Phenotypic and genotypic analysis of antimicrobial resistance and population structure of gastroenteritis-related Aeromonas isolates.

BACKGROUND: The population structure and the correlation between antimicrobial resistance (AMR) phenotypes and genotypes in Aeromonas species isolated from patients with gastroenteritis are not well understood. The aims of the study were to: (1) investigate the antimicrobial susceptibility profiles of Aeromonas species isolated from patients with gastroenteritis; (2) explore the relationship between AMR genes and resistance phenotypes; and (3) describe the population structure of these isolates and provide evidence of transmission events among them. METHODS: This microbiological survey was performed at the Microbiology Laboratory of the Emek Medical Center in Afula, Israel. Cultivation of Aeromonas was attempted from stool samples that tested positive by PCR. Antimicrobial susceptibility testing (AST) was performed using the Sensititre GN3F microdilution panel. Whole genome sequencing (WGS) was done using the Illumina NextSeq500/550 system. Phylogenetic studies involved multi-locus sequence typing (MLST) and core genome (cg) MLST. Resistance mechanisms were identified using the Comprehensive Antibiotic Resistance Database and compared with the AST results. RESULTS: The study included 67 patient-unique isolates. The species that were identified included A. caviae (n = 58), A. dhakensis (n = 3), A. media (n = 2), A. veronii (n = 2) and A. hydrophila (n = 2). Isolates were almost uniformly susceptible to amikacin, gentamicin, aztreonam, cefepime, ceftazidime, ciprofloxacin and meropenem. All isolates with the exception of 1-2 isolates were resistant to ampicillin, cefazolin and ampicillin-sulbactam which was compatible with the presence of the blaOXA genes. Variable resistance rates were observed to cefuroxime, cefoxitin, ceftriaxone, piperacillin-tazobactam that were not correlated with the presence of other ß-lactamase genes. Resistance to tetracycline and trimethoprim-sulfamethoxazole correlated with the presence of tetA and sul1, respectively. The population structure of A. caviae was highly diverse with the minority of the isolates (16/57) clustering into six defined sequence types. A cgMLST-based distance of four genes was found in one pair of isolates, suggesting common source transmission. CONCLUSIONS: A. caviae is the dominant species related to gastroenteritis and is characterized by a diverse population structure, with almost no evidence for common-source transmission. Resistance rates to most antimicrobial agents were low and partially matched with the presence of resistance genes.

Hospitalized Patients With Severe Coronavirus Disease 2019 During the Omicron Wave in Israel: Benefits of a Fourth Vaccine Dose.

BACKGROUND: Waning immunity and an increased incidence of coronavirus disease 2019 (COVID-19) during the Omicron outbreak led the Israeli Ministry of Health to recommend a fourth vaccine dose for high-risk individuals. In this study, we assessed its effect for hospitalized patients with severe breakthrough COVID-19. METHODS: In this multicenter cohort study of hospitalized adults with severe COVID-19 in Israel, from 15 to 31 January 2022, cases were divided according to the number of vaccinations received. Poor outcome was defined as mechanical ventilation or in-hospital death and was compared between 3- and 4-dose vaccinees using logistic regression. RESULTS: Included were 1049 patients, median age 80 years. Among them, 394 were unvaccinated, 386 and 88 had received 3 or 4 doses, respectively. The 3-dose group was older, included more males, and immunosuppressed patients but with similar outcomes, 49% vs 51% compared with unvaccinated patients (P = .72). Patients who received 4 doses were similarly older and immunosuppressed but had better outcomes compared with unvaccinated patients, 34% vs 51% (P < .01). We examined independent predictors for poor outcome in patients who received either 3 or 4 doses a median of 161 days or 14 days before diagnosis, respectively. Receipt of the fourth dose was associated with protection (odds ratio, 0.51; 95% confidence interval, .3-.87), as was remdesivir. Male sex, chronic renal failure, and dementia were associated with poor outcomes. CONCLUSIONS: Among hospitalized patients with severe breakthrough COVID-19, a recent fourth dose was associated with significant protection against mechanical ventilation or death compared with 3 doses.

Outcomes of octogenarians and nonagenarians with Pseudomonas aeruginosa bacteremia: a multicenter retrospective study.

BACKGROUND: P. aeruginosa bacteremia is a common and severe infection carrying high mortality in older adults. We aimed to evaluate outcomes of P. aeruginosa bacteremia among old adults (≥ 80 years). METHODS: We included the 464/2394 (19%) older adults from a retrospective multinational (9 countries, 25 centers) cohort study of individuals hospitalized with P. aeruginosa bacteremia. Bivariate and multivariable logistic regression models were used to evaluate risk factors for 30-day mortality among older adults. RESULTS: Among 464 adults aged ≥ 80 years, the mean age was 84.61 (SD 3.98) years, and 274 (59%) were men. Compared to younger patients, ≥ 80 years adults had lower Charlson score; were less likely to have nosocomial acquisition; and more likely to have urinary source. Thirty-day mortality was 30%, versus 27% among patients 65-79 years (n = 894) and 25% among patients < 65 years (n = 1036). Multivariate analysis for predictors of mortality among patients ≥ 80 years, demonstrated higher SOFA score (odds ratio [OR] 1.36, 95% confidence interval [CI] 1.23-1.51, p < 0.001), corticosteroid therapy (OR 3.15, 95% CI: 1.24-8.01, p = 0.016) and hospital acquired P. aeruginosa bacteremia (OR 2.30, 95% CI: 1.33-3.98, p = 0.003) as predictors. Appropriate empirical therapy within 24 h, type of definitive anti-pseudomonal drug, and type of regimen (monotherapy or combination) were not associated with 30-day mortality. CONCLUSIONS: In older adults with P. aeruginosa bacteremia, background conditions, place of acquisition, and disease severity are associated with mortality, rather than the antimicrobial regimen. In this regard, preventive efforts and early diagnosis before organ failure develops might be beneficial for improving outcomes.

The Effect of Macrolides on Mortality in Bacteremic Pneumococcal Pneumonia: A Retrospective, Nationwide Cohort Study, Israel, 2009-2017.

BACKGROUND: Previous cohort studies of pneumonia patients reported lower mortality with advanced macrolides. Our aim was to characterize antibiotic treatment patterns and assess the role of quinolones or macrolides in empirical therapy. MATERIALS: An historical cohort, 1 July 2009 to 30 June 2017, included, through active surveillance, all culture-confirmed bacteremic pneumococcal pneumonia (BPP) among adults in Israel. Cases without information on antibiotic treatment were excluded. Logistic regression analysis was used to assess independent predictors of in-hospital mortality. RESULTS: A total of 2016 patients with BPP were identified. The median age was 67.2 years (interquartile range [IQR] 53.2-80.6); 55.1% were men. Lobar pneumonia was present in 1440 (71.4%), multi-lobar in 576 (28.6%). Median length of stay was 6 days (IQR 4-11). A total of 1921 cases (95.3%) received empiric antibiotics with anti-pneumococcal coverage: ceftriaxone, in 1267 (62.8%). Coverage for atypical bacteria was given to 1159 (57.5%), 64% of these, with macrolides. A total of 372 (18.5%) required mechanical ventilation, and 397 (19.7%) died. Independent predictors of mortality were age (odds ratio [OR] 1.051, 95% confidence interval [CI] 1.039, 1.063), being at high-risk for pneumococcal disease (OR 2.040, 95% CI 1.351, 3.083), multi-lobar pneumonia (OR 2.356, 95% CI 1.741, 3.189). Female sex and macrolide therapy were predictors of survival: (OR 0.702, 95% CI .516, .955; and OR 0.554, 95% CI .394, .779, respectively). Either azithromycin or roxithromycin treatment for as short as two days was predictor of survival. Quinolone therapy had no effect. CONCLUSIONS: Empirical therapy with macrolides reduced odds for mortality by 45%. This effect was evident with azithromycin and with roxithromycin. The effect did not require a full course of therapy.

Healthcare-associated infection prevention and control practices in Israel: results of a national survey.

BACKGROUND: Healthcare-associated infection (HAI) is a common and largely preventable cause of morbidity and mortality. The COVID-19 pandemic has presented unprecedented challenges to health systems. We conducted a national survey to ascertain hospital characteristics and the use of HAI prevention measures in Israel. METHODS: We e-mailed surveys to infection prevention and control (IPC) leads of acute care hospitals in Israel. The survey included questions about the use of practices to prevent catheter-associated urinary tract infection (CAUTI), central line-associated bloodstream infection (CLABSI), ventilator-associated pneumonia (VAP), and Clostridioides difficile infection (CDI). The survey also assessed COVID-19 impact and healthcare worker well-being. RESULTS: IPC leads from 15 of 24 invited hospitals (63%) completed the survey. Only one-third of respondents reported strong support for IPC from hospital leadership. Although several prevention practices were used by all hospitals (e.g., maximum sterile barrier precautions for CLABSI and real-time assessment of environmental cleaning for CDI), use of other practices was suboptimal-particularly for CAUTI and VAP. COVID-19 had a profound impact on Israeli hospitals, with all hospitals reporting opening of new units to care for COVID patients and most reporting moderate to extreme financial hardship. All hospitals reported highly successful plans to vaccinate all staff and felt confident that the vaccine is safe and effective. CONCLUSION: We provide a status report of the IPC characteristics and practices Israeli hospitals are currently using to prevent HAIs during the COVID-19 era. While many globally accepted IPC practices are widely implemented, opportunities to increase the use of certain IPC practices in Israeli hospitals exist.

Hospitalised patients with breakthrough COVID-19 following vaccination during two distinct waves in Israel, January to August 2021: a multicentre comparative cohort study.

BackgroundChanging patterns of vaccine breakthrough can clarify vaccine effectiveness.AimTo compare breakthrough infections during a SARS-CoV-2 Delta wave vs unvaccinated inpatients, and an earlier Alpha wave.MethodsIn an observational multicentre cohort study in Israel, hospitalised COVID-19 patients were divided into three cohorts: breakthrough infections in Comirnaty-vaccinated patients (VD; Jun-Aug 2021) and unvaccinated cases during the Delta wave (ND) and breakthrough infections during an earlier Alpha wave (VA; Jan-Apr 2021). Primary outcome was death or ventilation.ResultsWe included 343 VD, 162 ND and 172 VA patients. VD were more likely older (OR: 1.06; 95% CI: 1.05-1.08), men (OR: 1.6; 95% CI: 1.0-2.5) and immunosuppressed (OR: 2.5; 95% CI: 1.1-5.5) vs ND. Median time between second vaccine dose and admission was 179 days (IQR: 166-187) in VD vs 41 days (IQR: 28-57.5) in VA. VD patients were less likely to be men (OR: 0.6; 95% CI: 0.4-0.9), immunosuppressed (OR: 0.3; 95% CI: 0.2-0.5) or have congestive heart failure (OR: 0.6; 95% CI: 0.3-0.9) vs VA. The outcome was similar between all cohorts and affected by age and immunosuppression and not by vaccination, variant or time from vaccination.ConclusionsVaccination was protective during the Delta variant wave, as suggested by older age and greater immunosuppression in vaccinated breakthrough vs unvaccinated inpatients. Nevertheless, compared with an earlier post-vaccination period, breakthrough infections 6 months post-vaccination occurred in healthier patients. Thus, waning immunity increased vulnerability during the Delta wave, which suggests boosters as a countermeasure.

Seroprevalence of SARS-CoV2 among Healthcare Workers: A Prospective Study.

BACKGROUND: Healthcare workers (HCWs) have close interaction with confirmed or suspected coronavirus disease 2019 (COVID-19) patients. Infection rates reported among HCWs is between 3% and 17%, and asymptomatic HCWs are a potential source of nosocomial transmission to vulnerable patients and colleagues. Universal mask use and good supply of personal protective equipment was implemented early at our institution. OBJECTIVES: To determine the rate of infection by the serologic status of HCWs during first three COVID-19 waves, based on occupation and risk of exposure, compared to Israeli general population. METHODS: We conducted a prospective cohort study at Emek Medical Center from April 2020 to April 2021. A total of 101 HCWs volunteered to be followed at six time points by a serology test and a questionnaire. RESULTS: A total of 101 HCWs completed six serologic tests. All participants were seronegative at the four initial tests. The cumulative seropositivity rate for COVID-19 in HCWs was 9.9% (10/101). Only three seropositive HCWs (2.97%) were hospital-acquired. CONCLUSIONS: Seroprevalence and seroconversion dynamics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in 101 HCWs during COVID-19 outbreaks at Emek Medical Center were similar to the epidemiological curve of positive polymerase chain reaction results of the Israeli population, as published by the Israeli Ministry of Health, at each time point. Universal mask use and infection control measures may have contributed to a low hospital infection rate.

Combination versus monotherapy as definitive treatment for Pseudomonas aeruginosa bacteraemia: a multicentre retrospective observational cohort study.

BACKGROUND: Pseudomonas aeruginosa bacteraemia is a common and serious infection. No consensus exists regarding whether definitive combination therapy is superior to monotherapy. We aimed to evaluate the impact of combination therapy on mortality. METHODS: This was a multicentre retrospective study (nine countries, 25 centres), including 1277 patients with P. aeruginosa bacteraemia during 2009-15. We evaluated the association between ß-lactam plus aminoglycoside or quinolone combination therapy versus ß-lactam monotherapy and mortality. The primary outcome was 30 day all-cause mortality. Univariate and multivariate Cox regression analyses were conducted, introducing combination as a time-dependent variable. Propensity score was conducted to adjust for confounding for choosing combination therapy over monotherapy. RESULTS: Of 1119 patients included, 843 received definitive monotherapy and 276 received combination therapy (59% aminoglycoside and 41% quinolone). Mortality at 30 days was 16.9% (189/1119) and was similar between combination (45/276; 16.3%) and monotherapy (144/843; 17.1%) groups (P = 0.765). In multivariate Cox regression, combination therapy was not associated with reduced mortality (HR 0.98, 95% CI 0.64-1.53). No advantage in terms of clinical failure, microbiological failure or recurrent/persistent bacteraemia was demonstrated using combination therapy. Likewise, adverse events and resistance development were similar for the two regimens. CONCLUSIONS: In this retrospective cohort, no mortality advantage was demonstrated using combination therapy over monotherapy for P. aeruginosa bacteraemia. Combination therapy did not improve clinical or microbiological failure rates, nor affect adverse events or resistance development. Our finding of no benefit with combination therapy needs confirmation in well-designed randomized controlled trials.

The Bacteriology of Acute Cholecystitis: Comparison of Bile Cultures and Clinical Outcomes in Diabetic and Non-Diabetic Patients.

BACKGROUND: Acute cholecystitis is one of the most common acute surgical diseases. Diabetic patients have been shown to have an increased risk for gallbladder disease, but the correlation between the severity of gallstone disease and diabetes is still debated. The aim of this study is to examine the possible difference in the disease process between patients with diabetes mellitus (DM) and those without. PATIENTS AND METHODS: A retrospective study was conducted of all patients who underwent percutaneous cholecystostomy between 2005 and 2015 at Emek Medical Center, Afula, Israel. Demographic and medical history including data on bile and blood culture results, antimicrobial susceptibility, and clinical outcomes were retrieved from patient files. RESULTS: The cohort included 272 patients. Mean age was 68 years old, 50.74% were male and 43.75% had diabetes mellitus. Bile cultures were obtained from 252 (92.64%) patients and were positive in 134 (53.2%) patients. In 11 patients (4%) two pathogens were isolated. Blood cultures obtained from 231 patients and were positive in 35 (15.2%). Escherichia coli was the most common isolate, and was seen in 22.3% of positive bile cultures and 40% of blood cultures. Although diabetic patients had significantly more positive bile cultures, the severity of the disease, according to the Tokyo guidelines, was not higher. CONCLUSIONS: Acute cholecystitis was neither more severe nor had significant difference in bacteriological properties when comparing diabetic patients to non-diabetic ones.

Candida Bloodstream Infection, a Dire Complication in Hospitalized COVID-19 Patients: Three Cases from a Single Center in Northern Israel.

BACKGROUND: Patients with severe coronavirus disease-2019 (COVID-19) are susceptible to superimposed infections. OBJECTIVES: To describe COVID-19 patients who presented with complications due to Candida bloodstream co-infection (candidemia) and their outcome in a single center in northern Israel (Emek Medical Center) during the second outbreak of COVID-19 in Israel (15 June 2020 to 20 September 2020). METHODS: A retrospective study of COVID-19 patients presenting with candidemia was conducted, including clinical and laboratory data. The incidence of candidemia among hospitalized COVID-19 patients was compared to a historical cohort of non-COVID-19 controls. RESULTS: Three COVID-19 patients complicated with candidemia were documented. All three patients died shortly after the detection of candidemia. Three different Candida sp. were isolated from the blood cultures: C. albicans, C. parapsilosis, and C. glabrata. The incidence of candidemia among COVID-19 patients was 0.679 episodes per 1000 hospital days. CONCLUSIONS: Our small sample suggests a much higher incidence of candidemia among COVID-19 patients compared to a historical cohort of non-COVID-19 controls. All clinicians treating COVID-19 patients in GICU should be aware of this complication.

Cat Scratch Disease Presenting as Fever of Unknown Origin Is a Unique Clinical Syndrome.

BACKGROUND: Fever of unknown origin (FUO) is a rare manifestation of cat scratch disease (CSD). Data regarding CSD-associated FUO (CSD-FUO), particularly in adults, are limited. We aimed to study disease manifestations and long-term clinical outcome. METHODS: A national CSD surveillance study has been conducted in Israel since 1991. Data are obtained using questionnaires, review of medical records, and telephone interviews. FUO was defined as fever of ≥14 days without an identifiable cause. CSD-FUO patients were identified in the 2004-2017 CSD national registry. Follow-up included outpatient clinic visits and telephone/e-mail surveys. RESULTS: The study included 66 CSD-FUO patients. Median age was 35.5 years (range, 3-88). Median fever duration was 4 weeks (range, 2-9). Relapsing fever pattern was reported in 52% of patients, weight loss in 57%, and night sweats in 48%. Involvement of ≥1 organs occurred in 59% of patients; hepatosplenic space-occupying lesions (35%), abdominal/mediastinal lymphadenopathy (20%), ocular disease (18%), and multifocal osteomyelitis (6%) were the most common. Malignancy, particularly lymphoma, was the initial radiological interpretation in 21% of patients; 32% underwent invasive diagnostic procedures. Of the 59 patients available for follow-up (median duration, 31 weeks; range, 4-445), 95% had complete recovery; 3 patients remained with ocular sequelae. CONCLUSION: This is the first attempt to characterize CSD-FUO as a unique syndrome that may be severe and debilitating and often mimics malignancy. Relapsing fever is a common clinical phenotype. Multiorgan involvement is common. Recovery was complete in all patients except in those with ocular disease.

Ceftazidime, Carbapenems, or Piperacillin-tazobactam as Single Definitive Therapy for Pseudomonas aeruginosa Bloodstream Infection: A Multisite Retrospective Study.

BACKGROUND: The optimal antibiotic regimen for Pseudomonas aeruginosa bacteremia is controversial. Although ß-lactam monotherapy is common, data to guide the choice between antibiotics are scarce. We aimed to compare ceftazidime, carbapenems, and piperacillin-tazobactam as definitive monotherapy. METHODS: A multinational retrospective study (9 countries, 25 centers) including 767 hospitalized patients with P. aeruginosa bacteremia treated with ß-lactam monotherapy during 2009-2015. The primary outcome was 30-day all-cause mortality. Univariate and multivariate, including propensity-adjusted, analyses were conducted introducing monotherapy type as an independent variable. RESULTS: Thirty-day mortality was 37/213 (17.4%), 42/210 (20%), and 55/344 (16%) in the ceftazidime, carbapenem, and piperacillin-tazobactam groups, respectively. Type of monotherapy was not significantly associated with mortality in either univariate, multivariate, or propensity-adjusted analyses (odds ratio [OR], 1.14; 95% confidence interval [CI], 0.52-2.46, for ceftazidime; OR, 1.3; 95% CI, 0.67-2.51, for piperacillin-tazobactam, with carbapenems as reference in propensity adjusted multivariate analysis; 542 patients). No significant difference between antibiotics was demonstrated for clinical failure, microbiological failure, or adverse events. Isolation of P. aeruginosa with new resistance to antipseudomonal drugs was significantly more frequent with carbapenems (36/206 [17.5%]) versus ceftazidime (25/201 [12.4%]) and piperacillin-tazobactam (28/332 [8.4%] (P = .007). CONCLUSIONS: No significant difference in mortality, clinical, and microbiological outcomes or adverse events was demonstrated between ceftazidime, carbapenems, and piperacillin-tazobactam as definitive treatment of P. aeruginosa bacteremia. Higher rates of resistant P. aeruginosa after patients were treated with carbapenems, along with the general preference for carbapenem-sparing regimens, suggests using ceftazidime or piperacillin-tazobactam for treating susceptible infection.

Detection of Ureaplasma Species by a Semi-Quantitative PCR Test in Urine Samples: Can It Predict Clinical Significance?

BACKGROUND: Ureaplasma species (Usp) are the most prevalent genital Mycoplasma isolated from the urogenital tract of both men and women. Usp may be commensals in the genital tract but may also be contributors to a number of pathological conditions of the genital tract. Because they can also just colonize the genital tract of healthy people, their pathogenic role can be difficult to prove. OBJECTIVES: The aim of the study was to evaluate the efficacy of a quantitative polymerase chain reaction (qPCR) method for the discrimination between infection and colonization by measuring prevalence of Usp in asymptomatic versus symptomatic patients. METHODS: Urine samples were tested for U. parvum and U. urealyticum using a semi-quantitative multiplex PCR technique for sexually transmitted diseases (Anyplex™ STI-7 Detection Kit, Seegene, South Korea). A total of 250 symptomatic and 250 asymptomatic controls were included. RESULTS: A strong positive result for U. parvum was significantly more prevalent in symptomatic compared to asymptomatic patients. This finding was observed especially in women and in the young group (15-35 years of age). No significant differences were observed between the prevalence in symptomatic and asymptomatic patients of U. parvum with low strength of positivity and for U. urealyticum in all groups by age, gender, and strength of positivity. CONCLUSIONS: The significant difference between the symptomatic and asymptomatic group in the highest positivity group for U. parvum using the Anyplex™ STI-7 detection kit in urine may indicate a high probability of infection rather than colonization, especially in women and young patients.

Bloodstream Infections Caused by Contaminants: Epidemiology and Risk Factors: A 10-Year Surveillance.

BACKGROUND: Skin colonization of microorganisms in blood cultures (BCs) are generally considered clinically non-significant and can be the source of a true infection, particularly in immunosuppressed patients. OBJECTIVES: To study the epidemiology and risk factors for bacteremia caused by contaminants. METHODS: This retrospective, descriptive study is based on adult BCs collected (2004-2013) and categorized as positive (True bacteremia [TrueB] or contamination) or negative. Clinical, demographic, and laboratory characteristics of BCs positive for the six most common potential contaminant pathogens (PCPs) that can cause TrueB and contamination (Coagulase-negative Staphylococcus [CoNS], Streptococcus viridans, Propionibacterium acnes, Corynebacterium spp., Bacillus spp., Clostridium spp.) were assessed. Ninety-two TrueB were identified vs. 196 contaminations (1:2 ratio). RESULTS: From 74,014 BCs, PCPs were found in 3735 samples, of which 3643 (97.5%) were contaminations and 92 (2.5%) were TrueB. The overall rate of BC contamination decreased during the study period from 6.7% to 3.8%. CoNS was the most common PCP. Bacillus spp. were only contaminants. Clostridium spp. and Streptococcus viridans were more often TrueB. In a multivariate model, predictors of TrueB included high creatinine levels, Streptococcus viridans in BC, and multiple positive BCs. A single culture of CoNS was strongly predictive of contamination. CONCLUSIONS: Ten years of data on BCs, focusing on six PCPs, demonstrates a significant, yet insufficient reduction in the rate of contamination. High creatinine level, isolation of Streptococcus viridans, and multiple positive BCs were predictors of TrueB, while growth of CoNS was strongly predictive of contamination. This model could assist in diagnostic and therapeutic decision making.

Seasonal Influenza Vaccination Effectiveness and Compliance among Hospital Health Care Workers.

BACKGROUND: Recent studies show that vaccination of health care workers (HCW) might reduce influenza transmission and mortality among hospitalized patients. No studies have compared the incidence of laboratory-proven influenza in vaccinated versus unvaccinated hospital HCW. OBJECTIVES: To evaluate the effectiveness of influenza vaccination among hospital HCW and to examine the attitudes of this population towards influenza vaccination. METHODS: We performed a prospective cohort study between 1 January and 30 April 2014 of 1641 HCW at our medical center; 733 were vaccinated and 908 were not. A random sample of 199 subjects was obtained: 97 vaccinated and 102 non-vaccinated. Participating individuals were contacted on a weekly basis during the flu season and were asked to report any respiratory or flu symptoms and, if positive, to undergo a polymerase chain reaction (PCR) test for influenza. Results: In the general HCW population vaccination was more frequent among physicians (298/498, 58%) than among nurses (324/862, 38%) and among males than females. Flu symptoms were reported by 20 of 199 participants, 13 in the non-vaccinated group (12.7%) and 7 in the vaccinated group (7.2%). A positive PCR test for influenza A virus was present in 4 of 20 people tested (20%). All positive cases were from the non-vaccinated group (P = 0.0953). CONCLUSIONS: Non-vaccinated HCW showed a higher, although not statistically significant, tendency for contracting laboratory-proven influenza than the vaccinated population. The main reasons for vaccination and non-vaccination were personal beliefs and habits. Education efforts are needed to improve compliance. Larger studies could further clarify this issue.

Chloramphenicol use and susceptibility patterns in Israel: a national survey.

BACKGROUND: Due to increasing antimicrobial resistance, there has been renewed interest in old drugs that have fallen into disuse because of toxic side effects. One such drug is chloramphenicol. Data on the use and susceptibility patterns to chloramphenicol in developed countries in recent years are limited. OBJECTIVES: To assess the susceptibility of bacteria to chloramphenicol, and evaluate the use of chloramphenicol in Israeli hospitals as influenced by infectious disease specialists' attitudes with regard to its potential harms. METHODS: A national survey was conducted in all Israeli hospitals. Questionnaires were sent to the directors of infectious disease units and included items on chloramphenicol susceptibility in clinical isolates, use of chloramphenicol for the treatment of inpatients, local recommendations for use of chloramphenicol, and concerns regarding side effects. RESULTS: Chloramphenicol is used in 83.3% of hospitals, mostly for the treatment of aspiration pneumonia. While 22.2% of infectious disease unit directors believe that chloramphenicol should be avoided because of dangerous side effects, 88.9% believe there is a place for chloramphenicol in the treatment of patients in this era of increasing antibiotic resistance. Chloramphenicol susceptibility is routinely assessed in 44.4% of hospitals, with high susceptibility rates found among gram-positive, gram-negative and anaerobic bacteria. CONCLUSIONS: In an era of increasing antibiotic resistance, many Israeli infectious disease unit directors believe that chloramphenicol has a role in the treatment of respiratory tract and other infections in hospitalized patients.

[HIGH ALTITUDE EXPOSURE IN TRAVELERS WITH PREEXISTING MEDICAL CONDITIONS].

The number of travelers visiting high altitude regions is increasing. High altitude areas have become more accessible in recent years, and reaching areas at altitudes over 3000 meters above sea level has become more common than before. In many circumstances older travelers, who are more likely to have pre-existing chronic diseases and for whom altitude and hypoxic condition might be a risk, reach high altitudes in a fast and tight schedule, therefore having a shorter time for adaptation and acclimatization. Pre-travel consultation, including the discussion of chronic illnesses and medication use, is therefore crucial for the reduction of the risk of acute mountain sickness and preventing the deterioration of their pre-existing medical conditions.

The effect of the transition to molecular diagnosis on the epidemiology and the clinical characteristics of bacterial gastroenteritis in Northern Israel.

BACKGROUND: The transition to PCR-based diagnosis of bacterial gastroenteritis (BGE) can increase the sensitivity but might reduce the clinical specificity. The aims of this study were (1) to compare the effect of the change from culture to PCR-based diagnostics on the reported incidence and positivity rates of BGE due to Salmonella, Shigella and Campylobacter species and (2) to compare the demographics, medical background, clinical characteristics and pre-analytic variables between cases with PCR-positive, culture-negative samples to cases with PCR-positive, culture-positive samples. METHODS: The study was performed at the Emek Medical Centre that serves a population of 0.5 million people in Northern Israel. The study included two parts: (1) a retrospective cohort study, comparing the incidence and positivity rates of laboratory-diagnosed BGE from January 2016 until December 22nd, 2019 when culture was the sole method to January 2020 until April 2023 when PCR was used; (2) a prospective cohort study, conducted between November 2020 until April 2023 that compared the demographics and clinical characteristics of BGE cases that were diagnosed by PCR alone versus cases that were diagnosed by both PCR and culture. RESULTS: The incidence rate between-periods comparability ratio was only 113% since the incidence rate did not increase during 2020, the first year of the COVID-19 pandemic. The sample positivity rate increased since 2020, with between-periods comparability ratio of 159%. In the second period, the sample positivity rates of culture vs. PCR alone differed between the pathogens and were 90.2%, 63.8% and 54.2% for Salmonella, Campylobacter and Shigella species, respectively (p < 0.001). The following variables were identified as independent predictors of culture positivity: (1) Salmonella infection (O.R. = 10.6, 95% C.I. 3.6-31.1, p < 0.001); (2) Shigella infection (O.R. = 0.46, 95% C.I.0.23-0.93, p = 0.032); (3) time from sample submission to culture (O.R.=0.73, 95% C.I. 0.58-0.92, p = 0.008); (4) the presence of abdominal pain (O.R. = 1.98, 95% C.I. 1.04-3.79, p = 0.038) and the PCR mean Ct value (O.R. = 0.89, 95% C.I.0.85-0.94, p < 0.001). CONCLUSIONS: The use of PCR had led to improved sensitivity, without noticeable decrease in the clinical specificity. This was especially important in the case of the more fastidious organisms.

Varicella-Zoster Virus-Induced Neurologic Disease After COVID-19 Vaccination: A Multicenter Observational Cohort Study.

Background: Early reports described an increased risk of herpes zoster following receipt of mRNA-based COVID-19 vaccines. The objective was to assess whether COVID-19 vaccine is associated with varicella-zoster virus-induced neurologic disease (VZV-ND). Methods: This multicenter retrospective case-control study with a test-negative design was conducted at 12 hospitals in Israel. We included all patients admitted with VZV-ND between January 2020 and December 2021 and matched controls with a negative polymerase chain reaction result for VZV in cerebrospinal fluid. Results: We identified 188 patients meeting the case definition of VZV-ND who were admitted during the study period. Cases were matched with 376 controls. There was no significant variation in the incidence of VZV-ND between 1 year preceding and 1 year following the deployment of BNT162b2 in Israel. Analysis of persons who had received at least 1 dose of COVID-19 vaccine (n = 259) showed similar proportions of VZV-ND and non-VZV-ND in 4 intervals (30, 42, 50, 60 days) following the last vaccine dose. The median time from the last vaccine dose to hospitalization with a neurologic syndrome was 53 days (IQR, 25-128) and 82 days (IQR, 36-132) for VZV-ND and non-VZV-ND, respectively, not reaching statistical significance (P = .056). The rate of VZV-ND in vaccinated patients was no different from the rate in the unvaccinated group (30.9% vs 35.4%, P = .2). Conclusions: We did not find an association between COVID-19 vaccine and VZV-ND. Since COVID-19 vaccine is now recommended yearly, every fall and winter, establishing the safety of the vaccine is of great importance.