Objectives:
What are the specific symptoms and comorbidities predicting severe COVID-19 and intensive care unit (ICU) admission?

Study design:
This review article included 7 retrospective cohort studies, conducted between December 2019 and February 2020, with a total of 1,813 COVID-19 patients.

Objectives:
The coronavirus disease 2019 (COVID-19) pandemic necessitates identifying laboratory markers to assist the clinicians in early recognition of severe disease. Given the unclear association of hypoalbuminemia and severe COVID-19, this review article has been conducted.

Does hypoalbuminemia (a low albumin level) increase risk of severe COVID-19 infection?

Objectives:
What is the burden of co-infections in patients with COVID-19?

Study design:
This review article included 30 studies (29 observational studies and one RCT) with a total of 3,834 COVID-19 patients.

Three studies reported fungal co-infections.

Objectives:
Does rotavirus vaccination reduce risk of rotavirus associated diarrhea in sub-Saharan Africa?

Study design:
This review article included 17 studies with a total of 176,698 participants and all were children less than 5 years of age.

There was no evidence of publication bias.

Results and conclusions:

Objectives:
Some studies of hospitalized patients suggested that the risk of death and/or severe illness due to COVID-19 is not associated with the use of angiotensin-converting enzyme inhibitors (ACEIs) and/or angiotensin II receptor type 1 blockers (ARBs). Nevertheless, some controversy still exists and there is limited information of the ACEIs/ARBs effect size on COVID-19 prognosis. Therefore, this review article has been conducted.

Objectives:
What are the effects of physical distance, face masks and eye protection on COVID-19 virus transmission in health-care and non-health-care (e.g., community) settings?

Study design:
This review article included 172 observational studies across 16 countries and 6 continents, with no randomised controlled trials (RCTs) and 44 relevant comparative studies in health-care and non-health-care settings (n = 25,697 patients).

Results and conclusions:   

Objectives:
Do dietary calcium intakes or calcium supplements increase risk of cardiovascular disease?
 
Study design:
This review article included 26 prospective cohort studies and 16 RCTs.

Results and conclusions:
The investigators found in cohort studies that dietary calcium intakes ranging from 200 to 1500 mg/d did not affect the risk of cardiovascular disease [relative risk = 0.96, 95% CI = 0.87 to 1.05].

Objectives:
Does face mask with or without hand wash reduce influenza-like illness (ILI) in community settings?

Study design:
This review article included 9 cluster RCTs. Of the 9 RCTs, 6 were done in household setting and 2 were done with university students as participants in university residence halls.
6 of these studies compared three arms of intervention - hand hygiene (hand wash) alone, both hand hygiene and triple-layered facial mask versus no intervention.

Objectives:
Studies reported associations of inflammatory markers with the severity of COVID-19, but conclusions were inconsistent. Therefore, this review article has been conducted.

Objectives:
Coronavirus disease 2019 (COVID-19) is an emerging disease that was first reported in Wuhan city, the capital of Hubei province in China and has subsequently spread worldwide. Risk factors for mortality have not been well summarized. Therefore, this review article has been conducted.

What are the risk factors for mortality from COVID-19 infection?

Study design:
This review article included 14 studies with 29,909 COVID-19 infected patients and 1,445 cases of death.