Detection of Chlamydia trachomatis Ocular Infection in Trachoma-Endemic Communities by rRNA Amplification
Jon L. Yang 1*,
Kevin C. Hong 2,
Julius Schachter 3,
Jeanne Moncada 3,
Takele Lekew 4,
Jenafir I. House 2,
Zhaoxia Zhou 2,
Melissa D. Neuwelt 2,
Tina Rutar 2,
Colleen Halfpenny 2,
Neelima Shah 2,
John P. Whitcher 2,
and
Thomas M. Lietman 2
1 Ophthalmology, University of California San Francisco, San Francisco, California, United States
2 F.I. Proctor Foundation, University of California San Francisco, San Francisco, California, United States
3 Department of Laboratory Medicine, University of California San Francisco, San Francisco, California, United States
4 ORBIS International, Addis Ababa, Ethiopia
* To whom correspondence should be addressed. E-mail: jonyang1{at}gmail.com.
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Abstract |
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Purpose: Trachoma remains the leading infectious cause of blindness worldwide. The World Health Organization (WHO) recommends mass antibiotic distributions in its strategy to eliminate blinding trachoma. In order to determine the most effective antibiotic treatment strategy it is essential to have a diagnostic test that can correctly measure the true status of ocular Chlamydia trachomatis infection in individuals, particularly following treatment. We compare a newer ribosomal ribonucleic acid (rRNA)-based amplification test to current DNA-based polymerase chain reaction (PCR) for the detection of C. trachomatis.
Methods: An rRNA-based assay and PCR were performed on swab specimens taken from the right upper tarsal conjunctiva of 240 children aged 1-5 years living among 16 endemic villages in the Gurage Zone, Ethiopia.
Results: The rRNA-based test detected ocular C. trachomatis infection in 142 (59%) subjects compared with 67 (28%) detected by PCR (McNemars test, p < 0.0001). The rRNA-based test gave positive results for all subjects that were positive by PCR, and also detected infection in 75 (31%) additional subjects.
Conclusions: The rRNA-based test appears to have significantly greater sensitivity than PCR for the detection of ocular C. trachomatis infection in children in trachoma-endemic villages. The increased sensitivity of the rRNA-based test may be due to its ability to detect low levels of C. trachomatis infection in individuals, which can occur especially following antibiotic treatment. Past studies using PCR to assess prevalence of infectious trachoma following community-wide antibiotic treatments could have underestimated the true prevalence of infection.
Key Words:
trachoma, Chlamydia trachomatis, RNA amplification
