Evaluation of diagnostic accuracy of 10 serological assays for detection of SARS-CoV-2 antibodies.

Antibody detection is essential to establish exposure, infection, and immunity to SARS-CoV-2, as well as to perform epidemiological studies. The worldwide urge for new diagnostic tools to control the pandemic has led to a quick incorporation in clinical practice of the recently developed serological assays. However, as only few comparative studies have been published, there is a lack of data about the diagnostic accuracy of currently available assays. We evaluated the diagnostic accuracy to detect Ig G, Ig M+A, and/or IgA anti SARS-CoV-2 of 10 different assays: lateral flow card immunoassays, 4 enzyme-linked immunosorbent assay (ELISA), and 3 chemiluminescent particle immunoassays (CMIA). Using reverse transcriptase polymerase chain reaction (RT-PCR) for COVID-19 as gold standard, sensitivity, specificity, PPV, and NPV were determined. Each assay was tested in 2 groups, namely, positive control, formed by 50 sera from 50 patients with SARS-CoV-2 pneumonia with positive RT-PCR; and negative control, formed by 50 sera from 50 patients with respiratory infection non-COVID-19. Sensitivity range of the 10 assays evaluated for patients with positive COVID-19 RT-PCR was 40-77% (65-81% considering IgG plus IgM). Specificity ranged 83-100%. VPP and VPN were respectively 81-100% and 61.6-81%. Among the lateral flow immunoassays, the highest sensitivity and specificity results were found in Wondfo® SARS-CoV-2 Antibody Test. ELISA IgG and IgA from EUROIMMUN® were the most sensitive ELISA. However, poor results were obtained for isolated detection of IgG. We found similar sensitivity for IgG with SARS-CoV-2 for Architect by Abbott® and ELISA by Vircell®. Results obtained varied widely among the assays evaluated. Due to a better specificity, overall diagnostic accuracy of the assays evaluated was higher in case of positive result. On the other side, lack of antibody detection should be taken with care because of the low sensitivity described. Highest diagnostic accuracy was obtained with ELISA and CMIAs, but they last much longer.

Several Plasmodium vivax relapses after correct primaquine treatment in a patient with impaired cytochrome P450 2D6 function.

BACKGROUND: Plasmodium vivax malaria is characterized by the presence of dormant liver-stage parasites, called hypnozoites, which can cause malaria relapses after an initial attack. Primaquine, which targets liver hypnozoites, must be used in combination with a schizonticidal agent to get the radical cure. However, relapses can sometimes occur in spite of correct treatment, due to different factors such as a diminished metabolization of primaquine. CASE PRESENTATION: In January 2019, a 21 years old woman with residence in Madrid, returning from a trip to Venezuela with clinical symptoms compatible with malaria infection, was diagnosed with vivax malaria. Chloroquine for 3 days plus primaquine for 14 days was the elected treatment. Two months later and after a second trip to Venezuela, the patient presented a second P. vivax infection, which was treated as the previous one. A third P. vivax malaria episode was diagnosed 2 months later, after returning from a trip to Morocco, receiving chloroquine for 3 days but increasing to 28 days the primaquine regimen, and with no more relapses after 6 months of follow up. The genotyping of P. vivax in the three malaria episodes revealed that the same strain was present in the different relapses. Upon confirmation of correct adherence to the treatment, non-description of resistance in the infection area and the highly unlikely re-infection on subsequent trips or stays in Spain, a possible metabolic failure was considered. CYP2D6 encodes the human cytochrome P450 isoenzyme 2D6 (CYP2D6), responsible for primaquine activation. The patient was found to have a CYP2D6*4/*1 genotype, which turns out in an intermediate metabolizer phenotype, which has been related to P. vivax relapses. CONCLUSIONS: The impairment in CYP2D6 enzyme could be the most likely cause of P. vivax relapses in this patient. This highlights the importance of considering the analysis of CYP2D6 gene polymorphisms in cases of P. vivax relapses after a correct treatment and, especially, it should be considered in any study of dosage and duration of primaquine treatment.

Intra-Abdominal Infections by Carbapenemase-Producing Enterobacteriaceae in a Surgical Unit: Counting Mortality, Stay, and Costs.

Background: Carbapenemase-producing Enterobacteriaceae (CPE)-related infections are a problem in public health at present, including intra-abdominal infections (IAI) and surgical populations. The aim of this study was to determine mortality and related risk factors, length of stay (LOS,) and costs for CPE-IAI in surgical patients. Patients and Methods: Review of CPE-related IAI acquired during admission in a general surgery department from January 2013 to December 2018. A mortality analysis was performed specifically in patients with CPE-IAI, and a global analysis of IAI including patients with CPE-IAI (cases) and matched patients with IAI by non-resistant bacteria (controls). Results: Forty patients with CPE-IAI were included, OXA-48-producing Klebsiella pneumoniae was present in 85%. Global mortality rate at 30 days for CPE-IAI was 17.5%; mortality-related factors were: solid tumor (p = 0.009), metastatic disease (p = 0.005), immunodeficiency (p = 0.039), blood transfusion (p = 0.009), and septic shock (p = 0.011). Predictors related to mortality for IAI in the global analysis included age (p = 0.046), Charlson index (p = 0.036), CPE isolation (p = 0.003), and septic shock (p < 0.001). Median global LOS was 43 days (IQR 27-64) in patients with CPE-IAI, and 27 days (IQR 18-35) in controls (p < 0.001). Median global cost of admission was $31,671 (IQR 14,006-55,745) for patients with CPE-IAI and $20,306 (IQR 11,974-27,947) for controls (p = 0.064). The most relevant locations of underlying disease for CPE-IAI were: colorectal (32.5%) with 57-day LOS (IQR 34-65) and cost of $42,877 (IQR 18,780-92,607), and pancreas (25%) with 60-day LOS (IQR 32-99) and cost of $56,371 (IQR 32,590-113,979). Conclusion: Carbapenemase-producing Enterobacteriaceae-related IAI is associated with substantial mortality, LOS, and costs. Factors related to CPE-IAI mortality are solid tumor, metastatic disease, immunodeficiency, blood transfusion, and septic shock. Carbapenemase-producing Enterobacteriaceae isolation in IAI implies higher risk of mortality.

Risk Factors for Intra-Abdominal Infections Caused by Carbapenemase-Producing Enterobacteriaceae in a Surgical Setting.

Background: The aim of this study was to identify risk factors for acquisition of intra-abdominal infections (IAI) caused by carbapenemase-producing Enterobacteriaceae (CPE) in surgical patients. Methods: A matched case-control study was performed. We included all cases with CPE-related IAI acquired during admission to a general surgery department from January 2013 to December 2018, and they were matched with control subjects with IAI caused by non-resistant bacteria (ratio 1:3). Independent risk factors were obtained by logistic regression. Results: Forty patients with IAI-CPE were matched with 120 control subjects. Independent risk factors for acquisition of IAI-CPE were previous hospitalization (odds ratio [OR] 2.56; 95% confidence interval [CI] l 1.01-6.49; p = 0.047), digestive endoscopy (OR 4.11; 95% CI 1.40-12.07; p = 0.010), carbapenem therapy (OR 9.54; 95% CI 3.33-27.30; p < 0.001), and aminoglycoside use (OR 45.41; 95% CI 7.90-261.06; p < 0.001). Conclusions: Four clinical factors can identify patients at high-risk of IAI-CPE.

Surgical site infection by carbapenemase-producing Enterobacteriaceae. A challenge for today's surgeons. / Infección de sitio quirúrgico asociada a enterobacterias productoras de carbapenemasas. Un desafío para el cirujano actual.

INTRODUCTION: Infections caused by carbapenemase-producing Enterobacteriaceae (CPE) are dramatically increasing worldwide, with an important impact on surgical patients. Our aim was to assess the clinical profile, outcomes, treatment, mortality and costs of CPE-related surgical site infection (SSI) in patients with abdominal surgery. METHODS: Review of CPE-related SSI in patients with abdominal surgery from January 2013 to December 2018. Patient factors and interventions present previously to the SSI identification were recorded, and a mortality analysis was also performed in patients with abdominal surgery and CPE-related organ/space SSI. RESULTS: Fifty patients were included: superficial incisional SSI 50%, deep incisional SSI 28%, organ/space SSI (or intra-abdominal infection) 70%. Klebsiella pneumoniae OXA-48 was present in 84%, and the most frequent were colorectal surgery (40%) and pancreatic surgery (20%). The antimicrobial susceptibility was: ceftazidime-avibactam 100%, amikacin 91.7%, tigecycline 89.1%, colistin 70.8%, meropenem 62.8%, imipenem 52.1%. An appropriate definitive antimicrobial treatment was administered in 86%, using a combined scheme in 76%. Global 30-day mortality rate for intra-abdominal infection was 20%, and mortality-related factors were: solid tumour (P=.009), solid metastasis (P=.009), septic shock (P=.02), blood transfusions (P=.03). Median global stay was 45 (IQR 26-67) days. Median global cost of hospitalization was €29,946 (IQR 15,405-47,749). CONCLUSIONS: The clinical profile of patients with CPE-related SSI associates several comorbidities, interventions, prolonged stay and elevated costs. Mortality-related factors in intra-abdominal infection are solid tumour, metastasis, septic shock or blood transfusions.

First national survey of the diagnosis of Helicobacter pylori infection in Clinical Microbiology Laboratories in Spain. / Primera encuesta nacional sobre el diagnóstico de la infección por Helicobacter pylori en los laboratorios de microbiología clínica en España.

INTRODUCTION: The aim of this study was to know, through a national survey, the methods and techniques used for the diagnosis of Helicobacter pylori (Hp) in the different Clinical Microbiology Services/Laboratories in Spain, as well as antibiotic resistance data. METHODS: The survey requested information about the diagnostic methods performed for Hp detection in Clinical Microbiology laboratories, including serology, stool antigen, culture from gastric biopsies, and PCR. In addition, the performance of antibiotic susceptibility was collected. Data on the number of samples processed in 2016, positivity of each technique and resistance data were requested. The survey was sent by email (October-December 2017) to the heads of 198 Clinical Microbiology Laboratories in Spain. RESULTS: Overall, 51 centers from 29 regions answered the survey and 48/51 provided Hp microbiological diagnostic testing. Concerning the microbiological methods used to diagnose Hp infection, the culture of gastric biopsies was the most frequent (37/48), followed by stool antigen detection (35/48), serology (19/48) and biopsy PCR (5/48). Regarding antibiotic resistance, high resistance rates were observed, especially in metronidazole and clarithromycin (over 33%). CONCLUSION: Culture of gastric biopsies was the most frequent method for detection of Hp, but the immunochromatographic stool antigen test was the one with which the largest number of samples were analyzed. Nowadays, in Spain, it concerns the problem of increased antibiotic resistance to 'first-line' antibiotics.

Mycobacterium lentiflavum as the main cause of lymphadenitis in pediatric population. / Mycobacterium lentiflavum como causa principal de linfadenitis en población pediátrica.

INTRODUCTION: Cervical lymphadenitis is the most common nontuberculous mycobacteria (NTM) infection in immunocompetent children, mainly in those under 5years. For many years Mycobacterium lentiflavum (M. lentiflavum) has been considered a rare NTM causing lymphadenitis. METHODS: A restrospective study was performed in pediatric patients with microbiologically confirmed NTM cervical lympahdenitis at the Niño Jesús Hospital in Madrid during 2009-2016. RESULTS: During the period studied, 28 cases of cervical lymphadenitis were recorded. In 23 (82.14%) and in 5 (17,85%) cases, M. lentiflavum and Mycobacterium avium were isolated, respectively. In those patients infected with M. lentiflavum, the most frequent location was sub-maxilar (43.47%); 15 (65.21%) were boys, global median age was 30,8 months and all cases showed a satisfactory evolution. CONCLUSION: We propose that M. lentiflavum should be considered an important emergent pathogen cause of cervical lymphadenitis in the pediatric population.

Specific Clinical Profile and Risk Factors for Mortality in General Surgery Patients with Infections by Multi-Drug-Resistant Gram-Negative Bacteria.

BACKGROUND: The incidence of gram-negative multi-drug-resistant (MDR) infections is increasing worldwide. This study sought to determine the incidence, clinical profiles, risk factors, and mortality of these infections in general surgery patients. PATIENTS AND METHODS: All general surgery patients with a clinical infection by gram-negative MDR bacteria were studied prospectively for a period of five years (2007-2011). Clinical, surgical, and microbiologic parameters were recorded, with a focus on the identification of risk factors for MDR infection and mortality. RESULTS: Incidence of MDR infections increased (5.6% to 15.2%) during the study period; 106 patients were included, 69.8% presented nosocomial infections. Mean age was 65 ± 15 years, 61% male. Extended-spectrum ß-lactamases (ESBL) Escherichia coli was the most frequent MDR bacteria. Surgical site infections and abscesses were the most common culture locations. The patients presented multiple pre-admission risk factors and invasive measures during hospitalization. Mortality was 15%, and related to older age (odds ratio [OR] 1.07), malnutrition (OR 13.5), chronic digestive conditions (OR 4.7), chronic obstructive pulmonary disease (OR 3.9), and surgical re-intervention (OR 9.2). CONCLUSION: Multi-drug resistant infections in the surgical population are increasing. The most common clinical profile is a 65-year-old male, with previous comorbidities, who has undergone a surgical intervention, intensive care unit (ICU) admission, and invasive procedures and who has acquired the MDR infection in the nosocomial setting.

Abdominal abscess due to NDM-1-producing Klebsiella pneumoniae in Spain.

We describe a clinical case of an abdominal abscess due to NDM-1-producing Klebsiella pneumoniae in a 35-year-old Spanish patient after hospitalization in India for perforated appendicitis and peritonitis. The strain belonged to the MLST type 231 and had multiple additional antibiotic resistance genes such as bla(CTX-M-15), armA methylase, aac(6')-Ib-cr, dfrA12, sul1 and qnrB and lack of porin genes ompK35 and ompK36. The patient was cured after abscess drainage.