Adenoviruses Associated with Acute Respiratory Diseases Reported in Beijing from 2011 to 2013

Background

Adenovirus is one of the most common causes of viral acute respiratory infections. To identify the types of human adenoviruses (HAdVs) causing respiratory illness in Beijing, a sentinel surveillance project on the viral aetiology of acute respiratory infection was initiated in 2011.

Principal findings

Through the surveillance project, 4617 cases of respiratory infections were identified during 2011-2013. Throat swabs (pharynx and tonsil secretions) were collected from all the patients, and 15 different respiratory viruses were screened by multiplex one-step PCR method. 45 were identified as adenovirus-positive from sporadic and outbreak cases of respiratory infection by a multiplex one-step RT-PCR method, and a total of 21 adenovirus isolates were obtained. Five HAdV types among three species, including HAdV-3 (species HAdV-B), HAdV-4 (species HAdV-E), HAdV-7 (species HAdV-B), HAdV-55 (species HAdV-B), and an undefined HAdV type (species HAdV-C) were identified. The comparison results of the penton base, hexon, and fiber gene sequences of the Beijing HAdV-3, HAdV-4, HAdV-7, and HAdV-55 strains in this study and those from the GenBank database indicated significant spatial and temporal conservation and stability of sequences within the genome; however, the phylogenetic relationship indicated that both strain BJ04 and strain BJ09 isolated in 2012 and 2013, respectively, may have recombined between HAdV-1 genome and HAdV-2 genome within species HAdV-C, indicating intraspecies recombination.

Conclusions

This study confirmed that at least 5 HAdV types including HAdV-3, HAdV-4, HAdV-7, HAdV-55 and an undefined HAdV type were co-circulating and were the causative agents of respiratory tract infections in recent years in Beijing. HAdV-3, HAdV-4, HAdV-7, and HAdV-55 showed the apparent stability of the genomes, while intraspecies recombination was identified in strain BJ04 and BJ09. The recombinants carrying penton base gene of HAdV-1 as well as hexon and fiber genes of HAdV-2 might be a novel type of HAdV worthy of further study.     

Analysis of severe human adenovirus infection outbreak in Guangdong Province,southern China in 2019

During 2018-2019, a severe human adenovirus (HAdV) infection outbreak occurred in southern China. Here, we screened 18 respiratory pathogens in 1704 children (≤ 14 years old) hospitalized with acute respiratory illness in Guangzhou, China, in 2019. In total, 151 patients had positive HAdV test results; 34.4% (52/151) of them exhibited severe illness. HAdV infection occurred throughout the year, with a peak in summer. The median patient age was 3.0 (interquartile range:1.1-5.0) years. Patients with severe HAdV infection exhibited increases in 12 clinical indexes (P ≤ 0.019) and decreases in four indexes (P ≤ 0.007), compared with patients exhibiting nonsevere infection. No significant differences were found in age or sex distribution according to HAdV infection severity (P > 0.05); however, the distributions of comorbid disease and HAdV co-infection differed according to HAdV infection severity (P < 0.05). The main epidemic types were HAdV-3 (47.0%, 71/151) and HAdV-7 (46.4%, 70/151). However, the severe illness rate was significantly higher in patients with HAdV-7 (51.4%) than in patients with HAdV-3 (19.7%) and other types of HAdV (20%) (P < 0.001). Sequencing analysis of genomes/capsid genes of 13 HAdV-7 isolates revealed high similarity to previous Chinese isolates. A representative HAdV-7 isolate exhibited a similar proliferation curve to the curve described for the epidemic HAdV-3 strain Guangzhou01 (accession no. DQ099432) (P > 0.05); the HAdV-7 isolate exhibited stronger virulence and infectivity, compared with HAdV-3 (P < 0.001). Overall, comorbid disease, HAdV co-infection, and high virulence and infectivity of HAdV-7 were critical risk factors for severe HAdV infection; these data can facilitate treatment, control, and prevention of HAdV infection.     

Phylogenetic analysis of the main neutralization and hemagglutination determinants of all human adenovirus prototypes as a basis for molecular classification and taxonomy

Human adenoviruses (HAdV) are responsible for a wide spectrum of diseases. The neutralization epsilon determinant (loops 1 and 2) and the hemagglutination gamma determinant are relevant for the taxonomy of HAdV. Precise type identification of HAdV prototypes is crucial for detection of infection chains and epidemiology. epsilon and gamma determinant sequences of all 51 HAdV were generated to propose molecular classification criteria. Phylogenetic analysis of epsilon determinant sequences demonstrated sufficient genetic divergence for molecular classification, with the exception of HAdV-15 and HAdV-29, which also cannot be differentiated by classical cross-neutralization. Precise sequence divergence criteria for typing (<2.5% from loop 2 prototype sequence and <2.4% from loop 1 sequence) were deduced from phylogenetic analysis. These criteria may also facilitate identification of new HAdV prototypes. Fiber knob (gamma determinant) phylogeny indicated a two-step model of species evolution and multiple intraspecies recombination events in the origin of HAdV prototypes. HAdV-29 was identified as a recombination variant of HAdV-15 (epsilon determinant) and a speculative, not-yet-isolated HAdV prototype (gamma determinant). Subanalysis of molecular evolution in hypervariable regions 1 to 6 of the epsilon determinant indicated different selective pressures in subclusters of species HAdV-D. Additionally, gamma determinant phylogenetic analysis demonstrated that HAdV-8 did not cluster with -19 and -37 in spite of their having the same tissue tropism. The phylogeny of HAdV-E4 suggested origination by interspecies recombination between HAdV-B (hexon) and HAdV-C (fiber), as in simian adenovirus 25, indicating additional zoonotic transfer. In conclusion, molecular classification by systematic sequence analysis of immunogenic determinants yields new insights into HAdV phylogeny and evolution.     

Severe Community-Acquired Pneumonia Caused by Human Adenovirus in Immunocompetent Adults: A Multicenter Case Series

Background

Severe community-acquired pneumonia (CAP) caused by human adenovirus (HAdV), especially HAdV type 55 (HAdV-55) in immunocompetent adults has raised increasing concerns. Clinical knowledge of severe CAP and acute respiratory distress syndrome induced by HAdV-55 is still limited, though the pathogen has been fully characterized by whole-genome sequencing.

Methods

We conducted a multicentre retrospective review of all consecutive patients with severe CAP caused by HAdV in immunocompetent adults admitted to the Emergency Department Intensive Care Unit of two hospitals in Northern China between February 2012 and April 2014. Clinical, laboratory, radiological characteristics, treatments and outcomes of these patients were collected and analyzed.

Results

A total of 15 consecutive severe CAP patients with laboratory-confirmed adenovirus infections were included. The median age was 30 years and all cases were identified during the winter and spring seasons. HAdV-55 was the most frequently (11/15) detected HAdV type. Persistent high fever, cough and rapid progression of dyspnea were typically reported in these patients. Significantly increased pneumonia severity index (PSI), respiratory rate, and lower PaO₂/FiO₂, hypersensitive CRP were reported in non-survivors compared to survivors (P = 0.013, 0.022, 0.019 and 0.026, respectively). The rapid development of bilateral consolidations within 10 days after illness onset were the most common radiographic finding, usually accompanied by adjacent ground glass opacities and pleural effusions. Total mortality was 26.7% in this study. Corticosteroids were prescribed to 14 patients in this report, but the utilization rate between survivors and non-survivors was not significant.

Conclusions

HAdV and the HAdV-55 sub-type play an important role among viral pneumonia pathogens in hospitalized immunocompetent adults in Northern China. HAdV should be tested in severe CAP patients with negative bacterial cultures and a lack of response to antibiotic treatment, even if radiologic imaging and clinical presentation initially suggest bacterial pneumonia.     

Frequent Detection of Human Adenovirus from the Lower Gastrointestinal Tract in Men Who Have Sex with Men

Background

The association between baseline seropositivity to human adenovirus (HAdV) type 5 and increased HIV acquisition in the Step HIV Vaccine Study has raised questions concerning frequency of acquired and/or persistent Adenovirus infections among adults at high risk of HIV-1 infection.

Methodology

To evaluate the frequency and pattern of HAdV shedding from the lower GI tract, we retrospectively tested rectal swabs for HAdVs in a cohort of 20 HSV-2 positive HIV-positive Peruvian men who have sex with men (MSM) undergoing rectal swabbing three times/week for 18 consecutive weeks, in a prospective study of HSV-2 suppression in HIV infection. Viral DNA was extracted and amplified using a sensitive multiplex PCR assay that detects all currently recognized HAdV types. Molecular typing of viruses was performed on selected samples by hexon gene sequencing. Baseline neutralizing antibody titers to HAdVs −5, −26, −35 and −48 were also assessed.

Principal Findings

15/20 individuals had HAdV detected during follow up. The median frequency of HAdV detection was 30% of samples (range 2.0% to 64.7%). HAdV shedding typically occurred on consecutive days in clustered episodes lasting a median of 4 days (range 1 to 9 days) separated by periods without shedding, suggesting frequent new infections or reactivation of latent infections over time. 8 of the 15 shedders had more than one type detected in follow-up. 20 HAdV types from species B, C, and D were identified, including HAdV-5, −26 and −48, HAdV types under development as potential vaccine candidates. 14/20 subjects were seropositive for HAdV-5; 15/20 for HAdV-26; 3/20 for HAdV-35; and 2/20 for HAdV-48. HAdV shedding did not correlate with CD4 count, plasma HIV-1 viral load, or titers to HAdV-5 or HAdV-35. The sole individual with HAdV-5 shedding was HAdV-5 seropositive.

Conclusions

HAdV shedding was highly prevalent and diverse, including types presently under consideration as HIV vaccine vectors. Subclinical HAdV infection of the GI tract is common among MSM in Peru; the prevalence of HAdV in the enteric tract should be evaluated in other populations. The association between ongoing recent enteric HAdV and the immune response to recombinant HAdV vaccines should be evaluated.     

Epidemiology and Clinical Characteristics of Respiratory Infections Due to Adenovirus in Children Living in Milan,Italy, during 2013 and 2014

To evaluate the predominant human adenovirus (HAdV) species and types associated with pediatric respiratory infections, nasopharyngeal swabs were collected from otherwise healthy children attending an emergency room in Milan, Italy, due to a respiratory tract infection from January 1 to February 28 of two subsequent years, 2013 and 2014. The HAdVs were detected using a respiratory virus panel fast assay (xTAG RVP FAST v2) and with a HAdV-specific real-time polymerase chain reaction; their nucleotides were sequenced, and they were tested for positive selection. Among 307 nasopharyngeal samples, 61 (19.9%) tested positive for HAdV. HAdV was the only virus detected in 31/61 (50.8%) cases, whereas it was found in association with one other virus in 25 (41.0%) cases and with two or more viruses in 5 (8.2%) cases. Human Enterovirus/human rhinovirus and respiratory syncytial virus were the most common co-infecting viral agents and were found in 12 (19.7%) and 7 (11.5%) samples, respectively. Overall, the HAdV strain sequences analyzed were highly conserved. In comparison to HAdV-negative children, those infected with HAdV had a reduced frequency of lower respiratory tract involvement (36.1% vs 55.2%; p = 0.007), wheezing (0.0% vs 12.5%; p = 0.004), and hospitalization (27.9% vs 56.1%; p<0.001). Antibiotic therapy and white blood cell counts were more frequently prescribed (91.9% vs 57.1%; p = 0.04) and higher (17,244 ± 7,737 vs 9,565 ± 3,211 cells/μL; p = 0.04), respectively, in children infected by HAdV-C than among those infected by HAdV-B. On the contrary, those infected by HAdV-B had more frequently lower respiratory tract involvement (57.1% vs 29.7%) but difference did not reach statistical significant (p = 0.21). Children with high viral load were absent from child care attendance for a longer period of time (14.5 ± 7.5 vs 5.5 ± 3.2 days; p = 0.002) and had higher C reactive protein levels (41.3 ± 78.5 vs 5.4 ± 9.6 μg/dL; p = 0.03). This study has shown that HAdV infections are diagnosed more commonly than usually thought and that HAdVs are stable infectious agents that do not frequently cause severe diseases. A trend toward more complex disease in cases due to HAdV species C and in those with higher viral load was demonstrated. However, further studies are needed to clarify factors contributing to disease severity to understand how to develop adequate preventive and therapeutic measures.     

Acute gastroenteritis and enteric viruses in hospitalised children in southern Brazil: aetiology,seasonality and clinical outcomes

Viral acute gastroenteritis (AG) is a significant cause of hospitalisation in children younger than five years. Group A rotavirus (RVA) is responsible for 30% of these cases. Following the introduction of RVA immunisation in Brazil in 2006, a decreased circulation of this virus has been observed. However, AG remains an important cause of hospitalisation of paediatric patients and only limited data are available regarding the role of other enteric viruses in these cases. We conducted a prospective study of paediatric patients hospitalised for AG. Stool samples were collected to investigate human adenovirus (HAdV), RVA, norovirus (NoV) and astrovirus (AstV). NoV typing was performed by nucleotide sequencing and phylogenetic analysis. From the 225 samples tested, 60 (26%) were positive for at least one viral agent. HAdV, NoV, RVA and AstV were detected in 16%, 8%, 6% and 0% of the samples, respectively. Mixed infections were found in nine patients: HAdV/RVA (5), HAdV/NoV (3) and HAdV/NoV/RVA (1). The frequency of fever and lymphocytosis was significantly higher in virus-infected patients. Phylogenetic analysis of NoV indicated that all of these viruses belonged to genotype GII.4. The significant frequency of these pathogens in patients with AG highlights the need to routinely implement laboratory investigations.     

Genomics-based re-examination of the taxonomy and phylogeny of human and simian Mastadenoviruses: an evolving whole genomes approach,revealing putative zoonosis,anthroponosis, and amphizoonosis

With the advent of high-resolution and cost-effective genomics and bioinformatics tools and methods contributing to a large database of both human (HAdV) and simian (SAdV) adenoviruses, a genomics-based re-evaluation of their taxonomy is warranted. Interest in these particular adenoviruses is growing in part due to the applications of both in gene transfer protocols, including gene therapy and vaccines, as well in oncolytic protocols. In particular, the re-evaluation of SAdVs as appropriate vectors in humans is important as zoonosis precludes the assumption that human immune system may be naïve to these vectors. Additionally, as important pathogens, adenoviruses are a model organism system for understanding viral pathogen emergence through zoonosis and anthroponosis, particularly among the primate species, along with recombination, host adaptation, and selection, as evidenced by one long-standing human respiratory pathogen HAdV-4 and a recent re-evaluation of another, HAdV-76. The latter reflects the insights on amphizoonosis, defined as infections in both directions among host species including “other than human”, that are possible with the growing database of nonhuman adenovirus genomes. HAdV-76 is a recombinant that has been isolated from human, chimpanzee, and bonobo hosts. On-going and potential impacts of adenoviruses on public health and translational medicine drive this evaluation of 174 whole genome sequences from HAdVs and SAdVs archived in GenBank. The conclusion is that rather than separate HAdV and SAdV phylogenetic lineages, a single, intertwined tree is observed with all HAdVs and SAdVs forming mixed clades. Therefore, a single designation of “primate adenovirus” (PrAdV) superseding either HAdV and SAdV is proposed, or alternatively, keeping HAdV for human adenovirus but expanding the SAdV nomenclature officially to include host species identification as in ChAdV for chimpanzee adenovirus, GoAdV for gorilla adenovirus, BoAdV for bonobo adenovirus, and ad libitum.     

Molecular Epidemiology and Phylogenetic Analysis of Human Adenovirus Caused an Outbreak in Taiwan during 2011

An outbreak of adenovirus has been surveyed in Taiwan in 2011. To better understand the evolution and epidemiology of adenovirus in Taiwan, full-length sequence of hexon and fiber coapsid protein was analyzed using series of phylogenetic and dynamic evolution tools. Six different serotypes were identified in this outbreak and the species B was predominant (HAdV-3, 71.50%; HAdV-7, 15.46%). The most frequent diagnosis was acute tonsillitis (54.59%) and bronchitis (47.83%). Phylogenetic analysis revealed that hexon protein gene sequences were highly conserved for HAdV-3 and HAdV-7 circulation in Taiwan. However, comparison of restriction fragment length polymorphism (RFLP) analysis and phylogenetic trees of fiber gene in HAdV-7 clearly indicated that the predominant genotype in Taiwan has shifted from 7b to 7d. Several positive selection sites were observed in hexon protein. The estimated nucleotide substitution rates of hexon protein of HAdV-3 and HAdV-7 were 0.234×10^-3 substitutions/site/year (95% HPD: 0.387~0.095×10^-3) and 1.107×10^-3 (95% HPD: 0. 541~1.604) respectively; those of the fiber protein of HAdV-3 and HAdV-7 were 1.085×10^-3 (95% HPD: 1.767~0.486) and 0.132×10^-3 (95% HPD: 0.283~0.014) respectively. Phylodynamic analysis by Bayesian skyline plot (BSP) suggested that using individual gene to evaluate the effective population size might possibly cause miscalculation. In summary, the virus evolution is ongoing, and continuous surveillance of this virus evolution will contribute to the control of the epidemic.     

Detection and molecular characterization of adenoviruses in Korean children hospitalized with acute gastroenteritis

Human adenoviruses (HAdVs) are an important cause of acute gastroenteritis in children. However, few studies on the epidemiology or types of HAdVs associated with acute gastroenteritis have been conducted in Korea. Therefore, in the present study, the incidence of HAdV in 2064 stool samples from Korean children hospitalized with acute gastroenteritis (2004-2006) was assessed and the types of viruses present determined. Polymerase chain reaction, sequencing, and phylogenic analyses revealed that 113 samples (5.5%) were HAdV-positive. While HAdVs were mainly detected during July to October, no seasonal difference between the enteric and non-enteric viruses in the incidence of HAdV was observed. HAdV-41 and HAdV-40 were found in 54 (47.8%) and 3 (2.6%) HAdV-positive samples, respectively. HAdV-3, HAdV-7, HAdV-2, HAdV-31, HAdV-4, and HAdV-37 were detected in 11 (9.7%), 5 (4.4%), 2 (1.7%), 2 (1.7%), 1 (0.8%), and 1 (0.8%) of sample(s), respectively. Thus, not only enteric, but also non-enteric, HAdVs may play an important role in acute gastroenteritis in Korean children.     

呼吸道感染病原菌分析

目的 了解老年人院内呼吸道感染与非老年人呼吸道感染病原菌分布情况。方法 回顾性调查１９９８年１月至１２月老年人院内呼吸道感染（老年组）的２８５份痰标本和同时期非老年人呼吸道感染（非老年组,含门诊和住院）的１１９２份痰标本的培养情况。结果 老年组阳性率为８９．１％（２５４／２８５）,其中２２份标本为混合感染,共检出病原菌２７６株,以非发酵菌占绝对优势（９７．８％）;非老年组阳性率为４０．３％（４８０／１１９２）,病原菌无明显集中趋势,非发酵菌２８．３％,肠杆菌科２３．８％,革兰阳性菌２５．０％,真菌２２．９％。结论 老年组阳性率明显高于非老年组（Ｘ＾２＝２１９．６,Ｐ〈０．００５）,病原菌以非发酵菌为主,非老年组病原菌各科细菌所占比例无明显差异,引起呼吸道感染的病原菌主要为条件致病菌。     

2015-2017年某综合医院医院感染现患率调查分析

摘要 目的：了解与掌握医院感染现状及抗菌药物的使用,为有效预防与控制医院感染提供科学依据。方法：采用横断面调查方法,对医院2015年9月12日、2016年9月7日、2017年8月23日住院患者医院感染横断面调查,并对调查的所有资料进行分析。结果：应调查4160例,实查4125例,实查率99.16%,实查率符合现患率调查要求。2015-2017年医院感染现患率分别为6.12%、4.58%、4.12%,三年调查现患率比较,差异有统计学意义（x²=6.537,P=0.038）。调查科室中综合ICU医院感染现患率最高,为30.30%,例次感染率为36.36%。2015-2017年医院感染部位均以下呼吸道最高,其次为泌尿道,血管相关最低。2015-2017年现患率调查统计病原菌共172株,以革兰阴性菌为主。2015-2017年调查抗菌药物使用率分别为27.54%、24.09%、23.32%,合计为24.99%,三年调查日的使用率比较,差异有统计学意义（x²=7.452,P=0.024）。病原学送检673例,送检率79.83%。结论：医院感染现患率调查有助于掌握医院感染现状,根据调查存在的问题,采取相应干预措施,可有效预防与控制医院感染。     

Immune risk phenotype is associated with nosocomial lung infections in elderly in-patients

Background

Nosocomial infections are extremely common in the elderly and may be related to ageing of the immune system. The Immune Risk Phenotype (IRP), which predicts shorter survival in elderly patients, has not been evaluated as a possible risk factor for nosocomial infection. Our aim was to assess the prevalence of nosocomial infections in elderly in-patients and to investigate potential relationships between nosocomial infections and the immunophenotype, including IRP parameters.

Results

We included 252 consecutive in-patients aged 70 years or over (mean age, 85 ± 6.2 years), between 2006 and 2008. Among them, 97 experienced nosocomial infections, yielding a prevalence rate of 38.5% (95% confidence interval, 32.5-44.5). The main infection sites were the respiratory tract (21%) and urinary tract (17.1%) When we compared immunological parameters including cell counts determined by flow cytometry in the groups with and without nosocomial infections, we found that the group with nosocomial infections had significantly lower values for the CD4/CD8 ratio and naive CD8 and CD4 T-cell counts and higher counts of memory CD8 T-cells with a significant increase in CD28-negative CD8-T cells. Neither cytomegalovirus status (positive in 193/246 patients) nor presence of the IRP was associated with nosocomial infections. However, nosocomial pneumonia was significantly more common among IRP-positive patients than IRP-negative patients (17/60 versus 28/180; p = 0.036).

Conclusion

Immunological parameters that are easy to determine in everyday practice and known to be associated with immune system ageing and shorter survival in the elderly are also associated with an elevated risk of nosocomial pneumonia in the relatively short term.     

急性脑梗死患者医院感染临床特点与影响因素分析

目的:探讨急性脑梗死患者医院感染临床特点及影响因素。方法:回顾性分析我院2018年1月至2019年12月诊断为急性脑梗死1175例患者临床资料,通过感染标本的培养及鉴定结果分析,探讨医院感染的病原菌种类及比例,进一步分析引起医院感染的危险因素。结果:1175例急性脑梗死患者中,发生医院感染99例,感染率8.4%;最常见感染部位为呼吸系统和泌尿系统;发生医院感染的99例临床标本微生物学培养及鉴定发现革兰氏阴性菌59例,革兰氏阳性菌37例,真菌3例,分别占比59.60%、37.37%及3.03%;发生医院感染的独立影响因素包括:年龄≥80岁、反复发作史、住院期间行气管插管、血清白蛋白<30 g/L、25-羟维生素D3<20 ng/mL,既往有慢性阻塞性肺病、NIHSS≥6。结论:急性脑梗死患者医院感染发生以呼吸道及泌尿道感染最常见,诸多因素可以引起医院感染发生,重视侵入性操作的管理外,对于营养不良等也要引起重视,从而降低医院感染率。     

肿瘤患者深部真菌感染的菌株分布及耐药性分析

探讨肿瘤患者深部真菌医院感染的病原菌分布特点及耐药现状。回顾性分析2008年1月至2009年12月哈尔滨医科大学第一临床医学院住院肿瘤患者送检标本分离出的173株真菌的分布及耐药情况。肿瘤患者深部真菌医院感染以下呼吸道感染为主,占76.3%,真菌种类主要是白假丝酵母菌(74.6%);真菌药敏试验结果表明,深部真菌对两性霉素B和5-氟胞嘧啶耐药率均5%;对伊曲康唑及伏立康唑的耐药率为0~6.5%;对氟康唑耐药率有上升趋势,为2.5%~25.0%。临床分离的真菌主要集中在呼吸道标本,以白假丝酵母菌为主,对抗真菌药物普遍敏感,应积极治疗,合理利用抗真菌药物,改善患者预后,减少耐药菌株的产生。     

不明病因儿童急性重症肝炎：数据及认识更新

近期不明原因儿童急性重症肝炎病例在全球多发，自苏格兰首次病例报道至今，已有33个国家通报了至少650例散发病例，相互间缺乏流行病学联系。患儿主要表现为急性肝炎。结合流行病学分析及临床表现初步推论，该疾患可能由感染所致。所有病例均排除甲、乙、丙、丁和戊型肝炎，实验室检测发现半数以上患儿人腺病毒(human adenovirus，HAdV)阳性，部分鉴定为HAdV-41型，提示腺病毒与此疾患发病存在关联性。主流病因推测并提出腺病毒基因重组、辅助因素诱导病毒嗜性改变假说，尤其是超抗原假说引发了广泛热议，即HAdV-41感染诱发严重急性呼吸综合征冠状病毒2(severe acute respiratory syndrome coronavirus 2，SARS-CoV-2)超抗原介导中毒性休克及肝细胞凋亡的发生。最终病因至今尚未明确。本文从流行病学调查、病因分析、病理表现、实验室检查、病原学检测、诊疗规范、现行病例隔离管理及预防消毒措施等方面对本疾患相关信息进行更新，以期总结对本病发病机制及诊疗的最新认识。     

下呼吸道不动杆菌医院感染的危险因素及耐药性分析

目的了解引起下呼吸道医院感染的不动杆菌耐药现状及存在的危险因素。方法用常规的方法对下呼吸道的标本进行病原菌的培养及分离,用全自动微生物分析仪VITEK 2对细菌进行鉴定及药物敏感性试验,同时对由不动杆菌引发的158例院内感染患者的危险因素进行分析。结果不动杆菌引起下呼吸道医院感染相关的危险因素主要为使用糖皮质激素类药物或机械插管或患有糖尿病等;除亚胺培南、左氧氟沙星、头孢吡肟、头孢哌酮、头孢哌酮/舒巴坦及头孢他啶等对不动杆菌有较好的体外抗菌活性外(耐药率小于40.0%),临床常用的其他多种抗菌药物耐药较严重,耐药率均在40.0%以上。结论糖皮质激素,机械插管,糖尿病等是不动杆菌引起下呼吸道医院感染的主要危险因素,不动杆菌对临床常用的抗生素有多重耐药性。     

Outbreak of acute respiratory disease caused by human adenovirus type 7 in a military training camp in Shaanxi,China

Outbreaks of ARD associated with HAdV have been reported in military populations in many countries. Here, we report an ARD outbreak caused by HAdV‐7 in a military training camp in Shaanxi Province, China, from February to March of 2012. Epidemic data and samples from the patients were collected, and viral nucleotides from samples and viral isolations were detected and sequenced. IgG and IgA antibodies against HAdV, and the neutralization antibodies against the viral strain isolated in this outbreak, were detected. Epidemiological study showed that all personnel affected were males with an average age of 19.1 years. Two peaks appeared on the epicurve and there was an 8‐day interval between peaks. Laboratory results of viral nucleotide detection carried out with clinical specimens were positive for HAdV (83.33%, 15/18). Further study through serum antibody assay, virus isolation and phylogenetic analysis showed that HAdV‐7 was the etiological agent responsible for the outbreak. IgA antibody began to appear on the 4th day after the onset and showed 100% positivity on the 8th day. The virus strain in the present outbreak was highly similar to the virus isolated in Hanzhong Shaanxi in 2009. We conclude that HAdV‐7 was the pathogen corresponding to the outbreak, and this is the first report of an ARD outbreak caused by HAdV‐7 in military persons in China. Vaccine development, as well as enhanced epidemiological and virological surveillance of HAdV infections in China should be emphasized.     

社区获得性肺炎非典型病原体分布及其流行特征

目的 了解社区获得性肺炎(CAP)非典型病原体感染的分布情况及其流行特征.方法 收集确诊为社区获得性肺炎患者278例,间接免疫荧光法(IFA)检测人血清中呼吸道9种主要的非典型性病原体的IgM抗体.结果 病原体检测阳性者150例,总阳性率54.O％.单一病原体感染中,肺炎支原体(MP) 125例(45.0％)、呼吸道合胞病毒( RSV) 27例(9.7％)、腺病毒22例(7.9％)、副流感病毒1、2和3型19例(6.8％)、乙型流感病毒16例(5.8％)、嗜肺军团菌血清1型13例(4.7％)、肺炎衣原体2例(0.7％)和甲型流感病毒1例(0.4％).混合感染共63例(22.7％),其中61例(21.9％)为MP与其他病原体的混合感染,病毒感染以RSV最常见,共27例(9.7％).CAP患者患有基础疾病共139例(50％),其余为无基础疾病者.基础疾病中以循环疾病和呼吸疾病最常见,各占总CAP患者的15,1％和13.0％.所有受检者MP阳性率最高,达45％,其中未成年组3～18岁中MP阳性率高达60.2％,而成人组18 ～50岁中MP阳性率高达81.8％.CAP春季病原体阳性检出率为46.9％,冬季病原体阳性检出率为63.8％(x2=7.752,P＜0.05).结论 非典型性病原体(特别是MP)感染在CAP患者中比例较大,其流行与分布跟病原体种类、基础疾病、年龄、季节等有一定的关系.     

6719例住院患者医院感染的监测结果分析

目的:分析我院住院患者医院感染的发病特点和危险因素。方法:利用前瞻性监测和回顾性分析方法对2012年1~3月我院收治的6719例住院患者中发生医院感染的病例进行调查分析。结果:6719例住院患者发生医院感染145例,感染率2.16%;感染部位以呼吸系统为首(59.3%),其余依次为为胃肠道(17.2%)和泌尿道(11.7%);ICU的感染率最高,为22.0%,其次为外科系统(4.03%)和内科系统(1.71%)。病原学检测送检率为51.0%,阳性率为78.3%,共检出118株病原菌,其中革兰氏阴性菌占57.6%,真菌占22.9%,革兰氏阳性菌占17.8%。导致院内感染的危险因素中最常见的为放疗化疗(31.0%)、气管切开(15.9%)、导尿插管(17.9%)。结论:加强医务人员的感控意识,强化卫生制度,严格执行无菌操作规程,合理应用抗菌药物是控制医院感染发生的重要措施。