Validation of algorithms using International Classification of Diseases for the identification of herpes zoster episodes requiring hospitalization in Quebec, Canada.

OBJECTIVE: We determined secular changes in the incidence of hospitalizations due to herpes zoster (HZh) and assessed the validity of HZ International Classification of Diseases (ICD) code algorithms for identifying HZh in a region of Quebec, Canada. METHODS: We performed a validation study as part of a retrospective cohort study of adult HZ patients hospitalized at Centre Hospitalier Universitaire de Sherbrooke during 2000-2017. Cases were identified using ICD codes from an inpatient administrative database. HZ cases identified by ICD-9 (053.xx) and ICD-10 (B02.x) codes were chart-confirmed, and performance characteristics of ICD code algorithms were calculated (positive predictive value [PPV] and sensitivity). RESULTS: Overall, 1314 hospitalizations with HZ diagnosis (HZh) with or without complications were identified during 2000-2017. Among the hospitalizations, 526 (44.4%) were due to active HZ disease or a complication related to a recent or previous HZ episode. These hospitalizations were due to active disease at the time of admission (340/526, 64.6%), HZ that developed during hospitalization (120/526, 22.8%), or a complication directly related to a recent or previous HZ episode (66/526, 12.6%). PPV was significantly higher when HZ was the primary diagnosis (276/310, 89%, 95% confidence interval [CI]: 85-92%) than when HZ was a secondary diagnosis (254/928, 27%, 95% CI: 25-30%) (p < 0.0001), and the PPV of a first secondary diagnosis (84/140, 60.0%, 95% CI: 51.3-68.2%) was higher than that of other secondary diagnoses (203/794, 25.6%, 95% CI: 22.6-28.8%) (p < 0.0001). An algorithm combining ICD codes and antiviral usage demonstrated the best sensitivity (86.3%, 95% CI: 83.1-89.1%) and PPV to identify HZh (100%, 95% CI: 99.2-100%). Poisson regression revealed no significant changes in HZh over time (incidence rate ratio: 0.98, 95% CI: 0.92-1.04%; p = 0.5). CONCLUSION: HZh incidence was stable over time. Prescription of antivirals might be a useful addition to ICD codes to identify HZh cases from administrative databases.

Identification of YbeY-Protein Interactions Involved in 16S rRNA Maturation and Stress Regulation in Escherichia coli.

YbeY is part of a core set of RNases in Escherichia coli and other bacteria. This highly conserved endoribonuclease has been implicated in several important processes such as 16S rRNA 3' end maturation, 70S ribosome quality control, and regulation of mRNAs and small noncoding RNAs, thereby affecting cellular viability, stress tolerance, and pathogenic and symbiotic behavior of bacteria. Thus, YbeY likely interacts with numerous protein or RNA partners that are involved in various aspects of cellular physiology. Using a bacterial two-hybrid system, we identified several proteins that interact with YbeY, including ribosomal protein S11, the ribosome-associated GTPases Era and Der, YbeZ, and SpoT. In particular, the interaction of YbeY with S11 and Era provides insight into YbeY's involvement in the 16S rRNA maturation process. The three-way association between YbeY, S11, and Era suggests that YbeY is recruited to the ribosome where it could cleave the 17S rRNA precursor endonucleolytically at or near the 3' end maturation site. Analysis of YbeY missense mutants shows that a highly conserved beta-sheet in YbeY-and not amino acids known to be important for YbeY's RNase activity-functions as the interface between YbeY and S11. This protein-interacting interface of YbeY is needed for correct rRNA maturation and stress regulation, as missense mutants show significant phenotypic defects. Additionally, structure-based in silico prediction of putative interactions between YbeY and the Era-30S complex through protein docking agrees well with the in vivo results. IMPORTANCE: Ribosomes are ribonucleoprotein complexes responsible for a key cellular function, protein synthesis. Their assembly is a highly coordinated process of RNA cleavage, RNA posttranscriptional modification, RNA conformational changes, and protein-binding events. Many open questions remain after almost 5 decades of study, including which RNase is responsible for final processing of the 16S rRNA 3' end. The highly conserved RNase YbeY, belonging to a core set of RNases essential in many bacteria, was previously shown to participate in 16S rRNA processing and ribosome quality control. However, detailed mechanistic insight into YbeY's ribosome-associated function has remained elusive. This work provides the first evidence that YbeY is recruited to the ribosome through interaction with proteins involved in ribosome biogenesis (i.e., ribosomal protein S11, Era). In addition, we identified key residues of YbeY involved in the interaction with S11 and propose a possible binding mode of YbeY to the ribosome using in silico docking.