Assessment of the clinical presentation and treatment of 353 cases of laboratory-confirmed leptospirosis in Hawaii, 1974-1998

Determinants of mortality and impact of therapy in patients with leptospirosis admitted for intensive care in a Sri Lankan hospital--a three year retrospective study

INTRODUCTION

Leptospirosis is a disease of epidemic proportions in Sri Lanka. There is paucity of data on the determinants of mortality and impact of therapy in patients with leptospirosis admitted to critical care settings in endemic territories.

METHODOLOGY

This retrospective cross-sectional study was performed in patients with serologically confirmed leptospirosis admitted to the intensive care unit of the General Hospital, Kalutara from January 2011 to April 2014. Associations between socio-epidemiological, clinical and laboratory parameters and patient mortality were examined.

RESULTS

Forty-five patients were included. The mean age was 49.11(SD = 16.95) and majority (92%) were male. Percentage mortality was 44.4%. Patient mortality was associated with age > 40 (p = 0.012), symptoms of uremia (p = 0.017), evidence of CNS involvement (p = 0.039), presence of oliguria (p = 0.002) and anuria (p = 0.014), presence of multi-organ dysfunction syndrome (MODS) (p < 0.001), CRP > 96 (p = 0.036), platelet count < 20,000 (p = 0.045), Potassium > 5.0 (p = 0.05), metabolic acidosis with pH < 7.2 (p = 0.03), INR > 2 (p = 0.037) and requirement of mechanical ventilation (p < 0.001). Cox regression analysis revealed MODS and potassium > 5 to be independently associated with mortality.

CONCLUSIONS

A high mortality rate is noted. The presence of MODS and serum potassium concentration > 5.0 was independently associated with mortality in this retrospective study of patients with confirmed leptospirosis in a critical care setting.

Clinical characteristics of laboratory-confirmed leptospirosis in Okinawa, Japan, 1974-2015: high incidence of Jarisch-Herxheimer reaction

BACKGROUND

Leptospirosis is a zoonotic disease known to have wide-ranging clinical manifestations. Despite a number of published case series, culture-confirmed series are few and there is a paucity of data on Jarisch-Herxheimer reaction (JHR) associated with treatment of leptospirosis. Our objective was to describe the clinical and epidemiological factors associated with leptospirosis in an endemic area of Japan, with a focus on the occurrence of JHR, an often unrecognized and likely underestimated phenomenon.

METHODS

We performed a retrospective observational study of laboratory-confirmed leptospirosis at a single center over a 40-year period.

RESULTS

We report 100 leptospirosis cases in 99 patients during the period 1974-2015. Seventy-four cases were diagnosed by culture, representing eight different serovars. JHR was seen in 23 (82%) of 28 cases, including 19 (90%) of 21 cases treated with bactericidal antibiotics compared to 4 (57%) of seven cases with bacteriostatic antibiotics (p=0.08).

CONCLUSIONS

We found a wide variety of clinical manifestations, epidemiological exposures, and causative serovars of disease in an endemic region of Japan. We also found that JHR occurs frequently, and its recognition may be important for the diagnosis and management of leptospirosis in the early stage when laboratory confirmation is pending.

Protein Carbonyl as a Biomarker of Oxidative Stress in Severe Leptospirosis, and Its Usefulness in Differentiating Leptospirosis from Dengue Infections

Pathogenesis of disease severity in leptospirosis is not clearly understood whether it is due to direct damage by pathogen or by adverse immune responses. Knowledge on biomarkers of oxidative stress which could be used in identifying patients with severe illness has shown to be of great value in disease management. Thus, the main aim of this study was to assess the damage to serum proteins and lipids, and their significance as biomarkers of oxidative stress in severe leptospirosis. In regions endemic for both leptospirosis and dengue, leptospirosis cases are often misdiagnosed as dengue during dengue epidemics. Therefore, the second aim was to assess the potential of the oxidative stress markers in differentiating severe leptospirosis from critical phase dengue. We measured serum antioxidants (uric acid and bilirubin), total antioxidant capacity (AOC), protein carbonyl (PC) and lipid hydroperoxide (LP) in patients with severe leptospirosis (n = 60), mild leptospirosis (n = 50), dengue during the critical phase (n = 30) and in healthy subjects (n = 30). All patient groups had similar total antioxidant capacity levels. However, the presence of significantly high uric acid and total bilirubin levels may reflect the degree of renal and hepatic involvement seen in severe leptospirosis patients (p<0.02). Serum PC and LP levels were significantly higher in leptospirosis patients compared to critical phase dengue infections (p<0.005). Moreover, high serum PC levels appear to differentiate SL from DC [area under the curve (AUC) = 0.96; p<0.001]. Serum PC may be a reliable biomarker of oxidative damage to serum proteins to identify severe leptospirosis patients (AUC = 0.99) and also to differentiate severe leptospirosis from mild cases (AUC = 0.78; p<0.005) indicating its contribution to pathogenesis. Use of serum PC as an indicator of leptospirosis severity and as an oxidative stress biomarker in differentiating leptospirosis from dengue would provide the opportunity to save lives via prompt patient management.

[A Case of Leptospirosis in which the Causative Pathogen was Detected Using Cerebrospinal Fluid PCR Eight Days after Onset]

We report a patient with leptospirosis caused by infection with Leptospira interrogans serovar Rachmati. A 30-year-old Japanese man took part in a survival camp on Iriomote Island, Okinawa, from July 9 to July 15, 2014. During the camp, he swam in the river and kayaked. He developed a high fever and fatigue 7 days after completing his trip and was admitted to our hospital on July 22. On admission, he complained of a posterior cervical pain and a loss of appetite. Laboratory findings revealed granulocytosis, mildly elevated AST and ALT levels, elevated BUN and Cr levels, and a significantly elevated CRP level. No pathogenic bacteria were isolated from blood, urine, or cerebrospinal fluid cultures. We included leptospirosis in the differential diagnosis because of the patient's history of participating in a survival camp on Iriomote Island. Minocycline 200 mg, p.o. showed an excellent efficacy. The Leptospira flagellar gene FlaB was detected using a cerebrospinal fluid PCR. A microscopic agglutination test (MAT) during the convalescent stage demonstrated significant increases in antibodies against L. interrogans serovar Rachmati, confirming the diagnosis of leptospirosis. A medical history including occupation and recent travel history, and an adequate specimen sampling are crucial for the accurate and early diagnosis of leptospirosis.

Leptospirosis-associated hospitalizations, United States, 1998-2009

Average cost and duration of hospitalizations were significantly greater than for other infectious diseases.

A small percentage of persons with leptospirosis, a reemerging zoonosis, experience severe complications that require hospitalization. The number of leptospirosis cases in the United States is unknown. Thus, to estimate the hospitalization rate for this disease, we analyzed US hospital discharge records for 1998–2009 for the total US population by using the Nationwide Inpatient Sample. During that time, the average annual rate of leptospirosis-associated hospitalizations was 0.6 hospitalizations/1,000,000 population. Leptospirosis-associated hospitalization rates were higher for persons >20 years of age and for male patients. For leptospirosis-associated hospitalizations, the average age of patients at admission was lower, the average length of stay for patients was longer, and hospital charges were higher than those for nonleptospirosis infectious disease–associated hospitalizations. Educating clinicians on the signs and symptoms of leptospirosis may result in earlier diagnosis and treatment and, thereby, reduced disease severity and hospitalization costs.

Mixed Methods Survey of Zoonotic Disease Awareness and Practice among Animal and Human Healthcare Providers in Moshi, Tanzania

Background

Zoonoses are common causes of human and livestock illness in Tanzania. Previous studies have shown that brucellosis, leptospirosis, and Q fever account for a large proportion of human febrile illness in northern Tanzania, yet they are infrequently diagnosed. We conducted this study to assess awareness and knowledge regarding selected zoonoses among healthcare providers in Moshi, Tanzania; to determine what diagnostic and treatment protocols are utilized; and obtain insights into contextual factors contributing to the apparent under-diagnosis of zoonoses.

Methodology/Results

We conducted a questionnaire about zoonoses knowledge, case reporting, and testing with 52 human health practitioners and 10 livestock health providers. Immediately following questionnaire administration, we conducted semi-structured interviews with 60 of these respondents, using the findings of a previous fever etiology study to prompt conversation. Sixty respondents (97%) had heard of brucellosis, 26 (42%) leptospirosis, and 20 (32%) Q fever. Animal sector respondents reported seeing cases of animal brucellosis (4), rabies (4), and anthrax (3) in the previous 12 months. Human sector respondents reported cases of human brucellosis (15, 29%), rabies (9, 18%) and anthrax (6, 12%). None reported leptospirosis or Q fever cases. Nineteen respondents were aware of a local diagnostic test for human brucellosis. Reports of tests for human leptospirosis or Q fever, or for any of the study pathogens in animals, were rare. Many respondents expressed awareness of malaria over-diagnosis and zoonoses under-diagnosis, and many identified low knowledge and testing capacity as reasons for zoonoses under-diagnosis.

Conclusions

This study revealed differences in knowledge of different zoonoses and low case report frequencies of brucellosis, leptospirosis, and Q fever. There was a lack of known diagnostic services for leptospirosis and Q fever. These findings emphasize a need for improved diagnostic capacity alongside healthcare provider education and improved clinical guidelines for syndrome-based disease management to provoke diagnostic consideration of locally relevant zoonoses in the absence of laboratory confirmation.

Zoonoses are diseases that are naturally transmitted between animals and humans. In Tanzania, research has shown that several zoonoses, including brucellosis, leptospirosis, and Q fever, are common, but under-diagnosed, causes of human illness. We conducted a mixed methods survey, combining quantitative and qualitative research techniques, of healthcare providers in Moshi, Tanzania. Four (40%) of 10 animal sector respondents and 15 (29%) of 52 human sector respondents reported seeing brucellosis cases in the past 12 months, while none reported cases of leptospirosis or Q fever. Nineteen (31%) respondents reported awareness of a local diagnostic test for human brucellosis, while one reported locally available diagnostic tests for human leptospirosis and Q fever. One (2%) respondent reported a locally available animal brucellosis test, and none reported tests for leptospirosis or Q fever in animals. Many respondents mentioned a lack of diagnostic testing resources during interviews. Our findings suggest that diagnostic testing capacity improvements alongside public health campaigns and healthcare provider education are key steps toward improving recognition and accurate diagnosis of zoonoses in this setting. An improved understanding of healthcare provider awareness, perceptions, and practices regarding zoonoses is critical for the design of effective programs to improve diagnosis and treatment of these diseases.

Leptospirosis and Peripheral Artery Occlusive Disease: A Nationwide Cohort Analysis

Data on the association between peripheral artery occlusive disease (PAOD) and leptospirosis are limited. We conducted a retrospective cohort study for determining whether leptospirosis is one of the possible risk factors for PAOD. Patients diagnosed with leptospirosis by using 2000 to 2010 data from the Taiwan National Health Insurance Research Database. Patients with leptospirosis without a history of PAOD were selected. For each leptospirosis patient, 4 controls without a history of leptospirosis and PAOD were randomly selected and frequency-matched for sex, age, the year of the index date, and comorbidity diseases. The follow-up period was from the time of the initial diagnosis of leptospirosis to the diagnosis date of PAOD, or December 31, 2011. The Cox proportional hazard regression models were used for analyzing the risk of PAOD. During the follow-up period, the cumulative incidence of PAOD was higher among the patients from the leptospirosis cohort than among the nonleptospirosis cohort (log-rank test, P < 0.001). In total, 29 patients with PAOD from the leptospirosis cohort and 81 from the nonleptospirosis cohort were observed with the incidence rates of 2.1 and 1.3 per 1000 person-years, respectively, yielding a crude hazards ratio (HR) of 1.62 (95% confidence interval [CI] = 1.44-1.81) and adjusted HR (aHR) of 1.75 (95% CI = 1.58-1.95).The risk of PAOD was 1.75-fold higher in the patients with leptospirosis than in the general population.

Early Indicators of Fatal Leptospirosis during the 2010 Epidemic in Puerto Rico

Background

Leptospirosis is a potentially fatal bacterial zoonosis that is endemic throughout the tropics and may be misdiagnosed as dengue. Delayed hospital admission of leptospirosis patients is associated with increased mortality.

Methodology/Principal Findings

During a concurrent dengue/leptospirosis epidemic in Puerto Rico in 2010, suspected dengue patients that tested dengue-negative were tested for leptospirosis. Fatal and non-fatal hospitalized leptospirosis patients were matched 1:1–3 by age. Records from all medical visits were evaluated for factors associated with fatal outcome. Among 175 leptospirosis patients identified (4.7 per 100,000 residents), 26 (15%) were fatal. Most patients were older males and had illness onset during the rainy season. Fatal case patients first sought medical care earlier than non-fatal control patients (2.5 vs. 5 days post-illness onset [DPO], p < 0.01), but less frequently first sought care at a hospital (52.4% vs. 92.2%, p < 0.01). Although fatal cases were more often diagnosed with leptospirosis at first medical visit (43.9% vs. 9.6%, p = 0.01), they were admitted to the hospital no earlier than non-fatal controls (4.5 vs. 6 DPO, p = 0.31). Cases less often developed fever (p = 0.03), but more often developed jaundice, edema, leg pain, hemoptysis, and had a seizure (p ≤ 0.03). Multivariable analysis of laboratory values from first medical visit associated with fatal outcome included increased white blood cell (WBC) count with increased creatinine (p = 0.001), and decreased bicarbonate with either increased WBC count, increased creatinine, or decreased platelet count (p < 0.001).

Conclusions/Significance

Patients with fatal leptospirosis sought care earlier, but were not admitted for care any earlier than non-fatal patients. Combinations of routine laboratory values predictive of fatal outcome should be considered in admission decision-making for patients with suspected leptospirosis.

Leptospirosis is a common tropical illness that results from exposure to the urine of animals infected with Leptospira bacteria. Because leptospirosis shares signs and symptoms with other common tropical illnesses such as dengue, identification of patients with leptospirosis can be challenging. Early identification of patients with leptospirosis is necessary to initiate antibiotic therapy and in some cases provide in-hospital management. During an epidemic of leptospirosis in Puerto Rico that occurred during a concomitant dengue epidemic, we identified leptospirosis patients by screening specimens from suspected dengue patients. Of 175 leptospirosis patients identified, 26 (15%) died. After comparing leptospirosis patients that died to patients of a similar age that were hospitalized but survived, we observed that fatal cases were more often sent home after their first medical visit. We next identified several routinely available laboratory values from patients’ first medical visit that were associated with patients that died. Clinicians can use such laboratory values to diagnose and hospitalize leptospirosis patients at increased risk for fatal outcome.

Ocular and cutaneous manifestation of leptospirosis acquired in Albania: A retrospective analysis with implications for travel medicine

Albania is an attractive tourism destination with an increasing volume of travel. As a Mediterranean country some tropical infectious diseases are present in certain areas of Albania, including leptospirosis, which is a zoonotic infectious disease prevalent around the world. The goal of this retrospective study is to describe the ocular and cutaneous manifestations of leptospirosis in Albanian patients and raise awareness to travelers travelling in and out of the country.

METHODS

We retrospectively studied 107 cases of leptospirosis, treated at "Mother Teresa" University Hospital Center, in Tirana, Albania between January 2009 and December 2014. All cases included in the analysis had a clinical and epidemiological presentation suggestive of leptospirosis, confirmed with ELISA (enzyme linked immunoassay) positive for IgM antibodies against Leptospira.

RESULTS

There were 89.7% males (n = 96) and 10.2% females (n = 11). Mean age at the time of diagnoses was 43.7 ± 17.8 years old (range 17-78). All patients were native and residents of Albania. Conjunctival suffusion was present in 81.3% of the cases, whereas subconjunctival hemorrhage was seen in 12 patients (11.2%). Uveitis was seen in 38.3% of the cases and all patients with uveitis presented a severe systemic disease. A cutaneous rash was present in 58.8% of patients. Other cutaneous manifestations include jaundice in 62.6% and intense pruritus in 5.6% of cases.

CONCLUSIONS

Ocular and cutaneous involvement happens more frequently in patients with Leptospirosis, than it was thought to be. Therefore the clinician should be more careful in his systemic evaluation of the disease.

Imported Flood-Related Leptospirosis From Palau: Awareness of Risk Factors Leads to Early Treatment

We describe two Japanese travelers with leptospirosis who visited Palau. Both travelers swam in Ngardmau Falls, which was flooded for two days after typhoon Phanfone. The diagnoses were confirmed by microscopic agglutination test or polymerase chain reaction. This is the first report of leptospirosis in travelers who returned from Palau. It should be noted that choosing the appropriate test to biologically confirm leptospirosis was highly time-dependent. Awareness of the risk factors for leptospirosis, mainly that of the exposure to contaminated fresh water after a flooding, would lead to an early and appropriate treatment before the confirmed diagnosis.

Neglected bacterial zoonoses

Bacterial zoonoses comprise a group of diseases in humans or animals acquired by direct contact with or by oral consumption of contaminated animal materials, or via arthropod vectors. Among neglected infections, bacterial zoonoses are among the most neglected given emerging data on incidence and prevalence as causes of acute febrile illness, even in areas where recognized neglected tropical diseases occur frequently. Although many other bacterial infections could also be considered in this neglected category, five distinct infections stand out because they are globally distributed, are acute febrile diseases, have high rates of morbidity and case fatality, and are reported as commonly as malaria, typhoid or dengue virus infections in carefully designed studies in which broad-spectrum diagnoses are actively sought. This review will focus attention on leptospirosis, relapsing fever borreliosis and rickettsioses, including scrub typhus, murine typhus and spotted fever group rickettsiosis. Of greatest interest is the lack of distinguishing clinical features among these infections when in humans, which confounds diagnosis where laboratory confirmation is lacking, and in regions where clinical diagnosis is often attributed to one of several perceived more common threats. As diseases such as malaria come under improved control, the real impact of these common and under-recognized infections will become evident, as will the requirement for the strategies and allocation of resources for their control.

Approach to clinical syndrome of jaundice and encephalopathy in tropics

A large number of patients present with jaundice and encephalopathy in tropical country like India and acute liver failure is the usual cause. Clinical presentation like ALF is also a complication of many tropical infections, and these conditions may mimic ALF but may have subtle differences from ALF. Moreover, what hepatologists see as acute liver failure in tropics is different from what is commonly described in Western Textbooks. Paracetamol overdose, which is possibly the commonest cause of ALF in UK and USA, is hardly ever seen in India. Most common etiology here is viral hepatitis (hepatitis E > hepatitis B> hepatitis A). Apart from ALF, one may also come across subacute hepatic failure (SAHF) as well as acute-on-chronic liver failure (ACLF) due to viral hepatitis. Interestingly, a host of other conditions can mimic ALF because clinical presentation in these conditions can be dominated by jaundice and encephalopathy. Malarial hepatopathy is possibly the best-known condition out of these and is not an uncommon manifestation of severe malaria. A similar presentation can also be seen in other common infections in tropics such as dengue fever, typhoid fever, leptospirosis, scrub typhus, amoebic liver abscesses, tuberculosis and other bacterial and fungal infections with or without human immunodeficiency virus (HIV) related disease. In many of these conditions, liver failure may not be underlying pathophysiology. Some pregnancy related liver diseases could also present with jaundice and encephalopathy. This review summarizes the commonly seen presentations in tropical country like India, where jaundice and encephalopathy dominate the clinical picture.

Leptospirosis in humans

Leptospirosis is a widespread and potentially fatal zoonosis that is endemic in many tropical regions and causes large epidemics after heavy rainfall and flooding. Infection results from direct or indirect exposure to infected reservoir host animals that carry the pathogen in their renal tubules and shed pathogenic leptospires in their urine. Although many wild and domestic animals can serve as reservoir hosts, the brown rat (Rattus norvegicus) is the most important source of human infections. Individuals living in urban slum environments characterized by inadequate sanitation and poor housing are at high risk of rat exposure and leptospirosis. The global burden of leptospirosis is expected to rise with demographic shifts that favor increases in the number of urban poor in tropical regions subject to worsening storms and urban flooding due to climate change. Data emerging from prospective surveillance studies suggest that most human leptospiral infections in endemic areas are mild or asymptomatic. Development of more severe outcomes likely depends on three factors: epidemiological conditions, host susceptibility, and pathogen virulence (Fig. 1). Mortality increases with age, particularly in patients older than 60 years of age. High levels of bacteremia are associated with poor clinical outcomes and, based on animal model and in vitro studies, are related in part to poor recognition of leptospiral LPS by human TLR4. Patients with severe leptospirosis experience a cytokine storm characterized by high levels of IL-6, TNF-alpha, and IL-10. Patients with the HLA DQ6 allele are at higher risk of disease, suggesting a role for lymphocyte stimulation by a leptospiral superantigen. Leptospirosis typically presents as a nonspecific, acute febrile illness characterized by fever, myalgia, and headache and may be confused with other entities such as influenza and dengue fever. Newer diagnostic methods facilitate early diagnosis and antibiotic treatment. Patients progressing to multisystem organ failure have widespread hematogenous dissemination of pathogens. Nonoliguric (high output) renal dysfunction should be supported with fluids and electrolytes. When oliguric renal failure occurs, prompt initiation of dialysis can be life saving. Elevated bilirubin levels are due to hepatocellular damage and disruption of intercellular junctions between hepatocytes, resulting in leaking of bilirubin out of bile caniliculi. Hemorrhagic complications are common and are associated with coagulation abnormalities. Severe pulmonary hemorrhage syndrome due to extensive alveolar hemorrhage has a fatality rate of >50 %. Readers are referred to earlier, excellent summaries related to this subject (Adler and de la Peña-Moctezuma 2010; Bharti et al. 2003; Hartskeerl et al. 2011; Ko et al. 2009; Levett 2001; McBride et al. 2005).

Widespread detection of antibodies to Leptospira in feral swine in the United States

As feral swine continue to expand their geographical range and distribution across the United States, their involvement in crop damage, livestock predation, and pathogen transmission is likely to increase. Despite the relatively recent discovery of feral swine involvement in the aetiology of a variety of pathogens, their propensity to transmit and carry a wide variety of pathogens is disconcerting. We examined sera from 2055 feral swine for antibody presence to six serovars of Leptospira that can also infect humans, livestock or domestic animals. About 13% of all samples tested positive for at least one serovar, suggesting that Leptospira infection is common in feral swine. Further studies to identify the proportion of actively infected animals are needed to more fully understand the risk they pose.

Globalization of leptospirosis through travel and migration

Leptospirosis remains the most widespread zoonotic disease in the world, commonly found in tropical or temperate climates. While previous studies have offered insight into intra-national and intra-regional transmission, few have analyzed transmission across international borders. Our review aimed at examining the impact of human travel and migration on the re-emergence of Leptospirosis. Results suggest that alongside regional environmental and occupational exposure, international travel now constitute a major independent risk factor for disease acquisition. Contribution of travel associated leptospirosis to total caseload is as high as 41.7% in some countries. In countries where longitudinal data is available, a clear increase of proportion of travel-associated leptospirosis over the time is noted. Reporting patterns is clearly showing a gross underestimation of this disease due to lack of diagnostic facilities. The rise in global travel and eco-tourism has led to dramatic changes in the epidemiology of Leptospirosis. We explore the obstacles to prevention, screening and diagnosis of Leptopirosis in health systems of endemic countries and of the returning migrant or traveler. We highlight the need for developing guidelines and preventive strategies of Leptospirosis related to travel and migration, including enhancing awareness of the disease among health professionals in high-income countries.

An integrated lab-on-chip for rapid identification and simultaneous differentiation of tropical pathogens

Tropical pathogens often cause febrile illnesses in humans and are responsible for considerable morbidity and mortality. The similarities in clinical symptoms provoked by these pathogens make diagnosis difficult. Thus, early, rapid and accurate diagnosis will be crucial in patient management and in the control of these diseases. In this study, a microfluidic lab-on-chip integrating multiplex molecular amplification and DNA microarray hybridization was developed for simultaneous detection and species differentiation of 26 globally important tropical pathogens. The analytical performance of the lab-on-chip for each pathogen ranged from 10² to 10³ DNA or RNA copies. Assay performance was further verified with human whole blood spiked with Plasmodium falciparum and Chikungunya virus that yielded a range of detection from 200 to 4×10⁵ parasites, and from 250 to 4×10⁷ PFU respectively. This lab-on-chip was subsequently assessed and evaluated using 170 retrospective patient specimens in Singapore and Thailand. The lab-on-chip had a detection sensitivity of 83.1% and a specificity of 100% for P. falciparum; a sensitivity of 91.3% and a specificity of 99.3% for P. vivax; a positive 90.0% agreement and a specificity of 100% for Chikungunya virus; and a positive 85.0% agreement and a specificity of 100% for Dengue virus serotype 3 with reference methods conducted on the samples. Results suggested the practicality of an amplification microarray-based approach in a field setting for high-throughput detection and identification of tropical pathogens.

Tropical diseases consist of a group of debilitating and fatal infections that occur primarily in rural and urban settings of tropical and subtropical countries. While the primary indices of an infection are mostly the presentation of clinical signs and symptoms, outcomes due to an infection with tropical pathogens are often unspecific. Accurate diagnosis is crucial for timely intervention, appropriate and adequate treatments, and patient management to prevent development of sequelae and transmission. Although, multiplex assays are available for the simultaneous detection of tropical pathogens, they are generally of low throughput. Performing parallel assays to cover the detection for a comprehensive scope of tropical infections that include protozoan, bacterial and viral infections is undoubtedly labor-intensive and time consuming. We present an integrated lab-on-chip using microfluidics technology coupled with reverse transcription (RT), PCR amplification, and microarray hybridization for the simultaneous identification and differentiation of 26 tropical pathogens that cause 14 globally important tropical diseases. Such diagnostics capacity would facilitate evidence-based management of patients, improve the specificity of treatment and, in some cases, even allow contact tracing and other disease-control measures.

The dangers of living in a tent in London

A middle-aged patient was admitted severely unwell with acute liver and renal failure of unknown cause. After extensive investigation the patient was found to have leptospirosis. We examine the investigations and management and discuss the disease itself.

A leptospirosis case presenting with thrombotic thrombocytopenic purpura

BACKGROUND

Leptospirosis is a zoonotic disease caused by spirochetes of the genus Leptospira. While the majority of leptospirosis cases occur in the tropics, some cases are also observed in temperate regions of developing countries. The disease has various clinical presentations ranging from a mild influenza-like form to a severe potentially fatal illness accompanied by multi-organ failure. However, atypical presentations of leptospirosis have occasionally been described. Here, a case of leptospirosis presenting as thrombotic thrombocytopenic purpura (TTP) is reported.

CASE REPORT

A 58-years-old male presented with fever, oliguria, darkening of urine, and visual hallucinations. Laboratory investigations revealed anaemia, severe thrombocytopaenia, elevated total bilirubin with indirect predominance, high lactate dehydrogenase, and increased urea (293 mg/dL) and creatinine (7.6 mg/dL) levels. He was diagnosed with TTP. Patient was thought leptospirosis due to atypical clinical manifestations. Leptospirosis was confirmed by strongly positive Microscopic Agglutination Test. Patient recovered completely with antibiotics and plasmapheresis.

CONCLUSION

Leptospirosis may be accompanied by thrombotic thrombocytopenic purpura in particular subtropic regions.

Towards the burden of human leptospirosis: duration of acute illness and occurrence of post-leptospirosis symptoms of patients in the Netherlands

BACKGROUND

Leptospirosis is a global zoonotic disease. Although important for the assessment of the burden of leptospirosis, data on the duration of the illness and the occurrence of post-leptospirosis complaints are not well documented. Hence the main objective of this study was to estimate the occurrence of persistent complaints and duration of hospital stay in laboratory confirmed leptospirosis patients in the Netherlands during 1985 to 2010. Additionally, several risk factors potentially impacting on the occurrence of post-leptospirosis complaints were investigated.

METHODS/PRINCIPAL FINDINGS

The duration of the acute phase of leptospirosis was 16 days (IQR 12-23); 10 days (IQR 7-16) were spent hospitalized. Eighteen fatal cases were excluded from this analysis. Complaints of leptospirosis patients by passive case investigations (CPC) derived from files on ambulant consultations occurring one month after hospital discharge, revealed persistent complaints in 108 of 236 (45.8%) laboratory confirmed cases. Data on persistent complaints after acute leptospirosis (PCAC), assessed in 225 laboratory confirmed leptospirosis cases collected through questionnaires during 1985-1993, indicated 68 (30.2%) PCAC cases. Frequently reported complaints included (extreme) fatigue, myalgia, malaise, headache, and a weak physical condition. These complaints prolonged in 21.1% of the cases beyond 24 months after onset of disease. There was no association between post-leptospirosis complaints and hospitalization. However, individuals admitted at the intensive care unit (ICU) were twice as likely to have continuing complaints after discharge adjusting for age and dialysis (OR 2.0 95% CI 0.8-4.8). No significant association could be found between prolongation of complaints and infecting serogroup, although subgroup analysis suggest that infection with serogroups Sejroe (OR 4.8, 95%CI 0.9-27.0) and icterohaemorrhagiae (OR 2.0, 95%CI 0.9-4.3 CI) are more likely to result in CPC than infections with serogroup Grippotyphosa.

CONCLUSION/SIGNIFICANCE

In addition to the acute disease, persistent complaints have an impact on the burden of leptospirosis.

Leptospiral uveitis - there is more to it than meets the eye!

Leptospirosis, caused by pathogenic species of genus Leptospira, is a highly prevalent zoonotic disease throughout many parts of the world, and an important emerging disease within the United States. Uveitis is a common complication of systemic infection in humans. A similar condition in horses is characterized by recurrent bouts of inflammation. In this article, we review advances in our understanding of leptospiral uveitis and its pathogenic mechanisms.

Leptospirosis: current situation and trends of specific laboratory tests

Leptospirosis is re-emerging as a worldwide zoonosis and is caused by bacteria of the genus Leptospira. Human leptospirosis is associated with high temperature and humidity. Laboratory tests are indispensible for the early diagnosis and proper disease management. The demand for suitable leptospirosis point-of-care diagnostic tests grows with the awareness and number of incidences. Confirmation is achieved by the microscopic agglutination test, bacterial cultivation, PCR or histopathologic methods. However, high costs, poor standardization and/or elaborate sample preparation prevent routine use at the point of care. Cost-efficient, but insensitive serological methods dominate the diagnostic landscape and, likewise, urgently need improvement toward greater compliance with some of the point-of-care criteria. Combined application of antigen and antibody detection methods increases accuracy, but also new development or transfer of diagnostic technologies should be considered useful. Nano- and microparticle technology may play a key role in improving future antigen detection methods.

Leptospirosis in elderly patients

Leptospirosis is a re-emerging zoonosis with broad clinical spectrum and high mortality in severe forms. The aim of this study was to analyze clinical manifestations, laboratory findings, epidemiological data, and management in elderly patients with leptospirosis. Toward that end, we performed a descriptive analysis of 15 leptospirosis elderly cases (age 60–78 years) treated at the Clinic of Infectious Diseases of University Hospital – Pleven (1976–2012). Patients were serologically confirmed by microscopic agglutination test. Twelve cases (80%) presented with the severe form of leptospirosis. Co-morbidity (hypertonic diseases, chronic pulmonary diseases, chronic alcohol abuse, and diabetes) was registered in 13 cases. All cases had fever, oliguria, conjunctival suffusions, hepatosplenomegaly. Jaundice (14/93%), hemorrhagic diathesis (13/87%), vomiting (11/73%), abdominal pain (10/67%), myalgia (7/47%) and hypotension (7/47%) also were observed. Renal dysfunction was expressed by increased blood urea nitrogen (mean 38.1 ± 24.1 mmol/L) and serum creatinine (mean 347.6 ± 179.8 μmol/L). Hepatic dysfunction was expressed by increased total serum bilirubin level (mean 274.6 ± 210.7 μmol/L) and slightly elevated aminotransferases (ASAT mean 125.8 ± 61.6 IU/L; ALAT mean 131.3 ± 126.5 IU/L). Five cases (33%) had a lethal outcome. In conclusion, leptospirosis in elderly patients is associated with severe course and higher risk for death, and requires prompt intensive treatment.

Leptospirosis: possibilities of early laboratory and clinical diagnosis

This retrospective study aims to identify and describe the problems associated with the laboratory and clinical diagnosis of leptospirosis. A total of 4,813 patients with suspected leptospirosis from an area of the Czech Republic, with a total population of 1.15 million, were examined during the period 2002–2010. Our study included only 855 patients: 545 men (mean age 41.03 ± 19.24) and 310 women (mean age 41.47 ± 20.3) who were examined using microscopic agglutination test (MAT) and a polymerase chain reaction (PCR). All patients and their physicians filled in questionnaires, which included anamnestic data, clinical symptoms and the results of laboratory tests. Out of total suspected, 89 patients (1.85%), tested positive for leptospirosis, of which 50 have been examined only serologically by MAT. Of 855 patients in our study undergoing both PCR and MAT tests, 39 have tested positive for leptospirosis. The most frequent symptom in patients with leptospirosis included fever (91.6%) and headache (69.4%). The correct laboratory diagnosis of leptospirosis depends on biological material being tested before the start of antibiotic treatment, since leptospires are extremely sensitive to antibiotics. Consequently, the PCR results alone may produce a false negative result after 24 hours following treatment with antibiotics.

Leptospirosis and Weil's disease in the UK

The recent high-profile death of a British Olympic rower from leptospirosis has raised awareness to this uncommon but potentially fatal disease. The re-emergence of the disease abroad is well documented in the literature, but less is known about cases in the UK. The increase in participation in water sports, foreign travel and often a combination of the two, has increased the exposure of tourists subsequently returning to the UK from areas of high prevalence. Leptospirosis is a zoonotic infection. The bacteria are shed in the urine of animals to the environment from where humans are infected by incidental hosts. There is a wide spectrum of severity of symptoms, from a self-limiting febrile illness to fatal pulmonary haemorrhage, renal or liver failure. It is thought that cases remain unrecognized every year in the UK, largely due to the mild nature of symptoms and the wide differential for febrile illness and partly due to lack of awareness among clinicians. This review examines the epidemiology of leptospirosis in the UK, over the period 2006-10, the clinical features, diagnostic techniques and treatment.

Acalculous cholecystitis: a rare presentation of leptospirosis progressing to Weil's disease

Leptospirosis is a zoonotic infection with higher incidence in tropics. Leptospirosis, is known for its variable manifestations, and is a clinical challenge for physicians in the tropics. Experienced clinicians, at times can mistake leptospirosis for non-medical conditions. A few reports of leptospirosis presenting as acalculous cholecystitis was found in review of literature. We intent to highlight acalculous cholecystitis as a rare but clinically significant presentation of leptospirosis.

Predictors of the development of myocarditis or acute renal failure in patients with leptospirosis: an observational study

Background

Leptospirosis has a varied clinical presentation with complications like myocarditis and acute renal failure. There are many predictors of severity and mortality including clinical and laboratory parameters. Early detection and treatment can reduce complications. Therefore recognizing the early predictors of the complications of leptospirosis is important in patient management. This study was aimed at determining the clinical and laboratory predictors of myocarditis or acute renal failure.

Methods

This was a prospective descriptive study carried out in the Teaching Hospital, Kandy, from 1st July 2007 to 31st July 2008. Patients with clinical features compatible with leptospirosis case definition were confirmed using the Microscopic Agglutination Test (MAT). Clinical features and laboratory measures done on admission were recorded. Patients were observed for the development of acute renal failure or myocarditis. Chi-square statistics, Fisher's exact test and Mann-Whitney U test were used to compare patients with and without complications. A logistic regression model was used to select final predictor variables.

Results

Sixty two confirmed leptospirosis patients were included in the study. Seven patients (11.3%) developed acute renal failure and five (8.1%) developed myocarditis while three (4.8%) had both acute renal failure and myocarditis. Conjunctival suffusion - 40 (64.5%), muscle tenderness - 28 (45.1%), oliguria - 20 (32.2%), jaundice - 12 (19.3%), hepatomegaly - 10 (16.1%), arrhythmias (irregular radial pulse) - 8 (12.9%), chest pain - 6 (9.7%), bleeding - 5 (8.1%), and shortness of breath (SOB) 4 (6.4%) were the common clinical features present among the patients. Out of these, only oliguria {odds ratio (OR) = 4.14 and 95% confidence interval (CI) 1.003-17.261}, jaundice (OR = 5.13 and 95% CI 1.149-28.003), and arrhythmias (OR = 5.774 and 95% CI 1.001-34.692), were predictors of myocarditis or acute renal failure and none of the laboratory measures could predict the two complications.

Conclusions

This study shows that out of clinical and laboratory variables, only oliguria, jaundice and arrhythmia are strong predictors of development of acute renal failure or myocarditis in patients with leptospirosis presented to Teaching Hospital of Kandy, Sri Lanka.

Pulmonary manifestations of leptospirosis

BACKGROUND

Pulmonary manifestations in leptospirosis are considered a major complication and are related to a poor prognosis. We present a large series of patients with pulmonary involvement using a practical approach based on the presence of acute respiratory failure (ARF).

METHODS

A retrospective study of patients with confirmed leptospirosis.

RESULTS

One hundred and sixty-nine patients with a laboratory-confirmed diagnosis of leptospirosis were investigated. One hundred and thirty-four patients (36.7±14 years of age) had pulmonary involvement. Severe pulmonary involvement was defined by evidence of ARF. Univariate analysis found the following factors related to severe pulmonary leptospirosis: dyspnoea (OR=10.14, p<0.0001), pulmonary crepitations (OR=4.8, p<0.0004), abnormal chest X-ray (OR=9.88, p<0.007) with alveolar shadowing (OR=8.12, p<0.0001), oliguria/anuria (OR=5.48, p<0.0001), hepatomegaly (OR=7.11, p< 0.0001), shock (OR=8.38, p< 0.0001), ICU admission (OR=60.08, p< 0.0001), dialysis (OR=4.87, p< 0.001), mechanical ventilation (OR=216, p< 0.0001) and development of nosocomial infection (OR=21.5, p< 0.0001). The mortality rate was significantly different between severe (40%) and non-severe (5.3%) pulmonary forms (OR=11.87, p< 0.0001). Multivariate analysis found two independent factors related to severe pulmonary involvement: dyspnoea (OR=10.18, p< 0.0001) and oliguria/anuria (OR=4.87, p< 0.0009). We performed a multivariate analysis to assess independent factors related to mortality and found: mechanical ventilation requirement (OR=27.85, p< 0.0001) and AST greater than 150 IU/L (OR=4.57, p< 0.02). Haemoptysis was associated with survival (OR=0.2, p< 0.02).

CONCLUSIONS

Severe pulmonary involvement in leptospirosis is associated with extensive disease involving other organs. The association of multiple factors is associated with severe forms of the disease and a high mortality rate.

Acute liver failure, autoimmune hepatitis, and leptospirosis: a case report

The etiology of acute liver failure varies widely in children, but the most common causes are viral hepatitis, drugs, and toxins. We report herein a case of autoimmune hepatitis and acute liver failure caused by leptospirosis, which is involved rarely in etiology.

Emergence, control and re-emerging leptospirosis: dynamics of infection in the changing world

Globally, leptospirosis poses an increasing public health problem, as evidenced by markedly increasing incidence rates and multiple outbreaks in all continents. Yet, the disease is severely neglected and hence, its global burden is largely unknown. The estimated incidence of about half a million severe human cases annually is probably an underestimation while the burden for animal health is unknown. It is anticipated that current international initiatives will assess the global burden of leptospirosis, while mathematical modelling of transmission dynamics will allow the identification and testing of appropriate intervention and outbreak response measures within the coming years.

Seasonality of human leptospirosis in Reunion Island (Indian Ocean) and its association with meteorological data

Background

Leptospirosis is a disease which occurs worldwide but particularly affects tropical areas. Transmission of the disease is dependent on its excretion by reservoir animals and the presence of moist environment which allows the survival of the bacteria.

Methods and Findings

A retrospective study was undertaken to describe seasonal patterns of human leptospirosis cases reported by the Centre National de Références des Leptospiroses (CNRL, Pasteur Institute, Paris) between 1998 and 2008, to determine if there was an association between the occurrence of diagnosed cases and rainfall, temperature and global solar radiation (GSR). Meteorological data were recorded in the town of Saint-Benoît (Météo France “Beaufonds-Miria” station), located on the windward (East) coast. Time-series analysis was used to identify the variables that best described and predicted the occurrence of cases of leptospirosis on the island. Six hundred and thirteen cases were reported during the 11-year study period, and 359 cases (58.56%) were diagnosed between February and May. A significant correlation was identified between the number of cases in a given month and the associated cumulated rainfall as well as the mean monthly temperature recorded 2 months prior to diagnosis (r = 0.28 and r = 0.23 respectively). The predictive model includes the number of cases of leptospirosis recorded 1 month prior to diagnosis (b = 0.193), the cumulated monthly rainfall recorded 2 months prior to diagnosis (b = 0.145), the average monthly temperature recorded 0 month prior to diagnosis (b = 3.836), and the average monthly GSR recorded 0 month prior to diagnosis (b = −1.293).

Conclusions

Leptospirosis has a seasonal distribution in Reunion Island. Meteorological data can be used to predict the occurrence of the disease and our statistical model can help to implement seasonal prevention measures.

Leptospirosis presenting in a woman with fulminant hepatic failure from Wilson's disease: a case report

Introduction

We report an unusual case of Wilson's disease that was revealed by presentation of leptospirosis. The prompt detection of this potentially life-threatening disease highlights the importance of careful investigation. To the best of our knowledge, this is the first reported case of leptospirosis involving the development of fulminant liver failure due to Wilson's disease.

Case presentation

A 17-year-old Caucasian woman presented with fever, rigors, vomiting and scleral jaundice. Following clinical and laboratory evaluation she was diagnosed with leptospirosis. After remission of this disease her condition inexplicably deteriorated. Further investigations revealed that she had Wilson's disease.

Conclusions

The unexplained deterioration of hepatic function in a young person in remission from leptospirosis should alert the clinician to the presence of an underlying disorder, such as Wilson's disease, the early detection of which is crucial to the prognosis. The mechanism that initiates the development of Wilson's disease is not fully understood, but it is thought that an intercurrent illness, such as viral infection or drug toxicity, could be implicated. In our case, leptospirosis appeared to precipitate the deterioration of liver function in a patient with Wilson's disease, advancing our knowledge of this association. This original case report could have a broader clinical impact across medicine.

Animal leptospirosis in small tropical areas

Leptospirosis is the most widespread zoonosis in the world. Humans become infected through contact with the urine of carrier animals, directly or via contaminated environments. This review reports available data on animal leptospirosis in ten tropical islands: Barbados, Martinique, Guadeloupe, Grenada, Trinidad, New Caledonia, Hawaii, French Polynesia, La Réunion and Mayotte. Leptospirosis is endemic in these insular wild and domestic fauna. Each island presents a specific panel of circulating serovars, closely linked with animal and environmental biodiversity, making it epidemiologically different from the mainland. Rats, mongooses and mice are proven major renal carriers of leptospires in these areas but dogs also constitute a significant potential reservoir. In some islands seroprevalence of leptospirosis in animals evolves with time, inducing changes in the epidemiology of the human disease. Consequently more investigations on animal leptospirosis in these ecosystems and use of molecular tools are essential for prevention and control of the human disease.

Differences in clinical manifestations of imported versus autochthonous leptospirosis in Austria and Germany

Leptospirosis, a zoonosis occurring worldwide, has a broad spectrum of clinical manifestations. Recently, various countries observed an increase of severe anicteric cases. In Austria and Germany, growing numbers of imported cases are notified in addition to autochthonous infections. The aim of this study was to assess whether imported and autochthonous cases differ in clinical manifestations and outcome. We retrospectively analyzed 24 imported and 35 autochthonous cases treated in six infectious disease units between 1998 and 2008. To compare disease severity, patients were classified according to established independent risk factors for fatal outcome. Although severe leptospirosis (i.e., presence of > or = 1 independent risk factors for death) occurred in similar proportions of imported (67%) and autochthonous (86%) infections (P = 0.1), imported cases were significantly fewer icteric (13% versus 69%; P < 0.0001). In conclusion, an increasing incidence of severe anicteric imported cases of leptospirosis should be anticipated with rising global travel activities.

Leptospirosis as a cause of fever in urban Bangladesh

We tested paired sera from 584 febrile persons in an low-income urban community in Bangladesh for evidence of Leptospira infection. A total of 8.4% of the persons met criteria for definite or probable infection. Persons with leptospirosis were older than those with undifferentiated fever in this population. The dominant infecting serogroups in Bangladesh differed from serogroups commonly reported in nearby regions.

Severe leptospirosis in hospitalized patients, Guadeloupe

We evaluated prognostic factors for leptospirosis in 168 consecutive hospitalized patients in Guadeloupe. Factors independently associated with severity included chronic hypertension or chronic alcoholism, late initiation of antibacterial therapy, abnormal chest auscultation results, icterus, oligoanuria, disorders of consciousness, elevated aspartate aminotransferase levels, hyperamylasemia, and Leptospira interrogans serovar Icterohemorrhagiae.

Leptospiral endostatin-like protein A is a bacterial cell surface receptor for human plasminogen

The spirochete Leptospira interrogans is a highly invasive pathogen of worldwide public health importance. Studies from our laboratories and another have demonstrated that L. interrogans can acquire host plasminogen on its surface. Exogenous plasminogen activators can then convert bound plasminogen into the functionally active protease plasmin. In this study, we extend upon those observations and report that leptospiral endostatin-like protein A (LenA) binds human plasminogen in a dose-dependent manner. LenA-plasminogen interactions were significantly inhibited by the lysine analog xi-aminocaproic acid, suggesting that the lysine-binding sites on the amino-terminal kringle portion of the plasminogen molecule play a role in the binding. Previous studies have shown that LenA also binds complement regulator factor H and the extracellular matrix component laminin. Plasminogen competed with both factor H and laminin for binding to LenA, which suggests overlapping ligand-binding sites on the bacterial receptor. Finally, LenA-bound plasminogen could be converted to plasmin, which in turn degraded fibrinogen, suggesting that acquisition of host-derived plasmin by LenA may aid bacterial dissemination throughout host tissues.

Travel-related leptospirosis in Israel: a nationwide study

Leptospirosis is re-emerging in developed countries as a travel-related infection. In this nationwide study of travel-related leptospirosis in Israel, all cases diagnosed at the Central Reference Laboratory for Leptospirosis, during 2002-2008 were retrospectively reviewed and only travel-related cases were included. During the study years, 20 (42%) of 48 leptospirosis cases in Israel were travel-related. Exposure occurred in Southeast Asia in 15 (75%) of 20 cases. The estimated yearly incidence of travel-related leptospirosis was 1.78/100,000 travelers compared with an incidence of endemic cases of 0.06/100,000 inhabitants (risk ratio = 29.6, 95% confidence interval = 16.7-52.4). Most patients (89%) were infected during water-related activities. Severe disease was present in 10 (55%) of 18 patients; 7 of them were presumptively infected with the Icterohaemorrhagiae serogroup. Thus, travel-related leptospirosis is becoming increasingly important in the epidemiology of leptospirosis in Israel. Leptospirosis should be suspected in any traveler with undifferentiated febrile illness, especially when water exposure is reported.

Strategies for diagnosis and treatment of suspected leptospirosis: a cost-benefit analysis

BACKGROUND

Symptoms and signs of leptospirosis are non-specific. Several diagnostic tests for leptospirosis are available and in some instances are being used prior to treatment of leptospirosis-suspected patients. There is therefore a need to evaluate the cost-effectiveness of the different treatment strategies in order to avoid misuse of scarce resources and ensure best possible health outcomes for patients.

METHODS

The study population was adult patients, presented with uncomplicated acute febrile illness, without an obvious focus of infection or malaria or typical dengue infection. We compared the cost and effectiveness of 5 management strategies: 1) no patients tested or given antibiotic treatment; 2) all patients given empirical doxycycline treatment; patients given doxycycline when a patient is tested positive for leptospirosis using: 3) lateral flow; 4) MCAT; 5) latex test. The framework used is a cost-benefit analysis, accounting for all direct medical costs in diagnosing and treating patients suspected of leptospirosis. Outcomes are measured in length of fever after treatment which is then converted to productivity losses to capture the full economic costs.

FINDINGS

Empirical doxycycline treatment was the most efficient strategy, being both the least costly alternative and the one that resulted in the shortest duration of fever. The limited sensitivity of all three diagnostic tests implied that their use to guide treatment was not cost-effective. The most influential parameter driving these results was the cost of treating patients with complications for patients who did not receive adequate treatment as a result of incorrect diagnosis or a strategy of no-antibiotic-treatment.

CONCLUSIONS

Clinicians should continue treating suspected cases of leptospirosis on an empirical basis. This conclusion holds true as long as policy makers are not prioritizing the reduction of use of antibiotics, in which case the use of the latex test would be the most efficient strategy.