Strategies for control of trachoma: observational study with quantitative PCR

Solomon, Anthony W.; Holland, Martin J.; Burton, Matthew J.; West, Sheila K.; Alexander, Neal; Aguirre, Aura; Massae, Patrick; Mkocha, Harran; Muñoz, Beatriz; Johnson, Gordon J.; Peeling, Rosanna W.; Bailey, Robin L.; Foster, Allen; Mabey, David

doi:10.1016/s0140-6736(03)13909-8

Cited by 212 publications

(209 citation statements)

References 16 publications

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“…41,42 Our study gives limited support to the idea that genetically determined reductions in the transcription efficiency of IFNg, which may permit greater multiplication of C. trachomatis following infection, are associated with an increased risk of scarring. Studies using quantitative PCR estimates of bacterial load have found that high bacterial loads in the conjunctiva are associated with intense disease, 43,44 and there is Cytokine SNPs linked to risk of severe trachoma A Natividad et al evidence linking intensity of conjunctival inflammation with scarring in later life. 45 Distal and proximal promoter variants thought to affect IL10 production were genotyped.…”

Section: Discussionmentioning

confidence: 99%

Risk of trachomatous scarring and trichiasis in Gambians varies with SNP haplotypes at the interferon-gamma and interleukin-10 loci

et al. 2005

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Experimental evidence implicates interferon gamma (IFNg) in protection from and resolution of chlamydial infection. Conversely, interleukin 10 (IL10) is associated with susceptibility and persistence of infection and pathology. We studied genetic variation within the IL10 and IFNg loci in relation to the risk of developing severe complications of human ocular Chlamydia trachomatis infection. A total of 651 Gambian subjects with scarring trachoma, of whom 307 also had potentially blinding trichiasis and pair-matched controls with normal eyelids, were screened for associations between single-nucleotide polymorphisms (SNPs), SNP haplotypes and the risk of disease. MassEXTEND (Sequenom) and MALDI-TOF mass spectrometry were used for detection and analysis of SNPs and the programs PHASE and SNPHAP used to infer haplotypes from population genetic data. Multivariate conditional logistic regression analysis identified IL10 and IFNg SNP haplotypes associated with increased risk of both trachomatous scarring and trichiasis. SNPs in putative IFNg and IL10 regulatory regions lay within the disease-associated haplotypes. The IFNg þ 874A allele, previously linked to lower IFNg production, lies in the IFNg risk haplotype and was more common among cases than controls, but not significantly so. The promoter IL10-1082G allele, previously associated with high IL10 expression, is in both susceptibility and resistance haplotypes.

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Section: Discussionmentioning

confidence: 99%

Risk of trachomatous scarring and trichiasis in Gambians varies with SNP haplotypes at the interferon-gamma and interleukin-10 loci

et al. 2005

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“…The technique has been used to detect Cp. pneumoniae [10,16,23,33], C. trachomatis [19], Cp. felis [12,13,20] and Cp.…”

Section: Discussionmentioning

confidence: 99%

Development of a Chlamydophila psittaci species-specific and genotype-specific real-time PCR

et al. 2005

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-A Chlamydophila psittaci species-specific real-time PCR targeting the rDNA ribosomal spacer was developed as well as a genotype-specific real-time PCR targeting the Cp. psittaci outer membrane protein A (ompA) gene. The SYBR Green-based species-specific real-time PCR detected Cp. psittaci genotypes A to F, and the recently discovered E/B genotype. The genotype-specific real-time PCR could easily distinguish genotypes C, D, F by use of TaqMan probes. Genotypes A, B and E could not be distinguished from each other by simply using TaqMan probes. For this purpose, non-fluorescent competitor oligonucleotides, had to be used next to the TaqMan probes. Genotype E/B could only be detected by use of a minor groove binder (MGB) probe. Both real-time PCR assays allowed reproducible, sensitive (10 rDNA or ompA copies/µL DNA extract) and specific detection of Cp. psittaci DNA. The genotype-specific real-time PCR was compared to ompA sequencing and ompA restriction fragment length polymorphism (RFLP) analysis using five Cp. psittaci field isolates (99, 61/8, 7344/2, 8615/1 and 7778B15) each consisting of two different genotypes. The currently developed real-time PCR assays were used in a case study on a veterinary school and a turkey farm. In the veterinary school, Cp. psittaci genotypes D, E/B and F infection were detected in all five groups of turkeys, and one veterinarian who was taking care of all these turkeys. On the turkey farm, the presence of two Cp. psittaci genotype B infection waves was demonstrated in one randomly selected turkey, the first wave at the age of 6 weeks, and the second at the age of 12 weeks.

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“…Using quantitative PCR in Tanzania, Elimination of Blinding Trachoma by the year we have shown 90% of infection within the 2020 (GET 2020) has endorsed a multifaceted community resides in pre-school children (West trachoma control program for countries endemic et al, 1991, 1996Solomon et al, 2003; West et for trachoma (WHA, 2003). There is sound public al., 2005).…”

Section: Introductionmentioning

confidence: 99%

Trachoma and ocular Chlamydia trachomatis rates in children in trachoma–endemic communities enrolled for at least three years in the Tanzania National Trachoma Control Programme

Mkocha¹,

Muñoz²,

West³

2009

Tanzania J Hlth Res

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Trachoma, a blinding eye disease caused by repeated and prolonged infection with Chlamydia trachomatis, is a significant public health problem for sub-Saharan Africa. Tanzania has had a National Trachoma Task Force since 1999, working on trachoma control in endemic districts. The objective of this study was twofold: first, to determine the current status of infection and clinical trachoma in these districts in Tanzania, and second, to determine if a combination of clinical signs could be used as a surrogate for infection. We conducted a survey for trachoma and infection with C. trachomatis in 75 villages in eight districts of Kongwa, Kilosa, Mpwapwa, Bahi, Kondoa, Manyoni, Monduli and Iramba in Tanzania, which have previously been shown to be endemic. In each village, a random sample of households, and of children within households, was taken for examination. Trachoma was graded using the World Health Organization system, which we expanded, and a swab taken to determine presence of infection. The rates of trachoma ranged from 0% in Iramba District to 15.17% in Monduli District, with large variation in villages within districts. Infection rates were generally lower than trachoma rates, as expected, and most districts had villages with no infection. A combination of clinical signs of trachoma in children, when absent, showed very high specificity for identifying villages with no infection. We conclude that these signs might be useful for monitoring absence of infection in villages, and that districts with trachoma prevalence between 10% and 15% should have village level rapid surveys to avoid unnecessary mass treatment.

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Strategies for control of trachoma: observational study with quantitative PCR

Cited by 212 publications

References 16 publications

Risk of trachomatous scarring and trichiasis in Gambians varies with SNP haplotypes at the interferon-gamma and interleukin-10 loci

Risk of trachomatous scarring and trichiasis in Gambians varies with SNP haplotypes at the interferon-gamma and interleukin-10 loci

Development of a Chlamydophila psittaci species-specific and genotype-specific real-time PCR

Trachoma and ocular Chlamydia trachomatis rates in children in trachoma–endemic communities enrolled for at least three years in the Tanzania National Trachoma Control Programme

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