Severe Legionnaires' disease.

BACKGROUND: Legionnaires' disease (LD) is a common but under-diagnosed cause of community-acquired pneumonia (CAP), although rapid detection of urine antigen testing (UAT) and advances in molecular testing have improved the diagnosis. LD entails intensive care unit (ICU) admission in almost one-third of cases, and the mortality rate ranges from 4% to 40%. This review aims to discuss recent advances in the study of this condition and to provide an update on the diagnosis, pathogenesis and management of severe LD. RESULTS: The overall incidence of LD has increased worldwide in recent years due to the higher number of patients with risk factors, especially immunosuppression, and to improvements in diagnostic methods. Although LD is responsible for only around 5% of all-cause CAP, it is one of the three most common causes of CAP requiring ICU admission. Mortality in ICU patients, immunocompromised patients or patients with a nosocomial source of LD can reach 40% despite appropriate antimicrobial therapy. Regarding pathogenesis, no Legionella-specific virulence factors have been associated with severity; however, recent reports have found high pulmonary Legionella DNA loads, and impairments in immune response and lung microbiome in the most severe cases. The clinical picture includes severe lung injury requiring respiratory and/or hemodynamic support, extrapulmonary symptoms and non-specific laboratory findings. LD diagnostic methods have improved due to the broad use of UAT and the development of molecular methods allowing the detection of all Lp serogroups. Therapy is currently based on macrolides, quinolones, or a combination of the two, with prolonged treatment in severe cases. CONCLUSIONS: Numerous factors influence the mortality rate of LD, such as ICU admission, the underlying immune status, and the nosocomial source of the infection. The host immune response (hyperinflammation and/or immunoparalysis) may also be associated with increased severity. Given that the incidence of LD is rising, studies on specific biomarkers of severity may be of great interest. Further assessments comparing different regimens and/or evaluating host-directed therapies are nowadays needed.

Pre-Exposure Prophylaxis and Treatment with Tixagevimab/Cilgavimab for COVID-19 among Immunocompromised Pediatric Patients.

Background: Patients treated with hemato-oncological malignancies (HO) or undergoing cellular therapies such as hematopoietic stem cell transplantation (HSCT) or chimeric antigen receptor T cells (CAR-T) were significantly affected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Despite the success of SARS-CoV-2 vaccination, immunocompromised patients remain at increased risk for severe coronavirus disease (COVID-19), rendering this group of population a high priority for additional prevention and treatment options. Tixagevimab and Cilgavimab (TIXA/CILGA, AZD7442, Evusheld®) is a combination of two fully human, long-acting monoclonal antibodies. TIXA/CILGA have been approved as pre-exposure prophylaxis and treatment in patients at risk of severe disease with impaired vaccine response. Our objective was to describe the efficacy and safety among immunocompromised pediatric patients. Methods: This was an observational multicenter cohort study of immunocompromised pediatric patients receiving TIXA/CILGA conducted at nine Polish centers of Pediatric Oncology, Hematology and Bone Marrow Transplantation. We analyzed patients in two groups; those treated with HO and those undergoing cellular therapies: HSCT or CAR-T cells. In addition, two other cohorts were identified: patients given TIXA/CILGA as pre-exposure prophylactic and therapeutic intervention. Results: A total of 78 patients were evaluated during the study period: 69 (88.5%) received TIXA/CILGA as pre-exposure prophylaxis and 9 (11.5%) as a treatment strategy. A total of 52 (66.6%) patients were treated with standard chemotherapy at HO departments; 21 (27%) underwent HSCT, and 5 (6.4%) received CAR-T cell therapy. All children with COVID-19 receiving TIXA/CILGA presented a mild degree of severity. The most common clinical manifestations were fever, cough and coryza. At least one adverse event (AE) was reported in two (3.8%) patients excluding standard injection site reactions. Reported AEs were mild or moderate in intensity. One child reported mild myalgia and one reported moderate bone pain and weakness. Conclusions: In our observational multicenter cohort study, we explored the use of TIXA/CILGA as pre-exposure prophylaxis and treatment for COVID-19 among immunocompromised pediatric patients. While our findings suggest a potential benefit in preventing and managing COVID-19 in this vulnerable population, it is important to note the study's non-comparative design. Our results highlight the need for well-designed clinical trials to confirm these observations and further assess the efficacy and safety of TIXA/CILGA in immunocompromised children.

Baseline immune status and the effectiveness of response to enteral nutrition among ICU patients with COVID-19: An observational, retrospective study.

OBJECTIVES: This study aimed to compare how immunocompromised and immunocompetent patients responded differently to enteral nutrition (EN) support in intensive care units (ICUs) during the COVID-19 pandemic, including serum nutritional biomarkers, inflammatory biomarkers, gastrointestinal (GI) intolerance symptoms, and clinical outcomes. METHODS: An observational, retrospective study was conducted in the ICUs of a teaching hospital in southwest China. We recruited a convenience sample of 154 patients between December 2022 and February 2023. We defined immunocompromise as primary immunodeficiency diseases, active malignancy, receiving cancer chemotherapy, HIV infection, solid organ transplantation, hematopoietic stem cell transplantation, receiving corticosteroid therapy with a target dose, receiving biological immune modulators, or receiving disease-modifying antirheumatic drugs or other immunosuppressive drugs. We conducted a Mann-Whitney U test, χ2 test, or generalized estimation equation model to explore the differences between immunocompromised and immunocompetent patients. RESULTS: Among the 154 study participants, 41 (27%) were defined as immunocompromised. The immunocompromised patients were younger than the immunocompetent patients. There were no statistically significant differences between the two groups with respect to serum nutritional biomarkers, inflammatory biomarkers, incidence of GI intolerance symptoms, and in-hospital mortality. However, the immunocompromised patients exhibited a longer hospitalization duration than the immunocompetent patients. CONCLUSION: We found that the immunocompromised patients spent more time in the hospital. These findings may help us to standardize the participants before EN interventional studies better and better individualize EN supports based on patients' immunity status.

Impact of next-generation sequencing on antimicrobial treatment in immunocompromised adults with suspected infections.

BACKGROUND: Prompt pathogen identification can have a substantial impact on the optimization of antimicrobial treatment. The objective of the study was to assess the diagnostic value of next-generation sequencing (NGS) for identifying pathogen and its clinical impact on antimicrobial intervention in immunocompromised patients with suspected infections. METHODS: This was a retrospective study. Between January and August 2020, 47 adult immunocompromised patients underwent NGS testing under the following clinical conditions: 1) prolonged fever and negative conventional cultures; 2) new-onset fever despite empiric antimicrobial treatment; and 3) afebrile with suspected infections on imaging. Clinical data, including conventional microbial test results and antimicrobial treatment before and after NGS, were collected. Data were analyzed according to documented changes in antimicrobial treatment (escalated, no change, or de-escalated) after the NGS results. RESULTS: The median time from hospitalization to NGS sampling was 19 d. Clinically relevant pathogens were detected via NGS in 61.7% of patients (29/47), more than half of whom suffered from fungemia (n=17), resulting in an antimicrobial escalation in 53.2% of patients (25/47) and antimicrobial de-escalation in 0.2% of patients (1/47). Antimicrobial changes were mostly due to the identification of fastidious organisms such as Legionella, Pneumocystis jirovecii, and Candida. In the remaining three cases, NGS detected clinically relevant pathogens also detected by conventional cultures a few days later. The antimicrobial treatment was subsequently adjusted according to the susceptibility test results. Overall, NGS changed antimicrobial management in 55.3% (26/47) of patientst, and conventional culture detected clinically relevant pathogens in only 14.9% of patients (7/47). CONCLUSION: With its rapid identification and high sensitivity, NGS could be a promising tool for identifying relevant pathogens and enabling rapid appropriate treatment in immunocompromised patients with suspected infections.

Safety and antibody response of the BNT162b2 SARS-CoV-2 vaccine in children aged 5-11 years with underlying diseases: A prospective observational study.

BACKGROUND: Data on the safety and antibody response of the BNT162b2 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccine in children aged 5-11 years with underlying diseases are limited. Thus, our study aimed to address this gap. METHODS: This prospective observational study investigated the antibody titers for SARS-CoV-2 spike protein receptor-binding domain (S-IgG) and nucleocapsid protein (N-IgG) in patients aged 5-11 years with chronic underlying diseases following two doses of BNT162b2. Additionally, a questionnaire was used to assess adverse events (AEs) arising within 7 days after each dose. Data on severe AEs arising within 28 days after each dose were extracted from the patients' electronic medical records. RESULTS: Among 122 patients, 24.6% (30/122) were immunocompromised. Furthermore, 79 patients experienced at least one AE following vaccination, but all recovered without sequelae, including one severe case after the first dose. The seropositivity rate after the second dose was 99.1% (116/117). Excluding 19 N-IgG-positive patients, the geometric mean antibody titer (GMT) was significantly higher in immunocompetent patients than in immunocompromised patients (1496 U/mL [95% confidence interval 1199-1862] vs. 472 U/mL [200-1119], p = 0.035). Additionally, the GMT of S-IgG was higher in N-IgG-positive patients than in N-IgG-negative patients (8203 [5847-11482] U/mL vs. 1127 [855-1486] U/mL, p < 0.001). CONCLUSIONS: BNT162b2 is acceptably safe and immunogenic for children aged 5-11 years with underlying diseases. Although seroconversion was satisfactory in immunocompromised patients, the titers were lower than in immunocompetent patients.

ICU-acquired infections in immunocompromised patients.

Immunocompromised patients account for an increasing proportion of the typical intensive care unit (ICU) case-mix. Because of the increased availability of new drugs for cancer and auto-immune diseases, and improvement in the care of the most severely immunocompromised ICU patients (including those with hematologic malignancies), critically ill immunocompromised patients form a highly heterogeneous patient population. Furthermore, a large number of ICU patients with no apparent immunosuppression also harbor underlying conditions altering their immune response, or develop ICU-acquired immune deficiencies as a result of sepsis, trauma or major surgery. While infections are associated with significant morbidity and mortality in immunocompromised critically ill patients, little specific data are available on the incidence, microbiology, management and outcomes of ICU-acquired infections in this population. As a result, immunocompromised patients are usually excluded from trials and guidelines on the management of ICU-acquired infections. The most common ICU-acquired infections in immunocompromised patients are ventilator-associated lower respiratory tract infections (which include ventilator-associated pneumonia and tracheobronchitis) and bloodstream infections. Recently, several large observational studies have shed light on some of the epidemiological specificities of these infections-as well as on the dynamics of colonization and infection with multidrug-resistant bacteria-in these patients, and these will be discussed in this review. Immunocompromised patients are also at higher risk than non-immunocompromised hosts of fungal and viral infections, and the diagnostic and therapeutic management of these infections will be covered. Finally, we will suggest some important areas of future investigation.

Prevention of legionella infections from toilet flushing cisterns.

INTRODUCTION: Immunocompromised patients are at an increased risk of severe legionella infections. We present the results of an outbreak investigation initiated following a fatal case of hospital-acquired legionellosis linked to contaminated water from a toilet-flushing cistern. Additionally, we provide experimental data on the growth of Legionella spp. in flushing cisterns and propose a straightforward protocol for prevention. METHODS: We monitored the growth of Legionella spp. in the building's hot- and cold-water systems using quantitative bacterial culture on selective agar. Molecular typing of Legionella pneumophila isolates from the infected patient and the water system was conducted through core-genome multi-locus sequence typing (cgMLST). RESULTS: Legionella contamination in the hospital building's cold-water system was significantly higher than in the hot-water system and significantly higher in toilet flushing cistern's water compared with cold water from bathroom sinks and showers. Isolates from the patient and from the flushing cistern of the patient's bathroom were identical by cgMLST. In an experimental setting, daily toilet flushing for a period of 21 days resulted in a 67% reduction in the growth of Legionella spp. in the water of toilet flushing cisterns. Moreover, a one-time disinfection of cisterns with peracetic acid, followed by daily flushing, decreased legionella growth to less than 1% over a period of at least seven weeks in these setting. CONCLUSIONS: One-time disinfection of highly contaminated cisterns with peracetic acid and daily toilet flushing as short-term measure can significantly reduce legionella contamination in flushing cisterns. These measures may aid in preventing legionella infection among immunocompromised patients.

Immunogenicity of tick-borne-encephalitis-virus-(TBEV)-vaccination and impact of age on humoral and cellular TBEV-specific immune responses in patients with rheumatoid arthritis.

Inactivated vaccines, such as tick-borne-encephalitis-virus-(TBEV) vaccine, have been discussed as less immunogenic in elderly and in immunocompromised patients. In this controlled cross-sectional cohort study, the antibody and cellular responses after TBEV-vaccination were investigated in 36 rheumatoid arthritis (RA) patients and 112 healthy controls (HC) by evaluating IgG-anti-TBEV concentration, neutralization and relative avidity index (RAI). Cellular reactivity was assessed by IFNgamma-producing spot-forming-units (SFU) by ELISPOT assay and flow cytometry. RA patients showed lower IgG-anti-TBEV compared to HC, which were influenced by age at and time since last TBEV vaccination and disease duration. High-responders regarding cellular immunity and avidity were less frequent in RA compared to HC. RA patients who had received booster vaccinations were more likely to demonstrate higher IgG-anti-TBEV responses compared to those who had not. In conclusion, RA patients showed a negative effect of age on anti-TBEV-IgG and immunological benefits of timely booster vaccination are suggested.

Management of Cytomegalovirus Infections in the Era of the Novel Antiviral Players, Letermovir and Maribavir.

Cytomegalovirus (CMV) infections may increase morbidity and mortality in immunocompromised patients. Until recently, standard antiviral drugs against CMV were limited to viral DNA polymerase inhibitors (val)ganciclovir, foscarnet and cidofovir with a risk for cross-resistance. These drugs may also cause serious side effects. This narrative review provides an update on new antiviral agents that were approved for the prevention and treatment of CMV infections in transplant recipients. Letermovir was approved in 2017 for CMV prophylaxis in CMV-seropositive adults who received an allogeneic hematopoietic stem cell transplant. Maribavir followed four years later, with an indication in the treatment of adult and pediatric transplant patients with refractory/resistant CMV disease. The target of letermovir is the CMV terminase complex (constituted of pUL56, pUL89 and pUL51 subunits). Letermovir prevents the cleavage of viral DNA and its packaging into capsids. Maribavir is a pUL97 kinase inhibitor, which interferes with the assembly of capsids and the egress of virions from the nucleus. Both drugs have activity against most CMV strains resistant to standard drugs and exhibit favorable safety profiles. However, high-level resistance mutations may arise more rapidly in the UL56 gene under letermovir than low-grade resistance mutations. Some mutations emerging in the UL97 gene under maribavir can be cross-resistant with ganciclovir. Thus, letermovir and maribavir now extend the drug arsenal available for the management of CMV infections and their respective niches are currently defined.

COVID-19 in immunocompromised patients after hematopoietic stem cell transplantation: a pilot study.

Data on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in patients at early stage of immune reconstitution after hematopoietic stem cell transplantation (HSCT) are limited. In the present study, we retrospectively investigated the incidence and clinical features of SARS-CoV-2 infection in patients who underwent HSCT in 2022. Patients (allo-HSCT, n = 80; auto-HSCT, n = 37) were consecutively included in the study. The SARS-CoV-2 infection rate was 59.8%, and the median interval of HSCT to coronavirus disease 2019 (COVID-19) was 4.8 (range: 0.5-12) months. Most patients were categorized as mild (41.4%) or moderate (38.6%), and 20% as severe/critical. No deaths were attributable to COVID-19. Further analysis showed that lower circulating CD8+ T-cell counts and calcineurin inhibitor administration increased the risk of SARS-CoV-2 infection. Exposure to rituximab significantly increased the probability of severe or critical COVID-19 compared with that of mild/moderate illness (P < .001). In the multivariate analysis, rituximab use was associated with severe COVID-19. Additionally, COVID-19 had no significant effect on immune reconstitution. Furthermore, it was found that Epstein-Barr virus infection and rituximab administration possibly increase the risk of developing severe illness. Our study provides preliminary insights into the effect of SARS-CoV-2 on immune reconstitution and the outcomes of allo-HSCT recipients.

Longevity of the humoral and cellular responses after SARS-CoV-2 booster vaccinations in immunocompromised patients.

We assessed the humoral and cellular immune responses after two booster mRNA vaccine administrations [BNT162b2 (Pfizer-BioNTech vaccine)] in cohorts of immunocompromised patients (n = 199) and healthy controls (HC) (n = 54). All patients living with HIV (PLWH) and chronic kidney disease (CKD) patients and almost all (98.2%) of the primary immunodeficiency (PID) patients had measurable antibodies 3 and 6 months after administration of the third and fourth vaccine dose, comparable to the HCs. In contrast, only 53.3% and 83.3% of the multiple sclerosis (MS) and rheumatologic patients, respectively, developed a humoral immune response. Cellular immune response was observed in all PLWH after administration of four vaccine doses. In addition, cellular immune response was positive in 89.6%, 97.8%, 73.3% and 96.9% of the PID, MS, rheumatologic and CKD patients, respectively. Unlike the other groups, only the MS patients had a significantly higher cellular immune response compared to the HC group. Administration of additional vaccine doses results in retained or increased humoral and cellular immune response in patients with acquired or inherited immune disorders.

Dual anti-viral treatment for persistent COVID-19 in immunocompromised hemato-oncological patients is associated with a favorable prognosis and minor side effects.

In hemato-oncological patients, COVID-19 can present as a persistent infection with ongoing symptoms and viral replication over a prolonged period of time. Data are scarce on the preferred treatment options for these patients. We describe our experience with a five-day course of dual anti-viral treatment with remdesivir and nirmatrelvir/ritonavir for hemato-oncological immunocompromised patients with persistent COVID-19. Fifteen patients with a history of lymphoma, CLL, and MM were included. Eight were male, median age was 74. All patients had an immediate clinical and virological response. In 73 % of patients, PCR for SARS-CoV-2 became negative at the end of treatment and the rest had an increase in PCR cycle threshold (CT) values, with a median increase of 6 cycles. After a follow-up of three months, 60 % of patients remained in full clinical and virological remission. None required invasive mechanical ventilation or died. The side effects we observed, neutropenia, lactatemia and elevated transaminases, were mild and almost all transient in nature. We conclude that dual anti-viral treatment appears to be a valid treatment option for persistent COVID-19.

Low-Dose vs Conventional-Dose Trimethoprim-Sulfamethoxazole Treatment for Pneumocystis Pneumonia in Patients Not Infected With HIV: A Multicenter, Retrospective Observational Cohort Study.

BACKGROUND: Trimethoprim-sulfamethoxazole (TMP-SMX) is an effective treatment for Pneumocystis jirovecii pneumonia (PCP) in immunocompromised patients with and without HIV infection; however, a high incidence of adverse events has been observed. Low-dose TMP-SMX is a potentially effective treatment with fewer adverse events; however, evidence is limited. RESEARCH QUESTION: What is the efficacy and safety of low-dose TMP-SMX for non-HIV PCP compared with conventional-dose TMP-SMX after adjusting for patient background characteristics? STUDY DESIGN AND METHODS: In this multicenter retrospective cohort study, we included patients diagnosed with non-HIV PCP and treated with TMP-SMX between June 2006 and March 2021 at three institutions. The patients were classified into low-dose (TMP < 12.5 mg/kg/d) and conventional-dose (TMP 12.5-20 mg/kg/d) groups. The primary end point was 30-day mortality, and the secondary end points were 180-day mortality, adverse events grade 3 or higher per the Common Terminology Criteria for Adverse Events v5.0, and initial treatment completion rates. Background characteristics were adjusted using the overlap weighting method with propensity scores. RESULTS: Fifty-five patients in the low-dose group and 81 in the conventional-dose group were evaluated. In the overall cohort, the average age was 70.7 years, and the proportion of women was 55.1%. The average dose of TMP-SMX was 8.71 mg/kg/d in the low-dose group and 17.78 mg/kg/d in the conventional-dose group. There was no significant difference in 30-day mortality (6.7% vs 18.4%, respectively; P = .080) or 180-day mortality (14.6% vs 26.1%, respectively; P = .141) after adjusting for patient background characteristics. The incidence of adverse events, especially nausea and hyponatremia, was significantly lower in the low-dose group (29.8% vs 59.0%, respectively; P = .005). The initial treatment completion rates were 43.3% and 29.6% in the low-dose and conventional-dose groups (P = .158), respectively. INTERPRETATION: Survival was similar between the low-dose and conventional-dose TMP-SMX groups, and low-dose TMP-SMX was associated with reduced adverse events in patients with non-HIV PCP.

Impact of bronchoalveolar lavage on the management of immunocompromised hosts.

BACKGROUND: Respiratory infections are an important cause of morbidity and mortality in immunocompromised individuals. Fiberoptic bronchoscopy with bronchoalveolar lavage (BAL) is an important tool to detect infectious agents in immunocompromised patients with low respiratory tract infections (LRTI). RESEARCH QUESTION: BAL changes the management of immunocompromised patients with suspected LRTI. STUDY DESIGN AND METHODS: Immunocompromised patients with a suspicion of LRTI underwent diagnostic BAL. The primary composite outcome consisted of pre-defined modifications in the management of the immunocompromised patients following BAL. We quantified the impact of bronchoscopy up to 30 days after the procedure. RESULTS: A total of 2666 visits from 1301 patients were included in the study and immunosuppression was classified as haematological (n = 1040; 544 patients), solid organ transplantation (n = 666; 107 patients) and other causes (n = 960; 650 patients). BAL led to a change in management in 52.36% (n = 1396) of all cases. This percentage, as well as the 30-day mortality differed significantly amongst the three groups. Age, C-reactive protein and aetiology of infection determined significantly the risk of 30-day mortality in all patients. In 1.89% (n = 50) of all cases, a combination of 2 respiratory viral agents was identified and 24.23% (n = 646) were diagnosed with a single respiratory viral agent. INTERPRETATION: BAL leads to changes in management in the majority of immunosuppressed patients. There is a high prevalence of multimicrobial infections and respiratory viral infections in immunocompromised patients with respiratory symptoms. Individual virus infection is associated with diverse risk of a negative outcome.

Efficacy and safety of tixagevimab-cilgavimab versus SARS-CoV-2 breakthrough infection in the hematological conditions.

BACKGROUND: Managing SARS-CoV-2 infection in frail and immunosuppressed patients still represents an open challenge, but, starting from the phase 3 PROVENT study, prophylaxis with tixagevimab-cilgavimab has improved the approach in this category of patients, guaranteeing a better outcome and inferior mortality. Real-life data in a heterogeneous cohort are few. METHODS: The aim of this study is to evaluate the benefit of prophylaxis with tixagevimab-cilgavimab in a cohort of 202 patients affected by different hematological diseases (lymphoproliferative, myeloproliferative, autoimmune, patients recently receiving a bone marrow transplant), active (with ongoing treatment), or in watch-and-wait strategy, followed in our center, during a median follow-up of 249 (45-325) days. RESULTS: An incidence of 44 breakthrough infections (21.8%) is reported, with no treatment-related adverse effects. Age ≥70 years, ongoing treatment (above all with monoclonal antibodies), baseline lymphoproliferative disorders, and prior virus exposure are identified as risk factors related to subsequent infection (p < 0.05). Moreover, the incidence is higher in low/nonresponse to prior vaccination (p = .002). Patients treated with tixagevimab-cilgavimab had a mild course of the infection and a reduction of the duration compared with preprophylaxis infection (11 vs. 15 days, p < .001). The concurrent treatment with anti-CD20 monoclonal antibodies and B-non-Hodgkin lymphoma still confers a higher duration of infection despite prophylaxis. No deaths attributable to the infection occurred. CONCLUSION: Prophylaxis treatment seems to be a valid and safe strategy, although not preventing breakthrough infection, but the severe complications associated with the infection and the possible delays in administering lifesaving therapies from long positivity.

Stenotrophomonas maltophilia outbreak originating from a pull-out faucet in a pediatric intensive care unit in Turkey: Insights from clinical records and molecular typing.

BACKGROUND: Nosocomial Stenotrophomonas maltophilia-related cases are rising and pose a threat to immunocompromised patients. Twelve patients from our pediatric intensive care unit (PICU) presented with S maltophilia-associated bloodstream infection. METHODS: This outbreak investigation includes 12 patients from PICU between the ages of 2 months and 4 years (mean 16 months, 7 male). To identify the origin, samples from all possible sources throughout the hospital were collected and ran through DNA isolation and Pulse Field Gel Electrophoresis. RESULTS: 120 samples were collected during the outbreak. 31 samples (26%) were positive for S maltophilia. 30 S maltophilia isolates were analyzed, 10 different genotypes were identified. Clustering isolates were grouped into 3 different clusters (tolerance and optimization 1.0, cutoff 90%). The largest cluster was genotype 1, which included 19 isolates, those belong to patients' samples and a sample from a pull-out faucet inside the PICU. The Pull-out faucet was the origin of the bloodstream infection. DISCUSSION: Pull-out faucets allow biofilm production, due its structure. Pulse Field Gel Electrophoresis identifies the transmission dynamics of the outbreak, with its high discriminatory power. CONCLUSIONS: Water sources should be monitored on a regular basis. Pull-out faucets enable bacterial overgrowth; therefore, we recommend water surveillance during outbreak investigations.

Impact of the multiplex molecular FilmArray Respiratory Panel on antibiotic prescription and clinical management of immunocompromised adults with suspected acute respiratory tract infections: A retrospective before-after study / Impacto del panel respiratorio molecular multiplex FilmArray ¿ en la prescripción de antibióticos y el manejo clínico de pacientes adultos inmunocomprometidos con sospecha de infección respiratoria aguda: un estudio retrospectivo antes/después

Abstract This study aimed to assess the impact of the implementation of a rapid multiplex molecular FilmArray Respiratory Panel (FRP) on the medical management of immunocompromised patients from a community general hospital. We conducted a single-center, retrospective, and before-after study. Two periods were evaluated: before the implementation of the FRP (pre-FRP) from April 2017 to May 2018 and after the implementation of the FRP (post-FRP) from January to July 2019. The inclusion criteria were immunocompromised patients over 18 years of age with suspected acute respiratory illness tested by conventional diagnostic meth-ods (pre-FRP) or the FilmArray™ Respiratory Panel v1.7 (post-FRP). A total of 142 patients were included, 64 patients in the pre-FRP and 78 patients in the post-FRP. The positive detec-tion rate was significantly higher in the post-FRP (63% vs. 10%, p <0.01). There were more patients receiving antimicrobial treatment in the pre-FRP compared with the post-FRP period (94% vs. 68%, p <0.01). A decrease in beta-lactam (89% vs. 61%, p <0.01) and macrolide (44% vs. 13%, p < 0.01) prescriptions were observed in the post-FRP. No differences were observed in oseltamivir use (22% vs. 13%, p = 0.14), changes in antimicrobial treatment, hospital admission rate, days-reduction in droplet isolation precautions, hospital length of stay (LOS), admission to intensive care unit (ICU), LOS in ICU, treatment failure and 30-day mortality. The implementa-tion of the FRP impacted patient care by improving diagnostic yield and optimizing antimicrobial treatment in immunocompromised adult patients.

Resumen El objetivo de este estudio fue evaluar el impacto de la implementación del panel respiratorio FilmArray® (FRP), un sistema automatizado de PCR multiplex, en el estándar de cuidado de pacientes adultos inmunocomprometidos en un hospital general. Es un estudio retrospectivo de un único centro con diseno antes/después. Los periodos evaluados fueron abril 2017-mayo 2018, previo a la implementación del FRP (pre-FRP), y enero 2019-julio 2019, luego de la implementación (post-FRP). Los criterios de inclusión fueron pacientes mayores de 18 años inmunocomprometidos con sospecha de infección respiratoria aguda a los que se les realizó, en pre-FRP, diagnóstico por métodos convencionales, y en post-FRP, el panel respiratorio FRP versión 1.7. Se incluyeron un total de 142 pacientes, 64 en pre-FRP y 78 en post-FRP. La tasa de positividad fue significativamente mayor en post-FRP frente a pre-FRP (63 vs. 10%, p<0,01). Hubo más pacientes con tratamiento antimicrobiano en pre-FRP que en post-FRP (94 vs. 68%, p <0,01). En pre-FRP hubo más pacientes tratados con betalactámicos (89 vs. 61%, p <0,01) y macrólidos (44 vs. 13%, p < 0,01). No se observaron diferencias significativas en el uso de oseltamivir (22 vs. 13%, p = 0,14), cambios en los tratamientos, número de hospitalizaciones, uso de aislamientos, duración de la estadía hospitalaria, ingreso a la unidad de cuidados intensivos, estadía en dicha unidad, falla de tratamiento y mortalidad a 30 días. El uso de FRP contribuyó a la atención del paciente mejorando el rendimiento diagnóstico y optimizando la terapia antimicrobiana en pacientes adultos inmunocomprometidos.

Features of Interferon Status and Methods of Its Correction in the Treatment of Patients with Atypical Chronic Active Herpesvirus Infections.

It is known that the imbalance of the IFN system is the cornerstone of the immunopathogenesis of atypical chronic active herpesvirus infections and is often associated not only with congenital, genetically determined defects, but also with acquired system dysregulation at different levels: receptor, molecular, at the level of a nuclear transducer of signal transmission. Based on the studied features of immunopathogenesis and the revealed disturbances in the antiviral immune defense system and the IFN system in patients with atypical chronic herpes viral infections, an integration program for correcting IFN status was developed, its clinical and immunological effectiveness was evaluated. Improved effectiveness of complex rehabilitation of immunocompromised patients with atypical chronic active herpes viral infections was demonstrated.