RESUMEN
Chlamydia trachomatis causes sexually transmitted infections and the blinding disease trachoma. Current data on C. trachomatis phylogeny show that there is only a single trachoma-causing clade, which is distinct from the lineages causing urogenital tract (UGT) and lymphogranuloma venerum diseases. Here we report the whole-genome sequences of ocular C. trachomatis isolates obtained from young children with clinical signs of trachoma in a trachoma endemic region of northern Australia. The isolates form two lineages that fall outside the classical trachoma lineage, instead being placed within UGT clades of the C. trachomatis phylogenetic tree. The Australian trachoma isolates appear to be recombinants with UGT C. trachomatis genome backbones, in which loci that encode immunodominant surface proteins (ompA and pmpEFGH) have been replaced by those characteristic of classical ocular isolates. This suggests that ocular tropism and association with trachoma are functionally associated with some sequence variants of ompA and pmpEFGH.
Asunto(s)
Proteínas de la Membrana Bacteriana Externa/genética , Chlamydia trachomatis/genética , Genoma Bacteriano/genética , Filogenia , Tracoma/microbiología , Adulto , Australia/epidemiología , Niño , Código de Barras del ADN Taxonómico , Enfermedades Endémicas , Humanos , Nativos de Hawái y Otras Islas del Pacífico , Serotipificación , Tracoma/etnologíaRESUMEN
The aim of this study was to describe the prevalence of anaemia, mean haematocrit levels, and the risk factors influencing haematocrit in participants of the 1995 National Survey of Lead in Children. A nationally-representative cross-sectional survey of children aged 1-4 years inclusive was done. Mean haematocrit and the proportion with anaemia using both the US and WHO haematocrit-based criteria were calculated. Multivariate regression was used to identify factors associated with haematocrit. Mean haematocrit level was 38.8% (95% CI: 38.6 - 39.1%) and varied with age of child, state/territory of residence and whether the child was taking supplements. It did not vary by sex, Aboriginal identification, maternal birthplace, whether the child ate meat or any other selected characteristic. The factors identified explained only 4% of the variation in haematocrit levels. The prevalence of anaemia was 3.3% (95% CI: 2.4 - 4.5%) based on the US criteria and 2.0% (95% CI: 1.3 - 3.1%) based on the WHO criteria. The prevalence of anaemia in this national survey was lower than the prevalence of iron deficiency anaemia reported in several more localised studies.