Detecting extra-ocular Chlamydia trachomatis in a trachoma-endemic community in Ethiopia: Identifying potential routes of transmission

Versteeg, Bart; Abdurahman, Oumer Shafi; Robinson, Ailie; Dumessa, Gebeyehu; Aga, Muluadam Abraham; Bejiga, Gemechu Shumi; Negussu, Nebiyu; Greenland, Katie; Czerniewska, Alexandra; Thomson, Nicholas R.; Cairncross, Sandy; Sarah, Virginia; Macleod, David; Solomon, Anthony W.; Logan, James G.; Burton, Matthew J.

doi:10.1371/journal.pntd.0008120

Cited by 36 publications

(41 citation statements)

References 19 publications

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“…Active trachoma can be an extremely common problem in children, with prevalence estimates of 60-90% (10). Ocular C. trachomatis is believed to be transmitted through hand-to-hand contact, sharing of towels, fomites, pillows, and eye-seeking ies (11).…”

Section: Introductionmentioning

confidence: 99%

Prevalence and associations of active trachoma among rural preschool children in Wadla district, northern Ethiopia

Kassaw

Abebe

Tegegne

et al. 2020

Preprint

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Background: Trachoma is a neglected eye disease and an important cause of preventable corneal blindness. In endemic areas, initial infection can occur in early childhood and following a recurrent episodes, it progresses to scarring and visual impairment. Trachoma disappeared from high income countries through enhancements of hygiene and sanitation but the disease is still a challenge in developing countries. In Ethiopia, data indicate that Amhara is the region with the highest prevalence of active trachoma. The aim of this study was to assess the prevalence and associations of active trachoma among rural preschool children in Wadla district, Amhara region, Ethiopia.Methods: In this study, 596 children were screened for signs of active trachoma by using cluster-sampling technique. Following pre-testing of the survey instrument in a different district, questions about socio-demographic status were delivered for heads of households. Integrated eye care workers, previously trained to undertake trachoma screening for one month, performed eye examination. The logistic regression model was used to look for associations of active trachoma.Results: The prevalence of active trachoma among rural preschool children in Wadla district was 22%. Low economic status (adjusted odds ratio [AOR]3.8 (95%CI 1.3–11.4), being 37–48 months old (4.2;1.5–12.0), living in a house with thatched roof (4.4;1.4–13.6), presence of flies in a home (4.6;2.1–9.9), once-weekly face-washing frequency (8.6;2.5–29.3), having a face that had not been washed for longer than a week (10.6;2.9–37.7), and not using soap (4.5;1.8–11.3) had association to active trachomaConclusion: The prevalence of active trachoma among rural pre-school children in Wadla district was high. This indicates that Trachoma is still a public health problem in the district. This high prevalence calls for further interventions to prevent future trachomatis blindness.

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Section: Introductionmentioning

confidence: 99%

Prevalence and associations of active trachoma among rural preschool children in Wadla district, northern Ethiopia

Kassaw

Abebe

Tegegne

et al. 2020

Preprint

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“…The study was nested within a cross-sectional study conducted in 247 randomly selected households with at least one child aged 1-9 years with clinically diagnosed trachomatous inflammation, follicular (TF) or trachomatous inflammation, intense (TI). 5,6 Children aged 1-9 years with TF/TI were eligible for inclusion in this sub-study.…”

Section: Methodsmentioning

confidence: 99%

“…DNA was extracted from the swabs using a commercially available kit (Biochain Blood and Serum kit, AMS Biotechnology Europe Ltd., Abingdon, UK) and tested using a previously described multiplex real-time quantitative polymerase chain reaction (qPCR) assay 6,8 to determine the presence of C. trachomatis. Samples were classified as C. trachomatis positive if amplification of the omcB (chromosomal) or pORF2 (plasmid) target was detected by qPCR in any well within 40 cycles.…”

Section: Methodsmentioning

confidence: 99%

Comparison of Face Washing and Face Wiping Methods for Trachoma Control: A Pilot Study

Czerniewska

Versteeg

Shafi

et al. 2020

The American Journal of Tropical Medicine and Hygiene

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Eye-to-eye transmission of Chlamydia trachomatis, the causative agent of trachoma, may be plausibly interrupted if faces are kept free of ocular and nasal discharge. Between April and June 2018, 83 children aged 1-9 years with active trachoma were recruited from 62 households and allocated to a face cleaning protocol: face washing with water, face washing with water and soap, or face wiping. Faces were examined for the presence of ocular and nasal discharge, and swabs were taken from faces and hands to test for C. trachomatis at baseline, immediately post protocol, and after 1, 2, and 4 hours (washing protocols). Washing with soap was more effective at removing ocular discharge than either washing with water (89% and 27% of discharge removed, respectively, P = 0.003) or wiping with a hand (42%, P = 0.013). The reduction in prevalence of ocular discharge was sustained for at least four hours. The prevalence of C. trachomatis on face swabs was reduced by all washing protocols. The importance of soap should not be overlooked during facial cleanliness promotion.

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“…face cloths, towels and items of clothing) [1][2][3][4][5][6][7][8]. Using quantitative PCR (qPCR), we have recently tested ocular swabs from 1220 individuals in 247 households living in Ethiopia and ocular Ct was detected in 2% of all ages (median omcB load 198.6 copies/μL (inter quartile range 23.2-3189.1 copies/μL)) [9]. Moreover, we demonstrated the presence of Ct DNA at non-ocular sites in individuals living in these households in Ethiopia where at least one resident had an ocular Ct infection detectable qPCR.…”

Section: Introductionmentioning

confidence: 99%

Viability PCR shows that non-ocular surfaces could contribute to transmission of Chlamydia trachomatis infection in trachoma

et al. 2020

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Background The presence of Chlamydia trachomatis (Ct) DNA at non-ocular sites suggests that these sites may represent plausible routes of Ct transmission in trachoma. However, qPCR cannot discriminate between DNA from viable and non-viable bacteria. Here we use a propodium monoazide based viability PCR to investigate how long Ct remains viable at non-ocular sites under laboratory-controlled conditions. Methods Cultured Ct stocks (strain A2497) were diluted to final concentrations of 1000, 100, 10 and 1 omcB copies/μL and applied to plastic, woven mat, cotton cloth and pig skin. Swabs were then systemically collected from each surface and tested for the presence Ct DNA using qPCR. If Ct DNA was recovered, Ct viability was assessed over time by spiking multiple areas of the same surface type with the same final concentrations. Swabs were collected from each surface at 0, 2, 4, 6, 8 and 24 hours after spiking. Viability PCR was used to determine Ct viability at each timepoint. Results We were able to detect Ct DNA on all surfaces except the woven mat. Total Ct DNA remained detectable and stable over 24 hours for all concentrations applied to plastic, pig skin and cotton cloth. The amount of viable Ct decreased over time. For plastic and skin surfaces, only those where concentrations of 100 or 1000 omcB copies/μL were applied still had viable loads detectable after 24 hours. Cotton cloth showed a more rapid decrease and only those where concentrations of 1000 omcB copies/μL were applied still had viable DNA detectable after 24 hours.

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Detecting extra-ocular Chlamydia trachomatis in a trachoma-endemic community in Ethiopia: Identifying potential routes of transmission

Cited by 36 publications

References 19 publications

Prevalence and associations of active trachoma among rural preschool children in Wadla district, northern Ethiopia

Prevalence and associations of active trachoma among rural preschool children in Wadla district, northern Ethiopia

Comparison of Face Washing and Face Wiping Methods for Trachoma Control: A Pilot Study

Viability PCR shows that non-ocular surfaces could contribute to transmission of Chlamydia trachomatis infection in trachoma

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