[Epidemiological investigation on a cluster epidemic of COVID-19 in a collective workplace in Tianjin].

Objective: To investigate and analysis the epidemiological characteristics of a cluster epidemic of COIVD-19 in a collective workplace in Tianjin, evduate the prevention and control measures based on limited evidence and experience in early period of COVID-19 epidemic. Methods: Descriptive research method was used to describe the distribution and other epidemiological characteristics of the cluster cases of COVID-19. Results: Since the onset of the first index case on January 15, ten confirmed COVID-19 cases had occurred in the workplace, and the epidemic had spread from the workplace to 4 families, infecting 7 family members. The median age of 17 cases was 55 (19-79) years. All the 10 employee cases were males, and in the family cases, 3 were males and 4 were females. Of the employee cases, 8 worked in CW workshop and 2 worked in administrative office building. The median exposure-onset interval of all the cases was 4 days, and the median exposure-onset interval was 4.5 days in the employee cases and 4 days in the family cases. The median onset-medical care seeking interval was 4 days in the non-isolated cases, 2.5 days in the cases with home isolation after onset, and 0.5 day in the cases with home isolation before onset. Conclusions: The clustering of COVID-19 cases was observed in this workplace in Tianjin, which affected 4 families. In the early stage of the epidemic, accurate and rapid blocking and control measures can completely prevent the large-scale spread of COVID-19.

[Investigation on the status of multidrug-resistant gram-negative bacteria induced by occupational exposure among medical staff in ICU].

Objective: To understand the natural carriage status of multidrug resistant gram-negative bacteria in ICU medical personmel and control growp of 69 hospitals in Tianjin. Methods: From April 2007 to October 2016, 2902 samples of nasal vestibule and hand swabs were collected from 1296 ICU medical personmel and 155 non medical personmel (control group) , and 14 kinds of antimicrobial agents were used to test the sensitivity of gram-negative bacilli. Results: 332 Gram-negative bacteria were isolated from medical personmel, of which 139 were multidrug resistant; 70 gram-negative bacteria were isolated from control group, and 20 of which were multidrug resistant. There was no significant difference (P>0.05) in the incidence of nasal vestibular colonization between medical personmel group (231/1296) and control group (32/155) . The control group (38/155) had a higher rate of hand bacteria carriage than medical staff group (101/1296) (P<0.01) . The proportion of multidrug resistant gram-negative bacteria was 28.57% (20/70) in control group, which was significantly lower than medical personmel group (41.87%, 139/332) (P<0.05) . Conclusion: For the nasal vestibule, the medical personnel and control guoup have the same gram-negative bacteria carrying rate, but the multidrug resistant bacteria isolation rate from the medical staff group are significantly higher which may due to vocational contamination of pathogen in ICU; while the gram-negative bacteria in the hands of the medical staff group are significantly lower than those of the control group, which might attribute to the difference of hand sanitation technique of two groups.

Presence, distribution and molecular epidemiology of multi-drug-resistant Gram-negative bacilli from medical personnel of intensive care units in Tianjin, China, 2007-2015.

BACKGROUND: Multi-drug-resistant Gram-negative bacteria (MDRGNB) have become an important cause of nosocomial infection in intensive care units (ICUs). AIMS: To investigate the molecular epidemiology of MDRGNB isolated from medical personnel (MP) and non-medical personnel (NMP) at 69 ICUs in Tianjin, China. METHODS: From April 2007 to October 2015, 2636 nasal and hand swab samples from 1185 MP and 133 NMP were cultured for GNB (including MDRGNB), meticillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). The susceptibilities of GNB to 14 antimicrobial agents were determined, and 80 MDRGNB were characterized using pulsed-field gel electrophoresis (PFGE) and dendrogram analysis. FINDINGS: In total, 301 GNB were identified in 269 MP, including 109 MDRGNB isolates in 104 MP. Forty-two GNB were isolated from 39 NMP, which included 20 NMP with MDRGNB. Overall, 8.8% of MP were colonized with MDRGNB, which greatly exceeded colonization rates with MRSA (0.9%) and VRE (0.1%). Three pairs of Klebsiella pneumoniae and one pair of Enterobacter aerogenes were indistinguishable from each other, but the majority of isolate tests had distinct PFGE profiles. CONCLUSIONS: The prevalence of MDRGNB was high among ICU MP in Tianjin, and greatly exceeded that of VRE and MRSA. There was no difference in the rates of nasal carriage of MDRGNB between MP and NMP, but NMP were significantly more likely to have hand colonization with MDRGNB. PFGE profiles showed that there was only limited sharing of strains of MDR E. aerogenes and K. pneumoniae between personnel.