Table 5. Comparison of pleural and non-pulmonary parenchymal abnormalities in COVID-19, SARS, MERS, and influenza (102-111).

Virus	Normal X-ray	Pleural effusion	Effusioncharacteristics	Pneumothorax	Mediastinal lymphadenopathy	Overall mortality (%)
COVID-19	About 20%	4.2–5.8% (typically later in the disease)	Lymphocyte predominant, exudative	Approximately 1%	2.9–5.4%	1–3
SARS	~20%	26% (typically later in the disease)	Not reported	11%	Not reported	9
MERS	~20%	~50% (develops early, often in the first week)	Not reported	Rare but associated with fatal outcome	Not reported	34
Influenza	Unknown	20–36%, early	Lymphocyte predominant	Very rare	Approximately 20%	0.1

COVID-19, coronavirus disease 19; MERS, middle east respiratory syndrome; SARS, severe acute respiratory syndrome.