The Cox model of predicting mortality among melioidosis patients in Northern Malaysia: A retrospective study

Predictors of mortality in culture-proven Burkholderia pseudomallei infections in a Singapore Tertiary Hospital

Burkholderia pseudomallei is a pathogen expanding in geographic range. We performed a retrospective study analyzing the clinical, microbiologic features of culture-proven melioidosis, and predictors of mortality based on data from a Singapore tertiary hospital between 2006- 2016. We found ICU admission, bacteremia, and mechanical ventilation to be associated with mortality.

Low leucocyte, neutrophil and lymphocyte count (tri-low phenotype) in melioidosis: A predictor of early mortality

Introduction

Melioidosis is a bacterial disease caused by Burkholderia pseudomallei, a gram-negative bacillus endemic to parts of Asia and Northern Australia. This study aimed to identify the role of total and differential leucocyte count in predicting 48-h mortality in patients with melioidosis.

Methodology

This retrospective cohort study included patients diagnosed with culture-proven melioidosis at Kasturba Medical College between 2017 and 2023. Total leucocyte count (TLC), absolute neutrophil count (ANC), and absolute lymphocytic count (ALC) were classified into low (first quartile), medium (second and third quartile) and high (last quartile). The chi-square test was used to compare each group's early (48-h) mortality.

Results

Of the 170 patients with culture-confirmed melioidosis, 24 patients died within 48 h. The mortality was significantly higher in those with low TLC, ANC and ALC. When all three parameters were found to be low (tri-low phenotype), the specificity in predicting mortality was 93.2 %.

Conclusion

Low TLC, ANC and ALC are significant predictors of mortality among melioidosis patients. There is a need to explore new strategies to improve clinical outcomes among melioidosis patients with tri-low phenotype.

Clinical Prediction Rules for In-Hospital Mortality Outcome in Melioidosis Patients

BACKGROUND

Melioidosis, a disease induced by Burkholderia pseudomallei, poses a significant health threat in tropical areas where it is endemic. Despite the availability of effective treatments, mortality rates remain notably elevated. Many risk factors are associated with mortality. This study aims to develop a scoring system for predicting the in-hospital mortality from melioidosis using readily available clinical data.

METHODS

The data were collected from Surin Hospital, Surin, Thailand, during the period from April 2014 to March 2017. We included patients aged 15 years and above who had cultures that tested positive for Burkholderia pseudomallei. The clinical prediction rules were developed using significant risk factors from the multivariable analysis.

RESULTS

A total of 282 patients with melioidosis were included in this study. In the final analysis model, 251 patients were used for identifying the significant risk factors of in-hospital fatal melioidosis. Five factors were identified and used for developing the clinical prediction rules, and the factors were as follows: qSOFA ≥ 2 (odds ratio [OR] = 2.39, p= 0.025), abnormal chest X-ray findings (OR = 5.86, p < 0.001), creatinine ≥ 1.5 mg/dL (OR = 2.80, p = 0.004), aspartate aminotransferase ≥50 U/L (OR = 4.032, p < 0.001), and bicarbonate ≤ 20 mEq/L (OR = 2.96, p = 0.002). The prediction scores ranged from 0 to 7. Patients with high scores (4-7) exhibited a significantly elevated mortality rate exceeding 65.0% (likelihood ratio [LR+] 2.18, p < 0.001) compared to the low-risk group (scores 0-3) with a lower mortality rate (LR + 0.18, p < 0.001). The area under the receiver operating characteristic curve (AUC) was 0.84, indicating good model performance.

CONCLUSIONS

This study presents a simple scoring system based on easily obtainable clinical parameters to predict in-hospital mortality in melioidosis patients. This tool may facilitate the early identification of high-risk patients who could benefit from more aggressive treatment strategies, potentially improving clinical decision-making and patient outcomes.

Epidemiology and genetic diversity of Burkholderia pseudomallei from Riau Province, Indonesia

Melioidosis is a bacterial infection caused by Burkholderia pseudomallei, that is common in tropical and subtropical countries including Southeast Asia and Northern Australia. The magnitude of undiagnosed and untreated melioidosis across the country remains unclear. Given its proximity to regions with high infection rates, Riau Province on Sumatera Island is anticipated to have endemic melioidosis. This study reports retrospectively collected data on 68 culture-confirmed melioidosis cases from two hospitals in Riau Province between January 1, 2009, and December 31, 2021, with full clinical data available on 41 cases. We also describe whole genome sequencing and genotypic analysis of six isolates of B. pseudomallei. The mean age of the melioidosis patients was 49.1 (SD 11.5) years, 85% were male and the most common risk factor was diabetes mellitus (78%). Pulmonary infection was the most common presentation (39%), and overall mortality was 41%. Lung as a focal infection (aOR: 6.43; 95% CI: 1.13-36.59, p = 0.036) and bacteremia (aOR: 15.21; 95% CI: 2.59-89.31, p = 0.003) were significantly associated with death. Multilocus sequence typing analysis conducted on six B.pseudomallei genomes identified three sequence types (STs), namely novel ST1794 (n = 3), ST46 (n = 2), and ST289 (n = 1). A phylogenetic tree of Riau B. pseudomallei whole genome sequences with a global dataset of genomes clearly distinguished the genomes of B. pseudomallei in Indonesia from the ancestral Australian clade and classified them within the Asian clade. This study expands the known presence of B. pseudomallei within Indonesia and confirms that Indonesian B. pseudomallei are genetically linked to those in the rest of Southeast Asia. It is anticipated that melioidosis will be found in other locations across Indonesia as laboratory capacities improve and standardized protocols for detecting and confirming suspected cases of melioidosis are more widely implemented.

The Predictive Factors Associated with In-Hospital Mortality of Melioidosis: A Cohort Study

Background and Objectives: Melioidosis is an infectious disease caused by Burkholderia pseudomallei, and it has a wide range of clinical symptoms. It is endemic in tropical areas, including Southeast Asia. Despite the availability of effective treatment, the mortality rate is still high, especially in patients presenting with septic shock. The aim of this study was to determine and explore clinical characteristics, microbiology, treatment outcomes, and factors associated with in-hospital mortality which could predict prognosis and provide a guide for future treatment. Materials and Methods: The population in this retrospective cohort study included all 262 patients with a diagnosis of melioidosis who were hospitalized at Surin Hospital, Surin, Thailand, from April 2014 to March 2017. We included patients older than 15 years with a positive culture for B. pseudomallei. Data regarding the clinical characteristics, microbiology, and treatment outcomes of the patients were collected and analyzed. The patients were divided into two groups dependent on outcome, specifically non-survival and survival. Logistic regression was performed to determine the risk factors associated with in-hospital mortality. Results: Out of the 262 patients with melioidosis during the study period, 117 (44.7%) patients died. The mean age was 57.2 ± 14.4 years, and 193 (73.7%) patients were male. The most common comorbidity was diabetes (123, 46.9%), followed by chronic kidney disease (35, 13.4%) and chronic liver disease (31, 11.8%). Four risk factors were found to be associated with in-hospital mortality, including age (adjusted odds ratio (aOR) 1.04, 95%CI: 1.01-1.07), respiration rate (aOR 1.18, 95%CI: 1.06-1.32), abnormal chest X-ray finding (aOR 4.79, 95%CI: 1.98-11.59), and bicarbonate levels (CO2) (aOR 0.92, 95%CI: 0.85-0.99). Conclusions: Our study identified age, respiration rate, abnormal chest X-ray finding, and CO2 levels are predictive factors associated with in-hospital mortality in melioidosis patients. Physicians should be aware of these factors, have access to aggressive treatment options, and closely monitor patients with these risk factors.

Outbreak investigation of NDM-producing Burkholderia cepacia causing neonatal sepsis in Pakistan

Aim: To investigate the outbreak of Burkholderia cepacia complex (BCC), mortality, antimicrobial resistance and associated risk factors in the neonatal intensive care unit. Method: Eighteen blood culture samples from neonates and twenty swab samples from different neonatal intensive care unit surfaces were collected. The VITEK 2 was used to confirm the isolates and generate the antibiogram. PCR was used to identify blaNDM. Results: Eighteen samples tested positive for BCC, and 10/18 (55.5%) of the neonates died. 13/18 (72%) of the neonates had late-onset neonatal sepsis, and 10/18 (55%) had low birth weight. Resistance to minocycline and chloramphenicol was 100%, 72.2% to meropenem; 72.2% NDM gene was found in neonates and was 20% from the environment. Conclusion: Outbreak of NDM-producing BCC resulting in high neonatal mortality in NICU.

Endemic melioidosis in central Taiwan-A longitudinal case cohort study

Background

Melioidosis is a systemic and suppurative disease endemic in the Southeast Asia. In Taiwan, most cases are reported in the southern region and no relevant profiles have been reported in central region. In this study, we performed the epidemiologic and clinical analyses from the melioidosis cases in central Taiwan.

Methods

The demographic, clinical, laboratory, radiologic, and outcome profiles were collected retrospectively and analyzed from patients whom Burkhoderia pseudomallei was isolated from clinical specimens during the 12-year study period (2011-2022).

Results

Totally 11 melioidosis cases (10 males and 1 female) were diagnosed, among them only 2 (18.2%) cases lived in suburban areas. Seven (63.6%) cases were diagnosed during 2019-2020, and diabetes mellitus was the most relevant comorbidity (5, 45.4%). All cases presented with fever at arrival, but only 4 (36.4%) and 2 (18.2%) cases presented with dyspnea and shock, respectively. Pneumonitis and extrapulmonary involvement were found in 5 cases (45.4%) each. Appropriate empiric and targeted antibiotic treatments were found in 4 (36.4%) and 10 (91.0%) case, respectively. Two cases (18.2%) succumbed to infection despite appropriate treatment including targeted antibiotics.

Conclusion

Melioidosis has become endemic in central Taiwan. Septic patients who present with suppurative or undetermined foci and have unsatisfied responses to standard treatment should arouse clinicians to take melioidosis into consideration.

Melioidosis and Burkholderia pseudomallei : progress in epidemiology, diagnosis, treatment and vaccination

PURPOSE OF REVIEW

Melioidosis and its causative bacterium Burkholderia pseudomallei are being found in unexpected locations and bacterial genotyping is providing new insights into global spread and where and how individuals are being infected. This review summarizes recent studies covering the epidemiology, diagnosis, treatment, and prevention of melioidosis.

RECENT FINDINGS

Whole-genome sequencing of B. pseudomallei from patients and environmental sampling is informing the phylogeography of B. pseudomallei at regional, continental, and global levels, while also defining the epidemiology for individual cases. The situation in Africa remains the most unresolved, while the evolving story of B. pseudomallei in the Americas may establish that B. pseudomallei is endemic in parts of southern USA. Guidelines for diagnosis and treatment of melioidosis are well established, and published mortality has decreased from 50% or higher to 10% or lower in some countries but access to laboratory and therapeutic resources are not available or are extremely limited in many melioidosis-endemic regions.

SUMMARY

The enormous clinical diversity of melioidosis and the complexities of laboratory diagnosis and of treatment make it a sentinel disease for highlighting the continuing global disparities in access to and provision of healthcare.

The Epidemiology of Melioidosis and Its Association with Diabetes Mellitus: A Systematic Review and Meta-Analysis

Melioidosis is an under-recognized fatal disease in humans, caused by the Gram-negative bacterium Burkholderia pseudomallei. Globally, more than 35,000 human melioidosis cases have been reported since 1911. Soil acts as the natural reservoir of B. pseudomallei. Humans may become infected by this pathogen through direct contact with contaminated soil and/or water. Melioidosis commonly occurs in patients with diabetes mellitus, who increase the occurrence of melioidosis in a population. We carried out a systematic review and meta-analysis to investigate to what extent diabetes mellitus affects the patient in getting melioidosis. We selected 39 articles for meta-analysis. This extensive review also provided the latest updates on the global distribution, clinical manifestation, preexisting underlying diseases, and risk factors of melioidosis. Diabetes mellitus was identified as the predominant predisposing factor for melioidosis in humans. The overall proportion of melioidosis cases having diabetes was 45.68% (95% CI: 44.8-46.57, p < 0.001). Patients with diabetes mellitus were three times more likely to develop melioidosis than patients with no diabetes (RR 3.40, 95% CI: 2.92-3.87, p < 0.001). The other potential risk factors included old age, exposure to soil and water, preexisting underlying diseases (chronic kidney disease, lung disease, heart disease, and thalassemia), and agricultural activities. Evidence-based clinical practice guidelines for melioidosis in patients with diabetes mellitus may be developed and shared with healthcare professionals of melioidosis endemic countries to reduce morbidity.