Nontypeable Haemophilus influenzae (NTHi), Streptococcus pneumoniae and
Moraxella catarrhalis are common bacterial agents of otitis media which is a major
cause of morbidity in young children. Mucosal immune responses are an integral part
of the immune defense against middle ear infection and it is known that certain
populations, including Australian Aboriginal children, are highly susceptible to disease.
The current study focussed on the development of the mucosal immunity to the three
bacterial pathogens in Aboriginal and non-Aboriginal children from birth to two years
of age, living in the Kalgoorlie-Boulder region of Western Australia. Salivary and
breast milk IgA levels were measured by the enzyme Linked immunosorbent assay. The
measured IgA levels, combined with socio-economic, demographic and bacteriological
data were analyzed statistically to determine the influential factors on the mucosal IgA
response in these children over time.
This study found that each antigen-specific IgA examined followed a distinct ontogeny
pattern and IgA responses differed significantly according to age, indigenous status and
feeding type. Indoors smoke exposure, maternal smoking, and sibling day care
attendance had some impact on salivary IgA levels in the children. However, household
crowding and the presence of older siblings had the most significant impact on salivary
IgA levels for children of different age groups. These two factors were correlated to
increased nasophayrngeal colonization by H. influenzae, S. pneumoniae and M.
catarrhalis and colonization status was also found to influence salivary IgA levels in the
children. No correlation between maternal breast milk IgA levels and child salivary IgA
levels was observed.
The results suggest that the degree of exposure to environmental factors rather than
immunological deficit is responsible for the observed differences in salivary IgA
responses between Aboriginal and non-Aboriginal children and modifying these factors
could lead to a reduction in the burden of otitis media experienced by the children.
Further studies correlating specific salivary IgA levels to diseases such as otitis media
will reveal the role of specific salivary IgA responses in the prevention of infection by
respiratory pathogens.
| Identifer | oai:union.ndltd.org:ADTP/233940 |
| Date | January 2003 |
| Creators | Kyaw-Myint, Su Mon, N/A |
| Publisher | University of Canberra. Applied Science |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | ), Copyright Su Mon Kyaw-Myint |
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