Osteoarticular Mycoses.

Osteoarticular mycoses are chronic debilitating infections that require extended courses of antifungal therapy and may warrant expert surgical intervention. As there has been no comprehensive review of these diseases, the International Consortium for Osteoarticular Mycoses prepared a definitive treatise for this important class of infections. Among the etiologies of osteoarticular mycoses are Candida spp., Aspergillus spp., Mucorales, dematiaceous fungi, non-Aspergillus hyaline molds, and endemic mycoses, including those caused by Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidioides species. This review analyzes the history, epidemiology, pathogenesis, clinical manifestations, diagnostic approaches, inflammatory biomarkers, diagnostic imaging modalities, treatments, and outcomes of osteomyelitis and septic arthritis caused by these organisms. Candida osteomyelitis and Candida arthritis are associated with greater events of hematogenous dissemination than those of most other osteoarticular mycoses. Traumatic inoculation is more commonly associated with osteoarticular mycoses caused by Aspergillus and non-Aspergillus molds. Synovial fluid cultures are highly sensitive in the detection of Candida and Aspergillus arthritis. Relapsed infection, particularly in Candida arthritis, may develop in relation to an inadequate duration of therapy. Overall mortality reflects survival from disseminated infection and underlying host factors.

Estimation of the determinants for HIV late presentation using the traditional definition and molecular clock-inferred dates: Evidence that older age, heterosexual risk group and more recent diagnosis are prognostic factors.

OBJECTIVES: HIV late presentation (LP) has been increasing in recent years in Europe. Our aim was to investigate the characteristics of LP in Greece using in addition to the traditional definition for LP, the time interval between HIV infection and diagnosis. METHODS: Our nationwide sample included HIV-1 sequences generated from 6166 people living with HIV (PLWH) in Greece during the period 1999-2015. Our analysis was based on the molecularly inferred HIV-1 infection dates for PLWH infected within local molecular transmission clusters of subtypes A1 and B. RESULTS: Analysis of the determinants of LP was conducted using either CD4 counts or AIDS-defining condition at diagnosis or the time from infection to diagnosis. Older age, heterosexual transmission risk group and more recent diagnosis were associated with increased risk for LP. In contrast to previous studies, people who inject drugs (PWID) had a shorter median time to diagnosis (0.63 years) compared to men who have sex with men (MSM) (1.72 years) and heterosexuals (2.43 years). Using HIV infection dates that provide an unbiased marker for LP compared to CD4 counts at diagnosis, which are age-dependent, we estimated that the time to diagnosis increased gradually with age. Migrants infected regionally do not differ with respect to LP status compared to native Greeks. CONCLUSIONS: We demonstrate that older people and heterosexuals are among those at higher risk for LP; and given the growing number of older people among newly diagnosed cases, tailored interventions are needed in these populations.

A study of the evolution of the third COVID-19 pandemic wave in the Athens metropolitan area, Greece, through two cross-sectional seroepidemiological surveys: March, June 2021.

We studied the third coronavirus disease 2019 (COVID-19) pandemic wave in Athens metropolitan area (3 738 901 inhabitants) through two seroepidemiological surveys. Persons presenting in 12 healthcare facilities across Athens in March and June 2021 were studied (764 and 901, respectively). Immunoglobulin G antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein were measured by a chemiluminescent microparticle immunoassay. In March the seroprevalence rate was 11.6%, meaning that 435 208 residents of Athens had evidence of immunity. The respective values in June were 55.7% and 2 082 568 residents. The highest seroprevalence rates attributed to SARS-CoV-2 infection were recorded in persons <18 years (16.3% in March and 31.6% in June), while immunity was mainly vaccine-induced in persons 18-64 years and >65 years. Infection-attributed immunity also increased in older-age groups. Wide ranges in seroprevalence rates were noted across areas in March and June. The highest seroprevalence rates were recorded in Piraeus (47.2%) and West Attica (37.5%). However, the highest increase (>5 times) occurred in Piraeus and the South Section of Athens, which are among the most densely populated areas in Athens. In both study periods, history of COVID-19 or febrile episode, and having a cohabitant with COVID-19 were associated with increased risk for seropositivity among unvaccinated persons (p values <0.001 for all). Residing in Piraeus, the South Section or West Attica was associated with increased risk for seropositivity in June (p values <0.001). Wide heterogeneity in seroprevalence rates was found across areas in Athens, which is mainly attributed to population density. The impact of population mobility and socioeconomic status should be explored.

Is Carbapenem-resistant Klebsiella pneumoniae Infection in Pediatric Bone Marrow Transplantation Recipients Inevitably Fatal?

Carbapenem resistance, most notably in Klebsiella pneumonia (KPC), results in infections associated with significant morbidity and mortality. Here we report 2 cases of adolescent patients with KPC infection after high-risk bone marrow transplantation, who eventually succumbed from other causes and review the epidemiology and treatment options for KPC infections in this vulnerable population.

Earlier treatment initiation is associated with a decreased number of HIV-1 subtype A1 transmissions in Greece.

OBJECTIVES: Subtypes A1 and B are the most prevalent HIV-1 clades in Greece. Subtype A1 epidemic is highly monophyletic and corresponds to transmissions that occurred locally. Our aim in this molecular epidemiology analysis was to investigate the role of early treatment in preventing new HIV-1 transmissions. METHODS: Our analysis focused on 791 subtype A1 sequences from treatment-naïve individuals in Greece. Estimation of infection dates was performed by molecular clock calculations using Bayesian methods. We estimated the time interval between (1) the infection and sampling dates (linkage to care window), (2) the sampling dates and antiretroviral therapy (ART) initiation (treatment window), and (3) the infection dates and ART initiation (transmissibility window) for the study population. We also inferred the putative source of HIV infections between individuals of different groups divided according to the length of treatment, linkage to care or transmissibility window. RESULTS: A significant decline was detected for the treatment window during 2014-2015 versus the 2 previous years (p=0.0273), while the linkage to care interval remained unchanged during the study period. Inference of the putative source of HIV infections suggested that individuals with a recent diagnosis or narrow transmissibility window (time period between HIV infection and ART initiation) were not sources of HIV infections to other groups. Contrarily, a significant number of HIV infections originated from individuals with longer transmissibility window interval. CONCLUSIONS: Our findings showed that the treatment window is decreasing over time, presumably due to the updated treatment guidelines. Our study also demonstrates that people treated earlier after infection do not transmit at high rates, thus documenting the benefits of early ART initiation in preventing ongoing HIV-1 transmission.

Toxoplasma gondii: How fatal is it in pediatric allogeneic bone marrow transplantation setting?

Toxoplasmosis is a disease of the immunocompetent population. However, cases of toxoplasma infection associated with immunosuppression have been reported, especially the first months after transplantation. Limited data are available about toxoplasma infection, occurring even many months post-transplant in pediatric patients with nonmalignant and malignant diseases. We report the cases of three patients with early and late disseminated toxoplasmosis and review the literature.

A comparative study of heterogeneous antibiotic resistance of microbial populations in conventional periprosthetic tissue cultures and sonication fluid cultures of orthopaedics explanted prostheses.

BACKGROUND: "Heterogeneity" describes a phenomenon where subpopulations of seemingly isogenic bacteria exhibit a range of susceptibilities to a particular antibiotic. We aim to investigate the frequency of heterogeneity among microbes isolated from infected prostheses, and its possible correlation with microbial resistance. METHODS: Between May 2014 and June 2019, we investigated 234 patients, at our institution, undergoing revision arthroplasty because of loosening of the prostheses or because of periprosthetic joint infection. All patients had periprosthetic tissue culture, sonication of prosthesis and direct inoculation of Sonication fluid into blood culture bottles. We assessed the presence of heterogeneity among all pathogens isolated from infected prostheses. RESULTS: Using standard non-microbiological criteria to determine periprosthetic joint infection, it was found that 143 patient (61.1%) had aseptic loosening while 91 patients (38.9%) had periprosthetic joint infection. Comparing the two methods, the results of our study showed that the method of sonication was significantly more sensitive than tissue culture [91% (83-96) vs. 43% (33-54); p < 0.005]. In this study, heterogeneity was reported in 15 cases, 16.5% of all infections and 6.4% in the total population. In our study, Staphylococcus epidermidis was the most commonly isolated strain followed by Staphylococcus aureus, at a rate of 35.2% and 19.8%, respectively. Antibiotics in which the microorganisms exhibited heterogeneous bacterial behavior most frequently were Gendamicin (5.3%), Vancomycin (4.9%). CONCLUSION: There is increasing evidence that heterogeneity can lead to therapeutic failure and that the detection of this phenotype is a prerequisite for a proper antibiotic choice to have a successful therapeutic effect.

Experimental Candida albicans osteomyelitis: Microbiologic, antigenic, histologic, and 18FDG-PET-CT imaging characteristics in a newly established rabbit model.

Candida osteomyelitis is a debilitating disease that is difficult to diagnose and treat. As there are no animal models or prospective studies for this uncommon infection, little is known about the pathogenesis, diagnosis, or treatment. We therefore sought to establish an animal model for the study of the pathophysiology, diagnostic modalities, and therapeutic interventions of Candida osteomyelitis. We developed a modified version of the Norden rabbit model of tibial osteomyelitis, in which the right tibia was inoculated intraoperatively with different inocula of C. albicans or normal saline as control. On days 7, 14, and 21 after inoculation, the animals underwent bone radiography, 18-fluoro-2-deoxy-D-glucose positron emission tomography combined with computed tomography (PET/CT) scan, and blood sampling for blood cultures, blood counts, erythrocyte sedimentation rate, and Candida mannan antigen serum levels. On day 21, animals were euthanized, and infected tibias harvested for culture and histology. Among eight evaluable animals inoculated with 1 × 106 to 1 × 107 cfu, histology and bone cultures established the presence of Candida osteomyelitis in seven, with a host response of neutrophils, mononuclear cells, multinucleate giant cells, fibrosis, and necrosis. Infected animals demonstrated radiological signs of osteomyelitis with significantly increased tracer uptake in 18FDG-PET/CT scans (P < .01) and elevated serum mannan levels (P < .01). All blood cultures were negative. Indices of inflammation were only slightly increased. In conclusion, we report successful establishment of a new animal model of Candida albicans osteomyelitis that may be applicable to advancing our understanding of the pathophysiology, diagnostic modalities, and treatment of this debilitating infection.

CD4 cell count response to first-line combination ART in HIV-2+ patients compared with HIV-1+ patients: a multinational, multicohort European study.

Background: CD4 cell recovery following first-line combination ART (cART) is poorer in HIV-2+ than in HIV-1+ patients. Only large comparisons may allow adjustments for demographic and pretreatment plasma viral load (pVL). Methods: ART-naive HIV+ adults from two European multicohort collaborations, COHERE (HIV-1 alone) and ACHIeV2e (HIV-2 alone), were included, if they started first-line cART (without NNRTIs or fusion inhibitors) between 1997 and 2011. Patients without at least one CD4 cell count before start of cART, without a pretreatment pVL and with missing a priori-defined covariables were excluded. Evolution of CD4 cell count was studied using adjusted linear mixed models. Results: We included 185 HIV-2+ and 30321 HIV-1+ patients with median age of 46 years (IQR 36-52) and 37 years (IQR 31-44), respectively. Median observed pretreatment CD4 cell counts/mm3 were 203 (95% CI 100-290) in HIV-2+ patients and 223 (95% CI 100-353) in HIV-1+ patients. Mean observed CD4 cell count changes from start of cART to 12 months were +105 (95% CI 77-134) in HIV-2+ patients and +202 (95% CI 199-205) in HIV-1+ patients, an observed difference of 97 cells/mm3 in 1 year. In adjusted analysis, the mean CD4 cell increase was overall 25 CD4 cells/mm3/year lower (95% CI 5-44; P = 0.0127) in HIV-2+ patients compared with HIV-1+ patients. Conclusions: A poorer CD4 cell increase during first-line cART was observed in HIV-2+ patients, even after adjusting for pretreatment pVL and other potential confounders. Our results underline the need to identify more potent therapeutic regimens or strategies against HIV-2.

Bone and joint infections caused by mucormycetes: A challenging osteoarticular mycosis of the twenty-first century.

Osteomyelitis and arthritis caused by mucormycetes are rare diseases that rank among the most challenging complications in orthopedic and trauma surgery. The aim of this work is to review the epidemiological, clinical, diagnostic, and therapeutic aspects of the osteoarticular mucormycosis with particular emphasis on high-risk patients. A systematic review of osteoarticular mucormycosis was performed using PUBMED and EMBASE databases from 1978 to 2014. Among 34 patients with median age 41 (0.5-73 years), 24 (71%) were males. While 12 (35%) were immunocompromised patients, 14 (41%) had prior surgery, and seven (21%) suffered trauma. Other underlying conditions included diabetes mellitus, hematological malignancies, transplantation, and corticosteroid therapy. The median diagnostic delay from onset of symptoms and signs was 60 (10-180) days. The principal mechanism of the infection was direct inoculation (n = 19; 56%), and in immunocompromised patients was usually hematogenous disseminated. The long bones were infected by trauma or surgery, while a wide variety of bones were involved by hematogenous dissemination. Combined surgery and amphotericin B treatment were implemented in 28 (82%) and eight (23%) had an unfavorable outcome. Osteoarticular mucormycosis occurs most frequently after trauma or surgical procedures. These infections are progressively destructive and more virulent in individuals with impaired immune systems. Early diagnosis, timely administration of amphotericin B, control of underlying conditions, and surgical debridement of infected tissue are critical for successful management of osteoarticular mucormycosis.

Aspergillus arthritis: analysis of clinical manifestations, diagnosis, and treatment of 31 reported cases.

Aspergillus arthritis is a debilitating form of invasive aspergillosis. Little is known about its epidemiology, clinical manifestations, laboratory features, treatment, and prognosis. Cases of Aspergillus arthritis were reviewed in the English literature from 1967 through 2015 for variables of arthritis with Aspergillus spp. recovered from joint and/or adjacent bone, underlying conditions, symptoms, signs, inflammatory biomarkers, diagnostic imaging, management, and outcome. Among 31 evaluable cases, 87% were males and 13% pediatric. Median age was 50 y (range 1-83 y). Seventeen (55%) patients were immunosuppressed with such conditions as hematological malignancies (26%), corticosteroids (39%), and/or transplantation (26%). Approximately one-half (52%) of patients had hematogenous seeding of the joint, and more than 80% had de novo infection with no prior antifungal therapy. Oligoarticular infection (2-3 joints) occurred in 45% and contiguous osteomyelitis was present in 61%. Clinical manifestations included pain (87%), edema (26%), and limited function (23%), with knees (35%), intervertebral discs (26%), and hips (16%) being most commonly infected. Aspergillus fumigatus constituted 77% of cases followed by Aspergillus flavus in 13%, Aspergillus niger in 3%, and not specified in 7%. Median ESR was 90 mm/hr and median CRP was 3.6 mg/dl. Median synovial fluid WBC was 17,200/µL (7,300-128,000) with 72% PMNs (range 61-92). Osteolysis occurred in 35%, and soft-tissue extension 47%. Nineteen patients (61%) were managed with combined medical and surgical therapy, 10 (32%) with medical therapy only, and 2 (6%) surgery only. Amphotericin B and itraconazole were the most frequently used agents with median duration of therapy of 219 days (range 30-545). Surgical interventions included debridement in 61%, drainage 19%, and amputation 6%. Complete or partial response was achieved in 71% and relapse occurred in 16%. Medical therapy was reinstituted with successful outcome in these patients. Overall survival was 65%. Aspergillus arthritis mainly develops as a de novo infection involving knees and intervertebral disks in immunocompromised patients with localizing symptoms. Contiguous osteomyelitis is frequently observed. Diagnosis is established by synovial fluid culture. Aspergillus arthritis is therapeutically challenging with most patients undergoing surgery and protracted antifungal therapy.

Circulating autoantibodies to endogenous erythropoietin are associated with chronic hepatitis C virus infection-related anemia.

BACKGROUND: Chronic hepatitis C virus (HCV) infection is associated with autoimmune phenomena and is often complicated by anemia. Circulating autoantibodies to endogenous erythropoietin (anti-EPO) have been detected in patients with chronic viral infections and were correlated to anemia. The present study aimed to determine anti-EPO prevalence in patients with chronic HCV infection and investigate its possible association with anemia. METHODS: Ninety-three consecutive patients (62 males and 31 females) with chronic HCV infection, who had never received antiviral therapy or recombinant EPO, were enrolled in the study. Circulating anti-EPO were detected in the serum by using an ELISA assay. Quantitative determination of serum EPO levels was done by radioimmunoassay. HCV RNA viral load measurement and genotype sequencing were also performed. RESULTS: Circulating anti-EPO were detected in 10.8% of HCV-infected patients and the prevalence of anti-EPO was significantly higher in patients with anemia (19.4% vs 5.3%, P=0.040) compared to that in those without anemia. Compared to anti-EPO negative cases, anti-EPO positive patients had higher frequency of anemia (70.0% vs 34.9%, P=0.030), lower EPO concentrations (median 16.35 vs 30.65 mU/mL, P=0.005), and higher HCV RNA viral load (median 891.5X103 vs 367.5X103 IU/mL, P=0.016). In multivariate regression analysis the presence of anti-EPO remained an independent predictor of anemia (adjusted OR: 14.303, 95% CI: 1.417-36.580, P=0.024). EPO response to anemia was less prominent among anti-EPO positive patients (P=0.001). CONCLUSIONS: Circulating anti-EPO are detected in a significant proportion of treatment-naive HCV-infected patients and are independently associated with anemia, suggesting a further implication of autoimmunity in the pathophysiology of HCV-related anemia.

Asymptomatic bacteriuria in women with autoimmune rheumatic disease: prevalence, risk factors, and clinical significance.

BACKGROUND: Data regarding the prevalence and clinical significance of asymptomatic bacteriuria (AB) in women with autoimmune rheumatic disease (ARD) are scarce. METHODS: In this prospective, case-control study, consecutive female outpatients with ARD were screened for AB. For each patient, demographics, type, duration, and treatment of underlying ARD, and risk factors for urinary tract infection (UTI), were recorded. Age-matched women with endocrine disease, without any autoimmune disease, not receiving immunosuppressive agents were used as controls. Subjects were followed up for 1 year for the development of symptomatic UTI. RESULTS: Two hundred sixty patients with ARD (mean age, 52.4 [standard deviation {SD}, 14.6] years) and 238 controls (mean age, 51.2 [SD, 16.5] years) were enrolled. The majority of patients with ARD (93.5%; 95% confidence interval [CI], 89.7%-95.9%) were receiving immunosuppressive agents. AB was detected in 24 patients with ARD (9.2%; 95% CI, 6.2%-13.4%) and in 22 controls (9.2%; 95% CI, 5.5%-12.9%) (P = 1.000). The most prevalent pathogen was Escherichia coli (16/24 [66%]). Independent predictors for AB among patients were diabetes (odds ratio [OR], 6.6; P = .008) and a longer ARD duration (>84 months; OR, 4.3; P = .018). During the 1-year follow-up, 9 patients with baseline AB remained persistently bacteriuric, whereas 11 were intermittently bacteriuric. Symptomatic UTI developed in 4 of 24 patients (16.7%; 95% CI, 6.1%-36.5%) with baseline AB vs 29 of 236 (12.3%; 95% CI, 8.6%-17.1%) without AB (P = .522). CONCLUSIONS: In our study, the prevalence of AB among women with ARD was not higher than that of controls, and AB was not associated with higher risk for symptomatic UTI. Risk factors for AB were longer duration of ARD and diabetes.

Comparison of national clinical practice guidelines and recommendations on vaccination of adult patients with autoimmune rheumatic diseases.

The aim of the study is to identify and compare national recommendations on vaccination of adult patients with autoimmune rheumatic diseases (ARDs) in Europe, North America, and Australia. We conducted a search for recommended immunizations in adult patients with ARDs in the Medline database and the Web sites of National Rheumatologic Societies, Ministries of Health, National Advisory Committees on Immunization, and other relevant National Scientific Societies. We compared national guidelines and identified points of agreement and differences. Guidelines on vaccination of adult patients with ARDs were identified in 21 countries. Points of agreement include administering influenza and pneumococcal vaccines in addition to inactivated age-appropriate or travel-related vaccines, and avoiding the use of live vaccines in immunocompromised patients with ARDs. The most important differences concern the steroid dose that induces immunosuppression, the time interval between live vaccines and the initiation of immunosuppressive treatment, herpes zoster vaccination, and the preferred pneumococcal vaccine in patients with ARDs. We observed significant differences among national recommendations on immunizations in patients with ARDs, reflecting the lack of evidence-based data.

Lung function at three months after hospitalization due to COVID­19 pneumonia: Comparison of alpha, delta and omicron variant predominance periods.

The coronavirus disease (COVID-19) pandemic has already affected millions of individuals, with increasing numbers of survivors. These data suggest that the pulmonary sequelae of the infection may have an effect on a wide range of individuals. The aim of the present study was to evaluate pulmonary function in patients hospitalized due to COVID-19 three months after hospital discharge. A total of 116 patients, 34 females and 82 males, with a mean age of 57.77±11.45 years, who were hospitalized due to COVID-19, underwent pulmonary function testing three months after their hospital discharge. Of these, 83 (71.6%) patients were hospitalized in the period of alpha variant predominance, 16 (13.8%) in the period of delta variant predominance and 17 (14.6%) in the omicron variant predominance period. The mean value of diffusion capacity for carbon monoxide (DLCO)% predicted (pred) was statistically higher in patients affected by the omicron variant (P=0.028). Abnormal values (<80% pred) of DLCO and total lung capacity (TLC) were observed in 28.4 and 20.7% of the patients, respectively. Active smoking was an independent predictor of abnormal values of forced expiratory volume in 1 sec % pred and TLC% pred [P=0.038; odds ratio (OR): 8.574, confidence interval (CI) 1.124-65.424 and P=0.004, OR: 14.733, CI 2.323-93.429, respectively], age was an independent predictor of abnormal values of forced vital capacity % pred and DLCO% pred (P=0.027, OR: 1.124, CI 1.014-1.246 and P=0.011, OR:1.054, CI 1.012-1.098, respectively); and female sex was an independent predictor of abnormal values of DLCO% pred (P=0.009, OR: 1.124, CI 1.014-1.246). Α significant percentage of hospitalized patients due to COVID-19 pneumonia will develop abnormal pulmonary function, regardless of the SARS-CoV-2 variant.

Efficacy of Tixagevimab/Cilgavimab as Pre-Exposure Prophylaxis against Infection from SARS-CoV-2 and Severe COVID-19 among Heavily Immunocompromised Patients: A Single-Center, Prospective, Real-World Study.

BACKGROUND: COVID-19 continues to pose a threat to immunocompromised individuals, even with vaccination. The monoclonal antibodies (mAbs) tixagevimab/cilgavimab (TXG/CIL) provide targeted prophylaxis against SARS-CoV-2 with the benefit of a prolonged half-life. Although approved for COVID-19 prevention, there is limited data on their effectiveness among heavily immunocompromised populations. METHODS: We conducted a prospective, observational study at Laiko General Hospital, Athens, Greece, from August to December 2022 to investigate the efficacy of TXG/CIL as a form of pre-exposure prophylaxis in immunocompromised patients. Data on breakthrough SARS-CoV-2 infections were collected over a six-month follow-up period. RESULTS: Of the 375 participants (mean age 61.3 ± 14.1 years; 59.7% male), 76 (20.3%) developed breakthrough SARS-CoV-2 infections, with an incidence of 3.81 cases/100 patient months. Hospitalization was required for 21 patients (5.6%), with a median stay of 14 days. Seven deaths were recorded, with only one attributed to COVID-19. Previous infection (OR 0.46, 95% CI 0.26-0.82) and hybrid immunity (OR 0.52, 95% CI 0.29-0.92) can protect against new infection. Solid organ malignancy significantly increased the risk of severe outcomes among those infected (OR 7.4, 95% CI 2.2-24.7, p = 0.001). CONCLUSIONS: TXG/CIL provides effective prophylaxis against COVID-19 in immunocompromised patients. Future strategies should focus on developing new mAb combinations to address emerging SARS-CoV-2 variants and protect vulnerable populations.

Effectiveness of COVID-19 vaccination against school absenteeism in children and adolescents hospitalized with COVID-19.

BACKGROUND: COVID-19 vaccination has been recommended for children to protect them and to enable in-person educational and social activities. METHODS: We estimated COVID-19 vaccination effectiveness (VE) against school absenteeism in children 5-17 years old hospitalized from September 1, 2021 through May 31, 2023. Full vaccination was defined as two vaccine doses. RESULTS: We studied 231 children admitted to hospital with COVID-19, including 206 (89.2 %) unvaccinated/partially vaccinated and 25 (10.8 %) fully vaccinated. Unvaccinated/partially vaccinated children were absent from school for longer periods compared to fully vaccinated children (median absence: 14 versus 10 days; p-value = 0.05). Multivariable regression showed that full COVID-19 vaccination was associated with fewer days of absence compared to no/partial vaccination on average (adjusted relative risk: 0.77; 95 % CI: 0.61 to 0.98). COVID-19 VE was 50.7 % (95 % CI: -11.3 % to 78.2 %) for school absenteeism above the median duration of absenteeism. CONCLUSIONS: Full COVID-19 vaccination conferred protection against school absenteeism in hospitalized school-aged children with COVID-19.

Evaluation of the influenza-like illness case definition and the acute respiratory infection case definition in the diagnosis of influenza and COVID-19 in healthcare personnel.

BACKGROUND: To evaluate the influenza-like illness (ILI) and acute respiratory infection (ARI) case definitions in the diagnosis of COVID-19 and influenza in healthcare personnel (HCP). METHODS: We followed a cohort of 5752 HCP from November 2022 to May 2023. Symptomatic HCP were tested for SARS-CoV-2 and influenza by real-time PCR and/or rapid antigen detection test. ILI was defined as the sudden onset of ≥1 systemic symptom and ≥1 respiratory symptom. ARI was defined as the sudden onset of ≥1 respiratory symptom. Patients with respiratory symptoms were grouped either as ILI or as ARI based on the presence of fever, malaise, headache and/or myalgia. RESULTS: Overall, 466 ILI cases and 383 ARI cases occurred. HCP with ILI had an adjusted odds ratio (aOR) of 22.05 [95% confidence interval (CI): 6.23-78.04] to be diagnosed with influenza. HCP with ARI had an aOR of 2.70 (95% CI: 1.88-3.88) to be diagnosed with COVID-19. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of ILI for influenza were 96.6%, 49.9%, 18.2%, and 99.2%, respectively. The sensitivity, specificity, PPV, and NPV of ARI for COVID-19 were 51.7%, 73.6%, 84.9%, and 34.8%, respectively. ILI and ARI had an overall correct classification rate of 89.6% and 74.1%, respectively. CONCLUSION: Our findings support the use of both ILI and ARI case definitions in the diagnosis of influenza and COVID-19 in HCP.

Comparison of morbidity and absenteeism due to COVID-19 and seasonal influenza in a large cohort of health care personnel in the 2022 to 2023 season.

BACKGROUND: To compare the morbidity and work absenteeism associated with coronavirus disease 2019 (COVID-19) and influenza among health care personnel (HCP) in 2022 to 2023. METHODS: We followed 5,752 hospital-based HCP in Greece from November 14, 2022 through May 28, 2023. Symptomatic HCP was tested for SARS-CoV-2 and influenza by real-time polymerase chain reaction and/or rapid antigen detection test. The association between the duration of absenteeism and the type of disease was estimated by multivariable regression models. RESULTS: A total of 734 COVID-19 cases and 93 influenza cases were studied. The mean duration of absence per COVID-19 case was 5.8days compared with a mean of absence of 3.6days per influenza case (P value <.001). Overall, COVID-19 accounted for 4,245days missed during the study period compared with 333days missed due to influenza. Multivariable regression estimates indicated that HCP with COVID-19 had 1.91 more days of absenteeism (95% confidence interval 1.67-2.15) compared with those with influenza, on average. CONCLUSIONS: As SARS-CoV-2 becomes endemic, COVID-19 remains the prevalent cause of morbidity and absenteeism among HCP, accounting for considerably more workdays missed compared with influenza. HCP should be up-to-date with COVID-19 booster vaccinations and annual influenza vaccination in order to protect them as well as health care systems from HCP absenteeism.