杭州地区小儿呼吸道合胞病毒感染流行特点与气象学因素

目的阐明杭州地区小儿呼吸道合胞病毒(RSV)感染流行特点及影响RSV感染流行的气象学因素。方法连续3年对住院肺炎患儿中RSV的检出率进行动态观察,将月平均气温、相对湿度及雨天分别与月RSV检出率进行相关性分析。结果3年共检测患儿13642例,RSV阳性率为25.8%,其中≤1岁组检出率33.1%,1～3岁组19.7%,>3岁组5.1%,各年龄组间检出率差异有统计学意义(χ2=763.7,P=0.000)。RSV感染率总体上11月份开始明显增高,流行持续到次年的3-4月份,但每年的流行仍存在差别。雨天与RSV检出率之间r=0.32(P=0.066);相对湿度与RSV检出率之间r=-0.27(P=0.117);平均气温与RSV检出率之间r=-0.83(P=0.000),RSV检出率与气温之间的回归方程式:检出率(%)=52.933-1.914×气温(℃)。结论RSV是目前引起小儿肺炎的主要病毒。RSV在≤1岁组感染率最高,年龄越大感染率越低。RSV在杭州地区的流行见于冬春季,但存在变化,低气温是导致RSV感染流行的主要因素。     

婴儿呼吸道合胞病毒急性下呼吸道感染的相关因素分析

目的：探究影响婴儿呼吸道合胞病毒急性下呼吸道感染的相关因素。方法选取2013年7月至2014年7月于浙江省金华市浦江县人民医院住院的急性下呼吸道感染（ ALRI）患儿1540例,根据浙江省金华市浦江县人民医院呼吸道合胞病毒（RSV）检测结果,将患儿分为RSV阳性组（n＝816）和RSV阴性组（n＝724）两组,对比两组患者的性别、年龄、出生体重、胎龄、发病季节、合并基础疾病、合并先心病、居住人口、家庭月收入、母乳喂养、家庭吸烟、妊娠合并糖尿病、妊娠合并高血压、孕母特应性疾病等。结果多因素分析发现,秋冬季节发病（OR＝1．579,95％CI＝1．172～2．127）、合并先心病（OR＝1．317,95％CI＝1．028～1．685）、孕母特应性疾病（OR＝1．802,95％CI＝1．235～2．631）是婴儿RSV相关ALRI的危险因素,而家庭月收入≥10千元（OR＝0．679,95％CI＝0．499～0．924）是其保护因素。结论秋冬季节发病、合并先心病、孕母特应性疾病的婴儿RSV相关ALRI发病率高,而家庭月收入≥10千元的家庭RSV相关ALRI发病率低。     

重症呼吸道合胞病毒肺炎的危险因素分析

目的分析重症呼吸道合胞病毒(RSV)肺炎的流行病学和相关危险因素。方法选取2018年1月1日—2019年12月31日杭州市儿童医院收治的RSV阳性且临床诊断为重症肺炎的患儿80例为重症组,RSV阳性且临床诊断为普通肺炎的患儿80例为普通组,采用Logistic多元回归分析重症RSV肺炎的危险因素。结果重症RSV肺炎单因素相关性分析显示秋冬季发病、小月龄、早产、剖宫产、低出生体质量、缺乏母乳喂养、哮喘家族史及患儿基础疾病因素差异均有统计学意义(均P<0.05)。多因素Logistic回归分析显示:发病季节、月龄、早产、剖宫产、低出生体质量、哮喘家族史及患儿基础疾病与重症RSV肺炎发生率呈现正相关;母乳喂养与重症RSV肺炎发生率呈现负相关,是其保护因素。结论秋冬季为重症RSV肺炎的好发季节,小月龄、早产儿、剖宫产、低出生体质量、哮喘家族史及基础疾病是重症RSV肺炎的危险因素,母乳喂养可降低重症RSV肺炎发生风险。     

重症呼吸道合胞病毒肺炎的危险因素分析

目的分析重症呼吸道合胞病毒(RSV)肺炎的流行病学和相关危险因素。方法选取2018年1月1日—2019年12月31日杭州市儿童医院收治的RSV阳性且临床诊断为重症肺炎的患儿80例为重症组,RSV阳性且临床诊断为普通肺炎的患儿80例为普通组,采用Logistic多元回归分析重症RSV肺炎的危险因素。结果重症RSV肺炎单因素相关性分析显示秋冬季发病、小月龄、早产、剖宫产、低出生体质量、缺乏母乳喂养、哮喘家族史及患儿基础疾病因素差异均有统计学意义(均P<0.05)。多因素Logistic回归分析显示:发病季节、月龄、早产、剖宫产、低出生体质量、哮喘家族史及患儿基础疾病与重症RSV肺炎发生率呈现正相关;母乳喂养与重症RSV肺炎发生率呈现负相关,是其保护因素。结论秋冬季为重症RSV肺炎的好发季节,小月龄、早产儿、剖宫产、低出生体质量、哮喘家族史及基础疾病是重症RSV肺炎的危险因素,母乳喂养可降低重症RSV肺炎发生风险。     

甘草活性成分抗呼吸道合胞病毒作用

目的研究甘草抗病毒活性成分（GX）体外抗呼吸道合胞病毒（RSV）的作用。方法采用中性红实验和观察细胞病变（CPE）法,以利巴韦林为阳性药,测定GX对RSV的抑制作用。结果GX的半数中毒浓度（TC50）为460.00μg/ml,半数有效抑制浓度（EC50）为23.53μg/ml,治疗指数（TI）为19.55;GX在RSV感染Hela细胞2,4,6,8,10 h后给药,对RSV复制均有明显的抑制作用（P〈0.01）;且GX对RSV有中和作用。结论GX在体外对RSV复制有明显的抑制作用。     

Risk factors for respiratory syncytial virus bronchiolitis hospital admission in New Zealand

This study assessed risk factors for respiratory syncytial virus (RSV) hospitalization and disease severity in Wellington, New Zealand. During the southern hemisphere winter months of 2003--2005, 230 infants aged < 24 months hospitalized with bronchiolitis were recruited. RSV was indentified in 141 (61%) infants. Comparison with data from all live hospital births from the same region (2003--2005) revealed three independent risk factors for RSV hospitalization: birth between February and July [adjusted risk ratio (aRR) 1.62, 95% confidence interval (CI) 1.5-2.29], gestation <37 weeks (aRR 2.29, 95% CI 1.48-3.56) and Māori ethnicity (aRR 3.64, 95% CI 2.27-5.85), or Pacific ethnicity (aRR 3.60, 95% CI 2.14-6.06). The high risk for Māori and Pacific infants was only partially accounted for by other known risk factors. This work highlights the importance of RSV disease in indigenous and minority populations, and identifies the need for further research to develop public health measures that can reduce health disparities.     

Animal models of respiratory syncytial virus infection

Human respiratory syncytial virus (hRSV) is a major cause of respiratory disease and hospitalisation of infants, worldwide, and is also responsible for significant morbidity in adults and excess deaths in the elderly. There is no licensed hRSV vaccine or effective therapeutic agent. However, there are a growing number of hRSV vaccine candidates that have been developed targeting different populations at risk of hRSV infection. Animal models of hRSV play an important role in the preclinical testing of hRSV vaccine candidates and although many have shown efficacy in preclinical studies, few have progressed to clinical trials or they have had only limited success. This is, at least in part, due to the lack of animal models that fully recapitulate the pathogenesis of hRSV infection in humans. This review summarises the strengths and limitations of animal models of hRSV, which include those in which hRSV is used to infect non-human mammalian hosts, and those in which non-human pneumoviruses, such as bovine (b)RSV and pneumonia virus of mice (PVM) are studied in their natural host.Apart from chimpanzees, other non-human primates (NHP) are only semi-permissive for hRSV replication and experimental infection with large doses of virus result in little or no clinical signs of disease, and generally only mild pulmonary pathology. Other animal models such as cotton rats, mice, ferrets, guinea pigs, hamsters, chinchillas, and neonatal lambs are also only semi-permissive for hRSV. Nevertheless, mice and cotton rats have been of value in the development of monoclonal antibody prophylaxis for infants at high risk of severe hRSV infection and have provided insights into mechanisms of immunity to and pathogenesis of hRSV. However, the extent to which they predict hRSV vaccine efficacy and safety is unclear and several hRSV vaccine candidates that are completely protective in rodent models are poorly effective in chimpanzees and other NHP, such as African Green monkeys. Furthermore, interpretation of findings from many rodent and NHP models of vaccine-enhanced hRSV disease has been confounded by sensitisation to non-viral antigens present in the vaccine and challenge virus.Studies of non-human pneumoviruses in their native hosts are more likely to reflect the pathogenesis of natural hRSV infection, and experimental infection of calves with bRSV and of mice with PVM result in clinical disease and extensive pulmonary pathology. These animal models have not only been of value in studies on mechanisms of immunity to and the pathogenesis of pneumovirus infections but have also been used to evaluate hRSV vaccine concepts. Furthermore, the similarities between the epidemiology of bRSV in calves and hRSV in infants and the high level of genetic and antigenic similarity between bRSV and hRSV, make the calf model of bRSV infection a relevant model for preclinical evaluation of hRSV vaccine candidates which contain proteins that are conserved between hRSV and bRSV.     

Peptide-based candidate vaccine against respiratory syncytial virus

We engineered a 21-mer peptide representing amino acids 170-190 of the respiratory syncytial virus (RSV) G protein as a fusion with the Alfalfa mosaic virus (AlMV) coat protein (CP), produced recombinant AlMV particles presenting this peptide (VMR-RSV) on their surfaces and tested the immunogenicity in vitro in human dendritic cells and in vivo in non-human primates. Significant pathogen-specific immune responses were generated in both systems: (i) human dendritic cells armed with VMR-RSV generated vigorous CD4+ and CD8+ T cell responses; (ii) non-human primates that received these particles responded by mounting strong cellular and humoral immune responses. This approach may validate the use of a novel RSV vaccine delivery vehicle in humans.     

Human metapneumovirus and respiratory syncytial virus, Brazil

We describe the epidemiologic and clinical characteristics of 111 children attending clinics and hospitals in Aracaju, northeast Brazil, with acute respiratory infections attributable to human metapneumovirus (HMPV), respiratory syncytial virus (RSV), or both in May and June 2002. Fifty-three (48%) children were infected with RSV alone, 19 (17%) with HMPV alone, and 8 (7%) had RSV/HMPV co-infections.     

Climatic factors and lower respiratory tract infection due to respiratory syncytial virus in hospitalised infants in northern Spain

Objective To analyse the influence of climatic factors on the number of hospitalised infants with respiratory syncytial virus (RSV) per week.Methods A retrospective observational case–control study was designed enrolling infants under 2 years of age, admitted to hospital between October 1995 and June 2000 with lower respiratory tract infection due to RSV. Climatic and seasonal data were included. The week variable was used as the study unit: weeks with more than one admission for the case group and weeks without admissions for the control group. The total number of weeks excluding summer months, from June to September, was 174.Results A total of 167 infants were admitted to hospital with lower respiratory tract infection due to RSV with a peak in January and February. There was 82 weeks with one or more admissions (case group) and 92 without admissions (control group). The case group demonstrated lower levels of humidity (absolute: 5.6 ± 1.5 vs. 6.5 ± 1.5; p < 0.001) and lower temperature (ground level: 0.4 ± 3.2 vs. 2.2 ± 3.5; p < 0.001). When climatic factors were analysed in a logistic regression model, absolute humidity (p < 0.001) was an independent variable associated with a higher risk of infection.Conclusions Low absolute humidity was independently associated with hospital admission of infants with lower respiratory tract infection due to RSV.     

Molecular epidemiology of respiratory syncytial virus in The Gambia

Respiratory syncytial virus (RSV) infection in The Gambia occurs seasonally in association with the rainy season. This study examined the genetic variability of RSV isolates from four consecutive epidemics from 1993-6. Each epidemic was made up of a number of variants which were replaced in subsequent epidemics. Analysis of attachment (G) protein gene sequences showed that isolates were closely related to those observed in the rest of the world. However, many isolates from 1993 and 1994 were unlike other isolates observed in the developed world during this period and were more similar to isolates from 1984 in Europe. In addition, the most commonly observed genotype in the UK in the 1990s was not detected in The Gambia during this period.     

Human metapneumovirus and severity of respiratory syncytial virus disease

We screened 23 children with severe respiratory syncytial virus (RSV) disease and 23 children with mild RSV disease for human metapneumovirus (HMPV). Although HMPV was circulating in Connecticut, none of the 46 RSV-infected patients tested positive for HMPV. In our study population, HMPV did not contribute to the severity of RSV disease.     

Clinical and epidemiological aspects of respiratory syncytial virus lower respiratory tract infections

This paper has analyzed respiratory syncytial virus lower respiratory tract infections in 201 hospitalized children. In children with wheezing, erythrocyte sedimentation rate (ESR) was significantly higher in those with pneumonia than with syndroma pertussis, while the white blood cell (WBC) count was significantly lower in patients with bronchitis than in those with bronchiolitis and syndroma pertussis. Bronchodilatators were applied in 75.6% and corticosteroids in 20% of patients. Ten patients were ventilated. Fatal disease outcome was observed in one infant. Twelve consecutive-year study of respiratory syncytial virus (RSV) infections showed that 27.3% of these diseases were bronchiolitis and pneumonia.