Urinary Antigen Test Research Articles

P439 Biomarker detection for the diagnosis of disseminated histoplasmosis in people living with HIV/ AIDS in Southern Brazil: a year of implementation

Poster session 3, September 23, 2022, 12:30 PM - 1:30 PMBackground: Disseminate histoplasmosis (DH) is an important opportunistic disease in HIV/AIDS patients.Objective: We aimed to report partial results of the implementation of the Histoplasma urinary biomarker as a routine test for the diagnosis of DH in people living with HIV/AIDS (PLWHA) admitted to a reference hospital in Southern Brazil.MethodsThe study was performed in a tertiary hospital, which is recognized as a regional reference center to 21 cities for the treatment of PLWHA. At this service, since the beginning of 2021, a new protocol for DH investigation was adopted, including the systematic execution of urinary antigen test for histoplasmosis (Histoplasma GM EIA, IMMY®) in PLWHA. We retrospectively evaluated data from all of these patients diagnosed with DH in the last 1 year, between March 2021 and March 2022. The study was approved by our university ethics committee (CEP/FURG; N° 234/2018).ResultsWithin the 12 months period, 243 patients from our hospital were investigated by Histoplasma GM EIA through urine samples. A total of 19 were diagnosed with DH through this test, resulting in a prevalence of 7.8%. Interestingly, nine of them were also investigated by antibody detection through immunodiffusion test (IMMY), being all negative in this serology. DH was the AIDS-defining illness in 21% of these patients (4/19), and co-infection with Mycobacterium tuberculosis was detected in 37% (7/19). Half of the patients (11/19) were severe immunosuppressed (CD4 + lymphocytes <100 cells/mm3), 21% (n = 4) had rates between 100 and 200 cells/mm3 and 21% (n = 4) had >200 cells/mm3. The majority of the patients (74%; n = 14) had advanced signs of DH, showing pulmonary impairment, weight loss, fever, neurological, and/or skin lesions and lymphadenopathy, suggesting late diagnosis, 16% (3/19) of the patients had few signs of DH (suggesting precocity), and two patients were diagnosed before the onset of the clinical manifestation, with the strategy of the use of GM Histoplasma EIA as a screening test. Although the antifungal treatment, five of them (35.7%) died.ConclusionThe systematic use of the test to detect a specific biomarker in urine samples had improved substantially the diagnosis of DH in PLWHA in our hospital (19 cases in one year). In addition, since we could diagnose DH with precocity in five patients, we suggest that in regions where DH is hyperendemic, the GM Histoplasma EIA could be used as a screening test for all AIDS patients, similar to what is preconized to cryptococcal disease. More robust studies are instigated to evaluate this strategy, and its benefits to an early diagnosis, resulting in a better quality of life, better prognosis, and consequently reduction of the mortality rate.

Microbiological findings and prescribing trends in SARS- CoV-2 positive patients in two United Kingdom Hospitals

ObjectiveTo describe antibiotic prescribing and microbiological findings in patients admitted to two London hospitals with COVID-19.MethodsThis is a retrospective review of confirmed SARS-CoV-2 infected adults admitted between 9th February and 10th May 2020. Demographics, critical care unit (CCU) admission, antibiotic prescribing and microbiology results within 10 days of COVID-19 diagnosis were analysed.Results1155 patients were identified. 32.9% (380) died. 12.4% (143) had positive microbiology. After excluding likely contaminants, 6.9% (80) had clinically significant microbiology. The most common organisms isolated from blood cultures were Escherichia coli 9.5% (7), Klebsiella pneumoniae 4.0% (3), and Staphylococcus aureus 2.7% (2). A high percentage of blood cultures yielded coagulase negative staphylococci (51/74, 68.9%) and likely represented contamination. Organisms isolated from lower respiratory tract samples included Candida albicans 44.4% (12), Staphylococcus aureus 22.2% (6), Klebsiella species 11.0% (3), Pseudomonas aeruginosa 11.0% (3), and Citrobacter species 11% (3). Legionella and pneumococcal urinary antigen tests were positive in 0/117 and 2/71 (2.8%) samples. 91% (1051) of patients received antibiotics. Clarithromycin (24.2% total antibiotic use) and amoxicillin (21%) were most frequently used, followed by piperacillin-tazobactam (12.6%), gentamicin (10.6%), co-amoxiclav (9.3%) and meropenem (3.2%). Piperacillin-tazobactam or meropenem use was associated with a higher length of stay and mortality.ConclusionsPositive microbiology in COVID-19 patients is uncommon. Antibiotic use was widespread, despite lack of microbiological evidence of co-infection. When present, positive microbiology was more likely due to gram negative bacteria. Current local clinical and antimicrobial guidelines have incorporated these findings and recommend against routine antibiotic use in COVID-19 patients.

Diagnostic accuracy of urinary antigen tests for pneumococcal pneumonia among patients with acute respiratory failure suspected pneumonia: a systematic review and meta-analysis

Background/objectivesUrinary antigen tests have been used for the rapid identification of Streptococcus pneumoniae infection in patients with pneumonia, thereby leading to earlier targeted therapy than when using conventional diagnostic culture...

Risk of Legionnaires' Disease from Cleaning Grease Traps

A 61-year-old man presented with a 3-days' history of fever and headache. On admission, his body temperature was 40°C, pulse rate was 99/min, and respiratory rate was 25/min. Serum CRP was elevated, and chest X-ray showed an opacity in the left upper lung field. Under the suspected diagnosis of community-acquired pneumonia, the patient was initiated on treatment with ampicillin/sulbactam, and oxygen supplementation via a nasal cannula at 2L/min. A review of the history revealed that his current occupation was maintenance of grease traps, which are chambers for removing grease from food waste before it enters the sewer pipe. Four days before onset of his symptoms, he had worked on a very dirty restaurant grease trap while wearing a poorly equipped face mask. Legionnaires' disease was suspected, and urinary antigen testing revealed a positive result. Sputum culture and PCR were also positive for Legionella pneumophila serogroup 1, the most common causative Legionella genus of acute pneumonic illness. The antibiotic was switched to intravenous levofloxacin at 500mg/day on day 2 of admission, and the patient's symptoms improved.

Diagnostic toolkit for tuberculosis: should we include urine lipoarabinomannan (LAM) detection in the WHO European Region?

Diagnostic toolkit for tuberculosis: should we include urine lipoarabinomannan (LAM) detection in the WHO European Region?

Bacterial etiology and pneumococcal urinary antigen in moderate exacerbation of chronic obstructive pulmonary disease.

BackgroundThis study aimed to establish nationwide data for the distributions of typical and atypical bacterial pathogens in Korean patients with moderate acute exacerbations of chronic obstructive pulmonary disease (AECOPD) and evaluate the clinical usefulness of a urinary antigen test (UAT) to detect Streptococcus pneumoniae.MethodsThis study was a post hoc analysis of a randomized controlled trial designed to compare oral zabofloxacin with moxifloxacin for treating outpatients with moderate AECOPD. From clinics across South Korea, 342 subjects with AECOPD were enrolled, and their blood, sputum, and urine samples were collected at baseline. A serologic test, sputum culture and polymerase chain reaction (PCR), and UAT were performed to identify bacterial pathogens. Bacterial prevalence and regional distributions were analyzed. The patients’ characteristics and clinical response between UAT-positive and UAT-negative groups were compared, as were the Streptococcus pneumoniae detection rates using conventional sputum culture and PCR versus UAT.ResultsThe most commonly isolated pathogen was Haemophilus influenzae (30.3%), followed by Streptococcus pneumoniae (24.7%) and Pseudomonas aeruginosa (14.0%), with no significant regional differences in bacterial distribution. Patients with positive UAT for Streptococcus pneumoniae showed no clinical failure when treated with respiratory quinolone (0.0%), whereas 11.8% of patients with negative UAT showed clinical failure (P=0.037). UAT showed moderate agreement with sputum culture by kappa coefficient (κ=0.476).ConclusionsThe bacterial prevalence in patients with moderate AECOPD in South Korea showed correlations with the global prevalence, without significant regional differences. In outpatient settings, UAT has the potential to be used as a supplemental tool with sputum culture as a guide for determining the suspicion of bacterial exacerbation.

Clinical Presentation of Legionella pneumophila Serogroup 1-Associated Pneumonia and Diffuse Alveolar Hemorrhage: A Case Report and Literature Review

Patient: Female, 44-year-old Final Diagnosis: Legionella pneumophila serogroup 1-associated pneumonia and diffuse alveolar hemorrhage Symptoms: Dyspnea Medication:— Clinical Procedure: Bronchoalveolar lavage Specialty: Infectious Diseases Objective: Rare disease Background:We report a case of diffuse alveolar hemorrhage (DAH) caused by Legionella pneumophila serogroup (SG) 1 and review the existing literature to identify risk factors and determine the prognosis of patients with Legionella pneumonia-associated DAH.Case Report:A 44-year-old woman was admitted to our hospital following the presentation of dyspnea for a few days. Chest computed tomography (CT) findings revealed “crazy-paving” pattern in the right upper lobe implicating DAH and consolidation in the lower lobe. Analysis of the bronchoalveolar lavage (BAL) fluid revealed DAH, with further analyses identifying L. pneumophila SG 1 as the causative agent. The patient was successfully treated with levofloxacin and a red blood cell transfusion and discharged on the 32nd day of hospitalization. A literature review of 6 reported cases (including our case) of Legionella pneumonia-associated DAH revealed that the median age of patients with DAH was 59 years (range, 44–75 years), involving female patients in 4 cases (67%) and the use of immunosuppressive drugs in 2 cases (33%). Three cases were BAL Legionella polymerase chain reaction (PCR)-positive and 4 cases were diagnosed using a urinary Legionella antigen test (one case was simultaneously PCR-positive). These infections were caused by L. pneumophila SG 1 in three cases and SG 3 in one case. Mechanical ventilation was used in 5 cases (83%) and one patient had an unfavorable prognosis. Steroids for DAH were used in 5 cases (83%), and 2 cases responded to this treatment.Conclusions:Our case highlights that clinicians should be aware of Legionella spp. as a cause of DAH in an immunocompe-tent host with “crazy-paving” pattern on chest CT, and perform a urinary antigen test and BAL PCR for diagnosis.

Cerebellar syndrome associated with legionellosis: A case report and literature review

IntroductionLegionnaire's disease is a community-acquired pneumonia caused by the Gram-negative bacterium Legionella pneumophila. This disease is often associated with neurological symptoms, the clinical presentation of which can be very varied. Case reportWe report a 47-year-old female patient who developed Legionnaires’ disease with cerebellar symptoms (ataxia, dysarthria and hypermetria). Laboratory tests revealed a biological inflammatory syndrome. The cerebrospinal fluid was sterile. Urinary antigen test and serology were positive for L. pneumophila. An interstitial syndrome of the right upper lobe was detected on chest computed tomography (CT) scan. Brain imaging (magnetic resonance imaging and CT angiography) showed no abnormalities. The outcome was favourable after treatment with spiramycin, levofloxacin and corticosteroids. DiscussionFew cases only (n=110) of Legionnaires’ disease with cerebellar symptoms have been reported in the literature. The pathogenic mechanism behind neurological dysfunction in patients with Legionnaires’ disease is unknown. Neurological symptoms improve with antibiotic therapy and corticosteroids. Extra-pulmonary forms of Legionnaires’ disease are frequent, with neurological symptoms being the most common symptoms. Cerebellar dysfunction may be underestimated and requires appropriate management with antibiotic therapy and corticosteroid therapy. Recommendations for the management of Legionnaire's disease with severe extra-pulmonary symptoms are needed.

Acute fibrinous and organizing pneumonia in a patient with Sjögren’s syndrome and Legionella pneumonia: a case report and literature review

BackgroundAcute fibrinous and organizing pneumonia (AFOP) is a rare clinicopathological condition. Studies in the literature have reported that AFOP may be associated with respiratory infections, such as respiratory syncytial virus, influenza virus, Pneumocystis jirovecii, Penicillium citrinum, and Chlamydia infections. However, AFOP associated with Legionella infection has not been reported previously. Here, we report a case of a patient with AFOP secondary to Sjögren’s syndrome and Legionella infection.Case presentationA 47-year-old man was admitted to the hospital because of fever, expectoration, and shortness of breath. Lung imaging showed irregular patchy consolidation. A diagnosis of Legionella pneumonia was initially considered on the basis of the patient’s history of exposure to soil before disease onset, signs of extrapulmonary involvement, and a positive Legionella urine antigen test result. However, the patient’s symptoms and lung imaging did not improve after treatment with levofloxacin, moxifloxacin, and tigecycline for Legionella infection. In addition, Sjögren’s syndrome was diagnosed on the basis of clinical manifestations and immunological indicators. Pathological changes associated with AFOP were confirmed from the results of ultrasound-guided percutaneous lung biopsy. The patient’s clinical symptoms improved rapidly after a short course of low-dose corticosteroid therapy, and lung imaging showed significant improvement.ConclusionsThe possibility of secondary AFOP should be considered when Legionella pneumonia does not improve after standard antibiotic therapy. Lung biopsy and histopathological examination are important for the adjustment of treatment strategy. Our case also highlights the importance of screening for autoimmune diseases in patients with AFOP.

Pneumococcal urinary antigen testing for antimicrobial guidance in community-acquired pneumonia–A register-based cohort study

ObjectivesTo evaluate the effect of pneumococcal urinary antigen test (UAT) usage on broad-spectrum antibiotic treatment in community-acquired pneumonia (CAP). MethodsPatients admitted to 32 Swedish hospitals between 2011 and 2014 were retrospectively included from the Swedish National Quality Register of CAP. Using propensity score matched data, stratified by CRB-65 score, we studied the effect of performing UAT and of positive test results on treatment with broad-spectrum β-lactam monotherapy (BSBM) and antibiotics with coverage for atypical bacteria compared to narrow-spectrum β-lactam monotherapy (NSBM). ResultsUAT was performed for 4,995/14,590 (34.2%) patients, 603/4,995 (12.1%) of whom had positive test results. At day three, performing UAT was not associated with decreased use of BSBM (OR 1.07, 95% CI 0.94–1.23) but was associated with increased atypical coverage among patients with CRB-65 score 2 (OR 1.47, 95% CI 1.06–2.02). A positive UAT was associated with decreased BSBM use (OR 0.39, 95% CI 0.25–0.60) and decreased atypical coverage (OR 0.25, 95% CI 0.16–0.37), predominantly in non-severe CAP. At day one, performing UAT was associated with atypical coverage among patients with CRB-65 scores 2 (OR 2.60, 95% CI 1.69–3.98) and 3–4 (OR 3.69, 95% CI 1.55–8.79), and a positive test reduced the odds of BSBM treatment among CRB-65 score 3–4 patients (OR 3.49, 95% CI 1.02–12.0). ConclusionsPerforming UAT had no overall effect on decreasing the use of BSBM treatment by day three of hospitalization, yet non-severely ill patients with positive UAT results were less likely to be treated with BSBM and antibiotics with atypical coverage.

A Legionella’s outbreak in a COVID-19 pandemic setting

In this report, the author intends to reinforce the need to test for another potencial causes of pneumonia which present with similar symptoms of SARS-CoV-2 infection and can also be responsible for outbreaks and sometimes fatal, particularly Legionnaires’ disease. Legionellabacteria are aerobic, gram-negative, ubiquitous freshwater and soil inhabitants. Pneumonia is the most commonly described manifestation of Legionella infection (Legionnaires’ disease), acquired through inhalation of aerosolized water droplets containing the bacteria. Legionella pneumophilais the most consistently reported species, being an important cause of severe community-acquired pneumonia that often requires hospitalization and is fatal in approximately 10% of cases. Most cases present sporadically, however, outbreaks can occur when there are appropriate conditions for bacteria to grow and spread, like stagnating water in piping systems in large facilities. Furthermore, the pathogenesis of Legionella pneumonia is complex and it is clinically and radiographically similar to other forms of pneumonia. In the context of pandemic COVID-19, the use of Legionella urinary antigen testing continues to be crucial and strongly recommended. Thus, in the outbreak faced in the author’s hospital, this screening method proved to be effective and all cases of Legionellapneumonia were promptly recognized and notified, allowing public health measures to be taken to prevent the development of other potencial clusters.

Application of Urine and Copro Antigen Assays after Primary Infection and Drug Treatment in an Experimental Opisthorchiasis Animal Model.

Infection by Opisthorchis viverrini causes significant health problems, including cholangiocarcinoma (CCA); thus control and elimination of this trematode is an important strategy for the reduction of CCA. Currently, urine and copro antigen detection is more sensitive than parasitological examination of the feces for the diagnosis of opisthorchiasis. Given limitations in human studies, we used an animal model to quantify the parasite antigen profiles in urine and feces in O. viverrine-infected hamsters, and postdrug treatment. The positive detections of O. viverrini antigen began from week 1 in urine and week 2 in feces after infection until week 28 of the study. The recoveries of O. viverrini worms were detected starting from week 1 and eggs of O. viverrini were detected in feces from week 3 after infection and remained detectable throughout the study period. There was a significant positive correlation of urine and copro antigen levels with the number of fecal egg counts (P < 0.01) and worm recovery (P < 0.01). In the drug-treatment experiment, treatment of infected hamsters with praziquantel significantly reduced worm burden, fecal egg output, and antigen in urine and feces compared with the untreated controls (P < 0.001). At 4 weeks posttreatment, the egg and worm reduction rates were 100% and 95.5%, respectively. The positive antigen detections in urine and feces corresponded with partial worm clearance from praziquantel treatment. This study demonstrated a direct link of urine and copro antigen tests with worms infecting the liver thereby reaffirming the reliability of urine and copro antigen assay in opisthorchiasis diagnosis.

Mandibular Blastomycosis in a 5-Year-Old Dog.

A case of localized oral mandibular blastomycosis is described in a five-year-old dog. Complete resolution of clinical signs and oral radiographic changes were seen following itraconazole therapy at 5 mg/kg/day for four and a half months. The patient remained free of Blastomyces at the one year follow up based on the Mira Vista Blastomyces urine antigen test by EIA (Enzyme Immunoassay)a. A literature review of localized blastomycosis cases in humans and dogs was performed, available diagnostic tests evaluated, and treatment comparisons made.

Legionnaires' disease - a qualitative study on Swiss physicians' approaches to the diagnosis and treatment of community-acquired pneumonia.

The number of reported cases of Legionnaires' disease has increased significantly over the last decade in Switzerland and abroad. Along with the number of cases, the volume of testing has increased as well, which has been partially attributed to a change in awareness of the disease. Yet, while there are numerous guidelines and recommendations for the case management of community-acquired pneumonia, little is known about how physicians in Switzerland perceive and manage Legionnaires' disease. This study aimed to investigate physicians' awareness of Legionnaires' disease, their information resources and their approach to the diagnosis and treatment of pneumonia (and thus Legionnaires' disease). Using a semi-structured interview guide, we conducted in-depth interviews with physicians from different levels of care and from the German-, French- and Italian-speaking regions of Switzerland. We conducted 46 interviews with physicians from university, cantonal and regional hospitals as well as with general practitioners (GPs) from all three language regions. Overall, the physicians working in hospitals indicated a similar level of awareness of Legionnaires' disease, and comparable diagnosis and treatment approaches. The Legionella urine antigen test (UAT) was reported to be routinely performed in inpatients. In contrast, GPs indicated lower levels of awareness, reflecting the fact that they treat pneumonia cases empirically without identification of the causative agent, in accordance with current guidelines. The value of the diagnostic tests in general and the Legionella UAT in particular was considered to be dependent on the (preferred) antibiotic treatment approach. Some physicians saw the test as redundant, as its result would not influence treatment. This was tied to concerns about the UAT's sensitivity and its limited use for the detection of Legionella pneumophila serogroup 1. Lastly, extrinsic constraints, such as financial and time considerations also affected physicians' testing and treatment preferences. Awareness of Legionnaires' disease is overall high, yet cases are mainly diagnosed and reported by hospitals. Improved diagnostic tools are needed to support physicians in reducing underestimation of Legionnaires' disease and optimise antibiotic stewardship without compromising patient health outcomes.

Association of Natural Waterways and Legionella pneumophila Infection in Eastern Wisconsin: A Case-Control Study.

Preliminary research has suggested possible associations between natural waterways and Legionella infection, and we previously explored these associations in eastern Wisconsin using positive L. pneumophila serogroup 1 urine antigen tests (LUAT) as diagnostic. This case-control study was a secondary analysis of home address data from patients who underwent LUAT at a single eastern Wisconsin health system from 2013 to 2017. Only zip codes within the health system's catchment area that registered ≥3 positive cases and ≥50 completed tests, as well as geographically adjacent zip codes with ≥2 positive cases and ≥50 tests, were included. A 1:3 ratio of cases to randomly selected controls was used. Home addresses were geocoded and mapped using ArcGIS software (Esri); nearest waterway and distance to home was identified. Distance to nearest waterway according to ArcGIS was verified/corrected using Google Maps incognito. Distances were analyzed using chi-squared and 2-sample t-tests. Overall, mean distance to nearest waterway did not differ between cases (2958 ± 2049 ft) and controls (2856 ± 2018 ft; P=0.701). However, in a subset of nonurban zip codes, cases were closer to nearest waterway than controls (1165 ± 905 ft vs 2113 ± 1710 ft; P=0.019). No association was found between cases and type of waterway. Further research is needed to investigate associations and differences between natural and built environmental water sources in relation to legionellosis.

Severe community-acquired pneumonia in Reunion Island: Epidemiological, clinical, and microbiological characteristics, 2016-2018.

No data are available on severe community-acquired pneumonia (CAP) in the French overseas department of Reunion Island. This is unfortunate as the microorganisms responsible for the disease are likely to differ from those in temperate regions due to a tropical climate and proximity to other islands of the Indian Ocean region. The aim of this study was to assess the epidemiological, clinical, prognosis, and microbiological characteristics of patients with severe CAP in Reunion Island. This retrospective study evaluated all patients with CAP aged >18 years and hospitalized in one of the two intensive care units of Reunion Island between 2016 and 2018. Microorganisms were identified by culture from blood and respiratory samples, multiplex polymerase chain reaction from respiratory samples, urinary antigen tests, and serology. Over the study period, 573 cases of severe CAP were recorded, with a mean incidence of 22 per 100,000 person-years. The most frequently isolated microorganism was influenza (21.9%) followed by Streptococcus pneumoniae (12%). The influenza virus was detected in affected patients all year round. Twenty-four patients with severe CAP came from another island of the Indian Ocean region (4.2%), mainly Madagascar (>50%). Two of these patients presented with melioidosis and 4 were infected with Acinetobacter spp. Our findings have major implications for the management of severe CAP in tropical regions. The most frequently isolated microorganism in patients with severe CAP in Reunion Island is influenza followed by S. pneumoniae. Physicians should be aware that influenza is the main cause of severe CAP in patients living in or returning from Reunion Island, where this virus circulates all year round.

Urinary Antigen Testing for Respiratory Infections: Current Perspectives on Utility and Limitations.

Pneumonia is a leading cause of hospitalization and death due to infection worldwide. Streptococcus pneumoniae and Legionella pneumophila remain among the most commonly identified bacterial pathogens. Unfortunately, more than half of all pneumonia cases today lack an etiologic diagnosis due to limitations in traditional microbiological methods like blood and sputum cultures, which are affected by poor sample collection, prior antibiotic administration, and delayed processing. Urinary antigen tests (UATs) for S. pneumoniae and L. pneumophila have emerged as powerful tools for improving the diagnosis of bacterial respiratory infections, enabling physicians to administer early directed therapy and improve antimicrobial stewardship. UATs are simple, rapid, and non-invasive diagnostic tests with high specificity (>90%) and moderate sensitivity (<80%). The potential impact of urinary antigen testing is especially significant for respiratory infections caused by Legionella. While all recommended community-acquired pneumonia (CAP) therapies are adequate for treating pneumococcal pneumonia, only certain antibiotics are effective against Legionella. Delayed therapy for Legionella is associated with worse clinical outcomes, which underscores the importance of rapid diagnostic methods like UATs. Despite their potential impact, current American Thoracic Society and Infectious Diseases Society of America (ATS/IDSA) guidelines argue against the routine use of urinary antigen testing for S. pneumoniae and L. pneumophila, except in patients with severe CAP and those with epidemiological risk factors for Legionella. Further research is necessary to evaluate the impact of early targeted treatment due to positive UAT results, as well as optimal strategies for UAT utilization. The purpose of this review is to summarize the UATs available for bacterial respiratory infections, describe current guidelines on their usage, and assess their impact on clinical outcomes and targeted therapy.

New testing guidelines for community-acquired pneumonia.

The purpose of this article is to review diagnostic testing recommendations outlined in the current American Thoracic Society (ATS)/Infectious Diseases Society of America (IDSA) community-acquired pneumonia (CAP) guideline and the 2021 ATS guideline for noninfluenza respiratory viruses. Diagnostic testing in CAP with gram stain, lower respiratory and blood cultures, Streptococcal and Legionella urinary antigens are not routinely recommended unless identified as severe CAP or with risk factors for Methicillin-resistant Staphylococcus aureus (MRSA) or Pseudomonas aeruginosa infection. Influenza virus testing remains a strong recommendation during periods of community viral spread.An additional 2021 ATS clinical practice guideline reviewed the use of molecular testing for noninfluenza viral pathogens in adults with suspected CAP and recommended testing in those hospitalized with severe CAP and/or various immunocompromising conditions. Diagnostic testing remains an important component of confirming and treating CAP. The CAP guideline includes recommendations surrounding diagnostic testing with lower respiratory gram stain and culture, blood cultures, Legionella and Pneumococcal urinary antigen, influenza viral testing and serum procalcitonin.There is a strong recommendation to obtain influenza virus testing during periods of community spread. However, the use of other diagnostics such as gram stain, lower respiratory and blood culture, and urinary antigen testing are dependent on severity of illness and whether a patient has been identified as having strong risk factors for MRSA or P. aeruginosa infection. The 2021 ATS clinical practice document did not routinely recommend testing noninfluenza respiratory viruses unless identified as having severe CAP and/or various immunocompromising conditions.

Bacterial co-infection at hospital admission in patients with COVID-19

ObjectivesWe described the current incidence and risk factors of bacterial co-infection in hospitalized patients with COVID-19.MethodsObservational cohort study was performed at the Hospital Clinic of Barcelona (February 2020–February 2021). All patients with COVID-19 who were admitted for >48 hours with microbiological sample collection and procalcitonin (PCT) determination within the first 48 hours were included.ResultsA total of 1125 consecutive adults met inclusion criteria. Co-infections were microbiologically documented in 102 (9.1%) patients. Most frequent microorganisms were Streptococcus pneumoniae (79%), Staphylococcus aureus (6.8%), and Haemophilus influenzae (6.8%). Test positivity was 1% (8/803) for blood cultures, 10.1% (79/780) for pneumococcal urinary antigen test, and 11.4% (15/132) for sputum culture. Patients with PCT higher than 0.2, 0.5, 1, and 2 ng/mL had significantly more co-infections than those with lower levels (p=0.017, p=0.031, p<0.001, and p<0.001, respectively). In multivariate analysis, oxygen saturation ≤94% (OR 2.47, CI 1.57–3.86), ferritin levels <338 ng/mL (OR 2.63, CI 1.69–4.07), and PCT higher than 0.2 ng/mL (OR 1.74, CI 1.11–2.72) were independent risk factors for co-infection at hospital admission owing to COVID-19.ConclusionsBacterial co-infection in patients hospitalized for COVID-19 is relatively common. However, clinicians could spare antibiotics in patients with PCT values <0.2, especially with high ferritin values and oxygen saturation >94%.

Diagnostic accuracy of urinary antigen tests for legionellosis: A systematic review and meta-analysis.

Urinary antigen tests (UATs) have been used for the early detection of legionellosis and have demonstrated moderate sensitivity and high specificity. However, the most recent systematic review and meta-analysis published in 2009 evaluated the accuracy of UATs; since then, UAT accuracy may have changed owing to advances and developments in UAT technology and epidemiological changes in the frequency of Legionella species that cause legionellosis. Therefore, this systematic review and meta-analysis aimed to update the accuracy of UATs for legionellosis among patients with suspected pneumonia. Overall, 1326 studies were screened, 21 of which fulfilled the eligibility criteria for quality assessment and meta-analysis. Data from 5772 patients, including 1368 (23.7%) with the target condition (i.e., suspected legionellosis), were included in the analysis. The overall quality of the included studies, which was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool, was unclear. The calculated pooled sensitivity and specificity were 0.79 (95% confidence interval [CI], 0.71-0.85) and 1.00 (95% CI, 0.99-1.00), respectively. Subpopulation analysis revealed that the accuracy of UATs for sensitivity and specificity for Legionella pneumophilia serogroup 1 was 0.86 (95% CI, 0.78-0.91) and 1.00 (95% CI, 0.99-1.00), respectively. This study demonstrated that the sensitivity and specificity of UATs were moderate and high, respectively, which is comparable to the results reported in 2009. Therefore, UATs may be a useful method for the early detection of legionellosis caused by Legionella pneumophila serogroup 1. The review protocol was prospectively registered with the University Hospital Medical Information Network Clinical Trials Registry (UMIN000041080).