Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “parainfluenza virus”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,657 records · Page 92Linked to original sources

Antibody response in children to antigen sites on human PIV-3 HN: correlation with known epitopes mapped by monoclonal antibodies.

The antibody response in children to known epitopes on the HN of human parainfluenza virus type 3 was investigated. Children's sera with Haemagglutination-Inhibition titres between 1/480 to 1/1280 were used. When tested by ELISA, this high-titre serum from each of five children blocked 7 of 17 specific anti-HN murine monoclonal antibodies by greater than 75% at 1 micrograms well-1 of antigen. However, four monoclonal antibodies were blocked less than or equal to 30%, while six were partially blocked between 50% and 75%. Antigen concentrations of 0.5, 1.5 and 2.0 micrograms well-1 did not substantially change this pattern. Comparison of our results with published antigenic maps indicated that antigenic site A on the HN protein was the site with the most significant antibody representation in the children's sera. These findings suggest that antigenic maps deduced using monoclonal antibodies need to be carefully interpreted before they are used in vaccine development. Murine monoclonal antibodies may not fully represent either qualitatively or quantitatively important antibody components of the human or murine immune response to human PIV-3 HN.

Antibodies, Monoclonal↗

Viral croup: a current perspective.

Viral croup is the most common cause of upper airway obstruction in children 6 months to 6 years of age. Parainfluenza virus accounts for the majority of cases. The disease is characterized by varying degrees of inspiratory stridor, barking cough, and hoarseness because of laryngeal and/or tracheal obstruction. The diagnosis is mainly a clinical one and diagnostic studies usually are not necessary. The management has altered dramatically in the past decade. Good evidence exists to support the routine use of corticosteroid in all children with croup. Intervention at an earlier phase of the illness will reduce the severity of the symptoms and the rates of return to a health care practitioner for additional medical attention, visits to the emergency department, and admission to the hospital. Most children respond to a single, oral dose of dexamethasone. For those who do not tolerate the oral preparation, nebulized budesonide or intramuscular dexamethasone are reasonable alternatives. Nebulized epinephrine should be reserved for patients with moderate to severe croup. Simultaneous administration of corticosteroid and epinephrine reduces the rate of intubation in patients with severe croup and impending respiratory failure.

Administration, Inhalation↗

Three membrane-proximal amino acids in the human parainfluenza type 2 (HPIV 2) F protein are critical for fusogenic activity.

In this study, we investigated the role of the membrane-proximal region of the human parainfluenza virus type 2 (HPIV2) F protein by mutational analysis, including deletion, insertion, and substitution. Deletion or replacement of the entire 12 amino acid region (aa 474-485) of the HPIV2 F protein completely abolished its fusion activity when coexpressed with the HPIV2 HN protein. Deletion of groups of four of aa 478-485, single alanine, or other amino acid substitutions among aa 478-485 had minimal or limited effects on HPIV2 F/HN-induced cell fusion. However, a significant reduction in, or complete inhibition of, fusion activity was observed when aa 474-477 were deleted, or the N475, F476, or F477 residues were singly substituted with alanine. In addition, insertions of four amino acids at this region or deletion of eight or more amino acids significantly reduced F protein fusion activity. The oligomerization patterns and levels of cell surface expression of the mutant F proteins were compared to those of the wild-type HPIV2 F protein. The mutant HPIV2 F proteins defective in fusion were also found to be unable to initiate hemifusion, indicating that there is a specific requirement for three specific amino acids as well as the spacing in this region for initiating lipid mixing.

Amino Acids↗

RNA editing-like phenomenon in paramyxovirus V gene mRNA observed in insect cells infected with a recombinant baculovirus.

The V gene of the paramyxovirus human parainfluenza virus type 2 (hPIV2) is transcribed into both V and P mRNA. The V mRNA is a faithful transcript of the V gene; however, the P mRNA is transcribed by an RNA-editing mechanism in hPIV2-infected mammalian cells. Recombinant baculoviruses (rBV) were constructed containing the wild-type V gene, which has seven G residues at its editing site, and a manipulated V gene with ten G residues at its editing site. A small amount of the P protein was synthesized, in addition to the V protein, when the wild-type V gene was expressed in rBV-infected insect cells. Furthermore, synthesis of the P protein increased when rBV containing the manipulated V gene was used to infect insect cells. Both the P and V proteins were detected after in vitro translation of mRNA from rBV-infected cells. Moreover, G-residue insertions and a deletion were detected in mRNA. Since the P protein was not detected after in vitro translation of V RNA that had been transcribed in vitro by T7 RNA polymerase, these results suggest that the non-encoded G residues were inserted and deleted during transcription in insect cells. This RNA editing-like phenomenon and the implications of the length of the G cluster are discussed.

Animals↗

A placebo-controlled trial of two intranasal vaccines to prevent tracheobronchitis (kennel cough) in dogs entering a humane shelter.

A placebo-controlled field trial was conducted to compare the effectiveness of intranasal (IN) vaccines containing Bordetella bronchiseptica and canine-parainfluenza virus, with (IN-BPA) or without (IN-BP) canine-adenovirus type 2, for prevention of kennel cough at a humane shelter. Dogs were examined on admission to the shelter and those without respiratory signs of disease were assigned daily, on a rotating basis, to receive one of three vaccines. We enrolled 972 healthy dogs. Dogs were monitored for up to 30 days post-vaccination for coughing and other clinical signs of respiratory disease. Thirty-three (10.7%; 95% confidence interval (CI): 7.2%, 14.2%) dogs in the IN-BP group, 36 (10.2%; CI: 7.0%, 13.4%) [corrected] dogs in the IN-BPA group, and 42 (13.5%; CI: 9.7%, 17.3%) [corrected] dogs in the IN-P group coughed spontaneously for > or = 1 day within 30 days of vaccination (P = 0.37). The IN-BP and IN-BPA vaccines were 20.7 and 24.4% effective, respectively, in reducing coughing compared with a placebo vaccine. The strongest prognostic factor for coughing (regardless of vaccine group) was the number of days spent at the shelter, with each additional day increasing the risk of coughing by 3% (95% CI: 1.01, 1.06) [corrected] The low incidence of coughing in the shelter during this study precluded observation of differences in vaccine effectiveness. No differences in vaccine-associated adverse events (coughing, sneezing, nasal or ocular discharge) were noted during the first 3 days post-administration or thereafter.

Adenoviridae↗

Changes in lung mechanics and reactivity with age after viral bronchiolitis in beagle puppies.

We measured changes with growth in lung function and airway reactivity after acute canine parainfluenza virus type 2 (CPI2, n = 5), canine adenovirus type 2 (CAV2, n = 7), and sequential CAV2-CPI2 (n = 6) infections or no infection (controls, n = 6) in beagle puppies (age approximately 79 days). In the CPI2 and CAV2 groups, a lower respiratory illness developed by day 3 postinfection with clinical recovery by day 14. In the CAV2-CPI2 group, puppies were inoculated initially with CAV2 and 12 days later with CPI2. In this group, illness persisted until day 14 after infection with CPI2. Lung resistance (RL), dynamic (Cdyn) and static (Cst) lung compliance, functional residual capacity (FRC), and responsiveness to aerosolized histamine were measured before infection and at periodic intervals until 239 +/- 43 days of age. Lung function data were analyzed using a longitudinal random effects model. In all groups, FRC, Cst, and Cdyn increased with age. In all infected groups, the regression slopes for Cdyn were steeper than in controls. RL decreased linearly with age without group slope differences. Histamine reactivity increased with age, but there were no differences in slope among groups. Lung pathological studies showed areas of obliterative bronchiolitis and chronic small airways inflammation particularly in the CAV2 and CAV2-CPI2 groups. Thus, viral bronchiolitis produces chronic small airways inflammation in beagle puppies and alters the changes in lung function occurring with growth. Histamine reactivity increases with age and is not modified by viral infection.

Adenoviridae Infections↗

The two major human metapneumovirus genetic lineages are highly related antigenically, and the fusion (F) protein is a major contributor to this antigenic relatedness.

The growth properties and antigenic relatedness of the CAN98-75 (CAN75) and the CAN97-83 (CAN83) human metapneumovirus (HMPV) strains, which represent the two distinct HMPV genetic lineages and exhibit 5 and 63% amino acid divergence in the fusion (F) and attachment (G) proteins, respectively, were investigated in vitro and in rodents and nonhuman primates. Both strains replicated to high titers (> or =6.0 log(10)) in the upper respiratory tract of hamsters and to moderate titers (> or =3.6 log(10)) in the lower respiratory tract. The two lineages exhibited 48% antigenic relatedness based on reciprocal cross-neutralization assay with postinfection hamster sera, and infection with each strain provided a high level of resistance to reinfection with the homologous or heterologous strain. Hamsters immunized with a recombinant human parainfluenza virus type 1 expressing the fusion F protein of the CAN83 strain developed a serum antibody response that efficiently neutralized virus from both lineages and were protected from challenge with either HMPV strain. This result indicates that the HMPV F protein is a major antigenic determinant that mediates extensive cross-lineage neutralization and protection. Both HMPV strains replicated to low titers in the upper and lower respiratory tracts of rhesus macaques but induced high levels of HMPV-neutralizing antibodies in serum effective against both lineages. The level of HMPV replication in chimpanzees was moderately higher, and infected animals developed mild colds. HMPV replicated the most efficiently in the respiratory tracts of African green monkeys, and the infected animals developed a high level of HMPV serum-neutralizing antibodies (1:500 to 1:1,000) effective against both lineages. Reciprocal cross-neutralization assays in which postinfection sera from all three primate species were used indicated that CAN75 and CAN83 are 64 to 99% related antigenically. HMPV-infected chimpanzees and African green monkeys were highly protected from challenge with the heterologous HMPV strain. Taken together, the results from hamsters and nonhuman primates support the conclusion that the two HMPV genetic lineages are highly related antigenically and are not distinct antigenic subtypes or subgroups as defined by reciprocal cross-neutralization in vitro.

Animals↗

Contributions of the structural proteins of severe acute respiratory syndrome coronavirus to protective immunity.

We investigated the contributions of the structural proteins of severe acute respiratory syndrome (SARS) coronavirus (CoV) to protective immunity by expressing them individually and in combinations from a recombinant parainfluenza virus (PIV) type 3 vector called BHPIV3. This vector provided direct immunization of the respiratory tract, the major site of SARS transmission, replication, and disease. The BHPIV3/SARS recombinants were evaluated for immunogenicity and protective efficacy in hamsters, which support a high level of pulmonary SARS-CoV replication. A single intranasal administration of BHPIV3 expressing the SARS-CoV spike protein (S) induced a high titer of SARS-CoV-neutralizing serum antibodies, only 2-fold less than that induced by SARS-CoV infection. The expression of S with the two other putative virion envelope proteins, the matrix M and small envelope E proteins, did not augment the neutralizing antibody response. In absence of S, expression of M and E or the nucleocapsid protein N did not induce a detectable serum SARS-CoV-neutralizing antibody response. Immunization with BHPIV3 expressing S provided complete protection against SARS-CoV challenge in the lower respiratory tract and partial protection in the upper respiratory tract. This was augmented slightly by coexpression with M and E. Expression of M, E, or N in the absence of S did not confer detectable protection. These results identify S among the structural proteins as the only significant SARS-CoV neutralization antigen and protective antigen and show that a single mucosal immunization is highly protective in an experimental animal that supports efficient replication of SARS-CoV.

Administration, Intranasal↗

Canine parainfluenza type 2 and Bordetella bronchiseptica infection produces increased bronchoalveolar lavage thromboxane concentrations in beagle puppies.

Acute infections in beagle puppies with canine parainfluenza virus type 2 (CP12), and CP12 in combination with Bordetella bronchiseptica (Bb) produce bronchiolitis and increased airways responsiveness to aerosolized histamine during the acute infection. In order to determine whether these observations were associated with increased levels of eicosanoids, the stable metabolites of thromboxane A2 and prostacylin, thromboxane B2 (TXB2) and 6-keto-prostaglandin F1 alpha (6-keto-PGF 1 alpha) respectively, and leukotriene B4 were measured in the bronchoalveolar lavage (BAL) fluid of 25 beagle puppies (age = 76 +/- 1 days, mean +/- SEM) 3-4 days after no infection (control, n = 6), inoculation with both CP12 and Bb (CP12-Bb, n = 11), inoculation with CP12 alone (CP12, n = 4), and inoculation with Bb alone (Bb, n = 4). In addition, plasma levels of TXB2 and 6-keto-PGF1 alpha were measured before and after infection in the CP12-Bb and control groups. The BAL concentration of thromboxane B2 was increased in the CP12-Bb group (520 +/- 120 pg/ml), but not in the CP12 (88 +/- 40 pg/ml), Bb (235 +/- 100 pg/ml), or control groups (120 +/- 60 pg/ml, p less than 0.01). There also was a borderline increase in BAL concentration of LTB4 in the CP12-Bb group. No differences were observed in the BAL concentration of 6-keto PGF1 alpha. Furthermore, neither TXB2 nor PGF1 alpha was elevated in the plasma of control or CP12-Bb puppies. These data suggest that increased thromboxane concentrations in BAL fluid are associated with histamine hyperresponsiveness during acute infection in the CP12-Bb group.

6-Ketoprostaglandin F1 alpha↗

Bronchoalveolar lavage fluid cytology reflects airway inflammation in beagle puppies with acute bronchiolitis.

Beagle puppies infected with both canine parainfluenza virus type 2 (CPI2) and Bordetella bronchiseptica (Bb) develop more severe acute bronchiolitis and airways hyperresponsiveness than do those infected with CPI2 or Bb alone. The aim of our study was to characterize the inflammatory response associated with airway hyperresponsiveness, and to determine whether the inflammatory cell response of bronchoalveolar lavage fluid (BALF) reflected changes in the bronchioles in this model. We investigated 25 beagle puppies (ages 76 +/- 5 days, mean +/- SEM) in four groups: controls (n = 6), or puppies inoculated with both CPI2 and Bb (CPI2-Bb) (n = 11), with only CPI2 (n = 4), or only Bb (n = 4). The puppies were killed 3-4 days after inoculation, the lungs excised, the intermediate lobe lavaged, and BALF and the bronchiolar wall tissue examined for neutrophils and other inflammatory cells. Control puppies had no evidence of inflammation. However, the CPI2-Bb puppies had developed cough and rhinitis, positive cultures for CPI2 and Bb, and a neutrophilic cellular response in both the bronchioles and the BALF. Puppies inoculated with only CPI2 or Bb had milder illnesses and no significant bronchiolar and BALF neutrophilic response. For all groups, the severity of bronchiolar wall inflammation correlated with the total number of BALF inflammatory cells, and bronchiolar wall neutrophil counts correlated with the percentage of neutrophils in the BALF. The illness and the airway hyperresponsiveness observed in the CPI2-Bb group were associated with airway neutrophilia. Our studies support the hypothesis that neutrophils are associated with airway dysfunction in this model, and the use of BALF to study the process.

Acute Disease↗

Intracellular processing and transport of NH2-terminally truncated forms of a hemagglutinin-neuraminidase type II glycoprotein.

Six amino-terminal deletion mutants of the NH2-terminally anchored (type II orientation) hemagglutinin-neuraminidase (HN) protein of parainfluenza virus type 3 were expressed in tissue culture by recombinant SV-40 viruses. The mutations consisted of progressive deletions of the cytoplasmic domain and, in some cases, of the hydrophobic signal/anchor. Three activities were dissociated for the signal/anchor: membrane insertion, translocation, and anchoring/transport. HN protein lacking the entire cytoplasmic tail was inserted efficiently into the membrane of the endoplasmic reticulum but was translocated inefficiently into the lumen. However, the small amounts that were successfully translocated appeared to be processed subsequently in a manner indistinguishable from that of parental HN. Thus, the cytoplasmic domain was not required for maturation of this type II glycoprotein. Progressive deletions into the membrane anchor restored efficient translocation, indicating that the NH2-terminal 44 amino acids were fully dispensable for membrane insertion and translocation and that a 10-amino acid hydrophobic signal sequence was sufficient for both activities. These latter HN molecules appeared to be folded authentically as assayed by hemagglutination activity, reactivity with a conformation-specific antiserum, correct formation of intramolecular disulfide bonds, and homooligomerization. However, most (85-90%) of these molecules accumulated in the ER. This showed that folding and oligomerization into a biologically active form, which presumably represents a virion spike, occurs essentially to completion within that compartment but is not sufficient for efficient transport through the exocytotic pathway. Protein transport also appeared to depend on the structure of the membrane anchor. These latter mutants were not stably integrated in the membrane, and the small proportion (10-15%) that was processed through the exocytotic pathway was secreted. The maturation steps and some of the effects of mutations described here for a type II glycoprotein resemble previous observations for prototypic type I glycoproteins and are indicative of close similarities in these processes for proteins of both membrane orientations.

Amino Acid Sequence↗

Monoclonal antibodies versus reverse transcription-PCR for detection of respiratory viruses in a patient population with respiratory tract infections admitted to hospital.

UNLABELLED: In the winter season 2001-2002, 239 nasopharyngeal aspirate and 15 bronchoalveolar lavage samples from 208 patients (135 pediatric and 73 adults, including 19 lung transplant recipients) admitted to hospital because of an acute respiratory tract infection were examined for rapid diagnosis of respiratory viruses by two diagnostic approaches: immunological, using specific monoclonal antibodies (MAb); and molecular, using specific reverse transcription (RT)-PCR assays. Both methods detected influenza viruses A (H1N1 and H3N2) and B, human parainfluenza virus types 1 to 3, human respiratory syncytial virus (hRSV) types A and B, and human adenoviruses. In addition, human coronavirus (hCoV) groups I (229E-like) and II (OC43-like), as well as the new human metapneumovirus (hMPV), types A and B, were searched for by RT-PCR alone. When results obtained by both methods were added, the overall percentage of patients positive for at least one respiratory virus peaked at 44.2%, involving 92/208 patients (81 pediatric, and 11 adults), while 116 patients (55.8%) were negative for any respiratory virus tested. The most common circulating virus was hRSV, infecting 54 (25.9%) patients (24 type A, and 30 type B strains), followed by hMPV, infecting 12 (5.8%) patients (7 type A and 5 type B strains). Coinfections by two respiratory viruses interested 11 (5.3%) patients, and 9 (81.8%) of these were infected by hRSV in association with another respiratory virus. In the great majority of infected children, hRSV and hMPV were associated with lower respiratory tract infections. In lung transplant recipients, viruses present in bronchoalveolar lavage appeared to be associated frequently with lower respiratory tract infections. IN CONCLUSION: the combination of immunological and molecular assays is the most sensitive approach to the diagnosis of respiratory viral infections; and infections caused by the less investigated hCoVs and hMPVs represent a fair proportion of respiratory infections.

Adenoviridae↗

Impact of human metapneumovirus and human cytomegalovirus versus other respiratory viruses on the lower respiratory tract infections of lung transplant recipients.

UNLABELLED: Viral respiratory tract infections in lung transplant recipients may be severe. During three consecutive winter-spring seasons, 49 symptomatic lung transplant recipients with suspected respiratory viral infection, and 26 asymptomatic patients were investigated for presence of respiratory viruses either in 56 nasopharyngeal aspirate or 72 bronchoalveolar lavage samples taken at different times after transplantation. On the whole, 1 asymptomatic (3.4%) and 28 symptomatic (57.1%) patients were positive for human metapneumovirus (hMPV, 4 patients), influenza virus A (3 patients), and B (2 patients), respiratory syncytial virus (2 patients), human coronavirus (2 patients), human parainfluenza virus (2 patients), rhinovirus (5 patients), while 4 patients were coinfected by 2 respiratory viruses, and 5 were infected sequentially by 2 or more respiratory viruses. In bronchoalveolar lavage samples, hMPV predominated by far over the other viruses, being responsible for 60% of positive specimens, whereas other viruses were present in nasopharyngeal aspirates at a comparable rate. RT-PCR (detecting 43 positive samples/128 examined) was largely superior to monoclonal antibodies (detecting 17 positive samples only). In addition, HCMV was detected in association with a respiratory virus in 4/18 HCMV-positive patients, and was found at a high concentration (>10(5) DNA copies/ml) in 3/16 (18.7%) patients with HCMV-positive bronchoalveolar lavage samples and pneumonia. Coinfections and sequential infections by HCMV and respiratory viruses were significantly more frequent in patients with acute rejection and steroid treatment. IN CONCLUSION: (i) about 50% of respiratory tract infections of lung transplant recipients were associated with one or more respiratory viruses; (ii) hMPV largely predominates in bronchoalveolar lavage of symptomatic lung transplant recipients, thus suggesting a causative role in lower respiratory tract infections; (iii) RT-PCR appears to be the method of choice for detection of respiratory viruses in lung transplant recipients, (iv) a high HCMV load in bronchoalveolar lavage is a risk factor for viral pneumonia, suggesting some measure of intervention for the control of viral infection.

Adult↗

Acute bronchiolitis: predisposing factors and characterization of infants at risk.

Fifty-one infants hospitalized because of acute bronchiolitis and 24 control children were prospectively followed until 2 years of age. Respiratory syncytial virus was detected initially in 31 index children, parainfluenza virus in two, and rhinovirus in one. More index children were born during the months April through September, and six index children had neonatal respiratory complications. The index children were breast-fed for shorter periods, lived in more crowded homes, and had more siblings. No significant differences were found for atopic background and atopic illness at 2 years of age. The index children had more respiratory infections and episodes of bronchopulmonary obstruction during the follow-up period (60% with three or more episodes). To characterize the hospitalized children, a discriminant analysis was performed. A discriminant function classified 47 of 51 index children as belonging to the index group and 21 of 24 control children to the control group.

Birth Weight↗

Phosphorylation of canine distemper virus P protein by protein kinase C-zeta and casein kinase II.

Transcription by nonsegmented negative-strand RNA viruses is mediated by the viral RNA-dependent RNA polymerase and transcriptional cofactor P. The P protein is activated by phosphorylation, an event initiated by cellular kinases. The kinase used differs among this group of RNA viruses; vesicular stomatitis virus and respiratory syncytial virus utilize casein kinase II (CKII), whereas human parainfluenza virus type 3 utilizes PKC isoform zeta (PKC-zeta) for activation of its P protein. To identify the cellular kinase(s) involved in the phosphorylation of the canine distemper virus (CDV) P protein, we used recombinant CDV P in phosphorylation assays with native kinase activities present in CV1 cell extracts or purified CKII and PKC isoforms. Here, we demonstrate that the CDV P protein is phosphorylated by two cellular kinases, where PKC-zeta has the major and CKII the minor activities. In contrast, the P protein of another member of the morbillivirus genus, measles virus, is phosphorylated predominantly by CKII, whereas PKC-zeta has only minor activity. Selective inhibition of PKC-zeta activity within CV1 cells eliminated permissiveness to CDV replication, indicating an in vivo role for PKC-zeta in the virus replication cycle. The broad tissue expression of PKC-zeta parallels the pantropic nature of CDV infections, suggesting that PKC-zeta activity is a determinant of cellular permissiveness to CDV replication.

Animals↗

Prospective study of the incidence, clinical features, and outcome of symptomatic upper and lower respiratory tract infections by respiratory viruses in adult recipients of hematopoietic stem cell transplants for hematologic malignancies.

Respiratory viruses (RVs) are known to be major causes of morbidity and mortality in recipients of hematopoietic stem cell transplants (HSCTs), but prospective long-term studies are lacking. We prospectively screened all adult HSCT recipients (172 allogeneic [alloHSCT] and 240 autologous [autoHSCT]) who underwent transplantation during a 4-year period (1999 to 2003) for the development of a first episode of symptomatic upper respiratory tract infections and/or lower respiratory tract infections (LRTI) by an RV. RVs studied were influenza A and B viruses (n=39), human respiratory syncytial virus (n=19), human adenoviruses (n=11), human parainfluenza viruses 1 to 3 (n=8), human enteroviruses (n=5), human rhinoviruses (n=3), and the recently discovered human metapneumoviruses (n=19). During the study, 51 and 32 cases of RV symptomatic infections were identified of alloHSCT and autoHSCT recipients (2-year incidence, 29% and 14%, respectively). Risk factors for progression of upper respiratory tract infection to LRTI included severe (<0.2x10(9)/L) and moderate (<0.2x10(9)/L) lymphocytopenia in alloHSCT (P=.02) and autoHSCT (P=.03). Death from LRTI was attributed to an RV in 8 alloHSCT recipients. Symptomatic RV had no effect on 2-year outcomes, with the possible exception of influenza A and B virus infections in autoHSCT: these were associated with nonrelapse mortality (P=.02). In conclusion, this prospective trial allows an estimation of the minimum incidence of a first RV infection in adult HSCT recipients and identifies risk factors for acquisition of an RV infection and progression to LRTI; this should aid in the design of future studies. In addition, human metapneumovirus should be added to the potentially serious causes of RV infections in HSCT.

Adult↗

Comparison of 9 different PCR primers for the rapid detection of severe acute respiratory syndrome coronavirus using 2 RNA extraction methods.

The sensitivity and specificity of various severe acute respiratory syndrome coronavirus (SARS-CoV) PCR primer and probe sets were evaluated through the use of commercial kits and in-house amplification formats. Conventional and real-time PCR assays were performed using a heat-block thermocycler ABI 9600, the Roche LightCycler version 1.2, or the ABI 7000 Sequence Detection System. The sensitivity of all primers was between 0.0004 and 0.04 PFU with viral cell lysate and between 0.004 and 0.4 PFU in spiked stool specimen per PCR assay. The primer sets for real-time PCR assays were at one least 1 log more sensitive than the primer sets used in the conventional PCR. A panel of viruses including swine gastroenteritis virus, bovine coronavirus, avian bronchitis virus (Connecticut strain), avian bronchitis virus (Massachusetts strain), human coronaviruses 229E and OC43, parainfluenza virus (type III), human metapneumovirus, adenovirus, respiratory syncytial virus, and influenza A were tested by all assays. All real-time PCR assays used probe-based detection, and no cross-reactivity was observed. With conventional PCR, analysis was performed using agarose gel electrophoresis and multiple nonspecific bands were observed. Two commercial extraction methods, magnetic particle capture and silica-based procedure were evaluated and the results were comparable. The former was less laborious with shorter time for completion and can easily be adapted to an automated system such as the MagNa Pure-LC, which can extract nucleic acid from clinical samples and load it into the sample capillaries of the LightCycler. As exemplified by this study, the continued refinement and evaluation of PCR procedures will greatly benefit the diagnostic laboratory during an outbreak of SARS.

Animals↗