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.     

Response of calves persistently infected with noncytopathic bovine viral diarrhea virus (BVDV) subtype 1b after vaccination with heterologous BVDV strains in modified live virus vaccines and Mannheimia haemolytica bacterin-toxoid

Seronegative persistently infected (PI) calves with bovine viral diarrhea virus (BVDV) subtype 1b were vaccinated with each of four modified live virus (MLV) BVDV vaccines and a Mannheimia haemolytica bacterin-toxoid. Nasal swabs and peripheral blood leukocytes (PBL) were collected for virus isolation and serums were collected after vaccination and tested for BVDV1a, BVDV1b, BVDV2, bovine herpesvirus-1 (BHV-1), bovine parainfluenza-3 virus (PI-3V), and bovine respiratory syncytial virus (BRSV) antibodies. M. haemolytica and Pasteurella multocida antibodies were detected using ELISA procedures. None of the PI calves developed mucosal disease (MD) after MLV vaccination. None of the BVDV PI calves seroconverted to BVDV1b after MLV vaccination. Calves receiving MLV vaccines seroconverted to the respective type/subtype in the vaccine. Calves receiving a MLV vaccine with noncytopathic (NCP) BVDV1 (subtype not designated) did not seroconvert to BVDV1a, BVDV1b, or BVDV2. The PI calves were positive for BVDV subtype 1b, in the PBL and nasal swabs throughout the study. Calves receiving each of three vaccines with known BVDV1a strains had BVDV1a positive samples after vaccination, in some but not all calves, up to Day 28. The PI BVDV1b calves did not respond with increased M. haemolytica antibodies after vaccination compared to BVDV negative calves receiving the same M. haemolytica vaccine.     

The pathogenesis of bovine virus diarrhoea virus infections

Bovine virus diarrhoea virus (BVDV) disease in cattle ranges from the transient acute infections, which may be inapparent or mild, to mucosal disease which is inevitably fatal. On occasions the acute infections can lead to clinical episodes of diarrhoea and agalactia but as these syndromes cannot be reproduced experimentally, the pathogenesis remains unclear. The immunosuppressive effect of acute BVDV infections can enhance the clinical disease of other pathogens and this may be an important part of the calf respiratory disease complex. Although BVDV antigen has been demonstrated within the lymphoid tissues, for prolonged periods, the evidence for viral latency remains to be proven. Venereal infection is shown to be important in the transfer of virus to the foetus and congenital infections can cause abortions, malformations and the development of persistently viraemic calves. The two biotypes of the virus, non-cytopathogenic and cytopathogenic, are described. Their sequential role in the pathogenesis of mucosal disease arises from the initial foetal infection with the non-cytopathogenic virus and the subsequent production of persistently viraemic calves. These calves may later develop mucosal disease as a result of superinfection with a "homologous" cytopathogenic virus. The possible origin of this biotype by mutation is discussed. Chronic disease is defined as a progressive wasting and usually diarrhoeic condition; it is suggested that this may develop following superinfection of persistently viraemic cattle with a "heterologous" cytopathogenic biotype.     

Formalin-inactivated bovine RSV vaccine influences antibody levels in bronchoalveolar lavage fluid and disease outcome in experimentally infected calves

Respiratory syncytial virus (RSV) causes severe respiratory disease in calves and human infants. In response to outbreaks, formalin inactivated (FI)-RSV vaccines were developed and found to exacerbate disease following a live RSV infection. We have reproduced vaccination induced disease enhancement in calves and screened various antibody isotypes in bronchoalveolar lavage fluid (BALF) from two studies: one with disease enhancement and another where moderate protection resulted from FI-bovine RSV (BRSV) vaccination. Semi-protected vaccinated calves produced BRSV-specific BALF IgG1, but not IgA and IgG2 prior to infection; whereas, calves with enhanced disease failed to develop BRSV-specific IgG1 in BALF. Ultimately, the formulation and delivery of RSV vaccines influences protective antibody levels in respiratory secretions.     

北京地区儿童ARI的鼻咽分泌物的病毒免疫荧光检测结果分析

目的 分析1997年3月－1999年3月两年间北京地区儿童急性呼吸道感染（ARI）的鼻咽分泌物病毒免疫荧光学检测结果。方法 选择1997年3月－1999年3月因急性呼吸道感染而在北京市儿童医院住院治疗的患儿,取其鼻咽分泌物做免疫荧光检测筛查七种呼吸道病毒抗原,阳性病例入选,分析其病历资料。结果 所有794例病人送检标本共796份,阳性228份（28．6％）,其中RSV196例（24．6％）、IA20(2．5％）、IB1例（0．12％）、ADV4例（0．5％）、PIV3 2例（0．25％）、RSV和PIV3 2例（0．25％）,RSV和IA3例 （0．38％）。RSV 和IA感染呈季节性分布。RSV组和IA组病人之间喘息症状并无差异。小年龄组病人与大年龄儿相当,呼吸快、更多存在低氧血症和二氧化碳潴留,病情重、吸氧者多。结论 北京地区两年以来儿童呼吸道感染的病毒学病因可能为呼吸道合胞病毒（RSV）、流感病毒（IA）、腺病毒（ADV）和副流感病毒3型（PIV3）,以RSV为主。RSV和IA有一定的季节变化。     

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.     

Age-dependent differences in cytokine and antibody responses after experimental RSV infection in a bovine model

Respiratory syncytial virus (RSV) causes severe respiratory disease in both infants and calves. As in humans, bovine RSV (BRSV) infections are most severe in the first 6 months of life. In this study, experimental infection with BRSV was performed in calves aged 1-5, 9-16 or 32-37 weeks. Compared to younger animals, older calves showed significantly less fever and lower TNFalpha levels and less virus-specific IFNgamma release. In addition, blood from older animals had more mononuclear cells, more B cells and stronger BRSV-specific IgA and neutralising antibody responses to infection. A strong "inflammatory" but weak humoral antiviral response in very young animals suggests that enhanced inflammation contributes to disease during RSV infection during the early postnatal period.     

Vaccination with recombinant modified vaccinia virus Ankara expressing bovine respiratory syncytial virus (bRSV) proteins protects calves against RSV challenge

Respiratory syncytial virus (RSV) is a major cause of severe respiratory disease in infants and calves. Bovine RSV (bRSV) is a natural pathogen for cattle, and bRSV infection in calves shares many features with the human infection. Thus, bRSV infection in cattle provides the ideal setting to evaluate the safety and efficacy of novel RSV vaccine strategies. Here, we have evaluated the efficacy and safety of modified vaccinia virus Ankara (rMVA)-based vaccine candidates, expressing the bovine RSV-F protein, either or not in combination with the G protein, in colostrums-deprived SPF calves born by caesarean section. Vaccination induced bRSV-specific IgG and CD8 T cell responses. Importantly, no IgE responses were detected. After bRSV challenge, rMVA vaccinated calves experienced less severe symptoms of lower respiratory tract disease compared to the mock-immunized control group. Immunized animals showed reduced pulmonary virus loads, and no eosinophilic infiltration or enhanced respiratory distress. In conclusion, candidate rMVA/bRSV vaccines induced protective and safe immune responses in calves.     

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。     

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.     

Maternally derived humoral immunity to bovine viral diarrhea virus (BVDV) 1a, BVDV1b, BVDV2, bovine herpesvirus-1, parainfluenza-3 virus bovine respiratory syncytial virus, Mannheimia haemolytica and Pasteurella multocida in beef calves, antibody decline by half-life studies and effect on response to vaccination

The passive immunity transferred to calves from their dams was investigated in a beef herd to determine half-life of antibody, estimated time to seronegative status and effect on immunization. One hundred two beef calves in a commercial ranch under standard management conditions were utilized. Samples were collected at branding (day 0). This was the first possible date to collect samples postcalving. This was approximately 2 months postcalving, and days 95 and 116. The calves were divided into two groups: vaccinates (51) and nonvaccinates (51). The calves were vaccinated with a commercial inactivated viral vaccine containing bovine viral diarrhea virus (BVDV)1a, BVDV2, bovine herpesvirus-1 (BHV-1), parainfluenza-3 virus (PI-3V), and bovine respiratory syncytial virus (BRSV) on days 0 and 95. Half of the vaccinated and unvaccinated calves also received one dose of an experimental Mannheimia haemolytica and Pasteurella multocida vaccine at day 95. Serums were tested for neutralizing antibody titers to BVDV1a, BVDV1b, BVDV2, BHV-1, PI-3V, and BRSV. Antibodies were detected by ELISA to M. haemolytica whole cell, M. haemolytica leukotoxin, and P. multocida outer membrane protein (OMP). The mean half-life of viral antibodies in nonvaccinated calves to each virus was: BVDV1a, 23.1 days (d); BVDV1b, 22.8 d; BVDV2, 22.9 d; BHV-1, 21.2 d; PI-3V, 30.3 d; and BRSV, 35.9 d. The mean half-life of viral antibodies was greater for vaccinates than for nonvaccinates for all viruses except BRSV. The calculated mean time to seronegative status for nonvaccinates based on titers at day 0 was: BVDV1a, 192.2 d; BVDV1b, 179.1 d; BVDV2, 157.8 d; BHV-1, 122.9 d; PI-3V, 190.6 d; and BRSV, 186.7 d. There was an active immune response after vaccination with two doses to all the viruses, except BRSV. Mean antibody titers of vaccinates at day 116 were statistically higher than nonvaccinates for all viruses except BRSV. However on an individual calf basis there were few seroconversions (four-fold rise or greater to BVDV1a, BVDV1b, BVDV2, PI-3V, or BRSV; or two-fold rise for BHV-1) in the presence of viral antibodies. The predicted time of seronegative status for a group of calves for vaccination programs may not be appropriate as there may be a range of titers for all calves at day 0. In this study the range for BVDV1a was 16-16,384; BVDV1b, 8-8192; BVDV2, 0-8192; BHV-1, 0-935; PI-3V, 8-2048; and BRSV, 8-4096. Using the half-life of 23 d for BVDV1a, the time thereafter for seronegative status would be 46 and 299 d compared to the calculated date of 192.2 d using the mean of estimated time to seronegative status for all the calves. There was an active humoral response in the vaccinated calves to M. haemolytica and P. multocida. Cowherd humoral immunity based on serum antibodies should be monitored as it may relate to transfer of maternal antibodies to calves. Exceptionally high levels of viral antibodies transferred to calves could interfere with the antibody response to vaccination.     

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 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.     

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.     

Cross-protective efficacy of a bovine viral diarrhea virus (BVDV) type 1 vaccine against BVDV type 2 challenge

A new genotype of bovine viral diarrhea virus (BVDV), designated BVDV type 2 (BVDV 2), has become prevalent in the field. BVDV 2 strains are antigenically distinct from currently available vaccine strains of the BVDV 1 genotype, raising concerns about cross-protection of these vaccines against BVDV 2 challenge. To determine cross-protective efficacy of a modified-live virus (MLV) vaccine containing BVDV 1 strain WRL (BVDV 1(WRL)), two studies were conducted in which the relative magnitude and duration of BVDV 1- and BVDV 2-specific serologic responses and protection against BVDV 2 challenge were determined. For the first study, 27 heifers were vaccinated (13 i.m. and 14 s.c.), while 13 heifers received negative control vaccine. Serum from the vaccinated heifers neutralized both BVDV 1 and BVDV 2 strains. The evolution and duration of BVDV 1 and BVDV 2 serologic responses were comparable, and antibody titers to BVDV 2 persisted through at least 105 days post-single vaccination. In a second, separate study, 17 calves were vaccinated (9 i.m. and 8 s.c.), and 11 calves were held as unvaccinated controls. Approximately seven months following vaccination, the calves were challenged intranasally with the 890 isolate of BVDV 2. Clinical signs of disease and fever were significantly reduced in vaccinates in comparison with controls. Vaccination eliminated nasal virus shedding in 87% of cattle and completely prevented viremia and leukopenia. These data indicate utility of BVDV 1(WRL) MLV vaccine in stimulation of long-term BVDV 2-specific serologic responses, protection against BVDV 2 challenge and reduction or elimination of virus shedding which can contribute to spread of BVDV 2 in herds.     

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.     

Immunogenicity of a modified-live virus vaccine against bovine viral diarrhea virus types 1 and 2, infectious bovine rhinotracheitis virus,bovine parainfluenza-3 virus,and bovine respiratory syncytial virus when administered intranasally in young calves

The immunogenicity of an intranasally-administered modified-live virus (MLV) vaccine in 3–8 day old calves was evaluated against bovine viral diarrhea virus (BVDV) types 1 and 2, infectious bovine rhinotracheitis (IBR) virus, parainfluenza-3 (PI-3) virus and bovine respiratory syncytial virus (BRSV). Calves were intranasally vaccinated with a single dose of a multivalent MLV vaccine and were challenged with one of the respective viruses three to four weeks post-vaccination in five separate studies. There was significant sparing of diseases in calves intranasally vaccinated with the MLV vaccine, as indicated by significantly fewer clinical signs, lower rectal temperatures, reduced viral shedding, greater white blood cell and platelet counts, and less severe pulmonary lesions than control animals. This was the first MLV combination vaccine to demonstrate efficacy against BVDV types 1 and 2, IBR, PI-3 and BRSV in calves 3–8 days of age.     

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.     

Sero-epidemiological studies of respiratory syncytial and adenoviruses in children in Ibadan, Nigeria, 1985-1988.

Retrospective and prospective serological surveys to determine the prevalence of respiratory syncytial virus (RSV) and adenovirus (ADV) infections in children with respiratory diseases were carried out from 1985 to 1988 at the University College Hospital, Ibadan, Nigeria. 306 sera from subjects between 3 months and 12 years old were assayed by complement fixation test for antibodies to both viruses. Second samples were available from 42 of the subjects for antibody conversion testing. The rate varied with age, period of the year and virus. Overall prevalences of 23.5% and 18.3% were obtained for RSV and ADV respectively. 2.6% of the subjects had antibodies to both viruses. Among 42 paired samples tested, 61.9% and 33.3% showed positive antibody conversion to RSV and ADV respectively. Although there was evidence of active circulation of both viruses throughout the year, infection with RSV was higher from September to January, while ADV infection was significantly higher during February and March. Antibody prevalence to both viruses increased with age up to a peak of 39.1% for RSV in children 5-6 years old and 32% for ADV in children 3-4 years old. None of the subjects aged 10 years and above was positive for both viruses. Both RSV and ADV are important agents of acute respiratory infection in children in Nigeria.     

Respiratory syncytial virus infection and meningococcal disease.

Although viral respiratory tract infections may predispose to meningococcal disease, strong evidence that they do so exists only for influenza. Data on laboratory reported cases of respiratory syncytial virus (RSV) infections and meningococcal disease in England and Wales from mid-1989 to mid-1994 were analysed. Although the rise in RSV cases preceded the rise in meningococcal disease cases each winter, the interval between the rise and fall of the two diseases was inconsistent, no association was found between time series after removal of the seasonal component, and there was no evidence that more cases of meningococcal disease occurred in winters with more RSV disease. RSV may have less effect on the two most likely mechanisms whereby influenza predisposes to meningococcal disease, namely lowered immunity and impaired pharyngeal defences.