Development of a prototype immunochromatographic test for rapid diagnosis of respiratory adenovirus infection

Different Clinical Manifestations of Adenoviral Infection Confirmed Using Point-of-Care Testing in a Group of Hospitalized Children

Objective: A restrospective analysis of the clinical picture (inflammatory markers, characteristics of fever, comorbidities) in different clinical manifestations of human adenovirus (HAdV) infections confirmed using point-of-care testing in a group of hospitalized children. Material and Methods: A total of 135 children with confirmed HAdV infections were divided into three groups according to their clinical symptoms: Group A—respiratory (n = 57), Group B—gastrointestinal (n = 40), and Griup C—mixed (n = 38). Results: Respiratory and mixed HAdV-infected patients, as compared with gastrointestinal HAdV-infected patients, were younger (median value (Me) and interquartile range (IQR) (months): 17 (12−30) and 17 (12−27) vs. 30 (16−50), p = 0.04), had a longer duration of fever (days): 3 (1−5) and 3 (1−4) vs. 1 (1−2), p = 0.01), and had higher C-reactive protein values (mg/L): 29.2 (10.4−69.1) and 28.7 (10.8−49.1) vs. <5 (<5−20.6), p < 0.001). There were no correlations between CRP levels and patient’s age, fever duration, the occurrence of acute otitis media and lower respiratory tract infection, and antibiotic treatment before admission. Conclusions: Patients with respiratory HAdV infections have fevers more often, the duration of the fever prior to admission is longer, and CRP levels are higher.

Potential Diagnostic and Prognostic Biomarkers for Adenovirus Respiratory Infection in Children and Young Adults

Human Adenoviruses (HAdV) are known to be potentially associated with strong inflammatory responses and morbidity in pediatric patients. Although most of the primary infections are self-limiting, the severity of clinical presentation, the elevation of the white blood cell count and inflammatory markers often mimic a bacterial infection and lead to an inappropriate use of antibiotics. In infections caused by HAdV, rapid antigen detection kits are advisable but not employed routinely; costs and feasibility of rapid syndromic molecular diagnosis may limit its use in the in-hospital setting; lymphocyte cultures and two-sampled serology are time consuming and impractical when considering the use of antibiotics. In this review, we aim to describe the principal diagnostic tools and the immune response in HAdV infections and evaluate whether markers based on the response of the host may help early recognition of HAdV and avoid inappropriate antimicrobial prescriptions in acute airway infections.

Simultaneous serodetection of major rat infectious pathogens by a multiplex immunochromatographic assay

Rapid and simple serologic tests that require only a small amount of blood without the euthanization of animals are valuable for microbial control in colonies of laboratory animals. In this study, we developed a multiplex immunochromatographic assay (ICA) for detection of antibodies to Sendai virus (also known as hemagglutinating virus of Japan), hantavirus, and sialodacryoadenitis virus, which are causative agents of major infectious diseases in rats. For this assay, an ICA strip was placed into a microtube containing 150 µl PBS and either 0.75 µl of rat serum or 1.5 µl of whole blood. Binding antibodies were visualized by using anti-rat IgG antibody-conjugated colloidal gold. Under these conditions, the multiplex ICA simultaneously and specifically detected antibodies to multiple antigens. Positive serum samples for each infectious disease were used to evaluate the sensitivity and specificity of the multiplex ICA. The sensitivities of the multiplex ICA for Sendai virus, hantavirus, and sialodacryoadenitis virus were 100%, 100%, and 81%, respectively. No nonspecific reactions were observed in any of the 52 positive sera against heterologous antigens. In addition, 10 samples of uninfected sera did not show any bands except for the control line. These observations indicate high specificity of the multiplex ICA. Moreover, the multiplex ICA could be applied to diluted blood. These results indicate that the multiplex ICA is appropriate for rapid and simple serological testing of laboratory rats.

Laboratory diagnosis of SARS-CoV-2: available approaches and limitations

The ongoing pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is one of the most devastating outbreaks witnessed in the last 100 years. The outbreak started in China and spread rapidly to almost every country, culminating in woefully overwhelmed health-care systems in most countries. The only approved diagnostic test to accompany radiographic evaluation is reverse transcription PCR. However, the applicability of this test in diagnosis and surveillance is challenged by a global shortage of reagents and the lack of well-equipped laboratories with specialized staff in several low- and middle-income countries. Loop-mediated isothermal amplification and CRISPR-based diagnostic assays have developed and expected to play a role however, their accuracy is still inferior to the recommended PCR approach. The need for the development of accurate and rapid diagnostic assays became apparent. Immunodiagnostic tests and other molecular approaches were developed and tested. Other recently developed point-of-care molecular tests are expected to be helpful in pandemic management as no particular skills are required from the operator. Fortunately, a number of serological tests have been granted authorization for use under the emergency situation by the US FDA for the diagnosis of SARS-CoV-2. The majority of recently authorized serological tests detect IgG and IgM in blood of infected individuals by on ELISA, chemiluminescence platforms or lateral flow cassettes.

Clinical evaluation of a rapid colloidal gold immunochromatography assay for SARS-Cov-2 IgM/IgG

BACKGROUND

Since December 2019, there had been an outbreak of COVID-19 in Wuhan, China. At present, diagnosis COVID-19 were based on real-time RT-PCR, which have to be performed in biosafe laboratory and is unsatisfactory for suspect case screening. Therefore, there is an urgent need for rapid diagnostic test for COVID-19.

OBJECTIVE

To evaluate the diagnostic performance and clinical utility of the colloidal gold immunochromatography assay for SARS-Cov-2 specific IgM/IgG anti-body detection in suspected COVID-19 cases.

METHODS

In the prospective cohort, 150 patients with fever or respiratory symptoms were enrolled in Taizhou Public Health Medical Center, Taizhou Hospital, Zhejiang province, China, between January 20 to February 2, 2020. All patients were tested by the colloidal gold immunochromatography assay for COVID-19. At least two samples of each patient were collected for RT-PCR assay analysis, and the PCR results were performed as the reference standard of diagnosis. Meanwhile 26 heathy blood donor were recruited. The sensitivity and specificity of the immunochromatography assay test were evaluated. Subgroup analysis were performed with respect to age, sex, period from symptom onset and clinical severity.

RESULTS

The immunochromatography assay test had 69 positive result in the 97 PCR-positive cases, achieving sensitivity 71.1% [95% CI 0.609-0.797], and had 2 positive result in the 53 PCR-negative cases, achieving specificity 96.2% [95% CI 0.859-0.993]. In 26 healthy donor blood samples, the immunochromatography assay had 0 positive result. In subgroup analysis, the sensitivity was significantly higher in patients with symptoms more than 14 days 95.2% [95% CI 0.741-0.998] and patients with severe clinical condition 86.0% [95% CI 0.640-0.970].

CONCLUSIONS

The colloidal gold immunochromatography assay for SARS-Cov-2 specific IgM/IgG anti-body had 71.1% sensitivity and 96.2% specificity in this population, showing the potential for a useful rapid diagnosis test for COVID-19. Further investigations should be done to evaluate this assay in variety of clinical settings and populations.

Multiplex Immunochromatographic Assay for Serologic Diagnosis of Major Infectious Diseases in Laboratory Mice

Serologic monitoring of infectious diseases is important for microbial control in colonies of laboratory mice. Rapid and simple tests that do not require killing animals are valuable for this purpose. In this study, we developed a multiplex immunochromatographic assay (ICA) for detection of antibodies to mouse hepatitis virus (MHV), Sendai virus (also known as hemagglutinating virus of Japan [HVJ]), and Clostridium piliforme (The pathogen that causes Tyzzer disease), which are major infectious diseases in mice. For this assay, an ICA strip was put into a microtube containing 150 μL PBS and either 0.75 μL mouse serum or 1.5 μL whole blood. Binding antibodies were visualized by using protein A-conjugated colloidal gold. Under these conditions, multiplex ICA simultaneously and specifically detected antibodies to multiple antigens. To evaluate the sensitivity and specificity of multiplex ICA, positive serum samples for each infectious disease were used. Sensitivities of the multiplex ICA test for MHV, HVJ, and C. piliforme were 100%, 100%, and 90%, respectively. No nonspecific reaction was observed in any of the 30 positive sera. In addition, 10 samples of uninfected sera did not show any bands except for the control line. These observations indicate high specificity of the multiplex ICA test. Moreover, the multiplex ICA could be applied to diluted blood. These results indicate that the multiplex ICA is appropriate for rapid, simple, and safe serologic testing of laboratory mice.