Application of Molecular Tools in the Control of Blinding Trachoma

Mabey, David; Solomon, Anthony W.

doi:10.4269/ajtmh.2003.69.11

Cited by 19 publications

(7 citation statements)

References 31 publications

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“…2 There has been a concomitant increased interest in diagnostic advances, including the potential applications of molecular testing. 3 DNA detection of C. trachomatis using the polymerase chain reaction (PCR) has been used to define the epidemiology of trachoma infections and to assess the effectiveness of mass treatment with azithromycin. 3,4 Insight into the molecular epidemiology of trachoma in the Northern Territory was recently provided by genetic studies characterizing the C. trachomatis outer membrane protein 1 (omp1) gene, which suggested that evolutionarily distinct strains of Ba and C serotypes are responsible for trachoma disease in northern Australia.…”

Section: Introductionmentioning

confidence: 99%

The Molecular Epidemiology of Ocular Chlamydia trachomatis Infections in Western Australia: Implications for Trachoma Control

Porter¹,

Mak²,

Chidlow³

et al. 2008

The American Journal of Tropical Medicine and Hygiene

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We studied the serovar distribution of Chlamydia trachomatis in patients with clinical eye disease in Western Australia. Most disease occurred in indigenous communities and was caused by trachoma serovars Ba and C. Serovar Ba was genetically homogeneous throughout Western Australia and identical to strains previously described in indigenous communities in Northern Territory. This finding probably results from movement of these populations, and suggests that a widely coordinated, rather than local or regional, approach is needed to control trachoma in mobile populations. Serovar C strains within Western Australia were homogeneous but distinct from those in Northern Territory, possibly because of inherent differences in transmissibility or differences in population movements among communities carrying the different serovars. Genital serovars were occasional causes of eye diseases in infants, adolescents, and adults in trachoma-endemic areas. These serovars should be considered in the differential diagnosis of acute follicular conjunctivitis in these groups.

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Section: Introductionmentioning

confidence: 99%

The Molecular Epidemiology of Ocular Chlamydia trachomatis Infections in Western Australia: Implications for Trachoma Control

Porter¹,

Mak²,

Chidlow³

et al. 2008

The American Journal of Tropical Medicine and Hygiene

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“…Thus, there are individuals with clinical signs of active disease in whom the organism cannot be detected and, conversely, C. trachomatis can be found in specimens from individuals lacking the characteristic signs and symptoms. This raises the question of the usefulness of the available microbiological tests as complementary aids for clinical diagnosis and epidemiological surveys [6].…”

Section: Introductionmentioning

confidence: 99%

Quality assessment of conjunctival specimens for detection of Chlamydia trachomatis by PCR in children with active trachoma

Barbeyrac

Goldschmidt

Malembic

et al. 2007

Clinical Microbiology and Infection

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One component of control programmes to eliminate trachoma is the treatment of Chlamydia trachomatis infection. A diagnosis of trachoma is based on clinical grounds, but the signs of active trachoma do not always correlate with the presence of C. trachomatis. During a therapeutic trial, the level of C. trachomatis infection in children with active trachoma in Guinea and Pakistan was assessed using a qualitative commercially available PCR that targeted the C. trachomatis plasmid. The influence of the quality of specimens on the efficiency of the PCR was investigated using two quantitative real-time PCRs targeting the specific omp1 gene of C. trachomatis and human chromosomal DNA, respectively. C. trachomatis was detected in c. 23% of children (aged 1-10 years) who presented with clinically active trachoma. Controls showed that PCR-related problems did not influence this detection rate. For 14% of the positive samples, C. trachomatis was detected in only one eye, with a significantly lower mean load of bacteria. These results suggest that epidemiological and therapeutic surveys should be conducted by sampling and testing both eyes. Moreover, the high variability of the cell load observed in the conjunctival swabs suggests that the effectiveness of swabbing may be questionable.

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“…They are extremely useful for detecting, quantifying, and genotyping C. trachomatis DNA (124). The nucleic acid amplification tests will there- fore continue to improve our understanding of the pathogenesis of infection, the role that persistent infection plays in the development of the blinding complications of trachoma, the epidemiology of ocular infection, and the impact of interventions designed to control trachoma blindness.…”

Section: Which Laboratory Tests Are Useful?mentioning

confidence: 99%

Diagnosis and Assessment of Trachoma

et al. 2004

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Trachoma is caused by Chlamydia trachomatis. Clinical grading with the WHO simplified system can be highly repeatable provided graders are adequately trained and standardized. At the community level, rapid assessments are useful for confirming the absence of trachoma but do not determine the magnitude of the problem in communities where trachoma is present. New rapid assessment protocols incorporating techniques for obtaining representative population samples (without census preparation) may give better estimates of the prevalence of clinical trachoma. Clinical findings do not necessarily indicate the presence or absence of C. trachomatis infection, particularly as disease prevalence falls. The prevalence of ocular C. trachomatis infection (at the community level) is important because it is infection that is targeted when antibiotics are distributed in trachoma control campaigns. Methods to estimate infection prevalence are required. While culture is a sensitive test for the presence of viable organisms and nucleic acid amplification tests are sensitive and specific tools for the presence of chlamydial nucleic acids, the commercial assays presently available are all too expensive, too complex, or too unreliable for use in national programs. There is an urgent need for a rapid, reliable test for C. trachomatis to assist in measuring progress towards the elimination of trachoma

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Application of Molecular Tools in the Control of Blinding Trachoma

Cited by 19 publications

References 31 publications

The Molecular Epidemiology of Ocular Chlamydia trachomatis Infections in Western Australia: Implications for Trachoma Control

The Molecular Epidemiology of Ocular Chlamydia trachomatis Infections in Western Australia: Implications for Trachoma Control

Quality assessment of conjunctival specimens for detection of Chlamydia trachomatis by PCR in children with active trachoma

Diagnosis and Assessment of Trachoma

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