Respiratory Syncytial Virus Antigen Research Articles

AIK-C measles vaccine expressing fusion protein of respiratory syncytial virus induces protective antibodies in cotton rats

Respiratory syncytial virus (RSV) is the most common cause of respiratory infection in infants, and no vaccine is available. In this report, recombinant AIK-C measles vaccines, expressing the RSV G or F protein of subgroup A (MVAIK/RSV/G or F), were investigated as a RSV vaccine candidate. MVAIK/RSV/G or F had the original ts phenotype and expressed RSV/G or F protein. Cross-reactive neutralizing antibodies against RSV subgroups A and B were detected in cotton rats immunized intramuscularly with MVAIK/RSV/F but not MVAIK/RSV/G. In cotton rats infected with RSV, RSV was recovered and lung histopathological finding was compatible with interstitial pneumonia, demonstrating thickening of alveolar walls and infiltration of mononuclear cells. When cotton rats immunized with MVAIK/RSV/F were challenged with homologous RSV subgroup A, no infectious RSV was recovered and very mild inflammation was noted without RSV antigen expression. When they were challenged with subgroup B, protective efficacy decreased. When cotton rats immunized with MVAIK/RSV/G were challenged with RSV subgroup A, low levels of infectious virus were recovered from lung. When challenged with subgroup B, no protective effects was demonstrated, demonstrating large amounts of RSV antigen in bronchial-epithelial cells. MVAIK/RSV/F is promising candidate and protective effects should be confirmed in monkey model.

Lenalidomide Enhances Multiple Myeloma Cytotoxicity Induced by a Novel Fc Domain-Engineered Anti-HM1.24 Monoclonal Antibody with Augmented NK Cell Degranulation

AbstractAbstract 4064HM1.24, an immunological target highly expressed on majority of multiple myeloma (MM) cells, has not been effectively targeted with therapeutic monoclonal antibodies (mAbs). Recently, XmAb5592, a novel Fc-domain engineered humanized anti-HM1.24 mAb with specific Fc-domain modification, was shown to induce >10-fold antibody-dependent cellular cytotoxicity (ADCC) and antibody dependent cellular phagocytosis against MM cells, when compared with the humanized normal anti-HM1.24 IgG1 (XmAb5627) from which it is derived (ASH Abstract#609, 2009). Here we investigated whether XmAb5592, when combined with other anti-MM drugs, further enhanced ADCC against MM cell lines and primary patient MM cells using Calcein-AM release ADCC assays and flow cytometric analysis for cell membrane CD107a to specifically quantitate NK cell (CD56+CD3-) activation. Addition of lenalidomide (10 μ M) in standard ADCC assays increased XmAb5592 (0.1 μ g/ml)-induced cell lysis against MM1S, MM1R, and RPMI8226 cells in the presence of peripheral blood mononuclear cells (PBMCs) from normal donors (n=2). Specifically, XmAb5592 (0.01, and 0.1 μ g/ml) combined with lenalidomide (2.5, 5, 10 μ M), in the presence or absence of IL-2 (100 units/ml), synergistically induced NK-mediated RPMI8226 MM cell lysis, as evidenced by combination index (CI) < 1 (0.08-0.89). Pre-incubation of PBMCs with additional IL-2 (100 units/ml) enhanced even stronger XmAb5592-induced cytotoxicity against MM cells than pretreatment with lenalidomide alone. Lenalidomide also enhanced PBMC effectors to kill primary patient MM cells. Cell surface CD107a, as a functional marker for NK cell activation dependent on granzyme B secretion, was further determined following target myeloma cell incubation, with or without NK cells and in the presence of mAbs. NK cells were activated by as low as 0.001 μ g/ml of XmAb5592 only in the presence of MM1S tumor cells. In contrast, neither XmAb6166, an Fc-domain knockout of XmAb5592 without NK binding, nor XmAb4614, a similar Fc-engineered mAb targeting respiratory syncytial virus (RSV) antigen, induced any cell surface CD107a on NK cells incubated with MM cells. Specific XmAb5592-induced CD107a-dependent NK cell degranulation further correlated with IFNγ secretion (r=0.7, p=0.03). XmAb5592 induced > 10-fold more potent NK degranulation than XmAb5627, which significantly correlated with MM cell lysis by ADCC, even in the presence of bone marrow stromal cells (BMSCs). Moreover, no significant HM1.24 was expressed on NK cells stimulated with or without IFN-α, suggesting minimal NK toxicity. XmAb5592 more potently (>10-fold) than XmAb5627 induces homotypic aggregation and adhesion of NK cells, which was further enhanced by lenalidomide. Finally, minimal HM1.24 expression was confirmed on different PBMC subsets including CD15+ (PMN), CD19+ (B), CD14+ (MC), and CD3+ (T) cells. These results indicate that lenalidomide further potentiates XmAb5592-induced myeloma cell killing via NK-mediated ADCC, providing a rationale to combine both novel drugs to improve patient outcome in MM. Disclosures:Muchhal:Xencor Inc: Employment. Desjarlais:Xencor Inc: Employment. Richardson:Gentium: Membership on an entity's Board of Directors or advisory committees, Research Funding. Munshi:Millennium Pharmaceuticals: Honoraria, Speakers Bureau. Anderson:Millennium Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.

Conserved cysteine residues within the attachment G glycoprotein of respiratory syncytial virus play a critical role in the enhancement of cytotoxic T-lymphocyte responses.

The cytotoxic T-lymphocyte (CTL) response plays an important role in the control of respiratory syncytial virus (RSV) replication and the establishment of a Th1-CD4+ T cell response against the virus. Despite lacking Major Histocompatibility Complex I (MHC I)-restricted epitopes, the attachment G glycoprotein of RSV enhances CTL activity toward other RSV antigens, and this effect depends on its conserved central region. Here, we report that RSV-G can also improve CTL activity toward antigens from unrelated pathogens such as influenza, and that a mutant form of RSV-G lacking four conserved cysteine residues at positions 173, 176, 182, and 186 fails to enhance CTL responses. Our results indicate that these conserved residues are essential for the wide-spectrum pro-CTL activity displayed by the protein.

Age related changes in T cell mediated immune response and effector memory to Respiratory Syncytial Virus (RSV) in healthy subjects

Respiratory syncytial virus (RSV) is the major pathogen causing respiratory disease in young infants and it is an important cause of serious illness in the elderly since the infection provides limited immune protection against reinfection. In order to explain this phenomenon, we investigated whether healthy adults of different age (20-40; 41-60 and > 60 years), have differences in central and effector memory, RSV-specific CD8+ T cell memory immune response and regulatory T cell expression status. In the peripheral blood of these donors, we were unable to detect any age related difference in term of central (CD45RA-CCR7+) and effector (CD45RA-CCR7-) memory T cell frequency. On the contrary, we found a significant increase in immunosuppressive regulatory (CD4+25+FoxP3+) T cells (Treg) in the elderly. An immunocytofluorimetric RSV pentamer analysis performed on these donors' peripheral blood mononuclear cells (PBMCs), in vitro sensitized against RSV antigen, revealed a marked decline in long-lasting RSV specific CD8+ memory T cell precursors expressing interleukin 7 receptor α (IL-7Rα), in the elderly. This effect was paralleled by a progressive switch from a Th1 (IFN-γ and TNF-α) to a Th2 (IL-10) functional phenotype. On the contrary, an increase in Treg was observed with aging. The finding of Treg over-expression status, a prominent Th2 response and an inefficient RSV-specific effector memory CD8+ T cell expansion in older donors could explain the poor protection against RSV reinfection and the increased risk to develop an RSV-related severe illness in this population. Our finding also lays the basis for new therapeutic perspectives that could limit or prevent severe RSV infection in elderly.

Comparison of methods for laboratory diagnosis of respiratory syncytial virus

Respiratory syncytial virus (RSV) still remains the main agent of lower respiratory tract infections in infants and young children, causing bronchiolitis and/or pneumonia leading to hospitalization and even to death in high-risk patients, such as premature babies. Its great impact on human health supports the need for rapid diagnostic methods in order to control and prevent the infection spread. In this study 63 samples from the respiratory tract were subjected to virological investigations usually applied in diagnostic routine: the research of RSV antigens in cells derived from the biological samples by immunofluorescence (IFD), as well as the rapid and the traditional cell culture methods (MR and MT, respectively).A third rapid test, the immunochromatographic assay TRU RSVTM (Meridian), for the research of RSV specific proteins, was applied retrospectively to the same samples stored at -80°C. Among the above considered routine methods, the most reliable for rapid diagnosis of RSV infection in our hands was IFD, which was able to reveal the greatest number of positive samples (54/63) and was therefore considered as the reference technique. The immunochromatographic assay TRU RSVTM identified 39/54 positive samples (72.2%), the bulk of which superposed with those also resulted positive with MR and/or MT (i.e. samples with high viral load). On the other hand, the immunochromatographic test was unable to detect RSV antigens in the majority of samples positive only with IFD (i.e. samples with low viral load).

Respiratory Syncytial Virus (RSV) RNA loads in peripheral blood correlates with disease severity in mice

BackgroundRespiratory Syncytial Virus (RSV) infection is usually restricted to the respiratory epithelium. Few studies have documented the presence of RSV in the systemic circulation, however there is no consistent information whether virus detection in the blood correlates with disease severity.MethodsBalb/c mice were inoculated with live RSV, heat-inactivated RSV or medium. A subset of RSV-infected mice was treated with anti-RSV antibody 72 h post-inoculation. RSV RNA loads were measured by PCR in peripheral blood from day 1-21 post-inoculation and were correlated with upper and lower respiratory tract viral loads, the systemic cytokine response, lung inflammation and pulmonary function. Immunohistochemical staining was used to define the localization of RSV antigens in the respiratory tract and peripheral blood.ResultsRSV RNA loads were detected in peripheral blood from day 1 to 14 post-inoculation, peaked on day 5 and significantly correlated with nasal and lung RSV loads, airway obstruction, and blood CCL2 and CXCL1 expression. Treatment with anti-RSV antibody reduced blood RSV RNA loads and improved airway obstruction. Immunostaining identified RSV antigens in alveolar macrophages and peripheral blood monocytes.ConclusionsRSV RNA was detected in peripheral blood upon infection with live RSV, followed a time-course parallel to viral loads assessed in the respiratory tract and was significantly correlated with RSV-induced airway disease.

Toll‐like receptor 4 Asp299Gly polymorphism in respiratory syncytial virus epidemics

The respiratory syncytial virus (RSV) antigen serves as ligand for Toll-like receptor (TLR) 4 that is a transmembrane signaling receptor in macrophages and dendritic cells. According to current evidence single nucleotide polymorphism involving amino acid 299 influences the susceptibility to severe RSV infections. The Asp299Gly allele has been shown to influence the TLR4-mediated signaling causing conformational change in the extracellular domain that recognizes pathogen-associated molecular patterns. The aim was to study the association between the TLR4 Asp299Gly polymorphism and the susceptibility to severe RSV bronchiolitis in infants. Altogether 312 cases and 356 controls, selected on the basis place of residence, date of birth, gender, and gestation at birth, were studied. When adjusted for multiple dependent variables, no allele or genotype frequency difference was found between the cases and the controls. Post hoc analysis revealed that during the year 2000 epidemics, the Gly299Gly genotype associated with protection against severe RSV and during 2004 epidemics Gly299Gly genotype and 299Gly allele associated with severe RSV. To conclude, we could not confirm the association of the Gly299 allele with severe RSV. This is consistent with the evidence that the susceptibility to severe RSV infection is principally dependent on environmental and constitutional factors. We propose that the risk of severe RSV infection may additionally depend on the interaction between individual TLR4 genotype and the particular RSV group causing bronchiolitis.

Detection and Control of a Nosocomial Respiratory Syncytial Virus Outbreak in a Stem Cell Transplantation Unit: The Role of Palivizumab

Respiratory syncytial virus (RSV) is a common community-acquired virus that causes upper and lower respiratory tract infections in children, hematologic malignancy patients, and hematopoietic stem cell transplant (HSCT) recipients. Nosocomial transmission of RSV in immunocompromised patients can significantly affect morbidity, mortality, and duration of hospitalization. Stringent infection control measurements are needed to control further hospital transmission. Prophylactic palivizumab was found to result in a significant reduction in hospitalization rates in high-risk children. In this article, we report a nosocomial outbreak of RSV in an adult HSCT unit (4 pods) from January 16 to February 4, 2004, including the infection control interventions used and the prophylactic administration of palivizumab in high-risk patients. Active surveillance identified 5 cases, a substantial increase from previous seasons (2 or 3 cases per season). All infected patients were isolated to 1 nursing pod and placed on contact isolation. All patients on the HSCT unit underwent rapid RSV antigen screening using nasal washes; this was repeated 1 week later, and 1 additional RSV case was identified. Patients identified to be at increased risk for RSV infection received prophylactic palivizumab. Routine screenings of the staff and visitors were undertaken. All patient and visitor areas were thoroughly cleaned with bleach. We educated health care workers about RSV transmission, highlighting proper hand hygiene and contact precautions. Four of 6 patients with RSV infection developed RSV pneumonia, and 2 of these patients died. Staff and visitors with upper respiratory symptoms were screened, and all were negative for RSV. Prophylactic palivizumab was administered in 16 patients who tested negative for RSV, but were considered to be at increased risk for RSV infection. None of these patients developed RSV infections. An RSV outbreak was controlled using prompt preventive measures, including cohorting patients, with a dedicated health care staff; contact isolation of patients; strict adherence to hand hygiene; and screening of visitors, family members, and health care staff for upper respiratory infection symptoms. Immunoprophylaxis with palivizumab, administered to high-risk patients, complemented strict infection control intervention. Thus, the role of palivizumab in the control of RSV hospital outbreaks merits further investigation.

Respiratory syncytial virus infection outbreak among pediatric patients with oncologic diseases and/or BMT

Respiratory syncytial virus (RSV) has been reported to cause severe morbidity and mortality among cancer patients receiving chemotherapy with or without autologous/allogeneic hematopoetic stem cell transplantation (HSCT). There have been few reports describing the outcome of RSV infection specifically among pediatric oncology patients. Two RSV infection outbreaks developed between February-April 2006 and January-March 2009 in hospitalized pediatric patients for various hemato-oncological diseases + or - HSCT. A survey of respiratory viruses was done using direct immunofluorescent antibody assay from nasopharyngeal washing aspirate. In two RSV infection outbreaks (2006 and 2009), RSV antigen was detected in 6/30 patients. Five of six patients with RSV antigen were all treated with 0.2-0.4 g/kg intravenous immune globulin (IVIG) and specific antiviral therapy, oral ribavirin (20-25 mg/kg/day in three doses). Five patients recovered fully, although two were retreated due to recurrent (+) RSV antigen and respiratory symptoms within 2 weeks. We did not give oral ribavirin to one patient with (+) RSV antigen due to mild symptoms. All patients are alive and well. In contrast with the outcome of RSV infection in adult oncology patients, the mortality associated with RSV infection in pediatric oncology patients even in post bone marrow transplantation (BMT) period, is low when diagnosed and treated early enough. Oral ribavirin might be an option together with IVIG in the treatment of RSV especially when other forms of antivirals could not be obtained. This approach will make it possible to give the scheduled anti-neoplastic therapy on time.

Inactivation of respiratory syncytial virus by zinc finger reactive compounds

BackgroundInfectivity of retroviruses such as HIV-1 and MuLV can be abrogated by compounds targeting zinc finger motif in viral nucleocapsid protein (NC), involved in controlling the processivity of reverse transcription and virus infectivity. Although a member of a different viral family (Pneumoviridae), respiratory syncytial virus (RSV) contains a zinc finger protein M2-1 also involved in control of viral polymerase processivity. Given the functional similarity between the two proteins, it was possible that zinc finger-reactive compounds inactivating retroviruses would have a similar effect against RSV by targeting RSV M2-1 protein. Moreover, inactivation of RSV through modification of an internal protein could yield a safer whole virus vaccine than that produced by RSV inactivation with formalin which modifies surface proteins.ResultsThree compounds were evaluated for their ability to reduce RSV infectivity: 2,2'-dithiodipyridine (AT-2), tetraethylthiuram disulfide and tetramethylthiuram disulfide. All three were capable of inactivating RSV, with AT-2 being the most potent. The mechanism of action of AT-2 was analyzed and it was found that AT-2 treatment indeed results in the modification of RSV M2-1. Altered intramolecular disulfide bond formation in M2-1 protein of AT-2-treated RSV virions might have been responsible for abrogation of RSV infectivity. AT-2-inactivated RSV was found to be moderately immunogenic in the cotton rats S.hispidus and did not cause a vaccine-enhancement seen in animals vaccinated with formalin-inactivated RSV. Increasing immunogenicity of AT-2-inactivated RSV by adjuvant (Ribi), however, led to vaccine-enhanced disease.ConclusionsThis work presents evidence that compounds that inactivate retroviruses by targeting the zinc finger motif in their nucleocapsid proteins are also effective against RSV. AT-2-inactivated RSV vaccine is not strongly immunogenic in the absence of adjuvants. In the adjuvanted form, however, vaccine induces immunopathologic response. The mere preservation of surface antigens of RSV, therefore may not be sufficient to produce a highly-efficacious inactivated virus vaccine that does not lead to an atypical disease.

Respiratory syncytial virus infection cases in congenital heart disease patients

Purpose : Respiratory syncytial virus (RSV) is one of the main pathogens causing lower respiratory infections (LRI) in young children, usually of limited severity. However, in congenital heart disease (CHD) patients, one of the high-risk groups for RSV infection, RSV can cause serious illnesses and fatal results. To elucidate the effects of RSV infection in CHD patients, we observed RSV infection cases among CHD patients and non-CHD patients. Methods : On admission of 343 LRI patients over 3 years, 77 cases of RSV infection were detected by the RSV antigen rapid test of nasopharyngeal secretion. We compared RSV infection cases among groups of CHD and non-CHD patients. Results : During the winter season, RSV caused 20–0% of LRI admissions in children. In patients with completely repaired simple left to right (L–R) shunt diseases such as ventricular septal defect, atrial septal defect, and patent ductus arteriosus, RSV infections required short admission days similar to non-CHD patients. In patients with repaired CHD other than simple L–R shunt CHD, for whom some significant hemodynamic problems remained, RSV infection required long admission days with severe clinical course. In children with unrepaired CHD, RSV infection mostly occurred in early infant age, with long admission days. RSV infections within a month after cardiac surgery also required long admission days and severe clinical course. Conclusion : To avoid the tragedic outcome of severe RSV infection in the CHD patients, efforts to find the subgroups of CHD patients at high risk to RSV infection are needed, and effective preventive treatment should be applied.

Breastfeeding reduces the severity of respiratory syncytial virus infection among young infants: A multi‐center prospective study

The objective of this study was to evaluate the effects of breastfeeding on the severity of respiratory syncytial virus infection in early infancy. A rapid test for respiratory syncytial virus (RSV) was administered by 16 general pediatricians from May 2002 to April 2005 in infants undergoing medical checkups for the common cold, all of whom were 100 days old or younger and had birthweights of more than 2500 g without underlying disease. Infants were divided into three groups: the Full breastfeeding group, the Partial group, and the Token group. RSV-positive cases were followed up for 10 days after the initial diagnosis and the following three points were investigated: (i) the incidence of hospitalization; (ii) the duration of hospitalization; and (iii) the incidence of requiring oxygen therapy. RSV antigen was detected in 203 of the total of 892 cases, and these were diagnosed as cases of RSV infectious disease. Although there were no significant differences in the hospitalization rate among the three groups, there were significant differences in the duration of hospitalization and the rate of requiring oxygen therapy. Multivariate logistic regression revealed that the requirement of oxygen therapy was significantly lower in the Full breastfeeding group (P= 0.032; odds ratio, 0.256; 95% confidence interval, 0.074-0.892). Breastfeeding reduces the severity of respiratory syncytial virus infection in early infancy.

Respiratory syncytial virus infection in the early period after open-heart surgery in pediatric patients: impacts on the postoperative course and treatment outcome.

Objective To summzarize the impacts of respiratory syncytial virus (RSV) infection in the early period(< 72 h) on the postoperative course after open-heart surgery in pediatric patients, and to discuss the expe-riences on therapeutic strategies. Method From March 2005 to March 2008, 39 patients diagnosed to be RSV in-fection confmned by RSV antigen test were prospectively enrolled into RSV-infeetion group. Anoth.er 39 patients were randomly 1 : 1 matched with age and same type of congenital heart disease (CHD) during the same period who also underwent open-heart surgery without RSV infection (nonRSV-infection group) as control group. The medical records of these patients were retrospectivdy reviewed. The duration of mechanical ventilation (MV), length of ICU stay and hospital stay were compared between the two groups with Paired Student's t test. Meanwhile Fisher' s exact test was used to compare the differences in noninvasive positive pressure ventilation, incidence rate of re-intubafion and severe postoperative complications between groups. Patients in both groups were further divided into subgroups aceonting to differences in age, cyanosis and pulmonary arterial pressure in order to identify the dif-ferent impacts of RSV infection in patients in different settings. Results All the patients were survived and dis-charged home. RSV infection significantly prolonged the duration of MV, ICU and hospital stay (all P < 0. 05).In addition, it significantly increased the incidence of pulmonary atelectasis (P < 0.05). In patients under 6 months old, RSV infection resulted in prolongation of MV, ICU and hospital stay (all P <0.05); furthermore, it significantly increased the incidence of complications of low cardiac output syndrome and bacteria co-infection (both P = 0.05). In patients over 24 months, RSV infection had no significant impacts in all the parameters which are compared between the two groups. In patients with cyanotic CHD, RSV infection significantly prolonged the duration of MV, ICU stay and hospital stay (all P < 0.05). In patients with cyanotic CHD, RSV infection significantly prolonged the duration of ICU stay and hospital stay (P <0.05). In patients with pulmonary hyper-tension, RSV infection significantly prolonged the duration of MV, ICU and hospital stay(all P <0.05), and in-creased the incidence rate of concomitant infection (P < 0.05). However, in patients without pulmonary hyper-tension, RSV infection only significantly increased the length of hospital stay (P < 0.05). Conclusions RSV in-fection in the early period after open-heart surgery in pediatric patients has significant adverse impacts on the post-operative course, especially in those patients under 6 months old, patients with pumonary hypertension or cyanotic CHD. Early diagnosis, and effective circulatory and respiratory support,alone with antivirus results in a satisfied outcome. Key words: Congenital heart defect; Respiratory syncytial virus; Complications; Pediatrics; Infection

Incidence and Severity of Respiratory Syncytial Virus Pneumonia in Rural Kenyan Children Identified through Hospital Surveillance

Although necessary for developing a rationale for vaccination, the burden of severe respiratory syncytial virus (RSV) disease in children in resource-poor settings remains poorly defined. We conducted prospective surveillance of severe and very severe pneumonia in children aged <5 years admitted from 2002 through 2007 to Kilifi district hospital in coastal Kenya. Nasal specimens were screened for RSV antigen by immunofluorescence. Incidence rates were estimated for the well-defined population. Of 25,149 hospital admissions, 7359 patients (29%) had severe or very severe pneumonia, of whom 6026 (82%) were enrolled. RSV prevalence was 15% (20% among infants) and 27% during epidemics (32% among infants). The proportion of case patients aged 3 months was 65%, and the proportion aged 6 months was 43%. Average annual hospitalization rates were 293 hospitalizations per 100,000 children aged <5 years (95% confidence interval, 271-371 hospitalizations per 100,000 children aged <5 years) and 1107 hospitalizations per 100,000 infants (95% confidence interval, 1012-1211 hospitalizations per 100,000 infants). Hospital admission rates were double in the region close to the hospital. Few patients with RSV infection had life-threatening clinical features or concurrent serious illnesses, and the associated mortality was 2.2%. In this low-income setting, rates of hospital admission with RSV-associated pneumonia are substantial; they are comparable to estimates from the United States but considerably underestimate the burden in the full community. An effective vaccine for children aged >2 months (outside the age group of poor responders) could prevent a large portion of RSV disease. Severity data suggest that the justification for RSV vaccination will be based on the prevention of morbidity, not mortality.

Respiratory syncytial virus infection of camels ( Camelus dromedaries)

This study aimed to investigate the occurrence of respiratory syncytial virus (RSV) infections in camels in Sudan. A total of 272 camel lung specimens showing pneumonia were collected from slaughter houses at four different areas in Sudan, additionally 8 specimens were collected from outbreaks of respiratory infection in camels. Using sandwich ELISA kits for RSV antigen detection 4 out of 280 tested lungs (1.4%) were positive, all were from Central Sudan (Tambool slaughter house). FAT was used to confirm the ELISA positives. Polymerase chain reaction RT/PCR was applied for the detection of RSV genome in camel lungs; 1 out of 4 ELISA positives was positive by RT/PCR. Using indirect ELISA kits 135 out of 495 (27.3%) camel sera showed antibodies to RSV, highest prevalence was observed in Western (33.5%) then Central (31.6%) and Eastern Sudan (23.5%). Based on the manufacturer specified calculations for OD readings, most of positive sera (90/135) were low reactive (1+). This is the first report for the detection of RSV antigen, genome and antibody in camels in Sudan.

Index of Suspicion in the Nursery

A 4-day-old term female infant is being evaluated for fever, with a rectal temperature of 100.9°F (38.2°C), and an episode of oxygen desaturation to 70% while breathing room air. The mother reports that the infant had increasing fussiness. Prenatal care and delivery were within normal parameters. She denies use of illicit drugs and is unsure of her group B Streptococcus status. The infant has eight to nine wet diapers and about 10 bowel movements per day. She consumes 1 to 2 oz of regular infant formula every 3 hours. The only finding of note on physical examination is the fever. Her neck is supple and has no abnormalities. A full sepsis evaluation is performed, including a complete blood count and blood, urine, and cerebrospinal fluid cultures. Respiratory syncytial virus antigen and influenza test results are negative. Radiographs of the chest and lungs appear normal. The infant is admitted and treatment with ampicillin and cefotaxime is begun. Thirteen hours later, the infant develops respiratory distress manifesting with stridor and desaturation while breathing room air. Physical examination at this time reveals a new cystic, moveable mass on the anterior triangle of her neck. Follow-up radiograph of the neck shows displacement of the trachea to the right. An 80% helium/20% oxygen mixture is started in the pediatric intensive care unit. Computed tomography (CT) scan of the neck and chest shows a 4.0×2.5-cm cystic lesion with an air-fluid level located in the anterior triangle of her neck slightly to the left of midline (Fig. 1). Thyroid study results are normal. Surgical removal of the cyst and histologic evaluation lead to the diagnosis. Figure 1. Computed tomography scan showing a cystic lesion with an air-fluid level in the anterior triangle of the neck. ### Hospital Course The patient was taken to the operating room the next day for neck exploration. …

Comparison of the BVDV, BHV-1, and BRSV anamnestic response to modified-live or inactivated vaccines in calves previously vaccinated with a modified-live virus vaccine.

The objective of this study was to compare the serological responses in cattle initially vaccinated with a modified-live virus (MLV) vaccine containing infectious bovine rhinotracheitis (IBR) virus, parainfluenza-3 (PI3) virus, bovine viral diarrhoea virus type 1 (BVDV1), bovine viral diarrhoea virus type 2 (BVDV2), and bovine respiratory syncytial (BRS) virus antigens, and subsequently re-vaccinated with either the same MLV vaccine or inactivated vaccine with oil adjuvants, containing the same viral antigens. A group of 145 nursing calves received an MLV vaccine containing IBR, PI3, BVDV1, BVDV2, and BRSV at one to two months of age. The calves were re-vaccinated with the same MLV vaccine at weaning, three-and-a-half months later. Approximately five months later, 45 of these animals were randomly selected and assigned to one of three treatment groups. Twenty calves received inactivated vaccine with oil adjuvants (IBR, PI3, BVDV1, BVDV2, BRSV); 20 received the same MLV vaccine that they had received as calves (IBR, PI3, BVDV1, BVDV2, BRSV); and five controls received the MLV sterile diluent. Following final vaccination, the animals receiving the inactivated vaccine with oil adjuvants had the highest titre response (P&lt;0.05) for IBRV, BRSV, BVDV1, and BVDV2.

Protective T cell immunity against respiratory syncytial virus is efficiently induced by recombinant BCG.

Respiratory syncytial virus (RSV) is one of the leading causes of childhood hospitalization and a major health burden worldwide. Unfortunately, because of an inefficient immunological memory, RSV infection provides limited immune protection against reinfection. Furthermore, RSV can induce an inadequate Th2-type immune response that causes severe respiratory tract inflammation and obstruction. It is thought that effective RSV clearance requires the induction of balanced Th1-type immunity, involving the activation of IFN-gamma-secreting cytotoxic T cells. A recognized inducer of Th1 immunity is Mycobacterium bovis bacillus Calmette-Guérin (BCG), which has been used in newborns for decades in several countries as a tuberculosis vaccine. Here, we show that immunization with recombinant BCG strains expressing RSV antigens promotes protective Th1-type immunity against RSV in mice. Activation of RSV-specific T cells producing IFN-gamma and IL-2 was efficiently obtained after immunization with recombinant BCG. This type of T cell immunity was protective against RSV challenge and caused a significant reduction of inflammatory cell infiltration in the airways. Furthermore, mice immunized with recombinant BCG showed no weight loss and reduced lung viral loads. These data strongly support recombinant BCG as an efficient vaccine against RSV because of its capacity to promote protective Th1 immunity.

Analysis and stability of the Respiratory Syncytial Virus antigen in a T3 generation of transgenic tomato plants

The integration, expression, and stability of the Respiratory Syncytial Virus (RSV)-F protein was analyzed in a T3 generation of transgenic cherry tomato, Solanum lycopersicum L. cv. Swifty Belle, plants. Expression of the RSV-F antigen, under the control of the fruit-specific promoter E-8, was investigated in T3 plants derived from a transgenic line, identified as #120. Transgene integration of the RSV-F gene in the T3 generation was initially determined by polymerase chain reaction (PCR). PCR analysis from line 120-7-2 revealed that all T3 plants were homozygous for the transgene; whereas, line 120-6-4 showed segregation for the transgene. Enzyme-linked immunosorbent assay (ELISA) was used to quantify levels of RSV-F protein in these plants, and protein levels ranged from 0–22 μg/g of fresh weight, with an average of ~3 μg/g fresh weight. Southern blot analysis of the highest expressing plants revealed presence of a single copy of the RSV-F transgene in these plants.

Prevalence of Bordetella pertussis and Bordetella parapertussis in Infants Presenting to the Emergency Department with Bronchiolitis

The clinical presentation of Bordetella pertussis can overlap with that of respiratory syncytial virus (RSV), and coinfection does occur, but management differs. The prevalence of B. pertussis is < 2% among Emergency Department (ED) patients with bronchiolitis. Our secondary hypothesis was that the prevalence of Bordetella parapertussis is also < 2% among these patients. Nasal washings were obtained from children up to 18 months of age (inclusive) who presented to a county hospital ED with a clinical diagnosis of bronchiolitis. These washings were frozen to -70°C before testing for B. pertussis and B. parapertussis using species-specific real-time polymerase chain reaction (PCR) assays. The assays were optimized to target conserved regions within a complement gene and the CarB gene, respectively. A Bordetella spp. genus-specific real-time PCR assay was designed to detect the Bhur gene of B. pertussis, B. parapertussis, and B. bronchiseptica. RSV antigen detection was also performed. There were 227 patients enrolled. After exclusions, 204 remained in the analysis. RSV antigen testing was positive in 109/186 (59%) of the patients in whom it was performed. All samples were tested for B. pertussis. B. parapertussis testing could not be completed on 23 samples. No cases (0/204; 95% confidence interval [CI] 0-1.8%) tested positive for B. pertussis or B. parapertussis (0/181; 95% CI 0-2%). The prevalence of B. pertussis in children presenting to the ED with bronchiolitis was < 2%.