Background: The viral shedding time (VST) of SARS-CoV-2 mainly determines its transmission and duration of infectiousness. However, it was heterogeneous in the existing studies. Here, we performed a meta-analysis to comprehensively summarize the VST of SARS-CoV-2. Methods: We searched PubMed, Web of Science, MedRxiv, BioRxiv, CNKI, CSTJ, and Wanfang up to October 25, 2020, for studies that reported VSTs of SARS-CoV-2. Pooled estimates and 95% CIs for the VSTs were calculated using log-transformed data. The VSTs in SARS-CoV-2 infections based on different demographic and clinical characteristics, treatments and specimens were stratified by subgroup analysis. Results: A total of 35 studies involving 3,385 participants met the inclusion criteria. The pooled mean VST was 16.8 days (95% CI: 14.8-19.4, I2 = 99.56%) in SARS-CoV-2 infections. The VST was significantly longer in symptomatic infections (19.7 days, 95% CI: 17.2-22.7, I2 = 99.34%) than in asymptomatic infections (10.9 days, 95% CI: 8.3-14.3, I2 = 98.89%) (P < 0.05). The VST was 23.2 days (95% CI: 19.0-28.4, I2 = 99.24%) in adults, which was significantly longer than that in children (9.9 days, 95% CI: 8.1-12.2, I2 = 85.74%) (P < 0.05). The VST was significantly longer in persons with chronic diseases (24.2 days, 95% CI: 19.2-30.2, I2 = 84.07%) than in those without chronic diseases (11.5 days, 95% CI: 5.3-25.0, I2 = 82.11%) (P < 0.05). Persons receiving corticosteroid treatment (28.3 days, 95% CI: 25.6-31.2, I2 = 0.00%) had a longer VST than those without corticosteroid treatment (16.2 days, 95% CI: 11.5-22.5, I2 = 92.27%) (P = 0.06). The VST was significantly longer in stool specimens (30.3 days, 95% CI: 23.1-39.2, I2 = 92.09%) than in respiratory tract specimens (17.5 days, 95% CI: 14.9-20.6, I2 = 99.67%) (P < 0.05). Conclusions: A longer VST was found in symptomatic infections, infected adults, persons with chronic diseases, and stool specimens.
In this meta-analysis, the VST was longer in symptomatic, adults (vs kids), chronic disease, and in stool specimens. Although this is interesting, from an EM perspective, it's not clear about this information as it doesn't address the length of VST after recovery from symptoms. CDC guidelines still remain the standard that individuals use. This may shape those guidelines, but until then, it is unlikely to change practice.
A very timely and useful article on viral-shedding time for SARS. This is important for EM physicians to help patients understand infectious times and isolation for discharge planning. This may also help when variants become an issue as well.
This is important to help institutions with guidelines for isolation, return to work, and repeat testing for "family members," etc. Earlier in the pandemic, every LTC facility and NH was struggling to make up rules for family visitations, etc. Some were asking for 2 negative tests within 48-72 hours to allow visitation to rehab facilities where the spouse was recovering from ICU care. It made no sense that positive tests 4-6 weeks out of infection meant no visitation, as clinically the VL would be low. This article may help to develop more appropriate guidelines.
I am concerned that they included very small studies and also non-peer reviewed studies. It's curious that so many of the included studies seemed to originate in Asia. I worry about generalizability as well. There are too many red flags for study quality here.
The clinical implication of these findings is not clear. If VST translates into infectiousness, the implications would be disquieting.
Very interesting paper describing viral spreading time. This spreading time varies with multiples factors, including age, chronic disease, steroid use, and symptoms. This is relevant information to be considered when we have to determine the duration of quarantine.
Uncertain how this should be used clinically.
Hopefully, the shed time will not gradually increase during the continued rapacity of the virus.
Important data in determining the infectiousness of COVID depending on source and severity of illness.
Important information for managing patients affected by COVID-19.
A good meta-analysis of viral shedding time.
Results are interesting and useful, but in interpretation it 'd be considered that RT PCR is not a viral culture, and does not allow determination of whether the virus is viable and transmissible. Accordingly, a positive test does not necessarily means that the patient can transmit the virus, and further studies are needed to verify this hypothesis (see: Liotti et al, JAMA 2021).