TY - JOUR
T1 - Determinants of trachoma endemicity using Chlamydia trachomatis ompA DNA sequencing
AU - Hsieh, Yu Hsiang
AU - Bobo, Linda D.
AU - Quinn, Thomas C
AU - West, Sheila K.
N1 - Funding Information:
We would like to thank the Kongwa Trachoma Project Team and Dr Robert Blount for their excellent assistance with field work. We also thank Fan-Chi Hsu for her suggestions on the statistical analyses and Dr Stuart Ray for help with phylogenetic software and critical comments on this paper. In addition, financial support of this work was received from the Edna McConnell Clark Foundation.
PY - 2001
Y1 - 2001
N2 - A six-year prospective study of Chlamydia trachomatis infection and ocular disease in Tanzanian village children was conducted to identify the determinants of trachoma endemicity using sequencing of ompA. Overall, 749 conjunctival samples were obtained, with 176 children sampled in both 1989 and 1995. 31.1% (233/749) were positive by PCR-enzyme immunoassay, and 76% (176/233) of the positives were sequenced in variable domains (VD) 1 to 4 (22 children in both 1989 and 1995). Twenty-six ompA genotypes of serovar A, and 19 of B/Ba were identified, and only 20% of genotypes identified in 1995 matched those found in 1989. In particular, B/Ba genotypes exhibited a 15-base region in VD 2 with increased nucleotide substitution, and these types were associated with age and water availability. Homotypic infection and infection with multiple genotypes and high chlamydial load did predict subsequent severe trachoma (odds ratio (OR) = 10.14, 95% confidence interval (CI): 1.71, 60.23; OR = 6.40, 95% CI: 0.75, 54.41; OR = 6.74, 95% CI: 0.82, 55.38, respectively). And, multitypic infection was clustered with residence of village and associated with familial cattle ownership. In conclusion, high ompA polymorphism and the inability of some hosts to clear infection with the same ompA genotype suggest two distinct but converging mechanisms of endemic severe trachoma.
AB - A six-year prospective study of Chlamydia trachomatis infection and ocular disease in Tanzanian village children was conducted to identify the determinants of trachoma endemicity using sequencing of ompA. Overall, 749 conjunctival samples were obtained, with 176 children sampled in both 1989 and 1995. 31.1% (233/749) were positive by PCR-enzyme immunoassay, and 76% (176/233) of the positives were sequenced in variable domains (VD) 1 to 4 (22 children in both 1989 and 1995). Twenty-six ompA genotypes of serovar A, and 19 of B/Ba were identified, and only 20% of genotypes identified in 1995 matched those found in 1989. In particular, B/Ba genotypes exhibited a 15-base region in VD 2 with increased nucleotide substitution, and these types were associated with age and water availability. Homotypic infection and infection with multiple genotypes and high chlamydial load did predict subsequent severe trachoma (odds ratio (OR) = 10.14, 95% confidence interval (CI): 1.71, 60.23; OR = 6.40, 95% CI: 0.75, 54.41; OR = 6.74, 95% CI: 0.82, 55.38, respectively). And, multitypic infection was clustered with residence of village and associated with familial cattle ownership. In conclusion, high ompA polymorphism and the inability of some hosts to clear infection with the same ompA genotype suggest two distinct but converging mechanisms of endemic severe trachoma.
KW - Chlamydia trachomatis
KW - Major outer membrane protein
KW - Molecular epidemiology
KW - Multi-genotype infection
KW - Persisting infection
KW - Trachoma
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U2 - 10.1016/S1286-4579(01)01400-9
DO - 10.1016/S1286-4579(01)01400-9
M3 - Article
C2 - 11377206
AN - SCOPUS:0034980151
SN - 1286-4579
VL - 3
SP - 447
EP - 458
JO - Microbes and Infection
JF - Microbes and Infection
IS - 6
ER -