Proactive infection control measures to prevent nosocomial transmission of carbapenem-resistant Enterobacteriaceae in a non-endemic area

Background Identification of hospitalized carbapenem-resistant Enterobacteriaceae （CRE）-positive patient is important in preventing nosocomial transmission.The objective of this study was to illustrate the implementation of proactive infection control measures in preventing nosocomial transmission of CRE in a healthcare region of over 3200 beds in Hong Kong between October 1,2010 and December 31,2011.Methods The program included active surveillance culture in patients with history of medical tourism with hospitalization and surgical operation outside Hong Kong within 12 months before admission,and ＂added test＂ as an opportunistic CRE screening in all fecal specimens submitted to the laboratory.Outbreak investigation and contact tracing were conducted for CRE-positive patients.Serial quantitative culture was performed on CRE-positive patients and the duration of fecal carriage of CRE was analyzed.Results During the study period,a total of 6533 patients were screened for CRE,of which 76 patients were positive （10 from active surveillance culture,65 from ＂added test＂,and 1 secondary case from contact tracing of 223 patients with no nosocomial outbreak）,resulting in an overall rate of CRE fecal carriage of 1.2％.The median time of fecal carriage of CRE was 43 days （range,13-119 days）.Beta-lactam-beta-lactamase-inhibitors,cephalosporins,and fluoroquinolones were associated significantly with high fecal bacterial load when used 90 days before CRE detection,while use of cephalosporins,carbapenems,and fiuoroquinolones after CRE detection are significantly associated with longer duration of carriage.The duration of fecal carriage of CRE also correlates significantly with the initial fecal bacterial load （Pearson correlation：0.53; P=0.02）.Conclusion Proactive infection control measures by enhanced surveillance program identify CRE-positive patients and data obtained are useful for the planning of and resource allocation for CRE control.

Comparison of clinical course of patients with severe acute respiratory syndrome among the multiple generations of nosocomial transmission

Background Severe acute respiratory syndrome (SARS) is characterized by both an atypical pneumonia and efficient nosocomial transmissin. However,it remains unknown whether the infectivity and the virulence of the pathogen will change throughout the successive transmission. This study was conducted to compare the clinical features and management regimens of patients with SARS among the multiple generations from nosocomial transmission initiated by a super-spreader. Methods The clinical data of 84 epidemiologically-linked SARS patients from a hospital outbreak were retrospectively studied. All patients,in whom a clear-cut transmission generation could be noted,had a direct or indirect exposure to the index patient and the epidemic successively propagated through the multiple generations of cases within a short period of time. Results There were 66 women and 18 men with mean age of (29.2 ± 10.3) years in this cluster;and 96.4% of whom were health care workers. Detailed contact tracing identified 35 (41.7%) first-generation cases,34 (40.5%) second-generation cases,and 15 (17.8%) third-generation cases. No statistical differences among the multiple generations of transmission were found in terms of age,gender,incubation period and length of hospital stay. With the advanced transmission generations,the initial temperature lowered,the number of cases with dry cough decreased. There were no statistical differences in the peak temperature and duration of fever,other accompanying symptoms,leucopenia;however,the time from initial pulmonary infiltrates to radiographic recovery shortened ( P <0.05). No differences were found in maximum number of lung fields involved,duration from the onset of fever to the occurrence of pulmonary infiltrates and time from the initial pulmonary infiltrate to its peak among the multiple transmission generations ( P >0.05). No statistical differences were found in modes of oxygen therapy and sorts of antibiotics prescribed among the various transmission generations ( P >0.05);however, as with the advanced transmission generations,the number of cases prescribed with methylprednisolone,human γ-globulin,interferon-α,antiviral drugs (oral ribavirin or oseltamivir) increased ( P <0.05) and time from admission to starting these medication shortened ( P <0.05). Conclusions There is no evidence that SARS infection will evolve or transmit within a fashion that permits it to become less powerful throughout the successive transmission within a short time.

Identifying the Risk of SARS-CoV-2 Infection and Environmental Monitoring in Airborne Infectious Isolation Rooms(AIIRs)

Healthcare workers(HCWs)are at high risk of occupational exposure to the new pandemic human coronavirus,SARSCoV-2,and are a source of nosocomial transmission in airborne infectious isolation rooms(AIIRs).Here,we performed comprehensive environmental contamination surveillance to evaluate the risk of viral transmission in AIIRs with 115 rooms in three buildings at the Shanghai Public Health Clinical Center,Shanghai,during the treatment of 334 patients infected with SARS-CoV-2.The results showed that the risk of airborne transmission of SARS-CoV-2 in AIIRs was low(1.62%,25/1544)due to the directional airflow and strong environmental hygiene procedures.However,we detected viral RNA on the surface of foot-operated openers and bathroom sinks in AIIRs(viral load:55.00–3154.50 copies/mL).This might be a source of contamination to connecting corridors and object surfaces through the footwear and gloves used by HCWs.The risk of infection was eliminated by the use of disposable footwear covers and the application of more effective environmental and personal hygiene measures.With the help of effective infection control procedures,none of 290 HCWs was infected when working in the AIIRs at this hospital.This study has provided information pertinent for infection control in AIIRs during the treatment of COVID-19 patients.

Risks and challenges of HIV infection transmitted via blood transfusion

Promoting biosafety regulations and techniques supports human health and protects individuals and groups from harmful incidents.Particular attention should be paid to those potential infectious hazards associated with blood and other bodily fluids,especially those highly transmitted infectious diseases,such as human immunodeficiency virus(HIV),one of the largest global health threats.Ensuring innovative and adaptive screening and laboratory techniques to reduce the possibility of HIV transmission are integral to managing the disease.We review here the evolution and success of blood screening techniques for HIV,along with current issues that still need to be addressed.Published academic articles and media reports about nosocomial HIV transmission events since 1981 were reviewed to identify current blood screening and transfusion safety trends across the globe,along with specific recommendations from the Chinese perspective.Although most initial screening was limited only to antibody and antigen testing,newer screening tests(such as nucleic acid testing),coupled with risk-based screening of donors,have led to reduced risk of HIV transmission and continues to reduce the“window period,”when an HIV-positive individual may test negative though they have been infected.Further examination of current guidelines and regulations across the globe are discussed,in order to understand where critical gaps in screening may exist.Through examination of this data,it is evident that huge strides have been made since the beginning of the epidemic;however improved technical training of staff and streamlined testing guidelines could help promote efficient screening of HIV,while also supporting those providing care.