Volume 45, Issue 3

The outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first recorded in Wuhan, China. The World Health Organization initially classified COVID-19 as a public health emergency and subsequently declared the disease a global pandemic. COVID-19 can take at least three distinct forms: severe acute distress syndrome with a potentially fatal outcome, mild respiratory illness (pneumonia with eventual recovery) and asymptomatic infection. All three disease forms have the potential to transmit the infection to healthy contacts. At present, real-time reverse transcription polymerase chain reaction (RT-PCR) is the only available laboratory tool to confirm the presence of viral RNA in patient specimens. These assays are designed to detect one or more (at least 2) SARS-CoV-2 RNA gene targets allowing the detection of the virus. Commercially available RT-PCR assays employ various gene targets of the viral genome in their assay systems. Additionally, there are differences in primer selection for the same gene region of SARS-CoV-2. At present, it is unclear whether the results from different RT-PCR assays are comparable in detecting the spectrum of COVID-19 manifestations. The purpose of the present article is twofold: first, to briefly focus on the findings of these reports; and second, to emphasize the various challenges and flaws that can potentially impact the diagnostic accuracy of RT-PCR testing for SARS-CoV-2.

Objectives Point-of-care antigen tests (PoC-AgTs) for the rapid detection of SARS-CoV-2 infection enable screening of additional populations with less effort, independent of laboratories and at a low cost. PoC-AgTs have therefore been included in national testing strategies with additional quality requirements to address limitations in specificity and sensitivity. Information given in the package inserts of the test providers should enable the user to evaluate the performance of a PoC-AgT in advance. The quality of this information has been independently assessed since the Corona Test Ordinance came into force in Germany in October 2020. Methods The completeness of analytical and diagnostic performance specifications was assessed for all package inserts publicly available via the Paul Ehrlich Institute (PEI). It was ascertained whether the minimum criteria, recommendations, and extended criteria of the PEI were comprehensibly fulfilled. The number of tests removed from the list by March 2021 was determined. Results By the closing date of the survey (17.11.2020), the PEI had listed 165 PoC-AgTs that formally fulfilled the minimum criteria and were thus reimbursed. A total of 78 identical systems were identified. Almost all providers were found to have gaps in the information on the validation results of their tests, meaning that an evaluation of performance is only possible to a limited extent. Until March 2021, 25 non-identical PoC-AgTs have been removed from the list. Conclusions Many PoC-AgTs could not be comprehensively evaluated based on the information provided by the provider. Users are therefore dependent on provider-independent sources of information.

Objectives The clinical implications of different blood indices in patients with coronavirus disease-2019 (COVID-19) were analyzed at different stages. Methods We compared blood test results of 17 COVID-19 patients treated in Jinhua Central Hospital between January 1 and March 5, 2020 at different stages. We also compared the initial blood results of 17 COVID-19 patients with 115 influenza virus A/B (Flu A/B)-positive patients, 19 Mycoplasma pneumonia (MP)-positive patients and 50 healthy subjects (HSs). Results (1) The white blood cell count (WBC) and absolute neutrophil count (NEU#) were lower in the SARS-CoV-2 group than in the MP and Flu A/B groups; the eosinophil percentage (EO%) and absolute eosinophil count (EO#) were lower in the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) group than in the MP group (p<0.05). (2) Aspartate aminotransferase (AST) levels were significantly lower when patients were discharged from the hospital (p<0.05), EO% and EO# recovered at discharge, and returned to normal levels during follow-up (p<0.05). (3) When the throat swab was nucleic acid-negative but the stool was still positive, lymphocyte percentage (LY%) and absolute lymphocyte count (LY#) decreased (p<0.05). (4) As the cycle threshold (Ct) value of the nucleic acid increased or decreased, EO# showed a consistent trend. Conclusions Blood cell count indices upon hospital admission could be helpful to give some tips of diagnosis of SARS-CoV-2-infection, Flu A/B-infection and MP-infection; AST and EO# could be used to predict the outcome of patients. Feces turned negative for nucleic acid more slowly than throat swabs; LY# was lower during the fecal-positive period and low Ct values of fecal nucleic acid were negatively associated with the patient’s recovery level.

Background Tests for diagnosing infectious diseases (ID-POCT) play a special role among the available point-of-care testing (POCT) methods. Methods A systematic literature search was performed in PubMed. Based on this literature review and our own experience, aspects associated with using molecular biological methods in the diagnostic amplification of pathogen DNA/RNA (nucleic acid testing = NAT) and/or signal amplification were discussed in an interdisciplinary manner. This resulted in the following recommendations for the near-patient use of NAT methods. Results Due to the current rise in the use of near-patient NAT testing (e.g., using disposable cartridges), recommendations are made for their implementation and appropriate clinical use in the hospital setting. Particular emphasis is placed on the analytical quality of the results. Furthermore, internal best-practice rules and selection criteria are proposed to ensure rapid diagnosis. Equally important are a medically valid interpretation of results and compliance with hygiene requirements. These recommendations emphasize that near-patient NAT should always be procured in conjunction with a (preferably) multidisciplinary institution responsible for POCT and knowledge of the test specifications and risks, as well as quality assurance need to be in place before they are carried out. Conclusions These recommendations are intended to improve patient safety and to avoid economically questionable expenditures.

Background Bloodstream infections (BSIs) are one of the most common infections seen in all age groups and in all locations. The current knowledge on the patterns of bacterial profile, and its antibiotic resistance are essential to design and implement appropriate interventions. This study was conducted to assess the prevalence and multi-drug resistance pattern of bacterial isolates among septicemia and/or bacteremia suspected cases in Ethiopia. Methods Searching was conducted in databases of PubMed, Research Gate, Scopus and Google Scholar. In addition, manual searching is also conducted in bibliographies of included studies and in other meta-analysis studies. Required data were extracted from articles published up to 2020 on the bacterial profile of septicemia in Ethiopia, and analyzed using comprehensive meta-analysis version 3.3.0 software. Results A total of 5,823 septicemia suspected cases were extracted from 18 included studies and the overall blood culture positive rate of 31.9% (95% CI: 0.261–0.382). Of these, the overall Gram positive and Gram negative isolates was 57.8% (95% CI: 0.534–0.584) and 42.2% (95% CI: 0.416–0.466), respectively. Among Gram positives, predominantly reported isolates was Staphylococcus  aureus (47.9%: 480 of 1,003), followed by Coagulase-Negative Staphylococcus (42.7%: 428 of 1,003), whereas among Gram negatives, the most frequently reported isolates was Klebsiella species (29.8%: 218 of 731), followed by Escherichia  coli (23.1%: 169 of 731). Significant levels of resistance was reported against ampicillin, amoxicillin, ceftriaxone, co-trimoxazole and tetracycline with a pooled resistance range of 40.6–55.3% in Gram positive and 52.8–85.7% in Gram negative isolates. The pooled estimates of multi-drugs resistance (MDR) was (66.8%) among Gram positives and (80.5%) among Gram negatives, with the overall MDR rate of (74.2%). Conclusions The reported blood culture positive rates among septicemia cases were relatively high. Second, the level of drug and multi-drug resistant isolates against commonly prescribed antibiotics was significant. However, the scarcity of data on culture confirmed septicemia cases as well as patterns of antimicrobial resistance may overshadow the problem.

Objectives Human parvovirus B19, the cause of fifth disease in children and transient arthropathy in adults, could induce autoimmunity and the production of autoantibodies. The aim of this study is to explore the relationship between B19 infection and autoantibodies upregulation in women and children. Methods Of 512 women and children in our hospital between 2016 and 2018, all cases simultaneously test anti-B19 IgM and autoantibodies like anti-nuclear antibody, anti-Sm and anti-double stranded DNA antibody were included in this study. Results Parvovirus B19 infection could significantly upregulate anti-nuclear antibody and anti-Sm, but not anti-double stranded DNA, the titer of autoantibodies is associated with the content of anti-B19 IgM, and the infection in children is accompanied with more obvious autoantibodies upregulation. Conclusions Our data shows that parvovirus B19 infection is related to autoantibodies production in both women and children, and the status of infection may associate with the titer of autoantibodies in parvovirus B19 infected patients.

Objectives Heat treatment is a convenient measure for pathogens inactivation. The authors investigated the effects of this method on blood concentrations of six commonly therapeutic drugs. Methods Plasma and whole blood were pretreated with or without heating at 56 °C for 30 min, and drug concentrations of vancomycin, methotrexate, valproic acid, digoxin, carbamazepine, and cyclosporine were examined. Results Increased valproic acid levels after plasma heating (63.2 ± 30.2 vs. 62.1 ± 29.8 mg/L, mean recovery 102.0%) and whole blood heating (64.5 ± 30.5 vs. 62.1 ± 29.8 mg/L, mean recovery 104.6%) were observed (both p<0.05), but these differences were not considered clinically important. Recoveries of vancomycin in heat treatments varied widely, with an average and significant decrease of 15.8% in value after whole blood heating (11.7 ± 8.1 vs. 13.7 ± 8.6 mg/L, p<0.05). Conclusions Plasma or whole blood heating at 56 °C for 30 min are feasible in pathogens inactivation during monitoring methotrexate, valproic acid, digoxin, carbamazepine, and cyclosporine. However, such pretreatment seems inappropriate in monitoring vancomycin concentrations. Those results highlight the need for caution when applying heat treatment for pathogens inactivation in therapeutic drug monitoring.

Objectives Mycoplasma pneumoniae is one of the common causative pathogens of community-acquired respiratory tract infections mainly in children and young adults. Rapid and accurate diagnostic techniques for identifying the causative pathogen would be useful for initiating treatment with an appropriate antibiotic. The purpose of the present study was to evaluate the sensitivity and specificity of a novel immunochromatographic assay using silver amplification technology using FUJI DRI-CHEM IMMUNO AG2 and FUJI DRI-CHEM IMMUNO AG cartridge Myco (FUJIFILM Co., Tokyo, Japan) for detection of M. pneumoniae . Methods Throat swab samples were collected from 170 pediatric patients who were diagnosed with bronchitis or pneumonia. The silver amplification immunochromatographic (SAI) assay was performed using these samples and the results were compared with those of real-time PCR. The time required for the SAI assay is approximately 20 min (5 min for sample preparation and 15 min for waiting time after starting the assay). Results The sensitivity and specificity of the SAI assay for detection of M. pneumoniae were 85.2 and 99.1%, respectively, and the assay showed positive and negative predictive values of 98.1 and 92.3%, respectively, compared with the results of real-time PCR. The diagnostic accuracy was 94.1%. Conclusions FUJI DRI-CHEM IMMUNO AG2 and FUJI DRI-CHEM IMMUNO AG cartridge Myco are appropriate for clinical use. The optimal timing of this assay is five days or more after the onset of M. pneumoniae infection. However, PCR or other molecular methods are superior, especially with regard to sensitivity and negative predictive value.