Use of Advanced Diagnostics for Timely Identification of Travel-associated Leptospira santarosai Infection in Four Adolescents Through Plasma Microbial Cell-free DNA Sequencing With the Karius Test

BACKGROUND

Leptospirosis is an important zoonotic infection worldwide. Diagnosis of leptospirosis is challenging given its nonspecific clinical symptoms that overlap with other acute febrile illnesses and limitations with conventional diagnostic testing. Alternative advanced diagnostics, such as microbial cell-free DNA (mcfDNA), are increasingly being used to aid in the diagnosis of infections and can be applied to pathogens with public health importance such as Leptospira , a nationally notifiable disease.

METHODS

The Karius Test uses plasma mcfDNA sequencing to detect and quantify DNA-based pathogens. This test offered through the Karius lab detected 4 cases of Leptospira santarosai during a 5-month period across the United States in 2021 and were clinically reviewed.

RESULTS

In our case series, 4 adolescents with recent travel to Central America (Costa Rica, n = 3 and Belize, n = 1) from April to August 2021 were diagnosed with leptospirosis. While a large workup was performed in all cases, mcfDNA testing was the first test to detect L. santarosai as the microbiological diagnosis in all cases.

CONCLUSIONS

Results of the Karius Test enabled rapid, noninvasive diagnosis of leptospirosis allowing for targeted therapy. Use of mcfDNA can be utilized for diagnosis of pathogens where conventional testing is challenging or limited. This in turn can enable quick diagnosis for targeted treatment and potentially aid in supporting case definitions of reportable diseases of public health concern.

Case Report: Locally Acquired Leptospirosis in a Minnesota Boy and His Dog

Leptospirosis affects numerous animal species, including domestic dogs, but documented transmission to humans is rare. Here, we describe epidemiologically linked cases in a 12-year-old Minnesota boy and his pet dog. While human leptospirosis is often thought of as a disease of tropical locations, this case report describes a rare documented example of local transmission in the northern United States, a region historically not perceived to be at high risk of Leptospira species transmission to humans. This case highlights an unusual presentation, with facial nerve palsy, underappreciated epidemiological risks, and diagnostic challenges of this reemerging infection.

Host-response transcriptional biomarkers accurately discriminate bacterial and viral infections of global relevance

Diagnostic limitations challenge management of clinically indistinguishable acute infectious illness globally. Gene expression classification models show great promise distinguishing causes of fever. We generated transcriptional data for a 294-participant (USA, Sri Lanka) discovery cohort with adjudicated viral or bacterial infections of diverse etiology or non-infectious disease mimics. We then derived and cross-validated gene expression classifiers including: 1) a single model to distinguish bacterial vs. viral (Global Fever-Bacterial/Viral [GF-B/V]) and 2) a two-model system to discriminate bacterial and viral in the context of noninfection (Global Fever-Bacterial/Viral/Non-infectious [GF-B/V/N]). We then translated to a multiplex RT-PCR assay and independent validation involved 101 participants (USA, Sri Lanka, Australia, Cambodia, Tanzania). The GF-B/V model discriminated bacterial from viral infection in the discovery cohort an area under the receiver operator curve (AUROC) of 0.93. Validation in an independent cohort demonstrated the GF-B/V model had an AUROC of 0.84 (95% CI 0.76-0.90) with overall accuracy of 81.6% (95% CI 72.7-88.5). Performance did not vary with age, demographics, or site. Host transcriptional response diagnostics distinguish bacterial and viral illness across global sites with diverse endemic pathogens.

Neurobiomarker and body temperature responses to recreational marathon running

OBJECTIVES

To assess how biomarkers indicating central nervous system insult (neurobiomarkers) vary in peripheral blood with exertional-heat stress from prolonged endurance exercise.

DESIGN

Observational study of changes in neuron specific enolase (NSE), S100 calcium-binding protein B (S100β), Glial Fibrillary Acid Protein (GFAP) and Ubiquitin carboxyl-terminal hydrolase isozyme L1 (UCHL1) at Brighton Marathon 2022.

METHODS

In 38 marathoners with in-race core temperature (Tc) monitoring, exposure (High, Intermediate or Low) was classified by cumulative hyperthermia - calculated as area under curve of Time × Tc > 38 °C - and also by running duration (finishing time). Blood was sampled for neurobiomarkers, cortisol and fluid-regulatory stress surrogates, including copeptin and creatinine (at rested baseline; within 30 min of finishing; and at 24 h).

RESULTS

Finishing in 236 ± 40 min, runners showed stable GFAP and UCH-L1 across the marathon and next-day. Significant (P < 0.05) increases from baseline were shown post-marathon and at 24 h for S100β (8.52 [3.65, 22.95] vs 39.0 [26.48, 52.33] vs 80.3 [49.1, 99.7] ng·L-1) and post-marathon only for NSE (3.73 [3.30, 4.32] vs 4.85 [4.45, 5.80] μg·L-1, P < 0.0001). Whilst differential response to hyperthermia was observed for cortisol, copeptin and creatinine, neurobiomarker responses did not vary. Post-marathon, only NSE differed by exercise duration (High vs Low, 5.81 ± 1.77 vs. 4.69 ± 0.73 μg·L-1, adjusted P = 0.0358).

CONCLUSIONS

Successful marathon performance did not associate with evidence for substantial neuronal insult. To account for variation in neurobiomarkers with prolonged endurance exercise, factors additional to hyperthermia, such as exercise duration and intensity, should be further investigated.

546. Resolution of a Cluster of Travel-Associated Leptospira santarosai Infection in Four Adolescents by Plasma Microbial Cell-Free DNA Detection with the Karius Test®

Background

Leptospira can cause severe infections but their diagnosis can be challenging. Diagnosis is limited by nonspecific, protean clinical symptoms; the fastidious nature of Leptospira; and poor specificity, sensitivity, and long turnaround times of serologic testing. Given these limitations, identifying epidemiological clusters of leptospirosis can be challenging. Rapid, non-invasive diagnosis of leptospirosis by microbial cell-free DNA (mcfDNA) next-generation sequencing (NGS) of plasma offers a means to overcome these limitations in individual diagnosis and public health epidemiological surveillance.

Methods

The Karius Test® (KT) detects and quantifies mcfDNA in molecules/µL (MPM) in plasma from a curated genomic database of &gt;20,000 organisms reporting on &gt;1000 pathogens through the Karius CLIA certified/CAP accredited lab (Redwood City, CA). Four KT detections of Leptospira santarosai were identified April - August 2021 across four independent United States institutions. Clinical review was performed by pediatric infectious diseases consultants.

Results

KT detected L. santarosai in four adolescents with travel to Costa Rica or Belize (Table). A broad work-up was performed in all patients. McfDNA NGS was the first test to identify L. santarosai as the diagnosis in all cases with an average time to diagnosis of 2.5+/- 0.58 days from sample collection, enabling narrowed, targeted antibiotic treatment. L. santarosai mcfDNA was positive in three patients despite pretreatment; average L. santarosai mcfDNA concentration was 173.5+/- 186.1 MPM. Leptospira serologies were confirmatory in three patients, potential epidemiological exposures were identified in all patients, and all recovered.

Conclusion

KT enabled rapid, non-invasive diagnosis of diverse manifestations of L. santarosai against a competing broad differential in four adolescent travelers returning from Costa Rica or Belize. The resolution of the etiology of this cluster of patients with leptospirosis demonstrates the potential utility of mcfDNA to quickly diagnose and support case definitions of reportable diseases and the potential importance of plasma mcfDNA NGS in public health and epidemiological surveillance.

Disclosures

Asim A. Ahmed, MD, Karius: Employee|Karius: Stocks/Bonds Sara Saporta-Keating, MS, MD, Pfizer: Co-investigator in investigator-driven study sponsored by Pfizer.

Microbial Characterization, Factors Contributing to Contamination, and Household Use of Cistern Water, U.S. Virgin Islands

Households in the United States Virgin Islands (USVI) heavily rely on roof-harvested rainwater stored in cisterns for their daily activities. However, there are insufficient data on cistern water microbiological and physicochemical characteristics to inform appropriate cistern water management. Cistern and kitchen tap water samples were collected from 399 geographically representative households across St. Croix, St. Thomas, and St. John and an administered survey captured household site and cistern characteristics and water use behaviors. Water samples were analyzed for Escherichia coli by culture, and a subset of cistern water samples (N = 47) were analyzed for Salmonella, Naegleria fowleri, pathogenic Leptospira, Cryptosporidium, Giardia, and human-specific fecal contamination using real-time polymerase chain reaction (PCR). Associations between E. coli cistern contamination and cistern and site characteristics were evaluated to better understand possible mechanisms of contamination. E. coli was detected in 80% of cistern water samples and in 58% of kitchen tap samples. For the subset of samples tested by PCR, at least one of the pathogens was detected in 66% of cisterns. Our results suggest that covering overflow pipes with screens, decreasing animal presence at the household, and preventing animals or insects from entering the cisterns can decrease the likelihood of E. coli contamination in USVI cistern water.

Leptospira borgpetersenii serovar Hardjo and Leptospira santarosai serogroup Pyrogenes isolated from bovine dairy herds in Puerto Rico

Leptospirosis is one of the most common zoonotic diseases in the world and endemic in the Caribbean Islands. Bovine leptospirosis is an important reproductive disease. Globally, cattle are recognized as a reservoir host for L. borgpetersenii serovar Hardjo, which is transmitted via urine, semen, and uterine discharges, and can result in abortion and poor reproductive performance. The dairy industry in Puerto Rico comprises up to 25% of agriculture-related income and is historically the most financially important agricultural commodity on the island. In this study, we report the isolation of two different pathogenic Leptospira species, from two different serogroups, from urine samples collected from dairy cows in Puerto Rico: L. borgpetersenii serogroup Sejroe serovar Hardjo and L. santarosai serogroup Pyrogenes. Recovered isolates were classified using whole-genome sequencing, serotyping with reference antisera and monoclonal antibodies, and immunoblotting. These results demonstrate that dairy herds in Puerto Rico can be concurrently infected with more than one species and serovar of Leptospira, and that bacterin vaccines and serologic diagnostics should account for this when applying intervention and diagnostic strategies.

Seroprevalence, distribution, and risk factors for human leptospirosis in the United States Virgin Islands

Background

The first documented human leptospirosis cases in the U.S. Virgin Islands (USVI) occurred following 2017 Hurricanes Irma and Maria. We conducted a representative serosurvey in USVI to estimate the seroprevalence and distribution of human leptospirosis and evaluate local risk factors associated with seropositivity.

Methodology/Principal findings

A stratified, two-stage cluster sampling design was used and consisted of three island strata and random selection of census blocks and then households. All eligible members of selected households were invited to participate (≥5 years old, resided in USVI ≥6 months and ≥6 months/year). Household and individual-level questionnaires were completed, and serum collected from each enrolled individual. Microscopic agglutination test serology was conducted, and bivariate and logistic regression analyses completed to identify risk factors for seropositivity.

In March 2019, 1,161 individuals were enrolled from 918 households in St. Croix, St. Thomas, and St. John. The territory-wide weighted seroprevalence was 4.0% (95% CI:2.3–5.7). Characteristics/exposures independently associated with seropositivity using logistic regression included contact with cows (OR: 39.5; 95% CI: 9.0–172.7), seeing rodents/rodent evidence or contact with rodents (OR: 2.6; 95% CI: 1.1–5.9), and increasing age (OR: 1.02; 95% CI: 1.002–1.04); full or partial Caucasian/White race was negatively correlated with seropositivity (OR: 0.02, 95% CI: 0.04–0.7). Bivariate analysis showed self-reported jaundice since the 2017 hurricanes (pRR: 5.7; 95% CI: 1.0–33.4) was associated with seropositivity and using a cover/lid on cisterns/rainwater collection containers (pRR: 0.3; 95% CI: 0.08–0.8) was protective against seropositivity.

Conclusions/Significance

Leptospirosis seropositivity of 4% across USVI demonstrates an important human disease that was previously unrecognized and emphasizes the importance of continued leptospirosis surveillance and investigation. Local risk factors identified may help guide future human and animal leptospirosis studies in USVI, strengthen leptospirosis public health surveillance and treatment timeliness, and inform targeted education, prevention, and control efforts.

Acute febrile illness among outpatients seeking health care in Bangladeshi hospitals prior to the COVID-19 pandemic

Understanding the distribution of pathogens causing acute febrile illness (AFI) is important for clinical management of patients in resource-poor settings. We evaluated the proportion of AFI caused by specific pathogens among outpatients in Bangladesh. During May 2019-March 2020, physicians screened patients aged ≥2 years in outpatient departments of four tertiary level public hospitals. We randomly enrolled patients having measured fever (≥100.4°F) during assessment with onset within the past 14 days. Blood and urine samples were tested at icddr,b through rapid diagnostic tests, bacterial culture, and polymerase chain reaction (PCR). Acute and convalescent samples were sent to the Centers for Disease Control and Prevention (USA) for Rickettsia and Orientia (R/O) and Leptospira tests. Among 690 patients, 69 (10%) had enteric fever (Salmonella enterica serotype Typhi orSalmonella enterica serotype Paratyphi), 51 (7.4%) Escherichia coli, and 28 (4.1%) dengue detected. Of the 441 patients tested for R/O, 39 (8.8%) had rickettsioses. We found 7 (2%) Leptospira cases among the 403 AFI patients tested. Nine patients (1%) were hospitalized, and none died. The highest proportion of enteric fever (15%, 36/231) and rickettsioses (14%, 25/182) was in Rajshahi. Dhaka had the most dengue cases (68%, 19/28). R/O affected older children and young adults (IQR 8-23 years) and was detected more frequently in the 21-25 years age-group (17%, 12/70). R/O was more likely to be found in patients in Rajshahi region than in Sylhet (aOR 2.49, 95% CI 0.85-7.32) between July and December (aOR 2.01, 1.01-5.23), and who had a history of recent animal entry inside their house than not (aOR 2.0, 0.93-4.3). Gram-negative Enterobacteriaceae were the most common bacterial infections, and dengue was the most common viral infection among AFI patients in Bangladeshi hospitals, though there was geographic variability. These results can help guide empiric outpatient AFI management.

Physiological and perceptual responses during walking at set and preferred pace in normal and overweight adults

BACKGROUND

This study aimed to investigate the influence of body weight, exercise modality, and pace on physiological and perceptual responses to determine the relation between perceptual and physiological responses.

METHODS

Aerobically untrained, normal weight, and overweight males and females participated. Participants were randomly assigned to one exercise condition for a 1-mile walk.

RESULTS

Prescribed pace resulted in a greater physiological stress than self-selected pace (all p < 0.001) through blood lactate (1.3 ± 0.4 vs 1.7 ± 0.5 mmol), systolic blood pressure (128.9 ± 10.3 vs 139.2 ± 13.2 mmHg), heart rate recovery (2.1 ± 1.7 vs 4.5 ± 2.6 min), oxygen consumption (15.1 ± 2.6 vs 18.1 ± 3.6 ml/kg/min), heart rate (111.7 ± 16.6 vs 134.4 ± 8.3 bpm), and energy expenditure (5.5 ± 1.4 vs 6.8 ± 1.7 kcal/min). Overweight individuals exhibited higher values than normal weight for heart rate (113 ± 8.8 vs 125.5 ± 13.2 bpm, p < 0.001), percentage of max heart rate (60.7 vs 69.0%, p < 0.001), percent of VO2peak (42.2 vs 55.6%, p < 0.001), and total energy expenditure (100.9 ± 27.4 vs 114.1 ± 33.5 kcal, p = 0.022). Greater perceived effort was seen on a treadmill (6.3 ± 0.5 vs 12.5 ± 2.0 RPE, p < 0.001) and at prescribed pace (6.5 ± 1.1 vs 8.9 ± 1.9 RPE, p < 0.001).

CONCLUSION

A novel finding of this study was the increased physiological stress and perception of effort on a treadmill and at a prescribed pace, while total energy expenditure showed no significant differences. This could indicate an unfavorable perception and less affective response to the treadmill modality. These results indicate exercise at self-selected pace in preferred environments promotes enjoyable experiences with similar health benefits as those during prescribed higher intensity exercise.

Mongooses (Urva auropunctata) as reservoir hosts of Leptospira species in the United States Virgin Islands, 2019-2020

During 2019-2020, the Virgin Islands Department of Health investigated potential animal reservoirs of Leptospira spp., the bacteria that cause leptospirosis. In this cross-sectional study, we investigated Leptospira spp. exposure and carriage in the small Indian mongoose (Urva auropunctata, syn: Herpestes auropunctatus), an invasive animal species. This study was conducted across the three main islands of the U.S. Virgin Islands (USVI), which are St. Croix, St. Thomas, and St. John. We used the microscopic agglutination test (MAT), fluorescent antibody test (FAT), real-time polymerase chain reaction (lipl32 rt-PCR), and bacterial culture to evaluate serum and kidney specimens and compared the sensitivity, specificity, positive predictive value, and negative predictive value of these laboratory methods. Mongooses (n = 274) were live-trapped at 31 field sites in ten regions across USVI and humanely euthanized for Leptospira spp. testing. Bacterial isolates were sequenced and evaluated for species and phylogenetic analysis using the ppk gene. Anti-Leptospira spp. antibodies were detected in 34% (87/256) of mongooses. Reactions were observed with the following serogroups: Sejroe, Icterohaemorrhagiae, Pyrogenes, Mini, Cynopteri, Australis, Hebdomadis, Autumnalis, Mankarso, Pomona, and Ballum. Of the kidney specimens examined, 5.8% (16/270) were FAT-positive, 10% (27/274) were culture-positive, and 12.4% (34/274) were positive by rt-PCR. Of the Leptospira spp. isolated from mongooses, 25 were L. borgpetersenii, one was L. interrogans, and one was L. kirschneri. Positive predictive values of FAT and rt-PCR testing for predicting successful isolation of Leptospira by culture were 88% and 65%, respectively. The isolation and identification of Leptospira spp. in mongooses highlights the potential role of mongooses as a wildlife reservoir of leptospirosis; mongooses could be a source of Leptospira spp. infections for other wildlife, domestic animals, and humans.

On the robustness of latent class models for diagnostic testing with no gold standard

It is difficult to estimate sensitivity and specificity of diagnostic tests when there is no gold standard. Latent class models have been proposed as a potential solution as they provide estimates without the need for a gold standard. Using a motivating example of the evaluation of point of care tests for leptospirosis in Tanzania, we show how a realistic violation of assumptions underpinning the latent class model can lead directly to substantial bias in the estimates of the parameters of interest. In particular, we consider the robustness of estimates of sensitivity, specificity, and prevalence, to the presence of additional latent states when fitting a two-state latent class model. The violation is minor in the sense that it cannot be routinely detected with goodness-of-fit procedures, but is major with regard to the resulting bias.

Pathology and One Health implications of fatal Leptospira interrogans infection in an urbanized, free-ranging, black-tufted marmoset (Callithrix penicillata) in Brazil

Leptospirosis is a zoonotic neglected disease of worldwide public health concern. Leptospira species can infect a wide range of wild and domestic mammals and lead to a spectrum of disease, including severe and fatal forms. Herein, we report for the first time a fatal Leptospira interrogans infection in a free-ranging nonhuman primate (NHP), a black-tufted marmoset. Icterus, pulmonary haemorrhage, interstitial nephritis, and hepatocellular dissociation were the main findings raising the suspicion of leptospirosis. Diagnostic confirmation was based on specific immunohistochemical and PCR assays for Leptospira species. Immunolocalization of leptospiral antigens and identification of pathogenic species (L. interrogans species) were important for better understanding the pathogenesis of the disease. One Health-related implications of free-ranging NHPs in anthropized areas and transmission dynamics of human and animal leptospirosis are discussed.

21 Suture School: A Socially Distanced Surgical Education

Introduction

Limited theatre exposure, cancelled practical teaching and placements abandoned due to COVID-19, has potential to damage the learning opportunities and experiences of medical students within surgery. We aimed to create and deliver an emergency small group teaching programme throughout the pandemic, targeted at increasing medical student confidence in basic surgical skills and inspiring interest in surgery.

Method

Multiple small-group teaching sessions were delivered to a cohort of 14 medical students recruited for work during the pandemic, whilst adhering to social distancing and sanitary measures. On completion of the programme and informal assessment of 11 surgical competencies, participants completed a follow up questionnaire to assess their improvement.

Results

70% reported improvement in 10 competencies and 30% across all 11 competencies. The greatest improvements were in abscess drainage and knot tying. 30% relayed increased interest in pursuing a surgical career. 80% were ‘more likely’ to attend theatres in future.

Conclusions

The teaching series facilitated increase in self-perceived confidence of students in basic surgical skills, whilst inspiring surgical interests. During challenging times, we must support learners to undertake activity that drives improvement in training for the wider benefit of health services. Innovative teaching programmes may reduce the impact of similar adversity in the future.

Clinical, diagnostic, and epidemiological features of a community-wide outbreak of canine leptospirosis in a low-prevalence region (Maricopa County, Arizona)

OBJECTIVE

To describe clinical, diagnostic, and epidemiological features of an outbreak of leptospirosis in dogs in Maricopa County, Ariz, from January 2016 through June 2017.

ANIMALS

71 case and 281 control dogs.

PROCEDURES

Cases were classified as confirmed, probable, suspect, or not a case on the basis of medical record data that fulfilled clinical, diagnostic, and epidemiological criteria. Potential exposures were assessed by owner survey. For the case-control investigation, control dogs were recruited through owner completion of a July 2017 survey. Summary statistics and ORs for case dog lifestyle factors were reported.

RESULTS

54 dogs were classified as confirmed and 17 as probable cases. For 4 dogs of a household cluster (5 confirmed and 3 probable), the highest microscopic agglutination titer was for serovar Djasiman (Leptospira kirschneri detected by PCR assay), and for 13 dogs of a community outbreak (49 confirmed and 14 probable cases), the highest titer was for serovar Canicola (Leptospira interrogans detected by PCR assay). The 44 case dogs included in the case-control investigation were 7.7 (95% CI, 3.5 to 16.7) and 2.9 times (95% CI, 1.3 to 6.6) as likely as control dogs to have visited dog daycare or to have been kenneled overnight at a boarding facility, respectively, 30 days prior to the onset of clinical signs or diagnosis.

CONCLUSIONS AND CLINICAL RELEVANCE

Diagnostic and epidemiological findings indicated 2 outbreaks. Transmission where dogs congregated likely propagated the community outbreak. Outbreaks of leptospiral infections can occur in regions of low prevalence, and a dog's exposure to areas where dogs congregate should be considered when making Leptospira vaccination recommendations.

First Reported Human Cases of Leptospirosis in the United States Virgin Islands in the Aftermath of Hurricanes Irma and Maria, September-November 2017

Objective

Following Hurricanes Irma and Maria, the first case of human leptospirosis ever identified in the US Virgin Islands (USVI) was reported to the Virgin Islands Department of Health. Leptospirosis is a potentially fatal bacterial disease caused by Leptospira species found in animal urine and urine-contaminated water and soil. Outbreaks can occur following extreme weather events.

Method

Additional cases of leptospirosis were identified in the 2.5 months post-hurricanes by reviewing emergency department (ED) records from territorial hospitals for patients demonstrating leptospirosis-consistent symptoms, testing symptomatic patients previously enrolled in the USVI arbovirus surveillance system (VIASS), and adding leptospirosis testing prospectively to VIASS. Available patient sera underwent local rapid diagnostic testing for anti-Leptospira IgM followed by confirmatory microscopic agglutination testing at the US Centers for Disease Control and Prevention. Water was collected from cisterns with epidemiologic links to confirmed cases and tested by real-time PCR (qPCR) for pathogenic Leptospira spp.

Results

Sixteen retrospectively identified symptomatic patients were enrolled in VIASS; 15 with available samples tested negative. Based on review of 5226 ED charts, 6 patients were further investigated; of these, 5 were tested of which 1 was positive. Prospective leptospirosis surveillance tested 57 additional patients; of these, 1 was positive. Water from 1 of 5 tested cisterns was found positive by qPCR.

Conclusions

This investigation documents the first 3 cases of leptospirosis reported in the USVI and demonstrates how VIASS successfully was adapted to establish leptospirosis surveillance. Contaminated cistern water was identified as a potential source for Leptospira spp. transmission, highlighting the need for additional post-hurricane remediation and disinfection guidance.

A Cross-Cutting Approach to Surveillance and Laboratory Capacity as a Platform to Improve Health Security in Uganda

Global health security depends on effective surveillance for infectious diseases. In Uganda, resources are inadequate to support collection and reporting of data necessary for an effective and responsive surveillance system. We used a cross-cutting approach to improve surveillance and laboratory capacity in Uganda by leveraging an existing pediatric inpatient malaria sentinel surveillance system to collect data on expanded causes of illness, facilitate development of real-time surveillance, and provide data on antimicrobial resistance. Capacity for blood culture collection was established, along with options for serologic testing for select zoonotic conditions, including arboviral infection, brucellosis, and leptospirosis. Detailed demographic, clinical, and laboratory data for all admissions were captured through a web-based system accessible at participating hospitals, laboratories, and the Uganda Public Health Emergency Operations Center. Between July 2016 and December 2017, the expanded system was activated in pediatric wards of 6 regional government hospitals. During that time, patient data were collected from 30,500 pediatric admissions, half of whom were febrile but lacked evidence of malaria. More than 5,000 blood cultures were performed; 4% yielded bacterial pathogens, and another 4% yielded likely contaminants. Several WHO antimicrobial resistance priority pathogens were identified, some with multidrug-resistant phenotypes, including Acinetobacter spp., Citrobacter spp., Escherichia coli, Staphylococcus aureus, and typhoidal and nontyphoidal Salmonella spp. Leptospirosis and arboviral infections (alphaviruses and flaviviruses) were documented. The lessons learned and early results from the development of this multisectoral surveillance system provide the knowledge, infrastructure, and workforce capacity to serve as a foundation to enhance the capacity to detect, report, and rapidly respond to wide-ranging public health concerns in Uganda.

Despite high-risk exposures, no evidence of zoonotic transmission during a canine outbreak of leptospirosis

Leptospirosis is a bacterial zoonosis that affects many mammals, including humans and dogs; dogs can transmit the bacteria to humans, but the frequency of transmission and highest risk exposures are poorly understood. During 2016-2017, the Maricopa County Department of Public Health, Arizona Department of Health Services and Centers for Disease Control and Prevention investigated the zoonotic potential of a canine leptospirosis outbreak in the Phoenix metro area. We identified symptomatic persons exposed to canine leptospirosis cases by conducting active and passive surveillance. We tested dog owners (n = 9) and animal care providers (n = 109) for serological evidence of Leptospira spp. infection (via the microscopic agglutination test [MAT]) and interviewed these persons about their specific exposures to canine cases and general exposures to canine blood and urine. Through surveillance, seven symptomatic persons were identified; six were tested and all were negative by MAT, and of these six, four persons were negative by PCR (two did not have PCR testing). All serosurvey participants (n = 118) were also seronegative. Among animal care providers, bare skin contact with urine/blood from a canine case was reported by 23.2%; two persons reported dog urine splashing in their face. Veterinary technicians were more likely to have bare skin contact with blood from a canine case compared to veterinarians and boarding facility staff (p < 0.001). Infection control practices were inconsistent; when working with specimens from a canine leptospirosis case, 44.6% of participants reported always wearing gloves when working with urine (i.e., collecting specimens), and 54.5% always wore gloves when working with blood. Veterinary technicians were also most likely to engage in all activities involving potential urine/blood contact, such as conducting laboratory tests (p < 0.01). We therefore recommend that veterinary technicians specifically receive targeted education about infection control practices. Our results suggest that dog-to-human transmission of leptospirosis is uncommon.

Post marathon cardiac troponin T is associated with relative exercise intensity

OBJECTIVES

This study aimed to investigate whether measures of cardiopulmonary fitness and relative exercise intensity were associated with high sensitivity cardiac troponin T (cTnT) rise after a road marathon.

METHODS

Fifty-two marathon runners (age 39±11 years, body mass 76.2±12.9kg, height 1.74±0.09m) attended the laboratory between 2 and 3 weeks prior to attempting the Brighton Marathon, UK. Running economy at 10kmh^-1 (RE10) and race pace (RERP), ventilatory threshold (VT) and VO₂max tests were completed. CTnT was measured within 48h prior to the marathon and within 10min of completing the marathon, using a high sensitivity assay. Heart rates (HR) were recorded throughout the marathon.

RESULTS

Runners demonstrated a significant increase in cTnT over the marathon (pre-race 5.60±3.27ngL^-1, post-race 74.52±30.39ngL^-1, p<0.001). Markers of endurance performance such as running economy (10kmh^-1 223±18mlkg^-1km^-1; race pace 225±22mlkg^-1km^-1), VT (38.5±6.4mlkg^-1min^-1) and V˙O₂max (50.9±7.7mlkg^-1min^-1) were not associated with post-race cTnT. Runners exercise intensity correlated with post-race cTnT (mean HR %VT 104±5%, r=0.50; peak HR %VT 118±8%, r=0.68; peak HR %V˙O₂max 96±6, r=0.60, p<0.05) and was different between the low, medium and high cTnT groups (p<0.05).

CONCLUSIONS

CTnT increases above reference limits during a marathon. Magnitude of cTnT rise is related to exercise intensity relative to ventilatory threshold and V˙O₂max, but not individuals' absolute cardiopulmonary fitness, training state or running history.

Acute kidney injury associated with endurance events-is it a cause for concern? A systematic review

INTRODUCTION

A growing body of evidence suggests even small rises in serum creatinine (SCr) are of considerable clinical relevance. Given that participants in endurance events are exposed to potential (repeated) renal insults, a systematic review was undertaken to collate current evidence for acute kidney injury (AKI), complicating such events.

METHODS

A systematic review of studies and case reports meeting inclusion criteria on Medline and EMBASE (inception to October 2015). Included: studies with markers of renal function before and after endurance or ultraendurance events; case reports of severe AKI. Two reviewers assessed risk of bias using the Newcastle-Ottawa scale.

RESULTS

Eleven case report publications (n=27 individuals) of severe AKI, were retrieved, with risk factors including systemic illness or nephrotoxic medications usually identified. From 30 studies of endurance and ultraendurance events, mean rise in SCr was 29 (±12.3) µmol/L after marathon or ultramarathon (17 studies, n=568 participants) events. Where follow-up tests were conducted, SCr returned to baseline within 48 hours. Rises in biomarkers suggest potential parenchymal insult, rather than simply muscle breakdown. However, evidence of long-term deleterious effects is lacking.

CONCLUSIONS

Raised levels of SCr are reported immediately after endurance events. It is not clear whether this is either clinically significant, or if repeated participation predisposes to long-term sequelae. The aetiology of severe exercise-associated AKI is usually multifactorial, with risk factors generally identified in the rare cases reported. On-site biochemistry, urine analysis and biomarkers of AKI may help identify collapsed runners who are at significant short-term risk and allow suitable follow-up.

Enhanced Surveillance for Fatal Dengue-Like Acute Febrile Illness in Puerto Rico, 2010-2012

BACKGROUND

Dengue is a leading cause of morbidity throughout the tropics; however, accurate population-based estimates of mortality rates are not available.

METHODS/PRINCIPAL FINDINGS

We established the Enhanced Fatal Acute Febrile Illness Surveillance System (EFASS) to estimate dengue mortality rates in Puerto Rico. Healthcare professionals submitted serum and tissue specimens from patients who died from a dengue-like acute febrile illness, and death certificates were reviewed to identify additional cases. Specimens were tested for markers of dengue virus (DENV) infection by molecular, immunologic, and immunohistochemical methods, and were also tested for West Nile virus, Leptospira spp., and other pathogens based on histopathologic findings. Medical records were reviewed and clinical data abstracted. A total of 311 deaths were identified, of which 58 (19%) were DENV laboratory-positive. Dengue mortality rates were 1.05 per 100,000 population in 2010, 0.16 in 2011 and 0.36 in 2012. Dengue mortality was highest among adults 19-64 years and seniors ≥65 years (1.17 and 1.66 deaths per 100,000, respectively). Other pathogens identified included 34 Leptospira spp. cases and one case of Burkholderia pseudomallei and Neisseria meningitidis.

CONCLUSIONS/SIGNIFICANCE

EFASS showed that dengue mortality rates among adults were higher than reported for influenza, and identified a leptospirosis outbreak and index cases of melioidosis and meningitis.

Feral Swine Leptospira Seroprevalence Survey in Hawaii, USA, 2007-2009

Leptospirosis is considered the most widespread of zoonotic diseases. It was a notifiable disease in the United States until 1995 and was reinstated to the list of nationally notifiable diseases in 2014. During the time of national surveillance, Hawaii consistently led the nation in reported annual incidence rates. Leptospirosis has remained a reportable disease in Hawaii. Significant changes have been documented since the early 1970s in the predominant serogroup infecting humans in Hawaii: infections due to Icterohaemorrhagiae have declined while infections due to Australis have increased. A recent study from Hawaii demonstrated that Australis was an uncommon infecting serogroup for small mammal hosts. Swine have not been previously studied in Hawaii but are well-recognized maintenance hosts for leptospires belonging to the Australis serogroup. This study was undertaken to assess the prevalence of Leptospira antibody in feral swine in Hawaii. From January 2007 through December 2009, blood samples were collected opportunistically from feral swine. Using the microscopic agglutination test, we found antibody titres ≥1 : 100 to leptospires in 272 (33.8%) of 804 feral swine. The most frequently reacting serovars to the swine sera were Icterohaemorrhagiae (Icterohaemorrhagiae serogroup) (41.5%) and Bratislava (Australis serogroup) (33.8%). The high seroprevalence and presumptively infecting serovars suggest a link between swine and human infection.

Seroepidemiology of leptospirosis in dogs from rural and slum communities of Los Rios Region, Chile

Background

Leptospirosis is a zoonotic disease of global importance and often neglected as a public health problem due to lack of awareness, under-diagnosis and under-reporting. Animals serve as a source of transmission through the shedding of Leptospira in their urine. Because of their proximity to humans, dogs may play a role in human infections. In order to assess and mitigate leptospirosis in dogs and the risk of transmission to humans it is important to understand the epidemiology of leptospirosis under natural conditions. This study aimed to characterize leptospirosis in owned dogs from three distinct community types. Blood, dog and household data were collected from 265 dogs in 190 households from 12 communities representing farms, rural villages, and urban slums in the Los Rios region, Chile. Serologic profiles with a 20-serovar microagglutination test panel were obtained. Binomial and multinomial logistic regression models were used to evaluate the associations between spatial, ecological, socio-economic variables and overall seropositivity as well as seropositivity to serogroup Canicola.

Results

Results from 247 dogs with no history of vaccination were used. Overall seroprevalence was 25.1% (62/247) with significant differences by community type: 10.9% (9/82) in dogs from farms, 22.3% (21/94) from rural villages, and 45.1% (32/71) from urban slums (p <0.001). This trend by community type was also observed for dogs with evidence of seropositivity to the Canicola serogroup. Factors associated with seropositive dogs included dog density and precipitation two-weeks prior to sampling. Presence of Leptospira positive puddles collected from the peri-domestic household environment was also associated with increased seropositivity.

Conclusions

Results suggest that leptospirosis is actively maintained in the dog population in this study region with notably distinct patterns by community type. Dog populations from rural villages, and urban slums in particular, showed evidence of high levels of transmission probably as a result of the combined effects of dog living conditions as well as community-level ecological and environmental factors.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-015-0341-9) contains supplementary material, which is available to authorized users.

Case series of fatal Leptospira spp./dengue virus co-infections-Puerto Rico, 2010-2012

Co-infection with pathogens that cause acute febrile illness creates a diagnostic challenge as a result of overlapping clinical manifestations. Here, we describe four fatal cases of Leptospira species/dengue virus co-infection in Puerto Rico. Although all patients sought care early, antibiotic administration was delayed for most. Steroids were administered to all patients, in most cases before antibiotics. These cases show the need for clinicians evaluating patients in or recently returned from the tropics with acute febrile illness to consider both dengue and leptospirosis. Furthermore, they illustrate the need for nucleic acid- or antigen-based rapid diagnostic tests to enable timely patient diagnosis and management. In particular, antibiotic therapy should be initiated early for patients with suspected leptospirosis, and steroids should not be administered to patients with suspected dengue.

Actionable diagnosis of neuroleptospirosis by next-generation sequencing

A 14-year-old boy with severe combined immunodeficiency presented three times to a medical facility over a period of 4 months with fever and headache that progressed to hydrocephalus and status epilepticus necessitating a medically induced coma. Diagnostic workup including brain biopsy was unrevealing. Unbiased next-generation sequencing of the cerebrospinal fluid identified 475 of 3,063,784 sequence reads (0.016%) corresponding to leptospira infection. Clinical assays for leptospirosis were negative. Targeted antimicrobial agents were administered, and the patient was discharged home 32 days later with a status close to his premorbid condition. Polymerase-chain-reaction (PCR) and serologic testing at the Centers for Disease Control and Prevention (CDC) subsequently confirmed evidence of Leptospira santarosai infection.

Epizootiological survey of small mammals as Leptospira spp. reservoirs in Eastern Croatia

In this survey we investigated a population of small mammals in Eastern Croatia in order to determine Leptospira carriage rates and identify circulating serovars. Out of 67 trapped animals, 20 (29.9%) isolates were obtained. Identification of isolates using microscopic agglutination test, pulsed field gel electrophoresis and multi locus sequence typing revealed that 10 (50.0%) isolates belong to serogroup Pomona, serovar Mozdok, 6 (30.0%) isolates to serogroup Australis, serovar Jalna, 2 (10.0%) isolates to serogroup Sejroe, serovar Saxkoebing, and 1 (5.0%) isolate to serogroup Grippotyphosa, serovar Grippotyphosa. One isolate from serogroup Bataviae was unable to be identified to the serovar level. Amplification of a 331-bp region of the locus LA0322 using real-time polymerase chain reaction determined that 12 (60.0%) isolates belong to L. kirschneri, 6 (30.0%) isolates to L. interrogans, and 2 (10.0%) isolates to L. borgpetersenii. Leptospira carriage rate was high (29.9%), which corresponds to a high incidence of human and domestic animal leptospirosis in Eastern Croatia. Furthermore, 90.0% of the isolates belong to serogroups Pomona, Australis and Sejroe which are also the most prevalent serogroups in humans in this area. These findings suggest that small mammals might be an important source of Leptospira spp. infection in Eastern Croatia.

A single multilocus sequence typing (MLST) scheme for seven pathogenic Leptospira species

Background

The available Leptospira multilocus sequence typing (MLST) scheme supported by a MLST website is limited to L. interrogans and L. kirschneri. Our aim was to broaden the utility of this scheme to incorporate a total of seven pathogenic species.

Methodology and Findings

We modified the existing scheme by replacing one of the seven MLST loci (fadD was changed to caiB), as the former gene did not appear to be present in some pathogenic species. Comparison of the original and modified schemes using data for L. interrogans and L. kirschneri demonstrated that the discriminatory power of the two schemes was not significantly different. The modified scheme was used to further characterize 325 isolates (L. alexanderi [n = 5], L. borgpetersenii [n = 34], L. interrogans [n = 222], L. kirschneri [n = 29], L. noguchii [n = 9], L. santarosai [n = 10], and L. weilii [n = 16]). Phylogenetic analysis using concatenated sequences of the 7 loci demonstrated that each species corresponded to a discrete clade, and that no strains were misclassified at the species level. Comparison between genotype and serovar was possible for 254 isolates. Of the 31 sequence types (STs) represented by at least two isolates, 18 STs included isolates assigned to two or three different serovars. Conversely, 14 serovars were identified that contained between 2 to 10 different STs. New observations were made on the global phylogeography of Leptospira spp., and the utility of MLST in making associations between human disease and specific maintenance hosts was demonstrated.

Conclusion

The new MLST scheme, supported by an updated MLST website, allows the characterization and species assignment of isolates of the seven major pathogenic species associated with leptospirosis.

Leptospirosis is a common zoonotic disease worldwide. Genotyping of the causative organisms provides important insights into disease transmission and informs preventive strategies and vaccine development. Multilocus sequence typing (MLST) is the most widespread genotyping methodology for bacterial pathogens, but the Leptospira scheme supported by a public MLST database is currently only applicable to L. interrogans and L. kirschneri. The purpose of this study was to extend the scheme to a total of seven pathogenic Leptospira species. This was achieved through the development of a modified scheme in which one of the seven MLST loci was replaced, together with newly designed primers for the remaining 6 loci. Comparison of the original and modified scheme demonstrated that they were very similar, hence sequence type (ST) assignments were largely carried over to the modified scheme. Phylogenetic trees reconstructed from concatenated sequences of the seven loci of the modified scheme demonstrated perfect classification of isolates into seven pathogenic species, which resided in clearly distinct phylogenetic clusters. Congruence was low between STs and serovars. The MLST scheme was used to gain new insights into the population genetic structure of Leptospira species associated with clinical disease and maintenance hosts in Asia.

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.

Outbreak of leptospirosis among Adventure Race participants in Florida, 2005

BACKGROUND

On 21 November 2005, a 32-year-old male resident of New York was hospitalized with suspected leptospirosis. He had participated in an endurance-length swamp race on 4-5 November 2005 outside of Tampa, Florida.

METHODS

We interviewed racers to assess illness, medical care, and race activities. A suspected case was defined as fever plus > or = 2 signs or symptoms of leptospirosis occurring in a racer after 4 November 2005. Individuals with suspected cases were referred for treatment as needed and were asked to submit serum samples for microscopic agglutination testing (MAT) and for rapid testing by the dot enzyme-linked immunosorbent assay dipstick immunoglobulin M immunoassay.

RESULTS

The Centers for Disease Control and Prevention and participating state health departments interviewed 192 (96%) of 200 racers from 32 states and Canada. Forty-four (23%) of 192 racers met the definition for a suspected case. The median age of the patients was 37 years (range, 19-66 years), and 128 (66.7%) were male. Fourteen (45%) of the 31 patients with suspected cases who were tested had their cases confirmed by serological testing (a single sample with MAT titer > or = 400), including the index case patient. Organisms of a potential novel serovar (species Leptospira noguchii) were isolated in culture from 1 case patient. Factors associated with increased risk of leptospirosis included swallowing river water (odds ratio [OR], 3.4; 95% confidence interval [CI], 1.6-7.0), swallowing swamp water (OR, 2.4; 95% CI, 1.1-5.2), and being submerged in any water (OR, 2.3; 95% CI, 1.1-4.7).

CONCLUSIONS

This report describes a leptospirosis outbreak that resulted in a high rate of symptomatic infection among adventure racers in Florida. The growing popularity of adventure sports may put more people at risk for leptospirosis, even in areas that have not previously been considered areas of leptospirosis endemicity.

A tale of two clades: monkeypox viruses

Human monkeypox was first recognized outside Africa in 2003 during an outbreak in the USA that was traced to imported monkeypox virus (MPXV)-infected West African rodents. Unlike the smallpox-like disease described in the Democratic Republic of the Congo (DRC; a Congo Basin country), disease in the USA appeared milder. Here, analyses compared clinical, laboratory and epidemiological features of confirmed human monkeypox case-patients, using data from outbreaks in the USA and the Congo Basin, and the results suggested that human disease pathogenicity was associated with the viral strain. Genomic sequencing of USA, Western and Central African MPXV isolates confirmed the existence of two MPXV clades. A comparison of open reading frames between MPXV clades permitted prediction of viral proteins that could cause the observed differences in human pathogenicity between these two clades. Understanding the molecular pathogenesis and clinical and epidemiological properties of MPXV can improve monkeypox prevention and control.

Reclassification of Leptospira parva Hovind-Hougen et al. 1982 as Turneriella parva gen. nov., comb. nov

Analysis of the G+C content, DNA–DNA relatedness to other leptospires and 16S rRNA gene sequence of Leptospira parva showed that this species was not related to other Leptospira species. On the basis of these data, it is proposed that Leptospira parva should be transferred to the genus Turneriella as Turneriella parva gen. nov., comb. nov., with strain HT (=NCTC 11395T=ATCC BAA-1111T) as the type strain.

Ultrasound-to-computer-tomography registration for image-guided laparoscopic liver surgery

BACKGROUND

The application of image-guided surgery (IGS) to laparoscopic liver resection and ablation is currently limited, but it would assist in intraoperative decision making regarding oncologic margins, ablation probe placement, and ablation tracking.

METHODS

Eight spherical surface targets on a liver phantom were imaged with an optically tracked laparoscopic ultrasound (US) probe. Ten US images of each target were registered to computer tomography (CT) images of the phantoms and then mapped to the CT scans. Accuracy of the registration was assessed by comparing the distance between the predicted target location and the position obtained directly from CT.

RESULTS

The average localization error was 5.3 mm. The errors resulted primarily from inaccurate US probe tracking but were otherwise insensitive to the variability that arises from manually identifying targets in US and CT images.

CONCLUSIONS

The results obtained for US-to-CT registration in a phantom model suggest that further investigations into its clinical use are warranted and that other IGS technologies could be applied to laparoscopic liver surgery as well.

Direct sequencing of SARS-coronavirus S and N genes from clinical specimens shows limited variation

Severe acute respiratory syndrome-associated coronavirus (SARS-CoV) emerged, in November 2002, as a novel agent causing severe respiratory illness. To study sequence variation in the SARS-CoV genome, we determined the nucleic acid sequence of the S and N genes directly from clinical specimens from 10 patients--1 specimen with no matched SARS-CoV isolate, from 2 patients; multiple specimens from 3 patients; and matched clinical-specimen/cell-culture-isolate pairs from 6 patients. We identified 3 nucleotide substitutions that were most likely due to natural variation and 2 substitutions that arose after cell-culture passage of the virus. These data demonstrate the overall stability of the S and N genes of SARS-CoV over 3 months during which a minimum of 4 generations for transmission events occurred. These findings are a part of the expanding investigation of the evolution of how this virus adapts to a new host.

Deliberate self-poisoning presenting at a rural hospital in Northern Ireland 1976-1996: relationship to prescribing

PURPOSE

This study reports on a project to monitor deliberate self-poisoning in a rural area of Northern Ireland over a 20-year period. Comparison is made with reports from large urban centres. In addition, a local prescribing database allows assessment of any association between psychotropic drug prescription and use for deliberate self-poisoning.

MATERIALS AND METHODS

Frequency of self-poisoning, demographic details and drugs used were recorded for all episodes of deliberate self-poisoning occurring at Craigavon Area Hospital for the years 1976, 1986, 1991 and 1996. It was possible to compare prescriptions of psychotropic drugs with their use for deliberate self-poisoning between the years 1991 and 1996 in the region served by the hospital, using the Defined Daily Dose (DDD) system.

RESULTS

In this rural area the pattern of deliberate self-poisoning has changed, as in urban centres, with a rise in frequency and the male/female ratio approaching unity. The pattern of drug use has altered, with paracetamol overtaking benzodiazepines as the most commonly used agent. More recently, antidepressants have become the second most frequently used drug class for this purpose. Psychotropic medications used for self-poisoning altered in proportion to their prescription between the years 1991 and 1996.

CONCLUSIONS

In the face of a continuing rise in deliberate self-poisoning, which is effecting both urban and rural areas, care should be taken to prescribe the least toxic agent available as this is associated with likely frequency of self-poisoning for most classes of psychotropic drug.

Reaching young Indonesian women through marriage registries: an innovative approach for anemia control

In an effort to build iron stores before pregnancy and reduce the high prevalence of anemia in Indonesia, the Ministry of Health/Indonesia and the MotherCare project implemented an anemia control program for newly wed women. As part of an existing program to counsel couples about marriage and require them to obtain tetanus toxoid immunization before obtaining a marriage certificate, women also were counseled to buy and take 30-60 iron-folate (IFA) tablets. Women (n = 344) were enrolled from one of three participating districts in South Kalimantan, Indonesia. At first monitoring, at least 30 d after baseline, 261 women were tested for hemoglobin and asked about their IFA tablet consumption and knowledge of information, education, and communications (IEC) materials promoted through the program. Results showed that there was a decrease in the prevalence of anemia from 23.8 to 14.0% over the course of the program, 98% of women had taken at least some IFA tablets and 56% had taken >30 tablets.