Table 1.

Etiologic distribution of community acquired pneumonia.

	Cases, no.	Proportion (%) among all CAP cases	Proportion (%) among microbiologically identified cases
Streptococcus pneumoniae	276	12.42	36.7
Staphylococcus aureus	109	4.90	14.5
Haemophilus influenzae	105	4.72	14
Klebsiella pneumoniae	105	4.72	14
Escherichia coli	17	0.76	2.26
Pseudomonas aeruginosa	83	3.73	11
Enterobacter spp.	18	0.81	2.39
Moraxella catarrhalis	24	1.08	3.19
Other Streptococcus spp.	9	0.40	1.2
Other Klebsiella spp.	6	0.27	0.8
Other Pseudomonas spp.	5	0.22	0.66
Acinetobacter spp.	7	0.31	0.93
Serratia marcescens	6	0.27	0.8
Stenotrophomonas maltophilia	4	0.18	0.53
Mycoplasma pneumoniae	5	0.22	0.66
Other bacteriaa	12	0.54	1.6
Respiratory virusesb	179	8.05	23.8
Undetermined	1469	66.14	–
Totalc	2221	100%	100%

CAP, Community-acquired pneumonia.

^aOther bacteria (no. of cases): Aeromonas caviae (2), Pantoea agglomerans (1), Burkholderia cepacia (1), Morganella morganii (2), CMV (2), Sphingomonas paucimobilis (1), Alcaligenes xylosoxidans ssp. denitrificans (1), Raoultella planticola (1), Citrobacter freundii (1).

^bRespiratory viruses (no. of cases): Rhinovirus (37), influenza A/B (31), Parainfluenza (21), Metapneumovirus (19), RSV (19), Adenovirus (16), Coronavirus OC43/HKU1 (15), Coronavirus 229E/NL63 (11), Enterovirus (11).

^cThe total count was smaller than the sum of the cases because of polymicrobial infection in some cases.