Does comorbidity index predict OPAT readmission?

Objectives

To determine if the Charlson comorbidity index (CCI) is an accurate predictor of unplanned readmissions for patients using outpatient parenteral antimicrobial therapy (OPAT) services.

Methods

Retrospective analysis of patients >16 years of age who had received OPAT at Lancashire Teaching Hospitals between 2019 and 2021. The number of unplanned hospitalizations was measured and categorized as OPAT related or non-OPAT related. The CCI for each patient group was calculated using an online tool, and logistic regression was used to assess the association between risk factors and risk of being readmitted.

Results

The cohort consisted of 741 patients. Unplanned readmission was seen in 112 patients (15.1%). The mean CCI score for patients with OPAT-related readmissions was 4.22, 0.92 higher than the mean for patients who were not readmitted (3.30). The mean CCI score for patients with non-OPAT-related readmissions was higher still at 4.89. The logistic regression showed that increased CCI, age, male gender and home location compared with clinic were associated with increased odds of readmission, although these effects did not meet statistical significance.

Conclusions

These results suggest that a higher CCI score is associated with a non-statistically significant increased risk of unplanned hospitalization. We concluded that the CCI may therefore be used in future decision-making regarding the acceptance of patients to OPAT and requires further investigation.

Q fever-the superstition of avoiding the word "quiet" as a coping mechanism: randomised controlled non-inferiority trial

OBJECTIVE

To determine the validity of the superstition that utterance of the word "quiet" in a clinical setting increases workload.

DESIGN

Prospective randomised controlled non-inferiority study.

SETTING

Microbiology department of a large teaching hospital in Lancashire, UK.

PARTICIPANTS

Two members of the medical microbiology team carried out the duty work on any given week day and an on-call team member on any weekend day. 29 days were assigned in which staff were to say "Today will be a quiet day" and 32 days were assigned in which staff were to refrain from saying the word "quiet" in any context.

INTERVENTIONS

Each day was randomly allocated to either saying "Today will be a quiet day" (intervention group) or refraining from saying the word "quiet" (control group) in any context.

MAIN OUTCOME MEASURES

The primary outcome was mean overall workload: a composite of number of clinically related telephone calls, clinically significant results, or validated results processed by the duty medical microbiology team during a 24 hour period referred to collectively as "clinical episodes." A difference of 30 clinical episodes was considered as the margin of non-inferiority. Secondary outcomes included the individual components of the primary outcome.

RESULTS

Workload was measured each day over a 61 day period (1 May to 30 June 2019). A mean 139.0 clinical episodes occurred on control days compared with 144.9 on days when the experimental intervention was uttered, a difference of 5.9 (95% confidence interval-12.9 to 24.7). The upper bound was less than the specified margin of 30, providing evidence for non-inferiority. No evidence of a difference in workload was found between interventions with any of the four components, whether considering unadjusted or adjusted analyses, or looking at the subgroups of week days or weekends.

CONCLUSIONS

The study findings refute the long held superstition that utterance of the word "quiet" impacts on clinical workload, and therefore it should not be avoided. In the era of considerable staff shortages and increased work related stress, doctors should look to other methods to increase resilience and protect their wellbeing and mental health.

TRIAL REGISTRATION

Lancashire Teaching Hospitals NHS Foundation Trust's research department SE-259.

A sputum sample processing method for community and mobile tuberculosis diagnosis using the Xpert MTB/RIF assay

The Xpert MTB/RIF assay can rapidly diagnose tuberculosis, but sputum samples cannot be safely processed unless in a lab. The septum sample pot allows safe handling of sputum and has allowed a mobile TB unit to run the assay in community settings. http://ow.ly/HOA130mS6LG.

Diagnostics in Ebola Virus Disease in Resource-Rich and Resource-Limited Settings

The Ebola virus disease (EVD) outbreak in West Africa was unprecedented in scale and location. Limited access to both diagnostic and supportive pathology assays in both resource-rich and resource-limited settings had a detrimental effect on the identification and isolation of cases as well as individual patient management. Limited access to such assays in resource-rich settings resulted in delays in differentiating EVD from other illnesses in returning travellers, in turn utilising valuable resources until a diagnosis could be made. This had a much greater impact in West Africa, where it contributed to the initial failure to contain the outbreak. This review explores diagnostic assays of use in EVD in both resource-rich and resource-limited settings, including their respective limitations, and some novel assays and approaches that may be of use in future outbreaks.

Genetic variation in Mycobacterium tuberculosis isolates from a London outbreak associated with isoniazid resistance

BACKGROUND

The largest outbreak of isoniazid-resistant (INH-R) Mycobacterium tuberculosis in Western Europe is centred in North London, with over 400 cases diagnosed since 1995. In the current study, we evaluated the genetic variation in a subset of clinical samples from the outbreak with the hypothesis that these isolates have unique biological characteristics that have served to prolong the outbreak.

METHODS

Fitness assays, mutation rate estimation, and whole-genome sequencing were performed to test for selective advantage and compensatory mutations.

RESULTS

This detailed analysis of the genetic variation of these INH-R samples suggests that this outbreak consists of successful, closely related, circulating strains with heterogeneous resistance profiles and little or no associated fitness cost or impact on their mutation rate.

CONCLUSIONS

Specific deletions and SNPs could be a peculiar feature of these INH-R M. tuberculosis isolates, and could potentially explain their persistence over the years.

Therapeutic drug monitoring of antimicrobials

As pathology services become more centralized and automated, the measurement of therapeutic antimicrobial drugs concentrations is increasingly performed in clinical biochemistry or 'blood science' laboratories. This review outlines key groups of antimicrobial agents: aminoglycosides, glycopeptides, antifungal agents and antituberculosis agents, their role in managing infectious diseases, and the reasons why serum concentration measurement is important.

Clinical application of a rapid lung-orientated immunoassay in individuals with possible tuberculosis

BACKGROUND

Immunological ex vivo assays to diagnose tuberculosis (TB) have great potential but have largely been blood-based and poorly evaluated in active TB. Lung sampling enables combined microbiological and immunological testing and uses higher frequency antigen-specific responses than in blood.

METHODS

A prospective evaluation was undertaken of a flow cytometric assay measuring the percentage of interferon-gamma synthetic CD4+ lymphocytes following stimulation with purified protein derivative of Mycobacterium tuberculosis (PPD) in bronchoalveolar lavage fluid from 250 sputum smear-negative individuals with possible TB. A positive assay was defined as >1.5%.

RESULTS

Of those who underwent lavage and were diagnosed with active TB, 95% (106/111) had a positive immunoassay (95% CI 89% to 98%). In 139 individuals deemed not to have active TB, 105 (76%) were immunoassay negative (95% CI 68% to 82%). Of the remaining 24% (34 cases) with a positive immunoassay, a substantial proportion had evidence of untreated TB; in two of these active TB was subsequently diagnosed. Assay performance was unaffected by HIV status, disease site or BCG vaccination. In culture-positive pulmonary cases, response to PPD was more sensitive than nucleic acid amplification testing (94% vs 73%). The use of early secretory antigen target-6 (ESAT-6) responses in 71 subjects was no better than PPD, and 19% of those with culture-confirmed TB and a positive PPD immunoassay had no detectable response to ESAT-6.

CONCLUSIONS

These findings suggest that lung-orientated immunological investigation is a potentially powerful tool in diagnosing individuals with sputum smear-negative active TB, regardless of HIV serostatus.

Evaluation of liquid culture for quantitation of Mycobacterium tuberculosis in murine models

Quantitation of bacterial load in tissues is essential for experimental investigation of Mycobacterium tuberculosis infection and immunity. We have used an automated liquid culture system to determine the number of colony forming units (CFU) in murine tissues and compared the results to those obtained by conventional plating on Middlebrook agar. There is an overall good correlation between results obtained by the two methods. Although less consistency and more contamination was observed in the automated liquid culture, the method is more sensitive, less labour intensive and allows the processing of large numbers of samples.

Mycobacterium tuberculosis lineage: a naming of the parts

There have been many reports of groups of related Mycobacterium tuberculosis strains described variously as lineages, families or clades. There is no objective definition of these groupings, making it impossible to define relationships between those groups with biological advantages. Here we describe two groups of related strains obtained from an epidemiological study in Tanzania, which we define as the Kilimanjaro and Meru lineages on the basis of IS6110 restriction fragment length polymorphism (RFLP), polymorphic GC rich sequence (PGRS) RFLP and mycobacterial interspersed repeat unit (MIRU) typing. We investigated the concordance between each of the typing techniques and the dispersal of the typing profiles from a core pattern. The Meru lineage is more dispersed than the Kilimanjaro lineage and we speculate that the Meru lineage is older. We suggest that this approach provides an objective definition that proves robust in this epidemiological study. Such a framework will permit associations between a lineage and clinical or bacterial phenomenon to be tested objectively. This definition will also enable new putative lineages to be objectively tested.