Development and evaluation of time‐resolved fluorescent immunochromatographic assay for quantitative detection of SARS‐CoV‐2 spike antigen

BackgroundThe spread of COVID‐19 worldwide caused by the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has necessitated efficient, sensitive diagnostic methods to identify infected people. We report on the development of a rapid 15‐minute time‐resolved fluorescent (TRF) lateral flow immunochromatographic assay for the quantitative detection of the SARS‐CoV‐2 spike protein receptor‐binding domain (S1‐RBD).ObjectivesOur objective was to develop an efficient method of detecting SARS‐CoV‐2 within 15 min of sample collection.MethodsWe constructed and evaluated a portable, disposable lateral flow device, which detected the S1‐RBD protein directly in nasopharyngeal swab samples. The device emits a fluorescent signal in the presence of S1‐RBD, which can be captured by an automated TRF instrument.ResultsThe TRF lateral flow assay signal was linear from 0 to 20 ng/ml and demonstrated high accuracy and reproducibility. When evaluated with clinical nasopharyngeal swabs, the assay was performed at >80% sensitivity, >84% specificity, and > 82% accuracy for detection of the S1‐RBD antigen.ConclusionThe new S1‐RBD antigen test is a rapid (15 min), sensitive, and specific assay that requires minimal sample preparation. Critically, the assay correlated closely with PCR‐based methodology in nasopharyngeal swab samples, showing that the detected S1‐RBD antigen levels correlate with SARS‐CoV‐2 virus load. Therefore, the new TRF lateral flow test for S1‐RBD has potential application in point‐of‐care settings.     

The SF-36 health status questionnaire in assessing patients with epistaxis secondary to hereditary hemorrhagic telangiectasia

BACKGROUND: This study assesses the ability of the short form 36 (SF-36), a validated health status survey, to measure the health of patients with epistaxis due to hereditary hemorrhagic telangiectasia (HHT). METHODS: Thirty-eight patients completed the SF-36 and symptom-specific questionnaires. They were asked to rate their epistaxis as severe, moderate, or mild. The SF-36 data are compared with a reference population and analyzed with respect to the subgroups. RESULTS: The scores for each dimension of health were significantly reduced (p < 0.05) when compared with the reference population for all dimensions except pain. When compared with the patients' ratings of severity, a significant correlation was detected in five dimensions (p < 0.05). CONCLUSION: The SF-36 reflects the reduced health status of patients with epistaxis due to HHT. Changes in the SF-36 score could be used as an outcome measure in assessing efficacy of treatment of this condition.     

Group A streptococcal supraglottitis

We describe four children with severe supraglottic infections caused by group A beta-hemolytic streptococci. In each case the clinical presentation suggested Hemophilus influenzae epiglottitis. In only one patient was there significant involvement of the epiglottis, whereas all had striking inflammation of the aryepiglottic folds. Group A beta-hemolytic streptococcus was isolated in blood cultures in two patients and from the supraglottic area and trachea in two others. Fever persisted for 6 to 22 days, and tracheal intubation was necessary for 2 to 16 days, despite appropriate antibiotic therapy. The evolution of streptococcal supraglottitis may be protracted, and it must be managed accordingly.     

Miscarriage risk for asymptomatic women after a normal first-trimester prenatal visit

OBJECTIVE: To estimate the risk of miscarriage among asymptomatic women after a prenatal visit between 6 and 11 weeks of gestation where proof of fetal viability of a singleton was obtained by office ultrasonography at the same visit. METHODS: This was a prospective cohort study performed over 2 years (March 2004-2006) at an antenatal clinic at a large tertiary hospital in Victoria, Australia. Those recruited were 697 asymptomatic women who attended their first antenatal visit between 6 (+2 days) and 11(+6 days) weeks of gestation, where evidence of fetal cardiac activity of a singleton was obtained by office ultrasonography. The main outcome measure was rates of miscarriage, stratified by gestation at presentation. RESULTS: One case was lost to follow-up. The risk of miscarriage among the entire cohort was 11 of 696 (1.6%). The risk fell rapidly with advancing gestation; 9.4% at 6 (completed) weeks of gestation, 4.2% at 7 weeks, 1.5% at 8 weeks, 0.5% at 9 weeks and 0.7% at 10 weeks (chi(2); test for trend P=.001). Most who miscarried received their ultrasound diagnoses many weeks after their visit; five (45%) were diagnosed in the second trimester, and all but one received their ultrasound diagnoses after 10 weeks of gestation. CONCLUSION: For women without symptoms, the risk of miscarriage after attending a first antenatal visit between 6 and 11 weeks is low (1.6% or less), especially if they present at 8 weeks of gestation and beyond. Our data could be used to reassure such women that the probability of progressing to later than 20 weeks of gestation is very good.     

Antibiotic resistance: a guide for effective prescribing in women's health

Current national and international trends in antibiotic resistance are becoming a public health crisis. Multi-drug resistant organisms are more prevalent in hospital settings and, alarmingly, are now being identified in the community. Over-reliance on broad-spectrum antibiotics, as well as inappropriate prescribing practices, play a significant role in encouraging the emergence of resistant organisms. This article reviews the mechanisms of bacterial resistance, current trends in national and international antibiotic resistance, and examines approaches to combat pathogens while sparing benign microbes.