A Longitudinal, Observational Study of Etiology and Long-Term Outcomes of Sepsis in Malawi Revealing the Key Role of Disseminated Tuberculosis

The association between blood urea nitrogen to albumin ratio and the 28 day mortality in tuberculosis patients complicated by sepsis

The relationship between blood urea nitrogen to albumin ratio (BAR) and the prognosis of patients with tuberculosis (TB) complicated by sepsis remains unclear. This study aimed to explore the association between BAR and overall patient prognosis. This was a retrospective cohort study of patients with TB complicated by sepsis who were admitted to the intensive care unit (ICU) of the Public Health Clinical Center of Chengdu between January 2019 and February 2023. The relationship between BAR values and prognosis in these patients was investigated using multivariate Cox regression, stratified analysis with interaction, restricted cubic spline (RCS), and threshold effect analysis. Sensitivity analyses were conducted to assess the robustness of the results. Our study included 537 TB patients complicated by sepsis admitted in the ICU, with a median age of 63.0 (48.0, 72.0) years; 76.7% of whom were men. The multivariate-restricted cubic spline analysis showed a non-linear association between BAR and patient prognosis. In the threshold analysis, we found that TB patients complicated by sepsis and a BAR < 7.916 mg/g had an adjusted hazard ratio (HR) for prognosis of 1.163 (95% CI 1.038-1.303; P = 0.009). However, when the BAR was ≥ 7.916 mg/g, there was no significant increase in the risk of death. The results of the sensitivity analysis were stable.

Causes, outcomes and diagnosis of acute breathlessness hospital admissions in Malawi: protocol for a multicentre prospective cohort study

Background

Hospital admission due to breathlessness carries a significant burden to patients and healthcare systems, particularly impacting people in low-income countries. Prompt appropriate treatment is vital to improve outcomes, but this relies on accurate diagnostic tests which are of limited availability in resource-constrained settings. We will provide an accurate description of acute breathlessness presentations in a multicentre prospective cohort study in Malawi, a low resource setting in Southern Africa, and explore approaches to strengthen diagnostic capacity.

Objectives

Primary objective: Delineate between causes of breathlessness among adults admitted to hospital in Malawi and report disease prevalence. Secondary objectives : Determine patient outcomes, including mortality and hospital readmission 90 days after admission; determine the diagnostic accuracy of biomarkers to differentiate between heart failure and respiratory infections (such as pneumonia) including brain natriuretic peptides, procalcitonin and C-reactive protein.

Methods

This is a prospective longitudinal cohort study of adults (≥18 years) admitted to hospital with breathlessness across two hospitals: 1) Queen Elizabeth Central Hospital, Blantyre, Malawi; 2) Chiradzulu District Hospital, Chiradzulu, Malawi. Patients will be consecutively recruited within 24 hours of emergency presentation and followed-up until 90 days from hospital admission. We will conduct enhanced diagnostic tests with robust quality assurance and quality control to determine estimates of disease pathology. Diagnostic case definitions were selected following a systematic literature search.

Discussion

This study will provide detailed epidemiological description of adult hospital admissions due to breathlessness in low-income settings, which is currently poorly understood. We will delineate between causes using established case definitions and conduct nested diagnostic evaluation. The results have the potential to facilitate development of interventions targeted to strengthen diagnostic capacity, enable prompt and appropriate treatment, and ultimately improve both patient care and outcomes.

Implementing the WHO AWaRe antibiotic book guidance in lower-resource settings: the case of the Lao PDR

In 2022, WHO released the WHO AWaRe (Access, Watch, Reserve) antibiotic book to promote the rational use of antibiotics. Here, we review the AWaRe antibiotic book from the perspective of implementation in low-resource settings, using the Lao PDR (Laos) as a case study. Not all recommendations in the AWaRe antibiotic book match the epidemiology of infectious diseases and antimicrobial susceptibility patterns in Laos and other low- and middle-income countries (LMICs), e.g. melioidosis, rickettsial disease and leptospirosis are common causes of sepsis and febrile illness in Laos but do not feature in the AWaRe book. Conversely, some infectious diseases like Clostridioides difficile-associated diarrhoea are in the AWaRe antibiotic book but rarely considered in Laos with no diagnostic tests available. Only 29/39 antibiotics in the AWaRe book are available in Laos, with no Reserve group antimicrobials available. The AWaRe book stimulates countries such as Laos to consider alternative diagnoses and include additional antimicrobials in the national essential medicines list (NEML). However, it should be updated to include regional important pathogens that are not included. Comprehensive antibiotic use guidelines alone might not assure appropriate use or control overuse of antibiotics. Access to antibiotics is challenging in low-resource settings in terms of unavailability in the country (low demand or small market size), patchy access, especially for those living in remote areas, and unaffordability. All these systemic factors can contribute to inappropriate use of antibiotics. Improved access to antibiotics, strengthening diagnostic capacity and promoting antibiotic stewardship should be combined.

HIV infection drives pro-inflammatory immunothrombotic pathway activation and organ dysfunction among adults with sepsis in Uganda

BACKGROUND

The global burden of sepsis is concentrated in high HIV-burden settings in sub-Saharan Africa (SSA). Despite this, little is known about the immunopathology of sepsis in persons with HIV (PWH) in the region. We sought to determine the influence of HIV on host immune responses and organ dysfunction among adults hospitalized with suspected sepsis in Uganda.

DESIGN

Prospective cohort study.

METHODS

We compared organ dysfunction and 30-day outcome profiles of PWH and those without HIV. We quantified 14 soluble immune mediators, reflective of key domains of sepsis immunopathology, and performed whole-blood RNA-sequencing on samples from a subset of patients. We used propensity score methods to match PWH and those without HIV by demographics, illness duration, and clinical severity, and compared immune mediator concentrations and gene expression profiles across propensity score-matched groups.

RESULTS

Among 299 patients, 157 (52.5%) were PWH (clinical stage 3 or 4 in 80.3%, 67.7% with known HIV on antiretroviral therapy). PWH presented with more severe physiologic derangement and shock, and had higher 30-day mortality (34.5% vs. 10.2%; P  < 0.001). Across propensity score-matched groups, PWH exhibited greater pro-inflammatory immune activation, including upregulation of interleukin (IL)-6, IL-8, IL-15, IL-17 and HMGB1 signaling, with concomitant T-cell exhaustion, prothrombotic pathway activation, and angiopoeitin-2-related endothelial dysfunction.

CONCLUSIONS

Sepsis-related organ dysfunction and mortality in Uganda disproportionately affect PWH, who demonstrate exaggerated activation of multiple immunothrombotic and metabolic pathways implicated in sepsis pathogenesis. Further investigations are needed to refine understanding of sepsis immunopathology in PWH, particularly mechanisms amenable to therapeutic manipulation.

Effect of resistance to third-generation cephalosporins on morbidity and mortality from bloodstream infections in Blantyre, Malawi: a prospective cohort study

BACKGROUND

The burden of antimicrobial resistance is a major threat to global health; however, prospective clinical outcome data from Africa are scarce. In Malawi, third-generation cephalosporins are the antibiotics of choice in patients admitted to hospital despite a rapid proliferation of resistance to these drugs. We aimed to quantify the effect of resistance to third-generation cephalosporins on mortality and length of hospital stay among patients with bloodstream infections.

METHODS

We did a prospective cohort study of patients admitted to Queen Elizabeth Central Hospital in Blantyre, Malawi. Patients of all ages who had positive blood cultures for Enterobacterales were included, with the exception of those from the genus Salmonella, and were followed up for 180 days. We characterised blood culture isolates using whole-genome sequencing and used Cox regression models to estimate the effect of resistance to third-generation cephalosporins on length of hospital stay, in-hospital mortality, and survival.

FINDINGS

Between Jan 31, 2018, and Jan 13, 2020, we recruited 326 patients, from whom 220 (68%) of 326 isolates were resistant to third-generation cephalosporins. The case fatality proportion was 45% (99 of 220) in patients with bloodstream infections that were resistant to third-generation cephalosporins, and 34% (36 of 106) in patients with bloodstream infections that were sensitive to third-generation cephalosporins. Resistance to third-generation cephalosporins was associated with an increased probability of in-hospital mortality (hazard ratio [HR] 1·44, 95% CI 1·02-2·04), longer hospital stays (1·5 days, 1·0-2·0) and decreased probability of discharge alive (HR 0·31, 0·22-0·45). Whole-genome sequencing showed a high diversity of sequence types of both Escherichia coli and Klebsiella pneumoniae. Although isolates associated with death were distributed across clades, we identified three E coli clades (ST410, ST617, and ST648) that were isolated from 14 patients who all died.

INTERPRETATION

Resistance to third-generation cephalosporins is associated with increased mortality and longer hospital stays in patients with bloodstream infections in Malawi. These data show the urgent need for allocation of resources towards antimicrobial resistance mitigation strategies in Africa.

FUNDING

Wellcome Trust and Wellcome Asia and Africa Programme.

Aetiology of hospitalized fever and risk of death at Arua and Mubende tertiary care hospitals in Uganda from August 2019 to August 2020

BACKGROUND

Epidemiology of febrile illness in Uganda is shifting due to increased HIV treatment access, emerging viruses, and increased surveillance. We investigated the aetiology and outcomes of acute febrile illness in adults presenting to hospital using a standardized testing algorithm of available assays in at Arua and Mubende tertiary care hospitals in Uganda.

METHODS

We recruited adults with a ≥ 38.0 °C temperature or history of fever within 48 h of presentation from August 2019 to August 2020. Medical history, demographics, and vital signs were recorded. Testing performed included a complete blood count, renal and liver function, malaria smears, blood culture, and human immunodeficiency virus (HIV). When HIV positive, testing included cryptococcal antigen, CD4 count, and urine lateral flow lipoarabinomannan assay for tuberculosis. Participants were followed during hospitalization and at a 1-month visit. A Cox proportional hazard regression was performed to evaluate for baseline clinical features and risk of death.

RESULTS

Of 132 participants, the median age was 33.5 years (IQR 24 to 46) and 58.3% (n = 77) were female. Overall, 73 (55.3%) of 132 had a positive microbiologic result. Among those living with HIV, 31 (68.9%) of 45 had at least one positive assay; 16 (35.6%) had malaria, 14 (31.1%) tuberculosis, and 4 (8.9%) cryptococcal antigenemia. The majority (65.9%) were HIV-negative; 42 (48.3%) of 87 had at least one diagnostic assay positive; 24 (27.6%) had positive malaria smears and 1 was Xpert MTB/RIF Ultra positive. Overall, 16 (12.1%) of 132 died; 9 (56.3%) of 16 were HIV-negative, 6 died after discharge. High respiratory rate (≥ 22 breaths per minute) (hazard ratio [HR] 8.05; 95% CI 1.81 to 35.69) and low (i.e., < 92%) oxygen saturation (HR 4.33; 95% CI 1.38 to 13.61) were identified to be associated with increased risk of death.

CONCLUSION

In those with hospitalized fever, malaria and tuberculosis were common causes of febrile illness, but most deaths were non-malarial, and most HIV-negative participants did not have a positive diagnostic result. Those with respiratory failure had a high risk of death.

Colonization dynamics of extended-spectrum beta-lactamase-producing Enterobacterales in the gut of Malawian adults

Drug-resistant bacteria of the order Enterobacterales which produce extended-spectrum beta-lactamase enzymes (ESBL-Enterobacterales, ESBL-E) are global priority pathogens. Antimicrobial stewardship interventions proposed to curb their spread include shorter courses of antimicrobials to reduce selection pressure but individual-level acquisition and selection dynamics are poorly understood. We sampled stool of 425 adults (aged 16-76 years) in Blantyre, Malawi, over 6 months and used multistate modelling and whole-genome sequencing to understand colonization dynamics of ESBL-E. Models suggest a prolonged effect of antimicrobials such that truncating an antimicrobial course at 2 days has a limited effect in reducing colonization. Genomic analysis shows largely indistinguishable diversity of healthcare-associated and community-acquired isolates, hence some apparent acquisition of ESBL-E during hospitalization may instead represent selection from a patient's microbiota by antimicrobial exposure. Our approach could help guide stewardship protocols; interventions that aim to review and truncate courses of unneeded antimicrobials may be of limited use in preventing ESBL-E colonization.