Surveillance of respiratory viral infections by rapid immunofluorescence diagnosis, with emphasis on the epidemiological development of respiratory syncytial virus infections

Surveillance of certain respiratory viral infections by applying immunofluorescence (IF) examinations to samples of nasopharyngeal secretions has been evaluated using a simplified procedure for the preparation of cell smears. Samples from 711 children living in different parts of Norway were examined during the winter 1982/83 and a positive diagnosis was made for 290 children (41%). Temporal epidemic peaks were observed for respiratory syncytial virus (RSV), parainfluenza virus type 3 and influenza virus. On the other hand, the monthly number of negative samples was almost constant throughout the period. Differences in timing of RSV outbreaks were observed between two regions in Norway. Compared to rapid IF diagnosis, RSV notifications obtained by serological examinations were delayed by several weeks. Rapid virus diagnosis by IF examinations with our simplified procedure for preparation of nasopharyngeal samples seems to be suitable for the epidemiological surveillance of respiratory viral infections, both for its simplicity of preparation of the samples and for its accuracy in defining the time of the actual virus infection. Nevertheless, the method is not without pitfalls; a close cooperation between those who take the specimens and the laboratory is essential, and the IF examinations should be performed by an experienced microscopist.     

Surveillance of respiratory viral infections by rapid immunofluorescence diagnosis, with emphasis on virus interference

During the 7-year period from September 1978 to August 1985, smear specimens of nasopharyngeal secretions from 3132 patients mainly hospitalized children, taken in different regions in Norway, were examined for respiratory viruses by the rapid immunofluorescence (IF) technique. A positive diagnosis for respiratory syncytial virus (RSV), parainfluenza virus type 1, 2 and 3 or influenza A and B virus was made for 896 patients (29%). The greatest prevalence for all these viruses was observed during the colder months with only sporadic cases during the summer months. A relative increase in parainfluenza virus activity, involving several parainfluenza virus types, was observed in every second autumn and during these periods only sporadic cases of RSV infection were diagnosed. Also both RSV and parainfluenza viruses were less frequently found during influenza virus epidemics and regional differences in RSV activity were observed. During the four autumn periods 1982-85 the monthly number of positive virus identifications by IF followed an epidemic curve, while the corresponding number of negative samples was relatively constant. The results of this study suggest interference between RSV, parainfluenza viruses and influenza virus in reaching their epidemiological peaks. It is suggested that interferon might be a mediator of this effect.     

Low incidence of nosocomial respiratory syncytial virus infections among children younger than 12 months in the Department of Pediatrics, Sophia Children's Hospital at Rotterdam

OBJECTIVE: To investigate the occurrence of nosocomial respiratory syncytial virus (RSV) infections and to compare their clinical features with those of community-acquired RSV infections. DESIGN: Retrospective. METHOD: Data were collected from the medical records of children younger than 12 months with RSV infection in the Department of Pediatrics of Sophia's Children's Hospital, Rotterdam, the Netherlands, in October-March 1992/'95. The diagnosis of 'RSV infection' was confirmed by a direct immunofluorescent assay and/or a viral culture on materials obtained from nasopharyngeal washes. A nosocomial RSV infection was defined as an infection which occurred more than 5 days after hospital admission for any underlying disease. RESULTS: During the 3 RSV seasons 1260 children were admitted. Of these 34 (2.7%) developed a nosocomial RSV infection. The number of nosocomial RSV infections decreased over the study period. At the department including the outpatient clinic 232 children were seen with a community-acquired RSV infection. Children with a nosocomial infection differed from children with a community-acquired infection only with regard to birth weight (2.5 kg versus 3.0 kg), cough (65% versus 92%) and feeding problems (100% versus 69%). Four children had bronchopulmonary dysplasia and nosocomial RSV infection; these required mechanical ventilation. CONCLUSION: The number of nosocomial RSV infections decreased over 3 years. The severity of nosocomial RSV infections was comparable with that of community-acquired RSV infections.     

Diagnosis and epidemiological surveillance of influenza and respiratory syncytial virus infections: interest of multiplex PCR

OBJECTIVE: Respiratory infections require a rapid etiological diagnosis for efficient management of cases. We evaluated multiplex PCR used for the diagnosis and the epidemiological surveillance of influenza and respiratory syncytial virus (RSV) infections. PATIENTS AND METHODS: Our study included 278 patients (mean age: 37.2+/-22.9 years) with flu or flu-like syndromes, consulting physicians affiliated with the GROG Poitou-Charentes or hospitalized in the Poitiers teaching hospital. A multiplex PCR detecting A(H3), A(H1) and B influenza viruses, and RSV A and B, was performed with both a direct examination by immunofluorescence and cell-culture. RESULTS: We diagnosed a viral infection in 139 (50.0%) patients: 99 cases of influenza A(H3), 2 cases of influenza A(H1), 28 cases of influenza B and 11 cases of RSV infections. The diagnosis yield in GROG patients (52.3%) was significantly higher than that observed in hospitalized patients (34.5%) (P=0.04). All techniques were correlated in 61% of cases. The multiplex PCR yielded 22.3% more positive samples compared to the conventional techniques. All positive samples by conventional techniques were also positive by multiplex PCR. We observed a perfect correlation between viral types and subtypes determined by PCR and cell-culture. CONCLUSION: Multiplex PCR is a sensitive technique allowing an efficient and rapid diagnosis of respiratory infections due to influenza and RSV.     

Coronavirus-related nosocomial viral respiratory infections in a neonatal and paediatric intensive care unit: a prospective study

The incidence of nosocomial viral respiratory infections (NVRI) in neonates and children hospitalized in paediatric and neonatal intensive care units (PNICU) is unknown. Human coronaviruses (HCoV) have been implicated in NVRI in hospitalized preterm neonates. The objectives of this study were to determine the incidence of HCoV-related NVRI in neonates and children hospitalized in a PNICU and the prevalence of viral respiratory tract infections in staff. All neonates (age< or =28 days) and children (age>28 days) hospitalized between November 1997 and April 1998 were included. Nasal samples were obtained by cytological brush at admission and weekly thereafter. Nasal samples were taken monthly from staff. Virological studies were performed, using indirect immunofluorescence, for HCoV strains 229E and OC43, respiratory syncytial virus (RSV), influenza virus types A and B, paramyxoviruses types 1, 2 and 3 and adenovirus. A total of 120 patients were enrolled (64 neonates and 56 children). Twenty-two samples from 20 patients were positive (incidence 16.7%). In neonates, seven positive samples, all for HCoV, were detected (incidence 11%). Risk factors for NVRI in neonates were: duration of hospitalization, antibiotic treatment and duration of parenteral nutrition (P<0.01). Monthly prevalence of viral infections in staff was between 0% and 10.5%, mainly with HCoV. In children, 15 samples were positive in 13 children at admission (seven RSV, five influenza and three adenovirus) but no NVRI were observed. In spite of a high rate of community-acquired infection in hospitalized children, the incidence of NVRI with common respiratory viruses appears low in neonates, HCoV being the most important pathogen of NRVI in neonates during this study period. Further research is needed to evaluate the long-term impact on pulmonary function.     

儿科重症监护室单一和多重呼吸道病毒感染对比分析

目的 探讨儿科重症监护室(PICU)患儿单一和多重呼吸道病毒感染情况的差异.方法 收集406例入住汕头大学医学院第二附属医院PICU合并有呼吸道感染患儿的咽拭子样本,采用多重PCR及常规PCR对咽拭子行16种呼吸道病毒检测,分析阳性病例的病毒感染情况及与患儿临床特征的关系.结果 406例样本中病毒检测阳性者252例,阳性率62.1％.阳性样本中,以其中鼻病毒(HRV)检出率最高,为105例(41.7％),其次为呼吸道合胞病毒(RSV)[63例(25.0％)]和腺病毒(HADV)[48例(19.0％)];单一病毒感染177例(70.2％),多重病毒感染75例(29.8％),包括66例双重病毒感染,9例三重病毒感染.多重病毒感染最多的病毒组合是HRV+RSV(16例).单一病毒感染和多重病毒感染的患儿中存在基础疾病的病例数分别为46例和6例,两者差异有统计学意义(x2=10.409,P＜0.01);而二者在性别、年龄、住院时间、上下呼吸道感染人数及小儿危重症评分上差异均无统计学意义(x2=3.430,Z=0.315,Z=0.336,x2=0.041,P均＞0.05).结论 呼吸道病毒是PICU中呼吸道感染性疾病的主要病原体之一;存在基础疾病的患儿以单一病毒感染为主,多重病毒与单一病毒感染对于疾病严重程度的影响没有明显差异.     

荧光定量PCR检测急性呼吸道感染患者常见呼吸道病毒的研究

目的分析2011年8月至2012年8月期间惠州市急性呼吸道感染病毒性病原谱的构成及流行特征,为临床诊断、治疗和呼吸道传染病的预防控制提供病原学依据。方法应用荧光定量PCR方法,对485例鼻咽拭子样本同时进行甲型流感病毒、乙型流感病毒、腺病毒、博卡病毒、副流感病毒、鼻病毒、呼吸道合胞病毒、人偏肺病毒、人冠状病毒的检测,并进行统计学分析。结果 485份样本中检出228份呼吸道病毒阳性的样本,阳性率为47.01%,其中混合感染20份,占阳性样本的8.77%。病毒病原谱构成前三位为乙型流感病毒、鼻病毒和甲型流感病毒。病毒检出阳性率的时间分布有一定规律性：1月至次年2月阳性率较高,不同月份检出的优势病毒不同。各年龄组病毒阳性率差异有统计学意义（χ2=19.414,P〈0.05）,不同年龄组病毒感染的病原谱构成也不同：0～5岁年龄组以鼻病毒为主;5岁以上各年龄组均以流感病毒为主。不同性别患者之间病毒核酸检出率差异无统计学意义（χ2=0.522,P〉0.05）。结论乙型流感病毒、鼻病毒和甲型流感病毒是惠州市急性呼吸道感染主要病原体。部分病原体的感染与年龄和季节有一定的关联;ARTI患者中部分合并感染其他呼吸道病毒,应长期监测呼吸道病毒的活动水平。     

儿童急性呼吸道感染病毒病原检测741例分析

目的了解当前沧州地区儿童急性呼吸道病毒感染(acute respiratory infection,ARI)病原学的状况,为临床儿童急性呼吸道感染提供病毒病原学诊断依据。方法选择2012年5月-2013年7月于河北省沧州市中心医院确诊的ARI住院患儿共74l例,取其鼻咽分泌物采用直接免疫荧光法检测7种病毒即呼吸道合胞病毒(RSV)、腺病毒(ADV)、副流感病毒Ⅰ、Ⅱ、Ⅲ((PIV 1、PIV 2、PIV 3)、流感病毒A、B(IFV A、IFV B)。结果 741例患儿中阳性212例,总阳性率28.6%。不同性别患儿间阳性率比较差异无统计学意义(P=0.753)。RSV是住院ARI患儿最主要病原,其次是PIV3;冬季病毒阳性检出率最高,为45%,秋季最低,为15%。年龄≤3岁组检测阳性率明显高于4~7岁组和≥8岁组,差异均有统计学意义。结论 RSV是导致沧州地区儿童呼吸道感染的主要病原体;病毒感染流行性有明显的季节特征,冬春季高发;不同年龄儿童对各种病毒存在不同的易感性。     

A comparison of influenza and respiratory syncytial virus infections among infants admitted to hospital with acute respiratory infections.

Among 741 children under 5 years admitted to hospital with respiratory infections during two winters, infection with influenza A virus was diagnosed in 70 (9%), with influenza B virus in 8 (1%), and with respiratory syncytial virus (RSV) in 259 (35%). Both influenza virus and RSV infections were diagnosed most frequently in children under the age of one year, and diagnosed more frequently in males than females. Influenza illnesses were more severe in boys than girls. Both infections occurred more often, but were not more severe, in children from a conurbation than in those from 'rural' areas. Convulsions were the cause of 36% of admissions with influenza A infections, but were rare in RSV infections. Bronchiolitis was the reason for 39% of admissions with RSV infections, but was rare in influenza infections. It is suggested that infants admitted to hospital are a good source of influenza virus strains for monitoring antigenic variation.     

Seasonal trends of viral respiratory tract infections in the tropics.

To evaluate the seasonal trends of viral respiratory tract infections in a tropical environment, a retrospective survey of laboratory virus isolation, serology and immunofluorescence microscopy in two large general hospitals in Singapore between September 1990 and September 1994 was carried out. Respiratory tract viral outbreaks, particularly among infants who required hospitalization, were found to be associated mainly with respiratory syncytial (RSV) infections (72%), influenza (11%) and parainfluenza viruses (11%). Consistent seasonal variations in viral infections were observed only with RSV (March-August) and influenza A virus (peaks in June, December-January). The RSV trends were associated with higher environmental temperature, lower relative humidity and higher maximal day-to-day temperature variation. Although the influenza A outbreaks were not associated with meteorological factors, influenza B isolates were positively associated with rainfall. These data support the existence of seasonal trends of viral respiratory tract infections in the tropics.     

儿童急性呼吸道感染578例病毒检测分析

目的 了解三门峡地区儿童急性呼吸道感染(ARI)的病毒病原学构成,指导临床诊断与治疗。方法 采集578例ARI住院患儿的鼻咽拭子,采用直接免疫荧光法检测7种病毒即呼吸道合胞病毒(RSV)、腺病毒(ADV)、副流感病毒Ⅰ、Ⅱ、Ⅲ(PIVⅠ～Ⅲ)、流感病毒A、B型(IVA、IVB)。结果 儿童ARI的病毒总检出率为61.59%,混合感染占45.22%。病毒总检出率冬季最高(77.35%)、夏季最低(25.00%)。下呼吸道感染的病毒总检出率高于上呼吸道感染。RSV、PIVⅢ、IVA的检出率位居前三位,分别为30.62%、28.89%、21.97%。RSV及PIVⅢ在秋冬季、下呼吸道感染、3岁以下患儿中检出率较高;IVA在冬季、上呼吸道感染患儿中检出率较高。结论 RSV 、PIVⅢ、IVA是三门峡地区儿童急性呼吸道感染的主要病毒病原。RSV 、PIVⅢ是秋冬季节婴幼儿下呼吸道感染的主要病原;IVA是冬季各年龄患儿上呼吸道感染的主要病原。通过检测儿童ARI的病毒病原,对尽早明确病毒病原,避免滥用抗生素具有重要意义。     

A survey of virus infections of the respiratory tract of cattle and their association with disease

A total of 1590 caves were investigated between May 1972 and December 1975. Twenty-two per cent were treated for respiratory disease and 2 . 5% died of pneumonia. Almost 80% of the respiratory illness occurred in six sharp outbreaks. Samples of virology were collected routinely from 127 healthy calves and from 354 calves treated for respiratory signs and comprised 1143 nasopharyngeal swabs and 1069 sera. Virus infections were detected on 540 occasions including 135 by parainfluenzavirus type 3 (Pi-3), 78 by respiratory syncytial virus (RSV), 103 by rhinovirus, 49 by bovine virus diarrhoea virus (BVDV), 29 by adenoviruses, 53 by reoviruses and 88 by enteroviruses. The seasonal and age distribution of infections differed between viruses. Only infections by RSV, Pi-3 and BVDV were significantly associated with disease.     

A survey of virus infections of the respiratory tract of cattle and their association with disease.

A total of 1590 caves were investigated between May 1972 and December 1975. Twenty-two per cent were treated for respiratory disease and 2 . 5% died of pneumonia. Almost 80% of the respiratory illness occurred in six sharp outbreaks. Samples of virology were collected routinely from 127 healthy calves and from 354 calves treated for respiratory signs and comprised 1143 nasopharyngeal swabs and 1069 sera. Virus infections were detected on 540 occasions including 135 by parainfluenzavirus type 3 (Pi-3), 78 by respiratory syncytial virus (RSV), 103 by rhinovirus, 49 by bovine virus diarrhoea virus (BVDV), 29 by adenoviruses, 53 by reoviruses and 88 by enteroviruses. The seasonal and age distribution of infections differed between viruses. Only infections by RSV, Pi-3 and BVDV were significantly associated with disease.     

2016—2018年53 851例急性呼吸道感染儿童七项病毒检测结果分析

目的 了解2016—2018年湖南省儿童医院就诊病人常见呼吸道病毒感染病原谱及病例流行病学特征。 方法 2016年1月—2018年12月期间,采集湖南省儿童医院门诊和住院病人急性呼吸道感染儿童鼻咽拭子标本,采用直接免疫荧光法对副流感病毒1-3型、呼吸道合胞病毒、流感病毒A与B型和腺病毒共七项呼吸道病毒抗原进行检测,对病例信息进行统计学分析。 结果 共采集检测病例53 851例,总阳性检出率为23.25%(12 519/53 851),副流感病毒1-3型、呼吸道合胞病毒、流感病毒A与B型和腺病毒阳性检出率分别为0.68%、0.10%、5.63%、13.44%、1.51%、0.74%和1.15%,呼吸道合胞病毒阳性率最高(χ²=23 427.78,P<0.001)。不同年份七项呼吸道病毒检出率存在差异(χ²=196.21,P<0.001);总阳性检出率冬季最高,夏季最低;呼吸道合胞病毒和副流感病毒3型阳性检出率随着时间波动较大,存在明显的季节性;年龄越小,总阳性检出率越高,0~1岁阳性检出率最高为29.93%;七项总阳性检出率男性高于女性(P=0.003),呼吸道合胞病毒阳性检出率男性高于女性(P=0.013)其它各项呼吸道病毒阳性检出率没有性别差异(P>0.05)。 结论 2016—2018年急性呼吸道感染儿童七项病毒阳性检出率存在明显差异,不同年份、不同季节、不同年龄、不同性别七项呼吸道病毒检出率亦存在差异,研究有助于临床诊断和制定预防感染的措施。     

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.     

半巢式RT-PCR法检测呼吸道合胞病毒

目的建立快速、敏感、特异的人呼吸道合胞病毒(Respiratory syncytial virus，RSV)检测方法。方法根据RSVF基因的保守序列设计3条引物，建立半巢式RT-PCR(semi-nested RT-PCR)检测方法。用该方法检测125例患急性下呼吸道感染的婴幼儿的鼻咽吸引物(nasopharyngeal aspirates，NPA)标本，同时对标本进行病毒分离和直接免疫荧光法检测。结果该半巢式RT-PCR灵敏度为0．1TCID50，用该方法在125例标本中共检出RSV阳性标本63例，阳性率50．4％。结论建立快速、敏感、特异的RSV半巢式RT-PCR检测方法，该方法适用于临床早期诊断和流行病学监测。     

儿童急性下呼吸道感染常见病毒的流行状态分析

目的分析长沙地区儿童急性下呼吸道感染（ALRTI）常见病毒的流行状态。方法对2007年9月至2008年8月本院儿科医学中心住院临床诊断为ALRTI的患儿1165例,采集患儿鼻咽部分泌物,应用RT—PCR进行常见呼吸道病毒核酸检测,包括RSV、HRV、PIV1～3、和IFA、IFB,PCR方法检测ADV,分析急性下呼吸道感染患儿病毒检出率及病毒感染与年龄、季节的关系。结果1165例患儿中,783例检出至少1种病毒,检出率为67．2％。其中RSV检出率27％,其次是HRV（17．4％）和PIV3（13．9％）。病毒感染的高峰在秋冬季节。不同年龄组病毒的总检出率比较差异有统计学意义,≤12个月组病毒检出率较高为67．5％,〉60个月组病毒检出率最低为42．9％。783例中2种或2种以上病毒混合感染检出率为36．3％,≤12个月组混合感染检出率最高为63．7％,〉36个月组混合感染检出率仅为8．5％。结论ALRTI患儿中常见病毒感染的高峰在秋冬季节;检出的呼吸道病毒中RSV感染检出率最高,其次为HRV和PIV3;≤12个月患儿病毒感染检出率及混合感染率最高;最常见的混合感染类型是RSV和HRV两种病毒混合感染。     

Respiratory syncytial virus infection in children with acute respiratory infections in Zambia.

Epidemiological research on respiratory syncytial virus (RSV) infections in children was carried out at the Virology Laboratory, University Teaching Hospital (UTH), in Lusaka, Zambia, from January-December 1996. Specimens including 736 nasal washings and 2424 throat swabs were collected from children with acute respiratory infections (ARI) and tested for RSV by enzyme immunoassay and by virus isolation. RSV was isolated in 62 (4.1%) of 1496 throat swabs collected from March to September and was detected in 99 (16.3%) of 609 nasal washings from March to November. The average RSV isolation rate was 2.6% and the average RSV detection rate was 13.5%. The highest RSV isolation (8.1%) and detection (30.5%) rates were in June 1996. RSV antibody in the 278 serum specimens collected from Zambian children, who were hospitalized in the paediatric ward, UTH, was detected using a standard neutralization test. The antibody positive rate was 60-80% in children > 4 years. It is evident that RSV is one of the main causal agents of ARI in children in Zambia.     

Acute respiratory infections in ambulatory malnourished children: a serological study

We studied the aetiological agents of acute respiratory infections occurring in an ambulatory population of 83 malnourished Jamaican-born children aged 6 to 32 months using serological methods for diagnosis. In 60% (38/63) of symptomatic children and in 25% (5/20) of those without reported disease the following microorganisms were observed: parainfluenza viruses in 15 children, influenza viruses in 12, adenovirus in 10, respiratory syncitial virus in 7 and Mycoplasma pneumoniae in 7 children. The prevalence of the viral infections apparently increased with the severity of malnutrition.     

婴幼儿呼吸道感染中病毒检测的临床意义

目的：了解婴幼儿急性呼吸道感染的病原学构成及临床特征,探究更快缓解临床症状的治疗方案。方法选取年龄为3个月至3岁之间因急性呼吸道感染住院治疗的婴幼儿179例,采集每例患儿鼻咽吸取物1份,运用直接免疫荧光法检测7项呼吸道病毒抗原,并分析其结果。结果在179例送检标本中,阳性检出率为35．2％,其中呼吸道合胞病毒感染占阳性标本的52．4％。病毒检测阳性患儿临床症状体征更明显（t＝5．016,P＜0．01）。结论病毒是婴幼儿呼吸道感染的主要病原,以呼吸道合胞病毒最常见。