Table 2.

Changes in pneumonia aetiology from the pre-COVID-19 era to the COVID-19 era

Pathogen species	Pre-COVID-19 era (n = 233)	COVID-19 era (n = 291)	P value
Bacteria	54 (23.2)	71 (24.4)	0.823
Gram-positive bacteria
Staphylococcus aureus	4 (1.7)	8 (2.7)	0.623
Streptococcus pneumoniae	4 (1.7)	0 (0.0)	0.082
Enterococci	5 (2.1)	4 (1.4)	0.736
Gram-negative bacteria
Klebsiella pneumoniae	5 (2.1)	11 (3.8)	0.409
Escherichia coli	1 (0.4)	5 (1.7)	0.335
Pseudomonas aeruginosa	9 (3.9)	11 (3.8)	1.000
Chlamydia pneumoniae	5 (2.1)	9 (3.1)	0.693
Acinetobacter baumannii	2 (0.9)	3 (1.0)	1.000
Mycoplasma pneumoniae	8 (3.4)	7 (2.4)	0.662
Mycobacterium tuberculosis	10 (4.3)	11 (3.8)	0.942
Others*	8 (2.8)	10 (3.4)	0.822
Fungus	38 (16.3)	55 (18.9)	0.512
Invasive aspergillosis	20 (8.6)	41 (14.1)	0.069
Pneumocystis jirovecii	18 (7.7)	20 (6.9)	0.838
Respiratory virus	71 (30.7)	19 (6.6)	< 0.001
Influenza A	7 (3.0)	1 (0.3)	0.036
Influenza B	1 (0.4)	0 (0.0)	0.913
Respiratory syncytial virus	10 (4.3)	6 (2.1)	0.227
Parainfluenza virus	15 (6.5)	2 (0.7)	0.001
Adenovirus	13 (5.6)	4 (1.4)	0.015
Metapneumovirus	2 (0.9)	0 (0.0)	0.386
Rhinovirus	22 (9.5)	5 (1.7)	< 0.001
Human coronavirus	7 (3.0)	2 (0.7)	0.093
Bocavirus	1 (0.4)	1 (0.3)	1.000
Diffuse alveolar haemorrhage	1 (0.4)	3 (1.0)	0.778
Cytomegalovirus	7 (3.0)	2 (0.7)	0.093
Unknown aetiology	92 (39.5)	133 (45.7)	0.180

Data are presented as number (percentage) or median (interquartile range). ^*Others: Non-tuberculosis mycobacterium (4), Legionella pneumoniae (3), Corynebacterium striatum (3), Enterobacter species (2), Achromobacter species (1), Staphylococcus haemolyticus (1), Moraxella catarrhalis (1), Stenotrophomonas maltophilia (1), Rothia mucilaginosa (1), Haemophilus influenzae (1)