Xiaoli Wang

A cluster randomized clinical trial comparing fit‐tested and non‐fit‐tested N95 respirators to medical masks to prevent respiratory virus infection in health care workers

Please cite this paper as: MacIntyre et al. (2011) A cluster randomized clinical trial comparing fit‐tested and non‐fit‐tested N95 respirators to medical masks to prevent respiratory virus infection in health care workers. Influenza and Other Respiratory Viruses DOI: 10.1111/j.1750‐2659.2010.00198.x.

Acceptance of a vaccine against pandemic influenza A (H1N1) virus amongst healthcare workers in Beijing, China.

Due to the advent of the new influenza A (H1N1) strain in 2009, many countries introduced mass immunization programs. Healthcare workers (HCWs) were amongst the key groups targeted for the vaccine in these programs. However, experience with the seasonal influenza vaccine has shown that there are multiple barriers related to the attitudes and perceptions of the population which influence uptake. The aim of this study was to determine pandemic influenza A (H1N1) vaccination rate amongst a group of Chinese HCWs and the associated factors around acceptance. A cross-sectional investigation of HCWs (doctors, nurses and technicians) from 19 hospitals in Beijing, China was conducted in January 2010. The main outcome measures were awareness, risk perception of H1N1, preventive measures and uptake of H1N1 vaccination during the pandemic. A total of 1657 HCWs completed the survey. A quarter of the participants reported receiving the pandemic influenza A (H1N1) vaccine. Occupation (being a doctor), receiving seasonal flu vaccine and believing in the effectiveness of the vaccine were all strongly associated with accepting the pandemic influenza A (H1N1) vaccine. Over a thousand participants (61%, 1008/1657) agreed that they were concerned about the side effects of the swine flu vaccine, while 758 (46%) were concerned that the vaccine had not been tested adequately. While studies reported high rates of willingness to receive the vaccine, in reality these did not transpire. Aside from promoting seasonal flu vaccination, authorities need to start educational campaigns much earlier in a pandemic. Programs that are simultaneously launched with the introduction of the vaccine will not be as successful, as those which have built momentum alongside the pandemic.

A Randomized Clinical Trial of Three Options for N95 Respirators and Medical Masks in Health Workers

RATIONALEnWe compared three policy options for the use of medical masks and N95 respirators in healthcare workers (HCWs).nnnOBJECTIVESnA cluster randomized clinical trial of 1,669 hospital-based HCWs in Beijing, China in the winter of 2009-2010.nnnMETHODSnParticipants were randomized to medical masks, N95 respirators, or targeted use of N95 respirators while doing high-risk procedures or barrier nursing. Outcomes included clinical respiratory illness (CRI) and laboratory-confirmed respiratory pathogens in symptomatic subjects.nnnMEASUREMENTS AND MAIN RESULTSnThe rate of CRI was highest in the medical mask arm (98 of 572; 17%), followed by the targeted N95 arm (61 of 516; 11.8%), and the N95 arm (42 of 581; 7.2%) (P < 0.05). Bacterial respiratory tract colonization in subjects with CRI was highest in the medical mask arm (14.7%; 84 of 572), followed by the targeted N95 arm (10.1%; 52 of 516), and lowest in the N95 arm (6.2%; 36 of 581) (P = 0.02). After adjusting for confounders, only continuous use of N95 remained significant against CRI and bacterial colonization, and for just CRI compared with targeted N95 use. Targeted N95 use was not superior to medical masks.nnnCONCLUSIONSnContinuous use of N95 respirators was more efficacious against CRI than intermittent use of N95 or medical masks. Most policies for HCWs recommend use of medical masks alone or targeted N95 respirator use. Continuous use of N95s resulted in significantly lower rates of bacterial colonization, a novel finding that points to more research on the clinical significance of bacterial infection in symptomatic HCWs. This study provides further data to inform occupational policy options for HCWs. Clinical trial registered with Australian New Zealand Clinical Trials Registry http://www.anzctr.org.au (ACTRN 12609000778280).

Severe, critical and fatal cases of 2009 H1N1 influenza in China

OBJECTIVEnFor severe, critical and fatal cases of 2009 H1N1 influenza in the winter in the Northern Hemisphere, the detailed features are not fully known. The aim of this study was to examine these features through describing these cases in Beijing, China in 2009.nnnMETHODSnData on severe, critical and fatal cases were collected via the Notifiable Disease Surveillance System and a designated surveillance system for managing 2009 H1N1 influenza cases in Beijing. The characteristics and risk factors of these cases were elucidated.nnnRESULTSnA total of 475 severe cases, 73 critical ones and 69 deaths were identified in 2009. The proportion of obesity was low, as well as pregnancy. About half of them had no underlying disease. Most of deaths had multi-organ failure, with a median interval from illness onset to death of ten days. Delay in visiting hospital, cardiovascular disease and allergy predicted a higher risk of severe disease, and cases aged 6-17 years were at lower risk. Cases not promptly receiving neuraminidase inhibitors were at increased risk of death.nnnCONCLUSIONSnAge and underlying disease are significantly associated with severity of outcomes of 2009 H1N1 influenza; prompt presentation to hospital and use of neuraminidase inhibitor were protective.

Increased norovirus activity was associated with a novel norovirus GII.17 variant in Beijing, China during winter 2014–2015

BackgroundNorovirus (NoV) is a leading cause of sporadic cases and outbreaks of acute gastroenteritis (AGE). Increased NoV activity was observed in Beijing, China during winter 2014–2015; therefore, we examined the epidemiological patterns and genetic characteristics of NoV in the sporadic cases and outbreaks.MethodsThe weekly number of infectious diarrhea cases reported by all hospitals in Beijing was analyzed through the China information system for disease control and prevention. Fecal specimens were collected from the outbreaks and outpatients with AGE, and GI and GII NoVs were detected using real time reverse transcription polymerase chain reaction. The partial capsid genes and RNA-dependent RNA polymerase (RdRp) genes of NoV were both amplified and sequenced, and genotyping and phylogenetic analyses were performed.ResultsBetween December 2014 and March 2015, the number of infectious diarrhea cases in Beijing (10,626 cases) increased by 35.6xa0% over that of the previous year (7835 cases), and the detection rate of NoV (29.8xa0%, 191/640) among outpatients with AGE was significantly higher than in the previous year (12.9xa0%, 79/613) (χ2u2009=u200953.252, Pu2009<u20090.001). Between November 2014 and March 2015, 35 outbreaks of AGE were reported in Beijing, and NoVs were detected in 33 outbreaks, all of which belonged to the GII genogroup. NoVs were sequenced and genotyped in 22 outbreaks, among which 20 were caused by a novel GII.17 strain. Among outpatients with AGE, this novel GII.17 strain was first detected in an outpatient in August 2014, and it replaced GII.4 Sydney_2012 as the predominant variant between December 2014 and March 2015. A phylogenetic analysis of the capsid genes and RdRp genes revealed that this novel GII.17 strain was distinct from previously identified GII variants, and it was recently designated as GII.P17_GII.17. This variant was further clustered into two sub-groups, named GII.17_2012 and GII.17_2014. During winter 2014–2015, GII.17_2014 caused the majority of AGE outbreaks in China and Japan.ConclusionsDuring winter 2014–2015, a novel NoV GII.17 variant replaced the GII.4 variant Sydney 2012 as the predominant strain in Beijing, China and caused increased NoV activity.

Comparing early outbreak detection algorithms based on their optimized parameter values

n Abstractn n Backgroundn Many researchers have evaluated the performance of outbreak detection algorithms with recommended parameter values. However, the influence of parameter values on algorithm performance is often ignored.n n n Methodsn Based on reported case counts of bacillary dysentery from 2005 to 2007 in Beijing, semi-synthetic datasets containing outbreak signals were simulated to evaluate the performance of five outbreak detection algorithms. Parameters’ values were optimized prior to the evaluation.n n n Resultsn Differences in performances were observed as parameter values changed. Of the five algorithms, space–time permutation scan statistics had a specificity of 99.9% and a detection time of less than half a day. The exponential weighted moving average exhibited the shortest detection time of 0.1 day, while the modified C1, C2 and C3 exhibited a detection time of close to one day.n n n Conclusionn The performance of these algorithms has a correlation to their parameter values, which may affect the performance evaluation.n n

Estimates of the true number of cases of pandemic (H1N1) 2009, Beijing, China.

During 2009, a total of 10,844 laboratory-confirmed cases of pandemic (H1N1) 2009 were reported in Beijing, People’s Republic of China. However, because most cases were not confirmed through laboratory testing, the true number is unknown. Using a multiplier model, we estimated that ≈1.46–2.30 million pandemic (H1N1) 2009 infections occurred.

Influenza vaccination amongst hospital health care workers in Beijing

BACKGROUNDnAnnual influenza vaccination is recommended for health care workers (HCWs) in many countries in order to reduce the morbidity associated with influenza in health care settings. However, compliance rates with influenza vaccination are commonly low.nnnAIMSnTo evaluate the current vaccination status of HCWs in Beijing, China, and examine their attitudes towards the disease and the vaccine.nnnMETHODSnIn January 2009, a survey was completed by 1909 HCWs in emergency departments, infection fever clinics, respiratory ward/outpatients clinics and pediatric medical departments of 24 hospitals in Beijing (99% response rate).nnnRESULTSnRespondents were categorized into three main groups by occupation: nursing (60%, n = 1143), medical (36%, n = 693) and other (4%, n = 73). When examining beliefs about the influenza vaccine, 57% (n = 1081) felt it was safe and 54% (n = 1028) thought it was effective. Less than 18% stated that they had been immunized in 2008; 40% (n = 765) or participants agreed with the statement the flu vaccine can cause flu in some people.nnnCONCLUSIONSnA better understanding of the barriers to vaccination in this population should facilitate the development of programs to make health care facilities a safer environment for both HCWs and patients.

Mask-wearing and respiratory infection in healthcare workers in Beijing, China

n Abstractn n Objectivesn The aim of the study was to determine rates of mask-wearing, of respiratory infection and the factors associated with mask-wearing and of respiratory infection in healthcare workers (HCWs) in Beijing during the winter of 2007/2008.n n n Methodsn We conducted a survey of 400 HCWs working in eight hospitals in Beijing by face to face interview using a standardized questionnaire.n n n Resultsn We found that 280/400 (70.0%) of HCWs were compliant with mask-wearing while in contact with patients. Respiratory infection occurred in 238/400 (59.5%) subjects from November, 2007 through February, 2008. Respiratory infection was higher among females (odds ratio [OR], 2.00 [95% confidence interval {CI}, 1.16-3.49]) and staff working in larger hospitals (OR, 1.72 [95% CI, 1.09-2.72]), but was lower among subjects with seasonal influenza vaccination (OR, 0.46 [95% CI, 0.28-0.76]), wearing medical masks (reference: cotton-yarn; OR, 0.60 [95% CI, 0.39-0.91]) or with good mask-wearing adherence (OR, 0.60 [95% CI, 0.37-0.98]). The risk of respiratory infection of HCWs working in low risk areas was similar to that of HCWs in high risk area.n n n Conclusionn Our data suggest that female HCWs and staffs working in larger hospitals are the focus of prevention and control of respiratory infection in Beijing hospitals. Mask-wearing and seasonal influenza vaccination are protective for respiratory infection in HCWs; the protective efficacy of medical masks is better than that of cotton yarn ones; respiratory infection of HCWs working in low risk areas should also be given attention.n n

Hospital Health Care Workers' Understanding of and Attitudes Toward Pandemic Influenza in Beijing

During a pandemic, health care workers (HCWs) will be essential to the health system response. This pre-pandemic study aimed to extend previous research by assessing the views, and intended behaviors of hospital HCWs in Beijing, China, regarding pandemic influenza. We undertook a cross-sectional investigation of a sample of HCWs from 24 hospitals in Beijing, China in January 2009. The main outcome measures were intentions regarding work attendance and quarantine, antiviral use and perceived preparation. Our study found that most HCWs perceived pandemic influenza to be very serious but very few were able to correctly define it. 74% (n=1406) of respondents accepted the risk of getting pandemic influenza as part of their job and 71% (n=1350) felt that they have the necessary knowledge to provide patient care during it. We identified two issues that could undermine the best of pandemic plans – the first, a low level of confidence in antivirals as an effective intervention; secondly, a high proportion of staff potentially engaging in inappropriate working behaviors