Etiological analysis of 61 286 hospitalized specimens from a tertiary hospital over 5 years

Objective To investigate the detection and distribution of hospitalized specimens from a tertiary hospital over 5 years. Methods Specimens of sputum, urine, blood, secretions and puncture fluid were collected from patients admitted to the Harrison International Peace Hospital from November 2013 to November 2018. The origin of specimens, the distribution of departments and the distribution of pathogenic bacteria isolated were analyzed retrospectively. Results A total of 61 286 specimens were sent for examination during the 5 years. The top 5 specimens were sputum culture (n = 18 302, 29.9%), sputum smear (n = 11 253, 18.4%), blood culture (n = 9 713, 15.8%), urine culture (n = 6 448, 10.5%) and secretion culture (n = 6 133, 10.0%), accounting for 84.6% (51 849/61 286). Sputum specimens accounted for 48.2% (29 555/61 286) with the largest proportion. The number of specimens from medical wards was much higher than that from surgical wards (specimens: 25 468 vs. 10 521), respiratory medicine, department of critical care medicine and emergency intensive care unit (EICU) were important sources of pathogenic specimens in the hospital, accounting for 29.8% (18 243/61 286) in total. The average positive rate of all specimens was 23.5% (14 424/61 286). The positive rates of sputum culture and urine culture were 29.7% (5 428/18 302) and 35.4% (2 281/6 448), respectively, while the positive rate of blood culture was only 6.6% (643/9 713). Escherichia coli was the most common pathogen in all specimens except for sputum culture and fecal culture. Escherichia coli [40.6% (926/2 281)], Klebsiella pneumoniae [9.2% (210/2 281)], Pseudomonas aeruginosa [8.2% (188/2 281)], Enterococcus faecalis (group D) [6.6% (151/2 281)] and Candida albicans [3.2% (73/2 281)] were the most common pathogens in urine culture. Klebsiella pneumoniae [24.1% (1 309/5 428)], Acinetobacter baumannii [21.3% (1 154/5 428)], Pseudomonas aeruginosa [15.1% (818/5 428)], Escherichia coli [6.5% (351/5 428)] and Maltose oligotrophomonas maltose [5.8% (316/5 428)] were the most common pathogens in sputum culture. Escherichia coli [36.5% (235/643)], Klebsiella pneumoniae [10.9% (70/643)], Pseudomonas aeruginosa [4.8% (31/643)], Staphylococcus epidermidis [3.4% (22/643)] and Staphylococcus humanis [3.3% (21/643)] were the most common pathogens in blood culture. Conclusion Specimens sent for examination by inpatients are mainly from internal medicine wards, mainly from sputum, blood and urine, and the detected pathogens are mainly Gram-negative bacteria. Key words: Hospitalized specimen; Etiological examination; Nosocomial infection