by mosquitoes and ticks are on the rise. The effective and sustainable control of these arthropod vectors is a puzzling challenge for public health worldwide. In the present review, I attempted to provide a concise and updated overview of the current mosquito and tick research scenario. The wide array of control tools recently developed has been considered, with special reference to those approved by the World Health Organization Vector Control Advisory Group (WHO VCAG), as well as novel ones with an extremely promising potential to be exploited in vector control programs. Concerning mosquitoes, a major focus has been given on genetically modified vectors, eave tubes, attractive toxic sugar baits (ATSB) and biocontrol agents. Regarding ticks, the recent development of highly effective repellents and acaricides (including nanoformulated ones) as well as behavior-based control tools, has been highlighted. In the second part of the review, key research questions about biology and control of mosquitoes and ticks have been critically formulated. A timely research agenda outlining hot issues to be addressed in mosquito and tick research is provided. Overall, it is expected that the present review will contribute to boost research and applications on successful mosquito and tick control strategies, along with an improved knowledge of their biology and ecology.

Human leptospirosis as a doubly neglected disease in Brazil

The aim of this article is to analyze discrepancies and informational gaps which produce a doubly neglected version of human leptospirosis in the Brazilian public health policy. To achieve this goal, we compared data on morbidity, mortality, hospital and social costs, population profiles, vector habits, social health determinants and diagnostic practices related to leptospirosis with another disease of higher recognition in Brazil: dengue fever. Our analysis shows that the arbitrariness of criteria for assigning health priorities, the invisibility of the population profile of human leptospirosis in official data and its mimetic character in clinic corroborate the production of a version of human leptospirosis that is invisible and, because of that, doubly neglected by the Brazilian public health policy. We conclude that these discrepancies and informational gaps are related to the fact that human leptospirosis affects a population which the State has no interest in keeping alive.

Low Levels of Knowledge, Attitudes and Preventive Practices on Leptospirosis among a Rural Community in Hulu Langat District, Selangor, Malaysia

Little is known on the knowledge, attitudes and preventive practices (KAP) of leptospirosis worldwide. This study embarked on assessing the KAP of leptospirosis among rural communities in Malaysia. A total of 444 participants (223 male; 221 female) aged between 18 and 81 years old were surveyed by using a self-administered questionnaire. A majority of participants had poor knowledge level (57.0%), unacceptable attitudes (90.3%) and unacceptable preventive practices (69.1%) on leptospirosis, and only 29.7% knew “rat-urine disease” as leptospirosis. Only 34.2% of the participants knew the bacteria could enter via wound lesions. Ethnicity and income were strongly associated with knowledge level and preventive practices, respectively (p-values < 0.05). As for attitudes, ethnicity, income and education type were significantly associated (p-values < 0.05). Only 36.5% of the participants were willing to see a doctor and did not mind if their house or surrounding area is dirty (59.7%). Surprisingly, only 32.9% had used rubber boots during floods. By logistic regression analysis, ethnicity was the only significant predictor for both knowledge level (an odds ratio (AOR) = 0.39, 95% confidence interval (CI) = 0.222–0.680) and preventive practices (AOR = 1.81, 95% CI = 1.204–2.734). Ethnicity (AOR = 0.40, 95% CI = 0.239–0.665), income (AOR = 1.58, 95% CI = 1.041–2.385) and education type (AOR = 3.69, 95% CI = 1.237–10.986) were strong predictors for attitudes. Among the KAP variables, attitude (AOR = 4.357, 95% CI = 2.613–7.264) was the only predictor for the preventive practices by logistic regression analysis. The KAP elements on leptospirosis are still lacking and poor health seeking behavior and attitudes are of our utmost concern. Thus, effective strategies should be planned to impart knowledge, and develop proactive approaches and good preventive modules on leptospirosis to this leptospirosis-prone community.

Recent Updates on Treatment of Ocular Microbial Infections by Stem Cell Therapy: A Review

Ocular microbial infection has emerged as a major public health crisis during the past two decades. A variety of causative agents can cause ocular microbial infections; which are characterized by persistent and destructive inflammation of the ocular tissue; progressive visual disturbance; and may result in loss of visual function in patients if early and effective treatments are not received. The conventional therapeutic approaches to treat vision impairment and blindness resulting from microbial infections involve antimicrobial therapy to eliminate the offending pathogens or in severe cases; by surgical methods and retinal prosthesis replacing of the infected area. In cases where there is concurrent inflammation, once infection is controlled, anti-inflammatory agents are indicated to reduce ocular damage from inflammation which ensues. Despite advances in medical research; progress in the control of ocular microbial infections remains slow. The varying level of ocular tissue recovery in individuals and the incomplete visual functional restoration indicate the chief limitations of current strategies. The development of a more extensive therapy is needed to help in healing to regain vision in patients. Stem cells are multipotent stromal cells that can give rise to a vast variety of cell types following proper differentiation protocol. Stem cell therapy shows promise in reducing inflammation and repairing tissue damage on the eye caused by microbial infections by its ability to modulate immune response and promote tissue regeneration. This article reviews a selected list of common infectious agents affecting the eye; which include fungi; viruses; parasites and bacteria with the aim of discussing the current antimicrobial treatments and the associated therapeutic challenges. We also provide recent updates of the advances in stem cells studies on sepsis therapy as a suggestion of optimum treatment regime for ocular microbial infections.

3D modelling of the pathogenic Leptospira protein LipL32: A bioinformatics approach

Leptospirosis is a widespread zoonotic disease caused by pathogenic Leptospira species (Leptospiraceae). LipL32 is an abundant lipoprotein from the outer membrane proteins (OMPs) group, highly conserved among pathogenic and intermediate Leptospira species. Several studies used LipL32 as a specific gene to identify the presence of leptospires. This research was aimed to study the characteristics of LipL32 protein gene code, to fill the knowledge gap concerning the most appropriate gene that can be used as antigen to detect the Leptospira. Here, we investigated the features of LipL32 in fourteen Leptospira pathogenic strains based on comparative analyses of their primary, secondary structures and 3D modeling using a bioinformatics approach. Furthermore, the physicochemical properties of LipL32 in different strains were studied, shedding light on the identity of signal peptides, as well as on the secondary and tertiary structure of the LipL32 protein, supported by 3D modelling assays. The results showed that the LipL32 gene was present in all the fourteen pathogenic Leptospira strains used in this study, with limited diversity in terms of sequence conservation, hydrophobic group, hydrophilic group and number of turns (random coil). Overall, these results add basic knowledge to the characteristics of LipL32 protein, contributing to the identification of potential antigen candidates in future research, in order to ensure prompt and reliable detection of pathogenic Leptospira species.