Applications of Tissue Culture to the Study of the Epidemiology of Respiratory Viruses

Stott, Edward J (1967) Applications of Tissue Culture to the Study of the Epidemiology of Respiratory Viruses. PhD thesis, University of Glasgow.

Abstract

The thesis is divided into two parts. The first section is concerned with tissue culture techniques and their use in the isolation and study of respiratory viruses. The second section describes the epidemiological results obtained from studies of respiratory illness. Problems associated with the growth of certain tissue cultures, particularly human embryonic diploid cell strains were investigated. Attempts were made to derive cell strains from various organs of 36 human embryos and methods were found for improving the low temperature preservation of these cells. Cell strains of human embryonic kidney fibroblasts were shown to be more sensitive to rhinoviruses than the widely used human embryonic lung cell strains. Detailed studies on eight cell strains also revealed differences in sensitivity to rhinoviruses between various lung cell strains and between various kidney cell strains. Three rhinovirus serotypes were discovered which appear to grow much more readily in kidney cells than in lung cells. Attempts to improve the sensitivity of tests for rhinovirus neutralizing antibodies were unsuccessful. Specific antisera were made against 15 rhinovirus strains and used in cross-neutralization studies. Twelve distinct serotypes were detected, 11 of which appear to be antigenically distinct from rhinoviruses so far described. Eighty-six rhinovirus strains were tested for haemagglutinating activity; no haemagglutination was detected. Factors affecting the isolation of respiratory syncytial (RS) virus are described, including the repeated loss of sensitivity of 'Bristol' HeLa cells after continuous culture for long periods. Attempts to improve the sensitivity of tests for RS virus neutralizing antibodies revealed that the addition of unheated rabbit serum to the serum-virus mixtures increased antibody titres two-to eight-fold. This unheated serum was valuable both in detecting neutralizing antibody responses in young children and in revealing antigenic variation among RS virus strains. Methods for concentrating RS virus onto aluminium hydroxide and for preparing strain-specific antisera were found. Two antigenically distinct RS virus strains and seven possibly intermediate strains were detected. A total of 302 viruses were isolated from respiratory secretions collected from 800 cases in Glasgow between January 1962 and April 1966. The viruses comprised 29 influenza viruses, 27 parainfluenza viruses, 83 RS viruses, 95 rhinoviruses, 26 herpes viruses, 24 adenoviruses and 18 enteroviruses. Most of the four strains of influenza A2 and 25 strains of influenza B were isolated from schoolchildren during three winter outbreaks. Parainfluenza viruses (7 type 1, one type 2, and 19 type 3) were found most commonly in children but showed no marked seasonal distribution. RS viruses were isolated only from young children during four winter outbreaks. Titration of RS neutralizing antibodies revealed that RS virus isolation was associated with an absence of antibody in children over 6 months but not in younger children. Fifty-eight of the 95 rhinoviruses could be identified serologically and belonged to 24 different serotypes. Rhinoviruses were found most often in young adults but occurred in all populations and age-groups; they were isolated most frequently in spring and autumn. Herpes simplex virus occurred most commonly in children in hospital. Adenoviruses, belonging to five different serotypes, and enteroviruses, belonging to at least nine different serotypes, were isolated only from children. Most enteroviruses were isolated during the summer. Three main population groups were studied: children and adults at home or at work, adults with chronic bronchitis and children in hospital. Ten per cent of 107 respiratory illnesses in children and 40% of 60 illnesses in adults, who were at home or at work, yielded rhinoviruses. Myxoviruses were found in 19% of these illnesses in children and in 10% of them in adults. The etiological significance of rhinoviruses in children at home could not be assessed because they were also found in 13% of symptomless contacts. Eighty-seven respiratory episodes in chronic bronchitics were investigated and rhinoviruses were isolated from 16% of them. Only one rhinovirus infection was not associated with an illness which affected the chest and 25% of bronchitic exacerbations were associated with rhinovirus infection. Virus isolation and serological results suggest that rhinoviruses can infect the lower respiratory tract of chronic bronchitics. Among children in hospital RS virus appeared to be the most important single cause of severe respiratory illness and was isolated from 20% of 402 children. Other myxoviruses and rhinoviruses were isolated from 7% and 8% respectively of these children. However, rhinoviruses were also found in 9% of children in hospital with diarrhoeal illnesses; myxoviruses were found only rarely in this group of children. Herpes simplex virus, adenoviruses and enteroviruses were isolated from both the respiratory and diarrhoeal groups of children. Detailed study of 19 rhinovirus infections in children in hospital indicated that these infections could cause lower respiratory illnesses.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Epidemiology, Virology
• Date of Award: 1967
• Depositing User: Enlighten Team
• Unique ID: glathesis:1967-78465
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 30 Jan 2020 15:21
• Last Modified: 30 Jan 2020 15:21
• URI: https://theses.gla.ac.uk/id/eprint/78465