Modelling of endemic carriage of Haemophilus influenzae in Aboriginal infants in Northern Australia

Abstract Aboriginal infants and children in rural communities in Northern Australia have high rates of nasopharyngeal carriage of nonencapsulated Haemophilus influenzae (NCHi), with positive swab rates of 76%. In this population, the acquisition of NCHi from soon after birth is associated with the o...

Full description

Saved in:
Bibliographic Details
Published in:FEMS immunology and medical microbiology 2001-08, Vol.31 (2), p.137-143
Main Authors: Smith-Vaughan, Heidi C., McBroom, James, Mathews, John D.
Format: Article
Language:English
Subjects:
Algorithms
Bacterial Typing Techniques
Biological and medical sciences
Birth
Carrier state
Children
Colonization
Endemic Diseases
Epidemiology
Fundamental and applied biological sciences. Psychology
Haemophilus influenzae
Haemophilus influenzae - classification
Haemophilus influenzae - isolation & purification
Humans
Infant
Infant, Newborn
Infants
Mathematical
Mathematical analysis
Mathematical models
Microbiology
Models, Biological
Molecular
Nasopharynx - microbiology
Native peoples
Northern Territory - epidemiology
Northern Territory - ethnology
Oceanic Ancestry Group
Otitis media
Otitis Media - epidemiology
Otitis Media - microbiology
Rural areas
Rural communities
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Abstract Aboriginal infants and children in rural communities in Northern Australia have high rates of nasopharyngeal carriage of nonencapsulated Haemophilus influenzae (NCHi), with positive swab rates of 76%. In this population, the acquisition of NCHi from soon after birth is associated with the onset of otitis media and with muco-purulent nasal discharge, while the long-term persistence of NCHi carriage is associated with the acquisition and turnover of large numbers of antigenically diverse strains. Mathematical models have been fitted to data on the acquisition and loss of encapsulated strains of H. influenzae and 43 different strains of NCHi in 10 children followed from early infancy for up to 2 years. Subject to plausible assumptions, the preferred model estimated the mean time to acquisition of a H. influenzae strain to be 7 days after first becoming exposed after birth. For an infant already carrying H. influenzae, each additional strain was acquired after a mean waiting period of 45 days. On average, 1.50 different strains of H. influenzae were detected in four colonies routinely typed from each positive swab, but it was estimated that another 2.55 strains were ‘hidden’ behind these more frequent strains. With an average of 4.05 strains per carrier, it was estimated that each strain was carried for an average of 137 days, although detected on only 37% of occasions. Thus we have developed mathematical models that provide estimates for duration of colonisation, time to colonisation, and number of colonising strains in a population in which H. influenzae is highly endemic, characterised by sequential and concurrent carriage of multiple strains in each infant.
ISSN:0928-8244
1574-695X
2049-632X
DOI:10.1111/j.1574-695X.2001.tb00510.x