Evaluation of two RT-PCR screening assays for identifying SARS-CoV-2 variants

Background

The recent emergence of new SARS CoV-2 variants (variants of concern, VOC) that spread rapidly and may lead to immune escape has emphasized the urgent need to monitor and control their spread.

Methods

We analyzed 2018 SARS-CoV-2 positive specimens collected between February 9 and March 22, 2021 using the Thermofisher® TaqPath™ COVID-19 CE-IVD RT-PCR kit (TaqPath) and the ID solutions® ID™ SARS-CoV-2/UK/SA Variant Triplex RT-PCR (ID triplex) assay to screen for VOCs.

Results

The ID triplex assay identified 62.8% of them as VOCs: 61.8% B.1.1.7 and 0.9% B.1.351/P.1. The agreement between the ID triplex results for B.1.1.7 and the TaqPath S gene target failure (SGTF)/ S gene target late detection (SGTL) profile for this variant agreed very well (k = 0.86). A low virus load was the main cause of discrepancies. Sequencing discordant results with both assays indicated that the TaqPath assay detected the B.1.1.7 lineage slightly better. Both assays suggested that the virus loads of B.1.1.7 variants were significantly higher than those of non-B.1.1.7 strains. Only 10/20 B1.351/P.1 strains detected with the ID triplex assay were confirmed by sequencing.

Conclusions

We conclude that the SGTF/SGTL profiles identified using the TaqPath assay and ID triplex results are suitable for detecting the B.1.1.7 lineage. The ID triplex assay, which rapidly determines all three current VOCs simultaneously, could be a valuable tool for limiting virus spread by supporting contact-tracing and isolation.

Characteristics of patients with respiratory allergy in France and factors influencing immunotherapy prescription: a prospective observational study (REALIS)

To describe the sensitization profile of respiratory allergies in France, identifying factors influencing the prescription of allergen immunotherapy (AIT) [Transversal phase (T)], and assess treatment efficacy, tolerability, compliance and satisfaction [Longitudinal phase (L)]. French allergists (600) and pneumo-allergists (600) were offered participation and asked to recruit the first 20 new patients with allergic rhinitis (AR) and/or asthma, consulting for a first time allergy check-up with skin prick-test (T), and 5 patients sensitized to pollens (skin test and/or specific IgE) for whom SLIT with pollens was prescribed (L). In the T phase, 2,714 patients were recruited by 169 specialists, mostly allergists (76.5%). The majority (98%) suffered from AR, alone (57.7%) or with asthma (40.3%) and 80.3% suffered from moderate-to-severe rhinitis, mostly persistent (65.8%). Asthma, when present, was mostly intermittent (63.7%) or mild persistent (20.1%). Sensitization to house dust mites was the most common (64.5%), followed by grass pollens (61.5%), tree pollens (41.6%) and cat danders (30.5%). Poly-sensitization was seen in 73.6% of patients. AIT, mostly sublingual, was recommended in 55.6% of the patients, mostly (78.1%) because of insufficient control with symptomatic treatments. The overall impact of symptoms on QOL, positive skin test to grass pollens, ocular pruritus and/or nasal obstruction and moderate-to-severe rhinitis were significant predictors of SLIT prescription. Poly-sensitization or concomitant asthma were not seen as deterrents. Most patients consulting a specialist for allergy testing suffer from moderate-to-severe rhinitis. Treatment in current practice includes immunotherapy in half of the patients, and follows ARIA recommendations.

[Skin sensitisation profiles of outpatients with symptoms of respiratory allergies]

AIM

The main objective of the survey was to determine the frequency of the mono and polysensitizations in patients consulting for respiratory allergy, rhinitis or/and asthma. The secondary objectives were to evaluate the severity, the number and the type of the sensitizations, the frequency of the asthma or rhinitis as a function of the sensitizations, the evolution of the sensitizations with age, and identify the principal responsible pneumallergens.

PATIENTS AND METHODS

The multicentric survey included a patient questionnaire allowing the collection and anonymous treatment of data on socio-demographic characteristics, clinical symptoms, cutaneous tests and sensitizations.

RESULTS

A sample of 505 patients, mean age 24 years, consulting for rhinitis or asthma, monosensitized (36%) or polysensitized (64%), was evaluated. The percentage of polysensitized patients was similar in asthmatics, patients with rhinitis, and patients with both asthma and rhinitis (60%, 65%, and 63%, respectively). The mean number of the sensitizations was 2.4 for patients with asthma, 2.6 for those with rhinitis, and 2.6 for patients with both asthma and rhinitis. The greater the severity of the rhinitis or asthma, the higher the number of the sensitizations. Sensitizations to acarids, gramineae and cat were the most frequent. When practioners were asked about their intention to undertake desensitization in polysensitized patients, 52% of them replied positively.

CONCLUSION

Data collected during this survey showed that a large proportion of the patients who consulted for rhinitis or asthma were monosensitized (36%). Sensitization to acarids was the most frequent. Even in polysensitized patients, more than half the practioners said they would use desensitization.

[Mandibular advancement surgery in patients with severe obstructive sleep apnea uncontrolled by continuous positive airway pressure. A retrospective review of 25 patients between 1998 and 2004]

INTRODUCTION

Continuous positive airway pressure (CPAP) is ineffective in some patients with obstructive sleep apnoea syndrome (OSAS) and some patients do not tolerate it. This study evaluated the outcomes of maxillo-mandibular advancement in OSAS patients without morbid obesity or severe maxillo-mandibular deformity who had first been treated with CPAP for at least 6 months.

METHODS

A retrospective study reporting on the experience of the CHU Toulouse Rangueil sleep disorder centre between 1998 and 2004. We performed polysomnography and cephalometry before and 3 months after surgery.

RESULTS

25 male patients with mean apnoea hypopnoea index at 45/hour (+/-15) were treated by maxillo-mandibular advancement. The mean age of participants was 48 years (+/-7), and the mean body mass index was 28 kg/m2 (+/-3.4). Cephalometry demonstrated a retroposition of the mandible (SNB < 80 degrees +/-5) and narrow linguopharyngeal space (ELP = 8 mm+/-3). 3 months after surgery the apnoea hypopnoea index (AHI) had decreased from 45+/-15 to 7+/-7 (p < 0.0001), the Epworth sleepiness scale decreased from 11+/-5 to 6+/-4 (p < 0.01). The linguopharyngeal space was larger (ELP = 14 mm). Success rate defined as an AHI < 15/hour was 89%, and 74% for an AHI < 10/hour. 16 patients underwent polysomnography one year after surgery. The results were the same. There were no post surgical complications, except for one patient who developed permanent labial hypoesthesia.

CONCLUSIONS

Maxillo-mandibular advancement seems to be an effective 2nd line therapy for the treatment of severe OSAS.