Positive Viral Isolation Research Articles

İnfluenza veya diğer solunum yolu virüsleri: kritik hastalarda akut solunum yetmezliğinin sebebi olarak önemli midir?

Respiratory virus infections may cause serious respiratory failure requiring intensive care unit (ICU) admission. The objective of this study was to evaluate the clinical features and the outcome in patients with acute respiratory failure (ARF) due to viral infections comparing etiological agents.ARF patients with positive viral serology were retrospectively recruited. Cohort was evaluated with regard to subgroups as influenza and other respiratory viruses (ORV), as well as survivors and nonsurvivors.Out of 938 admitted patients, 319 were followed as ARF and only 149 patients had viral respiratory panel results. In 49 patients with ARF, 52 positive viral results were detected and 47 patients with single positive viral isolates of either influenza or ORV were included. Among them, 62% had ORV with quite similar characteristics with influenza group apart from diabetes mellitus which was encountered more in influenza group (p= 0.02). Overall ICU mortality was 32% and there was no difference between the two groups (p= 0.42). Acute Physiology and Chronic Health Evaluation (APACHE) II score was independently associated with ICU mortality (OR: 1.25; 95% CI: 1.04-1.51; p= 0.02).This study emphasizes to consider the possibility of other respiratory viruses for the cause of ARF with similar characteristics and mortality as influenza species.

ABSTRACT 623

Background and aims: Children with burn injuries are commonly admitted to the PICU at RCWMCH, especially during winter when respiratory viruses are prevalent. Aims: To investigate the prevalence, spectrum and seasonality of respiratory viruses in children admitted to PICU with burn injuries, and describe the clinical outcomes of these children. Methods: Retrospective review of all children admitted to PICU with burn injuries over 55 months. The institutional human research ethics committee approved this study with waived consent. Results: Two-hundred admissions were recorded in 174 children (63.5% male) with burn injury. Fifty-one viruses were isolated in 45 admissions of 43 patients (24.7%). Sixteen viruses (31.3%) were isolated more than 48 hours after admission to PICU. Commonly identified viruses were Rhinovirus A (n=20 isolates), Adenovirus (n=15) and respiratory syncytial virus (n=5). A seasonal peak in burn injury and viral observations occurred over the winter months. Children with viral infections were younger (median (interquartile range, IQR,) age 18.7 (12.2 – 40.4) versus 33.3 (14.3 – 70.4) months, p=0.02) and had longer PICU admissions (median (IQR) 7 (4 – 11) vs. 3 (1 – 7) days, p<0.0001). There was no association between inhalational thermal injury and viral identification. Overall mortality was 12%, with no significant difference between those with and without positive viral isolates. Conclusions: Respiratory viruses are commonly isolated from children admitted to the PICU with burn injury who have symptoms compatible with respiratory infections and are associated with increased PICU length of stay. Further studies are required to examine the role of specific viruses in these children.

47. The identification of linear epitopes on the rabies virus glycoprotein employing phage display techniques

The infectivity of saliva, salivary and mammary glands, muscle, lung, kidney and liver of 87 cattle infected with paralytic rabies (positive viral isolation from brains) was studied. Fifty percent dilutions of saliva and tissue samples were inoculated intracerebrally into 10- to 15-day-old mice. Viral isolation in mice was confirmed by direct rabies fluorescent-antibody test and the antigenic variant of the isolates characterized by monoclonal antibodies. Rabies virus was isolated from 4.6% of salivary glands and from 1.6% of saliva samples. The rest of the peripheral tissues were negative. Cerebral and peripheral isolates belonged to vampire-bat antigenic variants. These results indicate that cattle infected by vampire bats may be a source of infection for man. The infection risk would depend on the type of contact between rabid cattle and man.

Virus isolation from saliva and salivary glands of cattle naturally infected with paralytic rabies

The infectivity of saliva, salivary and mammary glands, muscle, lung, kidney and liver of 87 cattle infected with paralytic rabies (positive viral isolation from brains) was studied. Fifty percent dilutions of saliva and tissue samples were inoculated intracerebrally into 10- to 15-day-old mice. Viral isolation in mice was confirmed by direct rabies fluorescent-antibody test and the antigenic variant of the isolates characterized by monoclonal antibodies. Rabies virus was isolated from 4.6% of salivary glands and from 1.6% of saliva samples. The rest of the peripheral tissues were negative. Cerebral and peripheral isolates belonged to vampire-bat antigenic variants. These results indicate that cattle infected by vampire bats may be a source of infection for man. The infection risk would depend on the type of contact between rabid cattle and man.

Dengue infection presenting with central nervous system manifestation.

The objective of this study was to investigate the possibility of dengue virus infection causing an abnormal neurologic presentation. Between 1996 and 1998, all pediatric patients with clinical manifestations of encephalitis-like illness who were admitted to the Department of Pediatrics, Siriraj Hospital were prospectively studied for any evidence of dengue virus infection. The diagnosis of dengue virus infection was based on mosquito viral isolation and serologic and polymerase chain reaction (PCR) evidence. Of 44 patients with the preliminary diagnosis of acute viral encephalitis, 8 were diagnosed with dengue infection. All of these 8 patients were diagnosed by serology. In addition to the serologic diagnosis, four also had positive PCR, one had positive viral isolation, and one had both positive PCR and viral isolation. Only two patients were diagnosed by serologic evidence alone. All except one had clinical courses and laboratory findings compatible with typical dengue infection. All had obvious encephalitic clinical manifestations with normal cerebrospinal fluid findings except one patient, who had mildly increased cerebrospinal fluid protein. All of these patients recovered completely and had benign clinical courses except one patient, who developed leakage symptoms. None had liver failure. Dengue virus can cause acute encephalopathy with fever. It can masquerade as other types of acute viral encephalitis. However, its clinical course and prognosis are usually favorable.

Viral aetiology of lower respiratory tract infection in young Malaysian children.

To study the viral aetiology of lower respiratory tract infection (LRTI) in young Malaysian children. A retrospective review was performed of LRTI patients aged less than 24 months who were admitted to the University Malaya Medical Centre between 1982 and 1997. Respiratory viruses in their nasopharyngeal secretion were identified by indirect immunofluorescence, viral culture, or both. A total of 5691 children were included in the study. The mean age was 8.6 +/- 6.6 months and the M:F ratio was 1.6:1. The most common diagnosis was pneumonia (52%) followed by bronchiolitis (45%) and croup (2%). Positive viral isolation rate was 22.0%. Respiratory syncytial virus (RSV) was the commonest virus isolated (84%), followed by parainfluenza virus (8%), influenza virus (6%) and adenovirus (2%). Patients with positive virus isolation were younger (7.8 +/- 6.2 vs 8.7 +/- 6.7 months, P = 0.0001) and were more likely to have bronchiolitis. Young Malaysian children admitted with LRTI had a 22% viral isolation rate and RSV was the commonest virus isolated.

The role of viral infection in adults with bronchopulmonary infections

We isolated the virus from the respiratory specimens of 16 patients (7.9%) when we investigated the bronchopulmonary infections of 203 adult patients by the viral isolation method for the diagnosis of the viral infection and transtracheal aspiration (TTA) for taking directly the specimen from the lower respiratory tract. The bronchopulmonary infections, isolated the virus, consisted of acute bronchitis (3 cases), pneumonia (8 cases) and the acute exacerbation of chronic lower respiratory infection (5 cases). The positive viral isolation consisted of Rhinovirus (11 strains), Herpes simplex virus I (3 strains), Parainfluenza virus III (1 strain) and Respiratory syncytial virus (1 stain). There were 9 transtracheal aspirates, 8 pharyngeal swabs and 5 nasal washings in the positive viral specimens. We experienced 5 cases who had the same virus isolated from both the upper respiratory tract and the lower respiratory tract. H. influenzae, P. aeruginosa and other bacteria were found in 14 of the 16 TTA cultures. These results suggest that the role of the viral infection is important either independently or relating the bacterial infection in the adult bronchopulmonary infections.