A simple score to predict severe leptospirosis

Peripartum Infections: A Position Statement of the Indian Society of Critical Care Medicine

This position statement reviews the evidence and rationale for the management of severe peripartum infections with a special focus on tropical infections and is tailored for resource-limited settings.

How to cite this article

Samavedam S, Sodhi K, Anand P, Bajwa SJS, Karnad DR, Karanth S, et al. Peripartum Infections: A Position Statement of the Indian Society of Critical Care Medicine. Indian J Crit Care Med 2024;28(S2):S92-S103.

Utility of demographic and clinical signs as diagnostic predictors for leptospiral uveitis: A retrospective study

PURPOSE

Leptospirosis is a waterborne zoonotic disease prevalent in tropical regions, causing significant morbidity and mortality. It can involve any organ in its primary stage, and uveitis is its late complication. While advanced laboratory diagnosis is available only in tertiary care centers globally, a cost-effective bedside assessment of clinical signs and their scoring could offer a provisional diagnosis.

AIM

To analyze the diagnostic potential of demographic and clinical signs in a large cohort of serologically confirmed leptospiral uveitis patients.

METHODS

In this retrospective study, demographic and clinical parameters of 876 seropositive leptospiral uveitis patients and 1042 nonleptospiral uveitis controls were studied. Multivariable logistic regression analysis with bootstrap confidence interval (CI) characterized the diagnostic predictors. The performance of the model was evaluated using the area under the receiver operating curve (AUROC).

RESULTS

Presence of nongranulomatous uveitis (odds ratio [OR] = 6.9), hypopyon (OR = 4.6), vitreous infiltration with membranous opacities (OR = 4.3), bilateral involvement (OR = 4), panuveitis (OR = 3.3), vasculitis (OR = 1.9), disc hyperemia (OR = 1.6), absence of retinochoroiditis (OR = 15), and absence of cystoid macular edema (OR = 8.9) emerged as predictive parameters. The AUROC value was 0.86 with 95% CI of 0.846-0.874. At a cut-off score of 40, the sensitivity and specificity were 79.5 and 78.4, respectively.

CONCLUSION

The study demonstrates that ocular signs can serve as diagnostic predictors for leptospiral uveitis, enabling primary care ophthalmologists to make bedside diagnosis. This can be further confirmed by laboratory methods available at tertiary care centers.

Analysing the outbreaks of leptospirosis after floods in Kerala, India

A growing number of studies have linked the incidence of leptospirosis with the occurrence of flood events. Nevertheless, the interaction between flood and leptospirosis has not been extensively studied to understand the influence of flood attributes in inducing new cases. This study reviews leptospirosis cases in relation to multiple flood occurrences in Kerala, India. Leptospirosis data were obtained for three years: 2017 (non-flood year) and two years with flooding-2018 (heavy flooding) and 2019 (moderate flooding). We considered the severity of flood events using the discharge, duration and extent of each flooding event and compared them with the leptospirosis cases. The distribution of cases regarding flood discharge and duration was assessed through descriptive and spatiotemporal analyses, respectively. Furthermore, cluster analyses and spatial regression were completed to ascertain the relationship between flood extent and the postflood cases. This study found that postflood cases of leptospirosis can be associated with flood events in space and time. The total cases in both 2018 and 2019 increased in the post-flood phase, with the increase in 2018 being more evident. Unlike the 2019 flood, the flood of 2018 is a significant spatial indicator for postflood cases. Our study shows that flooding leads to an increase in leptospirosis cases, and there is stronger evidence for increased leptospirosis cases after a heavy flood event than after a moderate flooding event. Flood duration may be the most important factor in determining the increase in leptospirosis infections.

Demographic and clinical risk factors associated with severity of lab-confirmed human leptospirosis in Colombia, 2015-2020

BACKGROUND

Leptospirosis is a common zoonoses and is a major global public health threat. Most cases are mild, typically presenting as a non-specific acute febrile illness. However, leptospirosis can have life-threatening manifestations, including pulmonary hemorrhage syndrome, and acute kidney injury. In Colombia, notification and lab-confirmation of suspected human cases are mandatory. However, little is known about the demographic and clinical factors associated with severe leptospirosis, which could help to reduce clinical complications and mortality. Our aim was to identify risk factors associated with severe leptospirosis, intensive care unit (ICU) admission, and mortality in lab-confirmed cases in Colombia, 2015-2020.

METHODS AND FINDINGS

We analyzed 201 lab-confirmed human leptospirosis cases by microagglutination test. We used a logistic regression to identify the demographic and clinical risk factors associated with severe leptospirosis, admission to ICU, and death. Most leptospirosis confirmed cases occurred in men (85.6%); the mean age was 36.7 years. We classified severe cases (43.3%) by clinical manifestations as renal (29.9%) and liver (27.4%) failure, multiple-organ failure (24.4%), septic shock (24.4%), Weil syndrome (18.4%), pulmonary hemorrhage (18.4%), and meningitis (2.5%), admitted to the ICU (30.3%), and fatal (8.5%). Clinical conditions associated with severe leptospirosis were dyspnea (OR: 5.54; 95% CI: 1.46 to 20.98), tachycardia (OR:9.69; 95% CI: 15.96 to 58.8), and rash (OR: 10.25; 95% CI: 25.01 to 42.08).

CONCLUSIONS

We identified demographic characteristics and clinical symptoms associated with severe leptospirosis in Colombia. We hope these results can support clinicians in providing timely treatment to leptospirosis patients to avoid preventable medical complications or deaths.

Development and validation of a simple machine learning tool to predict mortality in leptospirosis

Predicting risk factors for death in leptospirosis is challenging, and identifying high-risk patients is crucial as it might expedite the start of life-saving supportive care. Admission data of 295 leptospirosis patients were enrolled, and a machine-learning approach was used to fit models in a derivation cohort. The comparison of accuracy metrics was performed with two previous models-SPIRO score and quick SOFA score. A Lasso regression analysis was the selected model, demonstrating the best accuracy to predict mortality in leptospirosis [area under the curve (AUC-ROC) = 0.776]. A score-based prediction was carried out with the coefficients of this model and named LeptoScore. Then, to simplify the predictive tool, a new score was built by attributing points to the predictors with importance values higher than 1. The simplified score, named QuickLepto, has five variables (age > 40 years; lethargy; pulmonary symptom; mean arterial pressure < 80 mmHg and hematocrit < 30%) and good predictive accuracy (AUC-ROC = 0.788). LeptoScore and QuickLepto had better accuracy to predict mortality in patients with leptospirosis when compared to SPIRO score (AUC-ROC = 0.500) and quick SOFA score (AUC-ROC = 0.782). The main result is a new scoring system, the QuickLepto, that is a simple and useful tool to predict death in leptospirosis patients at hospital admission.

Prognostic Factors for Leptospirosis Infection Severity

BACKGROUND

Leptospirosis is an important health problem in Thailand. People infected with leptospirosis may not have any mild symptoms, whereas some people have acute and severe illnesses. It is crucial to strengthen critical patients' diagnosis and treatment to prevent severe complications and reduce mortality. This study was performed to explore a set of parameters for the prediction of severe leptospirosis illness under routine clinical practice.

METHODS

A case-control study was conducted in eight general hospitals in Thailand. Retrospective collection data were used, and key information was retrieved from inpatient medical files. Patients were grouped into two severity categories, severe and non-severe infection. Backward elimination was used to reach the final multivariate model.

RESULTS

The six significant predictors identified in the study were hemoptysis (OR = 25.80, 95% CI 5.69, 116.92), hypotension (blood pressure < 90/60 mmHg) (OR = 17.33, 95% CI 6.89, 43.58), platelet count < 100,000/µL (OR = 8.37, 95% CI 4.65, 15.09), white blood cell count (WBC) > 14,000/µL (OR = 5.12, 95% CI 2.75, 9.51), hematocrit ≤ 30% (OR = 3.49, 95% CI 1.61, 7.57), and jaundice (OR = 3.11, 95% CI 1.71, 5.65). These predictors could correctly predict the severity of leptospirosis infection in 91.31% of the area under the receiver operation curve (AuROC).

CONCLUSIONS

The results of this study showed that severe leptospirosis infections have identifiable predictors. The predictors may be used to develop a scoring system for predicting the level of severity.

Limited Awareness of Melioidosis in High-risk Populations Despite an Increasing Incidence of the Disease in Far North Queensland, Australia

The incidence of melioidosis, an opportunistic infection caused by Burkholderia pseudomallei, has recently doubled in Far North Queensland (FNQ), Australia. This contrasts with the local burden of dengue, which is nearing elimination, and the stable incidence of leptospirosis. This questionnaire-based study assessed the awareness of melioidosis among people in FNQ with risk factors for the disease, using awareness of leptospirosis and dengue as comparators. There were 427 respondents; 361 (85%) reported one or more risk factors for melioidosis. Only 69 of 361 (19%) had heard of melioidosis compared with 301 of 361 (83%) who had heard of dengue (P < 0.001) and 137 of 361 (38%) who had heard of leptospirosis (P < 0.001). In FNQ, Australia, there is an increasing local incidence of melioidosis, but there is limited awareness of the disease among high-risk individuals. Greater community awareness of melioidosis is necessary to implement strategies to prevent disease and expedite the presentation of patients with this life-threatening infection.

The epidemiology and outcomes of central nervous system infections in Far North Queensland, tropical Australia; 2000-2019

Background

The epidemiology of central nervous system (CNS) infections in tropical Australia is incompletely defined.

Methods

A retrospective study of all individuals in Far North Queensland, tropical Australia, who were diagnosed with a CNS infection between January 1, 2000, and December 31, 2019. The microbiological aetiology of the infection was correlated with patients’ demographic characteristics and their clinical course.

Results

There were 725 cases of CNS infection during the study period, meningitis (77.4%) was the most common, followed by brain abscess (11.6%), encephalitis (9.9%) and spinal infection (1.1%). Infants (24.3%, p<0.0001) and Aboriginal and Torres Strait Islander Australians (175/666 local residents, 26.3%, p<0.0001) were over-represented in the cohort.

A pathogen was identified in 513 cases (70.8%); this was viral in 299 (41.2%), bacterial in 175 (24.1%) and fungal in 35 (4.8%). Cryptococcal meningitis (24 cases) was diagnosed as frequently as pneumococcal meningitis (24 cases). There were only 2 CNS infections with a S. pneumoniae serotype in the 13-valent pneumococcal vaccine after its addition to the National Immunisation schedule in 2011. Tropical pathogens–including Cryptococcus species (9/84, 11%), Mycobacterium tuberculosis (7/84, 8%) and Burkholderia pseudomallei (5/84, 6%)–were among the most common causes of brain abscess. However, arboviral CNS infections were rare, with only one locally acquired case—a dengue infection in 2009—diagnosed in the entire study period. Intensive Care Unit admission was necessary in 14.3%; the overall case fatality rate was 4.4%.

Conclusion

Tropical pathogens cause CNS infections as commonly as traditional bacterial pathogens in this region of tropical Australia. However, despite being highlighted in the national consensus guidelines, arboviruses were identified very rarely. Prompt access to sophisticated diagnostic and supportive care in Australia’s well-resourced public health system is likely to have contributed to the cohort’s low case-fatality rate.

The seasonality of infections in tropical Far North Queensland, Australia: A 21-year retrospective evaluation of the seasonal patterns of six endemic pathogens

An understanding of the seasonality of infections informs public health strategies and assists clinicians in their management of patients with undifferentiated illness. The seasonality of infections is driven by a variety of environmental and human factors; however, the role of individual climatic factors has garnered much attention. This study utilises Poisson regression models to assess the seasonality of six important infections in tropical Australia and their association with climatic factors and severe weather events over a 21-year period. Melioidosis and leptospirosis showed marked wet season predominance, while more cases of rickettsial disease and cryptococcosis were seen in cooler, drier months. Staphylococcus aureus infections were not seasonal, while influenza demonstrated inter-seasonality. The climate did not significantly change during the 21 years of the study period, but the incidence of melioidosis and rickettsial disease increased considerably, highlighting the primacy of other factors-including societal inequality, and the impact of urban expansion-in the incidence of these infections. While anthropogenic climate change poses a threat to the region-and may influence the burden of these infections in the future-this study highlights the fact that, even for seasonal diseases, other factors presently have a greater effect on disease incidence. Public health strategies must also target these broader drivers of infection if they are to be effective.

Genetic diversity of Leptospira isolates in Lao PDR and genome analysis of an outbreak strain

Background

Although Southeast Asia is one of the most leptospirosis afflicted regions, little is known about the diversity and molecular epidemiology of the causative agents of this widespread and emerging zoonotic disease.

Methodology/Principal findings

We used whole genome sequencing to examine genetic variation in 75 Leptospira strains isolated from patients in the Lao PDR (Laos) between 2006 and 2017.

Eleven serogroups from 4 Leptospira species and 43 cgMLST-defined clonal groups (CGs) were identified. The most prevalent CG was CG272 (n = 18, 26.8%), composed of L. interrogans serogroup Autumnalis isolates. This genotype was recovered throughout the 12-year period and was associated with deaths, and with a large outbreak in neighbouring Thailand. Genome analysis reveals that the CG272 strains form a highly clonal group of strains that have, for yet unknown reasons, recently spread in Laos and Thailand. Additionally, accessory genes clearly discriminate CG272 strains from the other Leptospira strains.

Conclusions/Significance

The present study reveals a high diversity of Leptospira genotypes in Laos, thus extending our current knowledge of the pan- and core-genomes of these life-threatening pathogens. Our results demonstrate that the CG272 strains belong to a unique clonal group, which probably evolved through clonal expansion following niche adaptation. Additional epidemiological studies are required to better evaluate the spread of this genotype in Southeast Asia. To further investigate the key factors driving the virulence and spread of these pathogens, more intense genomic surveillance is needed, combining detailed clinical and epidemiological data.

Pathogenic Leptospira are the causative agents for leptospirosis, a neglected and emerging zoonosis occurring worldwide. In this study, we investigated the genetic diversity of Leptospira strains isolated from patients over a 12-year period in Lao PDR. Our genome analysis revealed a high diversity of Leptospira genotypes in this endemic country for leptospirosis, including a group of clonal strains which was responsible for a large outbreak in neighboring Thailand. Further progress in our understanding of the epidemiology of Leptospira circulating genotypes should contribute to the implementation of prevention and intervention measures to reduce the risk of leptospirosis transmission.

The Applicability of Commonly Used Severity of Illness Scores to Tropical Infections in Australia

Many patients with leptospirosis, melioidosis, and rickettsial infection require intensive care unit (ICU) admission in tropical Australia every year. The multi-organ dysfunction associated with these infections results in significantly elevated severity of illness (SOI) scores. However, the accuracy of these SOI scores in predicting death from these tropical infections is incompletely defined. This retrospective study was performed at Cairns Hospital, a tertiary-referral hospital in tropical Australia. All patients admitted to ICU with laboratory-confirmed leptospirosis, melioidosis, and rickettsial disease between January 1, 1999 and June 30, 2020, were eligible for the study. The ability of Acute Physiology and Chronic Health Evaluation (APACHE) II, APACHE III, Simplified Acute Physiology Scores (SAPS) II, and Sequential Organ Failure Assessment (SOFA) scores to predict death before ICU discharge was evaluated. Overall, 18 (12.1%) of the 149 included patients died: 15/74 (20.3%) with melioidosis, 2/54 (3.7%) with leptospirosis and 1/21 (4.8%) with rickettsial disease. However, the APACHE II, APACHE III, SAPS II, and SOFA scores significantly overestimated the case-fatality rate of all the infections; the disparity between the predicted and observed mortality was most marked in the cases of leptospirosis and rickettsial disease. Commonly used SOI scores significantly overestimate the case-fatality rate of melioidosis, leptospirosis, and rickettsial infections in Australian ICU patients. This may be at least partly explained by the unique pathophysiology of these infections, particularly leptospirosis and rickettsial disease. However, SOI scores may still be useful in facilitating the comparison of disease severity in clinical trials that examine patients with these pathogens.

Leptospirosis and Coinfection: Should We Be Concerned?

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

Anticipating the future: prognostic tools as a complementary strategy to improve care for patients with febrile illnesses in resource-limited settings

In low-income and middle-income countries, most patients with febrile illnesses present to peripheral levels of the health system where diagnostic capacity is very limited. In these contexts, accurate risk stratification can be particularly impactful, helping to guide allocation of scarce resources to ensure timely and tailored care. However, reporting of prognostic research is often imprecise and few prognostic tests or algorithms are translated into clinical practice.

Here, we review the often-conflated concepts of prognosis and diagnosis, with a focus on patients with febrile illnesses. Drawing on a recent global stakeholder consultation, we apply these concepts to propose three use-cases for prognostic tools in the management of febrile illnesses in resource-limited settings: (1) guiding referrals from the community to higher-level care; (2) informing resource allocation for patients admitted to hospital and (3) identifying patients who may benefit from closer follow-up post-hospital discharge. We explore the practical implications for new technologies and reflect on the challenges and knowledge gaps that must be addressed before this approach could be incorporated into routine care settings.

Our intention is that these use-cases, alongside other recent initiatives, will help to promote a harmonised yet contextualised approach for prognostic research in febrile illness. We argue that this is especially important given the heterogeneous settings in which care is often provided for patients with febrile illnesses living in low-income and middle-income countries.

The role of leptospiremia and specific immune response in severe leptospirosis

Leptospirosis can cause a high mortality rate, especially in severe cases. This multicenter cross-sectional study aimed to examine both host and pathogen factors that might contribute to the disease severity. A total of 217 leptospirosis patients were recruited and divided into two groups of non-severe and severe. Severe leptospirosis was defined by a modified sequential organ failure assessment (mSOFA) score of more than two or needed for mechanical ventilation support or had pulmonary hemorrhage or death. We found that leptospiremia, plasma neutrophil gelatinase-associated lipocalin (pNGAL), and interleukin 6 (IL-6) at the first day of enrollment (day 1) and microscopic agglutination test (MAT) titer at 7 days after enrollment (days 7) were significantly higher in the severe group than in the non-severe group. After adjustment for age, gender, and the days of fever, there were statistically significant associations of baseline leptospiremia level (OR 1.70, 95% CI 1.23–2.34, p = 0.001), pNGAL (OR 9.46, 95% CI 4.20–21.33, p < 0.001), and IL-6 (OR 2.82, 95% CI 1.96–4.07, p < 0.001) with the severity. In conclusion, a high leptospiremia, pNGAL, and IL-6 level at baseline were associated with severe leptospirosis.

Leptospirosis in Intensive Care Unit

Tropical infections constitute 20 - 30% of intensive care unit (ICU) admissions in developing countries. Leptospirosis is a spectrum with mild form presenting as an acute febrile illness with jaundice, complicating in few as acute kidney injury (AKI), acute respiratory distress syndrome (ARDS), disseminated intravascular coagulation (DIC), and multi-organ dysfunction syndrome (MODS). The poor prognostic markers are hemorrhagic ARDS, acute renal failure, DIC, severe metabolic acidosis, older age, chronic alcohol abuse, high SOFA score, and septic shock. The confirmatory diagnosis relies on antibody testing, such as microscopic agglutination test (MAT) and IgM ELISA, while the reverse transcription-polymerase chain reaction test being reserved for clinically suspected antibody negative cases. The spectrum of multi-organ involvement necessitates a complete hematological, biochemical workup, including electrocardiogram (ECG), chest X-ray, and two-dimensional echocardiography. Specific antimicrobial therapy consists of the following-benzylpenicillin, ceftriaxone, cefotaxime, and doxycycline. The reported mortality ranges from 6% to as high as 44%. Various ICU scores like SPiRO, THAI LEPTO score, and Faine's criteria have been useful in risk stratification. Optimizing intensive care treatment with appropriate antibiotics, lung protection ventilation strategies, strict fluid management, and if need be timely initiation of renal replacement therapy (RRT) helps in reducing mortality. How to cite this article: Karnik ND, Patankar AS. Leptospirosis in Intensive Care Unit. Indian J Crit Care Med 2021;25(Suppl 2): S134-S137.

Weil's Disease in an HIV-Infected Patient

Leptospirosis is a zoonosis caused by the spirochete Leptospira. Most cases of leptospirosis are mild to moderate and self-limited. The course of disease, however, may be complicated by multiorgan dysfunction with liver and kidney failure causing Weil's disease. Leptospirosis is also rare among HIV-infected patients. We report a case of an HIV-infected patient with Weil's disease.

A prospective study to evaluate the accuracy of rapid diagnostic tests for diagnosis of human leptospirosis: Result from THAI-LEPTO AKI study

BACKGROUND

Rapid diagnostic tests (RDTs) have become widely used in low-resource settings for leptospirosis diagnostic. This study aims to evaluate the diagnostic performance of the five commercially available RDTs to detect human IgM against Leptospira spp. in Thai population.

METHODOLOGY/PRINCIPAL FINDINGS

Ninety-nine serum samples from Leptospirosis suspicious patients were tested with five RDTs, including Medical Science Public Health, Leptocheck-WB, SD bioline, TRUSTline, and J.Mitra. The case definition was based on MAT, qPCR, and culture results. Diagnostic accuracy was determined based on the first day of enrollment in an overall analysis and stratified according to days post-onset of fever. The five RDTs had overall sensitivity ranging from 1.8% to 75% and specificity ranging from 52.3% to 97.7%. Leptocheck-WB had high sensitivity of 75.0%. The sensitivity of five RDTs increased on days 4-6 post-onset of fever, while the specificity of all tests remained relatively stable at different days post-onset of fever.

CONCLUSIONS/SIGNIFICANCE

The tested RDTs showed low sensitivity. Therefore, based on the present study, five commercially available RDTs might not be an appropriate test for acute leptospirosis screening in the Thai population.

The comparative ability of commonly used disease severity scores to predict death or a requirement for ICU care in patients hospitalised with possible sepsis in Yangon, Myanmar

OBJECTIVES

To determine the comparative prognostic utility of commonly used disease prediction scores in adults with presumed community-acquired sepsis in a resource-limited tropical setting.

METHODS

This prospective, observational study was performed on the medical ward of a tertiary-referral hospital in Yangon, Myanmar. The ability of the National Early Warning Score 2 (NEWS2), quick NEWS (qNEWS), quick Sequential Organ Failure Assessment (qSOFA) score, Universal Vital Assessment (UVA) and Sequential Organ Failure Assessment (SOFA) scores to predict a complicated inpatient course (death or requirement for intensive care unit (ICU) support) in patients with two or more systemic inflammatory response syndrome criteria was determined.

RESULTS

Among the 509 patients, 30 (6%) were HIV-seropositive. The most commonly confirmed diagnoses were tuberculosis (30/509, 5.9%) and measles (26/509, 5.1%). Overall, 75/509 (14.7%) died or required ICU support. All the scores except the qSOFA score, which was inferior, had a similar ability to predict a complicated inpatient course.

CONCLUSIONS

In this resource-limited tropical setting, disease severity scores calculated at presentation using only vital signs-such as the NEWS2 score-identified high-risk sepsis patient as well as the SOFA score, which is calculated at 24 h and which also requires laboratory data. Use of these simple clinical scores can be used to facilitate recognition of the high-risk patient and to optimise the use of finite resources.

Clinical Features of Rickettsial Infection in Children in Tropical Australia-A Report of 15 Cases

Rickettsial infections are an under-recognized cause of acute, undifferentiated fever in the tropics. In Asia, intensive care unit (ICU) admission rates as high as 21% and case-fatality rates of up to 5% have been reported. This 20-year retrospective audit of children and adults with serologically confirmed scrub typhus or spotted fever group (SFG) infection was performed at a tertiary-referral hospital in tropical Australia. There were 15 paediatric cases during the study period (11 scrub typhus, 3 SFG and 1 undifferentiated). Hypotension [5/15 (33%)], tachycardia [6/15 (40%)] and tachypnoea [6/15 (40%)] were common at presentation. Children were more likely to be hypotensive at admission than adults [5/15 (33%) vs. 5/118 (4%), p = 0.002]. However, no child died or was admitted to ICU, compared with 18/120 (15%) adults who required ICU support during the study period, one of whom died. Paediatric rickettsial infections have a relatively benign clinical course in tropical Australia with serious complications appearing far less frequently than have been reported in the Asian literature.

Clinical characteristics, outcomes, and predictors of leptospirosis in patients admitted to the medical intensive care unit: A retrospective analysis

BACKGROUND

Early diagnosis and detection of clinical deterioration of leptospirosis are challenges to all clinicians. This study aimed to report the characteristics and outcomes of patients admitted to the medical intensive care unit (MICU) for severe leptospirosis and to identify the clinical predictors of MICU admission.

METHODS

This was a 10-year retrospective study that included all patients diagnosed as leptospirosis, based on either serology or a Thai-Lepto score (TLS) of >4. All clinical characteristics and laboratory data were collected and compared between MICU cases and general ward cases. Binary logistic regression was applied to identify the independent factors for MICU admission.

RESULTS

Of the 68 patients who were diagnosed as leptospirosis based on inclusion criteria, 43 serologically-confirmed cases were subsequently analyzed. Fifty percent of the cases were admitted to the MICU and, compared with those admitted to the general ward, had higher Sequential Organ Failure Assessment (SOFA) score [10 (7-13) vs. 5 (2.2-5.6), p < 0.001]; higher TLS [7.5 (6.5-9.25) vs. 5.5 (3.5-6.5), p < 0.001]; lower mean arterial blood pressure (74.7 ± 15 mmHg vs. 84.2 ± 16.3 mmHg, p = 0.04); lower platelet count in ×10³ cell/mm³ [65 (52.8-105.8) vs. 159 (87.3-181.5), p = 0.008); higher total bilirubin level [4.4 (1.5-8.7) mg/dL vs. 1.2 (0.7-2.8) mg/dL, p = 0.01]; and required more inotropes and vasopressors (87% vs. 4.3%, p < 0.001), mechanical ventilator support (91.3% vs. 4.3%, p < 0.001), and renal replacement therapy (39.1% vs. 0%, p < 0.001). TLS, SOFA score, requirement for mechanical ventilation, and use of inotropes and vasopressors were the predictors of MICU admission. TLS > 6 and SOFA score >6 gave similar power to predict MICU admission.

CONCLUSION

Among patients with leptospirosis, TLS, SOFA score, inotrope or vasopressor requirement, and mechanical ventilator support were the independent predictors of MICU admission. TLS > 6 and SOFA score >6 indicated the need for MICU admission.

The applicability of commonly used predictive scoring systems in Indigenous Australians with sepsis: An observational study

Background

Indigenous Australians suffer a disproportionate burden of sepsis, however, the performance of scoring systems that predict mortality in Indigenous patients with critical illness is incompletely defined.

Materials and methods

The study was performed at an Australian tertiary-referral hospital between January 2014 and June 2017, and enrolled consecutive Indigenous and non-Indigenous adults admitted to ICU with sepsis. The ability of the ANZROD, APACHE-II, APACHE-III, SAPS-II, SOFA and qSOFA scores to predict death before ICU discharge in the two populations was compared.

Results

There were 442 individuals enrolled in the study, 145 (33%) identified as Indigenous. Indigenous patients were younger than non-Indigenous patients (median (interquartile range (IQR) 53 (43–60) versus 65 (52–73) years, p = 0.0001) and comorbidity was more common (118/145 (81%) versus 204/297 (69%), p = 0.005). Comorbidities that were more common in the Indigenous patients included diabetes mellitus (84/145 (58%) versus 67/297 (23%), p<0.0001), renal disease (56/145 (39%) versus 29/297 (10%), p<0.0001) and cardiovascular disease (58/145 (40%) versus 83/297 (28%), p = 0.01). The use of supportive care (including vasopressors, mechanical ventilation and renal replacement therapy) was similar in Indigenous and non-Indigenous patients, and the two populations had an overall case-fatality rate that was comparable (17/145 (12%) and 38/297 (13%) (p = 0.75)), although Indigenous patients died at a younger age (median (IQR): 54 (50–60) versus 70 (61–76) years, p = 0.0001). There was no significant difference in the ability of any the scores to predict mortality in the two populations.

Conclusions

Although the crude case-fatality rates of Indigenous and non-Indigenous Australians admitted to ICU with sepsis is comparable, Indigenous patients die at a much younger age. Despite this, the ability of commonly used scoring systems to predict outcome in Indigenous Australians is similar to that of non-Indigenous Australians, supporting their use in ICUs with a significant Indigenous patient population and in clinical trials that enrol Indigenous Australians.

Previously Derived Host Gene Expression Classifiers Identify Bacterial and Viral Etiologies of Acute Febrile Respiratory Illness in a South Asian Population

Background

Pathogen-based diagnostics for acute respiratory infection (ARI) have limited ability to detect etiology of illness. We previously showed that peripheral blood-based host gene expression classifiers accurately identify bacterial and viral ARI in cohorts of European and African descent. We determined classifier performance in a South Asian cohort.

Methods

Patients ≥15 years with fever and respiratory symptoms were enrolled in Sri Lanka. Comprehensive pathogen-based testing was performed. Peripheral blood ribonucleic acid was sequenced and previously developed signatures were applied: a pan-viral classifier (viral vs nonviral) and an ARI classifier (bacterial vs viral vs noninfectious).

Results

Ribonucleic acid sequencing was performed in 79 subjects: 58 viral infections (36 influenza, 22 dengue) and 21 bacterial infections (10 leptospirosis, 11 scrub typhus). The pan-viral classifier had an overall classification accuracy of 95%. The ARI classifier had an overall classification accuracy of 94%, with sensitivity and specificity of 91% and 95%, respectively, for bacterial infection. The sensitivity and specificity of C-reactive protein (>10 mg/L) and procalcitonin (>0.25 ng/mL) for bacterial infection were 100% and 34%, and 100% and 41%, respectively.

Conclusions

Previously derived gene expression classifiers had high predictive accuracy at distinguishing viral and bacterial infection in South Asian patients with ARI caused by typical and atypical pathogens.

The Predictive Factors for Severe Leptospirosis Cases in Kedah

Over the past decade, increased awareness about leptospirosis disease in developing and industrialized countries has resulted in increased numbers of leptospirosis cases being reported worldwide. About 5% to 15% of leptospirosis patients end up with severe forms of the disease. Complication due to leptospirosis requires monitoring, specific treatments, and intensive care admission, thus increasing the cost of treating severe leptospirosis cases. Currently, we have data on incident and mortality rates, but we do not have data on the number of patients with severe form of leptospirosis or how many patients have complications, and whether or not these complications were resolved. Therefore, we carried out this study to determine the predictive factors for severe leptospirosis cases in Kedah. We conducted a cross-sectional study. The data of patients diagnosed with leptospirosis were obtained from the surveillance unit, Kedah Health Department, through the e-notification system. These data were then sorted according to the hospitals where the patients were admitted. The patients’ medical records were collected, and their information was obtained using a checklist. A total of 456 confirmed leptospirosis cases were included in the study, with 199 patients classified as severe cases and 257 patients as mild cases, based on the Malaysian leptospirosis guidelines. Most patients were male (71.5%) with a mean SD age of 36.62 ± 20.75 years. The predictive factors for severe leptospirosis include abnormal lung sounds (OR: 3.07 [CI 1.58–6.00]), hepatomegaly (OR: 7.14 [1.10–45.98]), hypotension (OR: 2.16 [1.08–4.34]), leukocytosis (OR: 2.12 [1.37–3.29]), low hematocrit (OR: 2.33 [1.43–3.81]), and increased alanine aminotransferase (SGPT ALT) (OR: 2.12 [1.36–3.30]). In conclusion, knowing these predictive factors will help clinicians identify severe leptospirosis cases earlier and develop their treatment plans accordingly, to reduce the complications and death from severe leptospirosis.

Epidemiology, clinical and laboratory findings of leptospirosis in Southwestern Greece

Background: Leptospirosis is a zoonosis with global distribution. The aim of the present study was to determine epidemiological, clinical and laboratory characteristics of leptospirosis in Greece.Methods: We retrospectively reviewed the clinical and laboratory profile as well as the outcome of all adults with confirmed leptospirosis in our Tertiary Referral centre in Southwestern Greece from 2013 to 2017.Results: Thirty-one men and fourteen women (mean age: 55.5 ± 13.8 years), were diagnosed with leptospirosis based on compatible clinical course and positive serology for IgM antibodies. Thirty-two (71.1%) lived in rural areas and the majority of infections (88.8%) were autochthonous, acquired in Southwestern Greece. Eighteen patients (40%) reported occupational exposure. The most prevalent clinical feature was fever (93.3%), followed by headache (66%), hematuria (31.1%), conjunctival suffusion and hepatomegaly (26.6%), dyspnoea, tachypnoea and splenomegaly (17.7%). One patient died due to pulmonary hemorrhage. Increased CRP (median 19 mg/dL) was the most common laboratory abnormality detected (93.3%), followed by thrombocytopenia (80%), increased aminotransferases (AST in 73.3% and ALT in 66.6%), anemia (66.6%) and hematuria (>100 RBC per high power field) in 66.6%. Empiric treatment with at least one active antibiotic against Leptospira was administered in 40 patients (88.8%).Conclusions: We found a higher disease incidence in our area compared to previous reports in Greece. Clinical signs of leptospirosis are diverse and generally nonspecific. Further epidemiological studies conducted ideally at a national level are required to determine the true disease incidence and better understand risk factors associated with unfavorable outcomes.

Pulmonary haemorrhage in Weil's disease

Leptospirosisis a zoonosis caused by spirochaetes from the species Leptospira. The more severe form of leptospirosis, known as Weil’s disease, is characterised by the triad of jaundice, renal impairment and haemorrhages. Pulmonary involvement occurs in 20%–70% of the patients, with severity ranging from non-productive cough to respiratory failure mainly due to pulmonary haemorrhage. Recognition of Weil’s disease in patients presenting with pulmonary symptoms can be difficult. This case illustrates a classic case of pulmonary haemorrhagic involvement in Weil’s disease.

Severe leptospirosis in tropical Australia: Optimising intensive care unit management to reduce mortality

Background

Severe leptospirosis can have a case-fatality rate of over 50%, even with intensive care unit (ICU) support. Multiple strategies–including protective ventilation and early renal replacement therapy (RRT)–have been recommended to improve outcomes. However, management guidelines vary widely around the world and there is no consensus on the optimal approach.

Methodology/Principal findings

All cases of leptospirosis admitted to the ICU of Cairns Hospital in tropical Australia between 1998 and 2018 were retrospectively reviewed. The patients’ demographics, presentation, management and clinical course were examined. The 55 patients’ median (interquartile range (IQR)) age was 47 (32–62) years and their median (IQR) APACHE III score was 67 (48–105). All 55 received appropriate antibiotic therapy, 45 (82%) within the first 6 hours. Acute kidney injury was present in 48/55 (87%), 18/55 (33%) required RRT, although this was usually not administered until traditional criteria for initiation were met. Moderate to severe acute respiratory distress syndrome developed in 37/55 (67%), 32/55 (58%) had pulmonary haemorrhage, and mechanical ventilation was required in 27/55 (49%). Vasopressor support was necessary in 34/55 (62%). Corticosteroids were prescribed in 20/55 (36%). The median (IQR) fluid balance in the initial three days of ICU care was +1493 (175–3567) ml. Only 2/55 (4%) died, both were elderly men with multiple comorbidities.

Conclusion

In patients with severe leptospirosis in tropical Australia, prompt ICU support that includes early antibiotics, protective ventilation strategies, conservative fluid resuscitation, traditional thresholds for RRT initiation and corticosteroid therapy is associated with a very low case-fatality rate. Prospective studies are required to establish the relative contributions of each of these interventions to optimal patient outcomes.

Severe leptospirosis continues to carry a high mortality. To improve outcomes, several countries have developed national guidelines for the management of severe disease. However, there is substantial variation in these guidelines despite the fact that severe leptospirosis has a very similar presentation around the world. In tropical Australia, the case-fatality rate of severe leptospirosis is only 4%. This retrospective study reviewed 55 patients with leptospirosis requiring support in an Australian Intensive Care Unit (ICU) in an effort to identify the management strategies that might explain these excellent outcomes. The low case-fatality rate was associated with prompt multimodal ICU support that included early antibiotics, protective ventilation strategies, conservative fluid resuscitation, traditional thresholds for renal replacement therapy initiation and corticosteroid therapy. However prospective, multinational studies–which include the resource-poor settings that bear the greatest burden of disease–are necessary to define which of these interventions have the greatest therapeutic value.

The epidemiology and clinical features of rickettsial diseases in North Queensland, Australia: Implications for patient identification and management

Background

Rickettsial infections are a common cause of hospitalization in tropical settings, although early diagnosis is challenging in the rural locations where these infections are usually seen.

Methods

This retrospective, clinical audit of microbiologically-confirmed cases of scrub typhus or spotted fever group (SFG) rickettsial infection between 1997 and 2016 was performed a tertiary referral hospital in tropical Australia. Clinical, laboratory and radiological findings at presentation were correlated with the patients’ subsequent clinical course.

Results

There were 135 locally-acquired cases (95 scrub typhus, 37 SFG, 3 undifferentiated). There were nine hospitalizations during the first 5 years of the study period and 81 in the last 5 years (p for trend = 0.003). Eighteen (13%) of the 135 cases required ICU admission, all of whom were adults. A greater proportion of patients with SFG infection required ICU support (8/37 (22%) compared with 10/95 (11%) scrub typhus cases), although this difference did not reach statistical significance (p = 0.10). Three (8%) of the 37 patients with SFG infection had severe disease (1 died, 2 developed permanent disability) versus 0/95 scrub typhus patients (p = 0.02). Adults with a high admission qSOFA score (≥2) had an odds ratio (OR) of 19 (95% CI:4.8–74.5) for subsequent ICU admission (p<0.001); adults with a high NEWS2 score (≥7) had an OR of 14.3 (95% CI:4.5–45.32) for ICU admission (p<0.001). A patient’s respiratory rate at presentation had strong prognostic utility: if an adult had an admission respiratory rate <22 breaths/minute, the negative predictive value for subsequent ICU admission was 95% (95% CI 88–99).

Conclusions

In the well-resourced Australian health system outcomes are excellent, but the local burden of rickettsial disease appears to be increasing and the clinical phenotype of SFG infections may be more severe than previously believed. Simple, clinical assessment on admission has prognostic utility and may be used to guide management.

Rickettsial infections are a common cause of hospitalization in tropical settings, although early, definitive diagnosis is challenging in the rural and remote locations where they are usually seen. It is important to recognise rickettsial infections early in their disease course as they can lead to life-threatening multi-organ failure if specific anti-rickettsial antimicrobial therapy is not prescribed promptly. In tropical Australia, scrub typhus and spotted fever group (SFG) rickettsiae are the dominant rickettsial pathogens and this twenty-year retrospective series examines the clinical and laboratory findings which might facilitate their recognition. The study highlights the infections’ increasing local clinical burden and reports that over 20% of the SFG cases in the series required Intensive Care Unit (ICU) admission, suggesting that severe SFG disease may be more common than previously believed. Simple, clinical prediction scores—calculated at presentation—identified patients who would subsequently require ICU admission. Importantly, they were also able to identify patients at low risk of disease progression. These entirely clinical scores—which can be calculated rapidly at the bedside—have the potential to facilitate the management of patients with scrub typhus and SFG infection, particularly in resource-limited settings which have the greatest burden of disease.