The burden of persistent symptoms after COVID-19 (long COVID): a meta-analysis of controlled studies in children and adults.

BACKGROUND: Previous meta-analyses estimating the prevalence of the post-COVID-19 condition (PCC) were confounded by the lack of negative control groups. This may result in an overestimation of the prevalence of those experiencing PCC, as these symptoms are non-specific and common in the general population. In this study, we aimed to compare the burden of persistent symptoms among COVID-19 survivors relative to COVID-19-negative controls. METHODS: A systematic literature search was conducted using the following databases (PubMed, Web of Science, and Scopus) until July 2023 for comparative studies that examined the prevalence of persistent symptoms in COVID-19 survivors. Given that many of the symptoms among COVID-19 survivors overlap with post-hospitalization syndrome and post-intensive care syndrome, we included studies that compare the prevalence of persistent symptoms in hospitalized COVID-19 patients relative to non-COVID-19 hospitalized patients and in non-hospitalized COVID-19 patients relative to healthy controls that reported outcomes after at least 3 months since infection. The results of the meta-analysis were reported as odds ratios with a 95% confidence interval based on the random effects model. RESULTS: Twenty articles were included in this study. Our analysis of symptomatology in non-hospitalized COVID-19 patients compared to negative controls revealed that the majority of symptoms examined were not related to COVID-19 infection and appeared equally prevalent in both cohorts. However, non-COVID-19 hospitalized patients had higher odds of occurrence of certain symptoms like anosmia, ageusia, fatigue, dyspnea, and brain fog (P < 0.05). Particularly, anosmia and ageusia showed substantially elevated odds relative to the negative control group at 11.27 and 9.76, respectively, P < 0.05. In contrast, analysis of hospitalized COVID-19 patients compared to those hospitalized for other indications did not demonstrate significantly higher odds for the tested symptoms. CONCLUSIONS: The persistent symptoms in COVID-19 survivors may result from hospitalization for causes unrelated to COVID-19 and are commonly reported among the general population. Although certain symptoms exhibited higher odds in non-hospitalized COVID-19 patients relative to controls, these symptoms are common post-viral illnesses. Therefore, the persistent symptoms after COVID-19 may not be unique to SARS-CoV-2. Future studies including well-matched control groups when investigating persistent symptoms in COVID-19 survivors are warranted to draw a firm conclusion.

Gustatory dysfunction in relation to circumvallate papilla's taste buds structure upon unilateral maxillary molar extraction in Wistar rats: an in vivo study.

Background: The interaction between taste sensation and dentoalveolar innervation is still under research.  teeth loss can alter taste thresholds in humans, but the underlying mechanisms are still obscure. This study investigated the effect of unilateral maxillary molars extraction on the structure of circumvallate papilla in rats. Methods: Thirty-two male Wister rats, aged 3-4 months were randomly distributed into four groups (one control and 3 experimental ) each including 8 animals. The rats were euthanized 3, 6 or 9 weeks following the procedure. The changes in trough length and the taste buds structure and number of both sides of CVP were investigated using routine histological examination followed by statistical analysis. Results: the trough toward the extraction side was obviously shorter with a noticeable decrease of taste buds' number than the non-extraction side. Taste buds were reduced in size and most of them showed signs of degeneration which was more evident in group II followed by group III, less deformity detected in group IV in comparison to the preceding 2 experimental groups. the non-extraction side of all experimental groups showed normal trough length and generally normal histology of taste buds.   Conclusions: Maxillary molars extraction has a degenerative effect on the structure of  taste buds and gustatory epithelium which were more marked at the extraction side and showed improvement upon elongation of follow up period.

Comparison of seropositivity of human T lymphotropic virus type 1 in mycosis fungoides patients and normal volunteers: a case-control study and review of literature.

BACKGROUND: There have been controversial reports about the possible association between mycosis fungoides (MF), its leukemic variant Siotazary syndrome (SS) and human T lymphotropic virus type 1 (HTLV-1) in different geographical regions. AIMS: The purpose of this study was to explore any association between MF and presence of HTLV-1 infection in Iran. METHODS: In a case-control setting, 150 clinically and histopathologically proven MF patients had been admitted to the tertiary referral skin center during a 10-year period and another 150 normal volunteers had been compared with each other for the presence of HTLV-1 infection. Enzyme-linked immunosorbent assay (ELISA) was used to detect antibodies against HTLV-1, and positive results were confirmed with western blotting. RESULTS: Only three MF patients had HTLV-1 infection, whereas two cases of normal subjects had the infection (P > 0.05). The only three seropositive MF patients were male and from North-Eastern Iran. CONCLUSION: This study showed that MF does not correlate with HTLV-1 infection in Iran.