Clustering cases of Chlamydia psittaci pneumonia mimicking COVID-19 pneumonia

Table 2 The imaging findings of patients with coronavirus disease 2019 and psittacosis

	Psittacosis (n = 6)	COVID-19 (n = 13)	P value
Predominant lesion type			0.221
GGO	0 (0)	5 (38.5)
Consolidation	3 (50)	5 (38.5)
Mixed GGO and consolidation	3 (50)	3 (23.1)
Air bronchogram	6 (100)	8 (61.5)	0.128
Vascular enlargement	1 (16.7)	12 (92.3)	0.003
Margin (uneasily differentiated)	6 (100)	8 (61.5)	0.128
Reticulation	5 (75)	9 (69.2)	1.000
Pleural effusions	6 (100)	1 (7.7)	0.002
Craniocaudal distribution			0.026
Upper lung predominant	0 (0)	2 (15.4)
Lower lung predominant	6 (100)	4 (30.8)
No craniocaudal distribution	0 (0)	7 (53.8)
Transverse distribution			0.255
Central	0 (0)	0 (0)
Peripheral	6 (100)	9 (69.2)
No transverse distribution	0 (0)	4 (30.8)
Lung region distribution			0.001
Unilateral	6 (100)	2 (15.4)
Bilateral	0 (0)	11 (84.6)
Number of involved lung lobes			0.006
1	6 (100)	2 (15.4)
2	0 (0)	3 (23.1)
3	0 (0)	0 (0)
4	0 (0)	5 (38.5)
5	0 (0)	5 (38.5)

Note: The data are presented as the numbers (percentages). GGO: Ground-glass opacity.