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The evolving nature of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has necessitated periodic revisions of COVID-19 patient treatment and discharge guidelines. Since the identification of the first COVID-19 cases in November 2019, the World Health Organization (WHO) has played a crucial role in tackling the country-level pandemic preparedness and patient management protocols. Among others, the WHO provided a guideline on the clinical management of COVID-19 patients according to which patients can be released from isolation centers on the 10th day following clinical symptom manifestation, with a minimum of 72 additional hours following the resolution of symptoms. However, emerging direct evidence indicating the possibility of viral shedding 14 days after the onset of symptoms called for evaluation of the current WHO discharge recommendations. In this review article, we carried out comprehensive literature analysis of viral shedding with specific focus on the duration of viral shedding and infectivity in asymptomatic and symptomatic (mild, moderate, and severe forms) COVID-19 patients. Our literature search indicates that even though, there are specific instances where the current protocols may not be applicable ( such as in immune-compromised patients there is no strong evidence to contradict the current WHO discharge criteria.

Depression continues to be a major global health problem. Although antidepressants are used for its treatment, efficacy is often inconsistent. Thus, the search for alternative therapeutic medicines for its treatment is still important. In this study, the antidepressant-like effect of Pseudospondias microcarpa extract (30–300 mg kg−1, p.o.) was investigated in two predictive models of depression—forced swimming test and tail suspension test in mice. Additionally, the mechanism(s) of action involved were assessed. Acute treatment with the extract dose dependently reduced immobility of mice in both models. The antidepressant-like effect of the extract (100 mg kg−1, p.o.) was blocked by p-chlorophenylalanine and cyproheptadine but not prazosin, propranolol, or yohimbine. Concomitant administration of d-cycloserine and the extract potentiated the anti-immobility effect. In contrast, d-serine, a full agonist of glycine/NMDA receptors, abolished the effects. Anti-immobility effects of PME were prevented by pretreatment of mice with L-arginine (750 mg kg−1, i.p.) and sildenafil (5 mg kg−1, i.p.). On the contrary, pretreatment of mice with L-NAME (30 mg kg−1, i.p.) or methylene blue (10 mg kg−1, i.p.) potentiated its effects. The extract produces an antidepressant-like effect in the FST and TST that is dependent on the serotoninergic system, NMDA receptor complex, and the nitric oxide pathway.

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