Risk Factors for Persistent Anosmia and Dysgeusia in Children with SARS-CoV-2 Infection: A Retrospective Study

Long COVID in Children and Adolescents: A Critical Review

(1) Background: Data on persisting symptoms after SARS-CoV-2 infection in children and adolescents are conflicting. Due to the absence of a clear pathophysiological correlate and a definitive diagnostic test, the diagnosis of Long COVID currently rests on consensus definitions only. This review aims to summarise the evidence regarding Long COVID in children and adolescents, incorporating the latest studies on this topic. (2) Methods: We designed a comprehensive search strategy to capture all relevant publications using Medline via the PubMed interface, with the initial literature search conducted in April 2023. To be included, publications had to present original data and include >50 participants with Long COVID symptoms aged between 0 and18 years. (3) Results: A total of 51 studies met the inclusion criteria, with most studies originating from Europe (n = 34; 66.7%), followed by the Americas (n = 8; 15.7%) and Asia (n = 7; 13.7%). Various study designs were employed, including retrospective, cross-sectional, prospective, or ambispective approaches. Study sizes varied significantly, with 18/51 studies having fewer than 500 participants. Many studies had methodological limitations: 23/51 (45.1%) studies did not include a control group without prior COVID-19 infection. Additionally, a considerable number of papers (33/51; 64.7%) did not include a clear definition of Long COVID. Other limitations included the lack of PCR- or serology-based confirmation of SARS-CoV-2 infection in the study group. Across different studies, there was high variability in the reported prevalence of Long COVID symptoms, ranging from 0.3% to 66.5%, with the majority of studies included in this review reporting prevalences of approximately 10-30%. Notably, the two studies with the highest prevalences also reported very high prevalences of Long COVID symptoms in the control group. There was a relatively consistent trend for Long COVID prevalence to decline substantially over time. The prevalence of Long COVID appeared to differ across different paediatric age groups, with teenagers being more commonly affected than younger children. Furthermore, data suggest that children and adolescents are less commonly affected by Long COVID compared to adults. In children and adolescents, Long COVID is associated with a very broad range of symptoms and signs affecting almost every organ system, with the respiratory, cardiovascular, and neuropsychiatric systems being most commonly affected. (4) Conclusions: The heterogeneity and limitations of published studies on Long COVID in children and adolescents complicate the interpretation of the existing data. Future studies should be rigorously designed to address unanswered questions regarding this complex disease.

Post-Acute Sequelae of SARS-CoV-2 Infection and Its Impact on Adolescents and Young Adults

This review discusses the varying definitions for post-acute sequelae of SARS CoV-2 infection (PASC) in adolescents and young adults (AYAs), symptom profiles of AYAs with PASC, and assessment and management strategies when AYAs present with symptoms concerning for PASC. Additionally, it reviews the impact that PASC can have on AYAs and includes strategies for providers to support AYAs with PASC. Finally, it concludes with a discussion around equity in the care of AYAs with possible PASC.

Assessment of anosmia/hyposmia in post-COVID-19 patients: a cross-sectional study in an eastern province of Saudi Arabia

Background and aim It has been shown that olfactory dysfunction is one of Coronavirus disease-2019 (COVID-19)common and puzzling symptoms that may persist weeks after the infection. This study aimed for the objective assessment of persisting olfactory dysfunction in post-COVID-19 patients. It also investigated the factors associated with the development of such symptoms in the Eastern Province of Saudi Arabia.

METHODS

A cross-sectional study that was conducted in the Department of Physiology, College of Medicine, Imam Abdulrahman bin Faisal University, Khobar, Saudi Arabia. One hundred and forty-seven participants were included in this study, and sixty of them agreed  to participate in the objective testing using the Connecticut Chemosensory Clinical Research Center (CCCRC) olfaction test.

RESULTS

There was a significant correlation between the following factors: (1) Persistence of anosmia/hyposmia and the time of onset of anosmia/hyposmia (P=0.015). (2) Persistence of anosmia/hyposmia and the duration of anosmia/hyposmia (P=0.012). (3) Duration of anosmia/hyposmia and the duration of COVID-19 symptoms (P=0.010). Interestingly, there was a significant association between the subjective participants' claim of anosmia/hyposmia and the score of their objective assessment (P=0.026).

CONCLUSION

The current study demonstrated that post-COVID-19 participants with delayed onset of anosmia/hyposmia and/or longer duration of either anosmia/hyposmia or COVID-19 symptoms were prone to have persistent olfactory dysfunction. Further studies are necessary to uncover the underlying pathophysiology and management of this olfactory dysfunction in COVID-19 patients.

Association between virus variants, vaccination, previous infections, and post-COVID-19 risk

OBJECTIVES

The SARS-CoV-2 Omicron variant has spread rapidly and has been the dominant variant since 2022. The course of acute infection, in a vaccinated population, with Omicron is milder compared with earlier variants. However, little is known about how the occurrence of long-term symptoms after Omicron infection compared with other variants is modulated by previous infections and/or vaccinations.

METHODS

Participants of the DigiHero study provided information about their SARS-CoV-2 infections, vaccinations, and symptoms 12 or more weeks after infection (post-COVID-19 condition - PCC).

RESULTS

Participants infected with wildtype SARS-CoV-2 had the highest PCC risk (adjusted odds ratio [aOR] 6.44, 95% confidence interval (CI): 5.49; 7.56), followed by participants infected with Alpha and Delta compared with the reference group (individuals infected with Omicron having received three or more vaccinations). Among those infected with a specific variant, the number of preceding vaccinations was not associated with a risk reduction for PCC, whereas previous infection was strongly associated with a lower PCC risk (aOR 0.14, 95% CI 0.07; 0.25).

CONCLUSIONS

While infection with Omicron is less likely to result in PCC compared with previous variants, lack of protection by vaccination suggests a substantial challenge for the healthcare system during the early endemic period. In the midterm, the protective effects of previous infections can reduce the burden of PCC.

Vaccination against SARS-CoV-2 Does Not Protect against the Development of Anosmia in a Hamster Model

Anosmia, a total or partial loss of the ability to smell, is one of the most frequently documented sequelae of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Persistent anosmia is associated with a decrease in quality of life. Here, we assess the impact of virus lineage and vaccination status on anosmia development in the golden Syrian hamster model. To characterize anosmia driven by current variants, we assessed olfactory function in hamsters infected with SARS-CoV-2 lineages A, BA.2, BA.5, BQ.1, and BQ.1.1 using a buried food detection test. We found that significant anosmia occurs upon infection with all variants with a significant correlation between disease severity and degree of anosmia. Moreover, we found that vaccination with either the Pfizer (BNT16b2) or Moderna (mRNA-1273) mRNA vaccines does not protect against anosmia, despite protection against severe disease.