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Biomedical subjects

Anthony W Solomon

Publications and source records attributed to Anthony W Solomon.

At least 19 recordsLinked to original sources
PubMed2006

Effect of 3 years of SAFE (surgery, antibiotics, facial cleanliness, and environmental change) strategy for trachoma control in southern Sudan: a cross-sectional study.

BACKGROUND: A trachoma control programme was started in southern Sudan in 2001. We did a 3-year evaluation to quantify uptake of SAFE (surgery, antibiotics, facial cleanliness, and environmental change) interventions, and to assess the prevalence of active trachoma and unclean faces. METHODS: Cross-sectional surveys, including clinical assessment of trachoma (WHO simplified system) and structured questionnaires, were done in four intervention areas at baseline and follow-up. Process indicators were uptake of SAFE components; primary outcome indicators included trachomatous inflammation-follicular (TF) and unclean face in children aged 1-9 years. FINDINGS: There was heterogeneous uptake of SAFE between intervention areas. Surgical coverage was low in all areas (range 0.5% of 428 individuals in Katigiri to 6% of 5002 in Kiech Kuon), antibiotic uptake ranged from 14% of 1257 individuals in Kiech Kuon to 75% of 954 in Katigiri, health education ranged from 49% of 190 households in Kiech Kuon to 90% of 182 in Padak, and latrine coverage from 3% of households in Tali to 16% in Katigiri. Substantial decreases in prevalence of TF and unclean faces were recorded in Katigiri and Tali, two of three sites where uptake of antibiotics and health education was high: TF decreased by 92% (95% CI 87-96) and 91% (86-95), respectively, and unclean face decreased by 87% (78-94) and 38% (22-52), respectively. Moderate effects were recorded in Padak, an area with high coverage, with a 28% (14-41) decrease in TF and a 16% (7-25) decrease in unclean face. No evidence of decline was seen in Kiech Kuon, where uptake of antibiotics and health education was low, with a 2% (-10 to 12) decrease in TF and a 10% (-3 to 23) decrease in unclean face. INTERPRETATION: Our results show that substantial falls in active trachoma can occur where SAFE is implemented, and that good results could be achieved with the SAFE strategy in other trachoma-endemic areas.

Anti-Bacterial Agents↗
PubMed2006

Field evaluation of a rapid point-of-care assay for targeting antibiotic treatment for trachoma control: a comparative study.

BACKGROUND: Trachoma results from repeated episodes of conjunctival infection with Chlamydia trachomatis and is the leading infectious cause of blindness. To eliminate trachoma, control programmes use the SAFE strategy (Surgery, Antibiotics, Face cleanliness, and Environmental improvement). The A component is designed to treat C trachomatis infection, and is initiated on the basis of the prevalence of the clinical sign trachomatous inflammation-follicular (TF). Unfortunately, TF correlates poorly with C trachomatis infection. We sought to assess a newly developed point-of-care (POC) assay compared with presence of TF for guiding the use of antibiotics for trachoma control. METHODS: We compared performance outcomes of the POC assay and presence of TF using commercial PCR as a comparator in 664 children aged 1-9 years in remote, trachoma-endemic villages in Tanzania. Signs of trachoma were graded according to the WHO simplified trachoma grading system. FINDINGS: Of 664 participants, 128 (19%) were positive for ocular C trachomatis infection by PCR. Presence of TF had a sensitivity of 64.1% (95% CI 55.8-72.4), specificity of 80.2% (76.8-83.6), and positive predictive value of 43.6% (36.5-50.7). By contrast, the POC assay had a sensitivity of 83.6% (77.2-90.0), specificity of 99.4% (98.8-100.0), and positive predictive value of 97.3% (94.2-100.3). Interagreements and intra-agreements between four novice operators were 0.988 (0.973-1.000) and 0.950 (0.894-1.000), respectively. INTERPRETATION: The POC assay is substantially more accurate than TF prevalence in identifying the presence or absence of infection. Additional studies should assess the use of the assay in the planning and monitoring of trachoma control activities.

Anti-Bacterial Agents↗
PubMed2006

The relationship between prevalence of active trachoma, water availability and its use in a Tanzanian village.

This study aimed to establish the relationship between the prevalence of active trachoma in children, water availability and household water use in a village in Tanzania. Nine hundred and fourteen children aged 1-9 years were examined for signs of trachoma. Data were collected on time taken to collect water, amount of water collected and other trachoma risk factors. In a sub-study, 99 randomly selected households were visited twice daily on two consecutive days to document patterns of water use. The prevalence of active trachoma in the children examined was 18.4% (95% CI 15.9-20.9). Active trachoma prevalence increased with increasing water collection time (OR 2.25; 95% CI 1.13-4.46) but was unrelated to the amount of water collected. In the sub-study, active trachoma prevalence was substantially lower in children from households where more water was used for personal hygiene (P for trend < or =0.01), independent of the total amount of water used. The allocation of water to hygiene was predicted by lower water collection time. The key element in the relationship between water availability and trachoma is the allocation of water within households. Collection time may influence both the quantity of water collected and its allocation within the household.

Child↗
PubMed2006

Chlamydial positivity of nasal discharge at baseline is associated with ocular chlamydial positivity 2 months following azithromycin treatment.

BACKGROUND: Trachoma is the leading infectious cause of blindness. Routes of transmission remain unclear. In this study, the relationship between Chlamydia trachomatis Amplicor-positive nasal discharge and Amplicor-positive ocular swabs was investigated (Amplicor; Roche, Indianapolis, IN). METHODS: A longitudinal study was conducted in Tanzania and The Gambia. Eyes were graded for active trachoma; ocular swabs were taken to test for C. trachomatis. Children with visible nasal discharge had swabs taken of this material. Participants were offered systemic antibiotics. Two months after treatment, participants were re-examined. RESULTS: Of the 1128 children participating, 188 (17%) had nasal discharge. Among 188 children with nasal discharge, 64 (34%) nasal swabs were PCR positive. There was a strong correlation between active disease/ocular chlamydial positivity and positive nasal discharge. Children with Amplicor-positive ocular swabs were 9.9 times more likely to have Amplicor-positive nasal discharge than were children without ocular positivity (95% CI: 4.34-22.53). Two months after treatment, 16% had an Amplicor-positive ocular swab. Children with positive nasal discharge at baseline were 5.2 times more likely to have an Amplicor-positive ocular swab at 2 months than were children without Amplicor-positive nasal discharge at baseline (95% CI: 1.54-17.23), after adjusting for baseline ocular positivity, gender, and study site. CONCLUSIONS: Nasal discharge may provide a source of reinfection with C. trachomatis, after antibiotic treatment for trachoma, either through transfer of secretions from nose to eye or from nasal secretions transferred to bed sheets or dirty clothes and back to the eye; alternatively, nasal discharge may be an indicator of severe persistent ocular chlamydial infection that is not cleared with a single dose of antibiotics.

Anti-Bacterial Agents↗
PubMed2006

The SAFE strategy for trachoma control: Using operational research for policy, planning and implementation.

Trachoma is a neglected disease and also the world's leading infectious cause of blindness. It causes misery, dependency and is a barrier to development. Trachoma is controlled by a WHO-endorsed integrated strategy of surgery for trichiasis, antibiotic therapy, facial cleanliness and environmental improvement, which is known by the acronym SAFE. The strategy is based on evidence from field trials and is continually being refined by operational research that informs national policy and planning; the strategy has affected both programme delivery and implementation. As a result of the findings of operational research, surgery is now frequently conducted by paramedics in communities rather than by ophthalmologists in hospitals; yearly mass distribution of a single oral dose of azithromycin has replaced the use of topical tetracycline; and the promotion of better hygiene, face-washing and the use of latrines are used to reduce transmission. Those who implement programmes have been equal partners in conducting operational research thus reducing the "know-do" gap and minimizing the lag that often exists between the completion of trials and putting their results into practice. Operational research has become a part of practice. Although there are still many questions without answers, national programme coordinators have a reasonable expectation that trachoma control programmes based on SAFE will work.

Anti-Bacterial Agents↗
PubMed2006

Operational evaluation of the use of photographs for grading active trachoma.

We evaluated the reliability of photographs to verify field diagnoses of active trachoma. We examined 956 residents of a trachoma-endemic village for signs of trachoma using the World Health Organization simplified grading system. Two photographs of the right eye of 948 persons were independently graded (masked to field assessment) by the field examiner and two other experienced graders. There was only moderate agreement between field assessment and the subsequent photographic evaluations by the three graders. When we counted ungradable photographs as disagreements, mean kappa scores for the signs trachomatous inflammation (follicular [TF]) and trachomatous inflammation (intense [TI]) were 0.44 and 0.51, respectively. There was also only fair-to-moderate agreement between the three assessments (by different examiners) of the photographs. Either the signs TF and TI themselves are not as reliable as previously believed, or photographs should be used for their diagnosis only when reliability testing demonstrates better agreement than found here.

Adolescent↗
PubMed2005

Infection with Chlamydia trachomatis after mass treatment of a trachoma hyperendemic community in Tanzania: a longitudinal study.

BACKGROUND: Data from studies done in communities where trachoma is mesoendemic suggest that ocular infection with Chlamydia trachomatis can be eliminated after one mass treatment with antibiotics. However, there are no comparable long-term data from trachoma hyperendemic communities. Our aim, therefore, was two-fold: first, to ascertain the disease pattern of trachoma and ocular infection with C trachomatis in a trachoma hyperendemic community after mass treatment; and, second, to ascertain the risk factors for incident infection. METHODS: We did a longitudinal study of a trachoma hyperendemic community (n=1017) in Tanzania. We did surveys, including ocular swabs, at baseline, 2, 6, 12, and 18 months to identify the presence, and quantity, of C trachomatis after single mass treatment of all individuals aged 6 months or older with azithromycin 20 mg per kg; pregnant women without clinical disease received topical tetracycline. FINDINGS: Mass treatment (coverage 86%) significantly reduced the prevalence of infection from 57% (495 of 871) to 12% (85 of 705) at 2 months. Infection remained fairly constant to 12 months, with evidence of increasing numbers and load of infection by 18 months post-treatment. Incident infection at 6 months was 3.5-times more likely if another member of the household had more than 19 organisms per swab at 2 months. Travel outside the village, and visitors to the household, did not increase the risk of infection within households up to 12 months. INTERPRETATION: In this trachoma hyperendemic community, infection levels after high antibiotic coverage persisted at a low level to 18 months, with evidence for re-emergence after 1 year. Fairly light loads of infection were associated with household transmission. Yearly mass treatment over a few years could be sufficient to eliminate infection.

Administration, Oral↗
PubMed2005

Acceptability of azithromycin for the control of trachoma in Northern Tanzania.

Trachoma causes blindness; the prevention strategy includes mass antibiotic treatment. In a community in Northern Tanzania offered mass treatment with azithromycin for the control of trachoma, we used focus group discussions, individual interviews, questionnaires and direct observation to quantify, explore and contextualize reasons for acceptance or refusal of the drug. In the village studied, 76% of the population eligible to receive azithromycin were treated. Uptake was significantly higher among women (79% treated) than men (72%). Factors affecting acceptability included: local prevention norms (such as the belief that injections, rather than oral medicine, should be used for prevention); perceptions of drugs in general and azithromycin in particular; perceptions of the distribution team's expertise; witnessing adverse effects in others; and the timing, quality and quantity of information about azithromycin and its availability. Familiarity with trachoma as a blinding disease was significantly associated with uptake. Individuals who refused treatment seemed to be less altruistic than other respondents. Neither socio-economic status nor use of traditional healers was related to uptake. Pre-distribution community assessment and community education, advance notice of the distribution, standardized distribution guidelines and improved distributor training are recommended to maximize acceptance of azithromycin in future campaigns.

Adult↗
PubMed2005

Participatory evaluations of trachoma control programmes in eight countries.

OBJECTIVES: Trachoma is a major cause of blindness. The objective of this initiative was to conduct participatory process evaluations of the trachoma control programmes receiving support from the International Trachoma Initiative in eight countries. METHODS: During each 2- to 4-week evaluation we analysed information collected at the central, district and community level through interviews, focus groups, questionnaires, direct observation of trachoma control activities, and existing data. RESULTS: Mapping and assessment of disease prevalence had been completed in four of eight countries. Integration of trachoma control activities into national planning and district-level service provision varied. Intersectoral partnerships to implement the SAFE strategy (i.e. surgery, antibiotics, facial cleanliness and environmental change) were well established in a few countries. In all eight countries, the number of surgeries performed annually was insufficient; and quality of surgery was rarely monitored. Mass distribution of antibiotics was carried out well in extremely resource-poor settings and good coverage was achieved, although the strategy for antibiotic distribution varied. Inadequate water and sanitation remained a major problem in all programme areas. Monitoring of programme activities was generally inadequate. The Morocco programme is an example from which lessons and processes can be learnt and adapted to other programme countries. CONCLUSIONS: Significant achievements have been made in implementing the SAFE strategy. Scaling up of activities to true national coverage should be planned and implemented provided the resources can be made available. Further standardization of how to assess, implement and monitor trachoma control activities will facilitate expansion of the programme.

Africa↗
PubMed2005

Impact of mass distribution of azithromycin on the antibiotic susceptibilities of ocular Chlamydia trachomatis.

In a community of Tanzania where trachoma is endemic, we cultured conjunctival swabs from all residents who had active trachoma and were PCR positive for ocular Chlamydia trachomatis, both before (43 isolates) and 2 months after (9 isolates) mass antibiotic treatment. No clinically or programmatically significant increase in azithromycin or tetracycline resistance was observed.

Azithromycin↗
PubMed2005

Mass treatment and the effect on the load of Chlamydia trachomatis infection in a trachoma-hyperendemic community.

PURPOSE: Trachoma remains a leading cause of blindness. Determining the most effective antibiotic treatment strategy is essential for the success of country-based trachoma control programs. METHODS: Baseline and 2-month follow-up examinations were performed in a trachoma-hyperendemic village. All residents were offered azithromycin for trachoma after baseline was determined. Infection with Chlamydia trachomatis and chlamydial load were determined by PCR. Clinical trachoma status was evaluated. A high chlamydial load was defined as a higher than median chlamydial load among those with infection. Risk factors were examined in multiple logistic regression models. Associations are presented as odds ratios and 95% confidence intervals. RESULTS: At baseline, 57% of participants were infected with C. trachomatis. Although clinical trachoma correlated with infection, 23% of participants with high chlamydial loads showed no clinical signs. Adults represented only 10% of the population with high loads. Treatment significantly decreased the proportion positive in the community and the load in the community. However, 27% of individuals with high loads at baseline who received treatment also were infected at 2 months. Of those, 93% with high loads at 2 months were aged < or =10 years. CONCLUSIONS: Although most of the chlamydial load in this community resided in children, 10% of the high load resided in adults, most of whom did not have follicular trachoma and in whom the infection would be missed under treatment strategies that focus on clinical disease or children. These data support a mass treatment strategy for hyperendemic communities, at least as a first approach. In addition, treatment of children age < or =2 years should be reexamined, as >30% with high loads at baseline remained infected at 2 months, despite monitored treatment according to weight.

Adolescent↗
PubMed2004

Mass treatment with single-dose azithromycin for trachoma.

BACKGROUND: Trachoma, caused by repeated ocular infection with Chlamydia trachomatis, is an important cause of blindness. Current recommended dosing intervals for mass azithromycin treatment for trachoma are based on a mathematical model. METHODS: We collected conjunctival swabs for quantitative polymerase-chain-reaction assay of C. trachomatis before and 2, 6, 12, 18, and 24 months after mass treatment with azithromycin in a Tanzanian community in which trachoma was endemic. For ethical reasons, at 6, 12, and 18 months, we gave tetracycline eye ointment to residents who had clinically active trachoma. RESULTS: At baseline, 956 of 978 residents (97.8 percent) received either one oral dose of azithromycin or (if azithromycin was contraindicated) a course of tetracycline eye ointment. The prevalence of infection fell from 9.5 percent before mass treatment to 2.1 percent at 2 months and 0.1 percent at 24 months. The quantitative burden of ocular C. trachomatis infection in the community was 13.9 percent of the pretreatment level at 2 months and 0.8 percent at 24 months. At each time point after baseline, over 90 percent of the total community burden of C. trachomatis infection was found among subjects who had been positive the previous time they were tested. CONCLUSIONS: The prevalence and intensity of infection fell dramatically and remained low for two years after treatment. One round of very-high-coverage mass treatment with azithromycin, perhaps aided by subsequent periodic use of tetracycline eye ointment for persons with active disease, can interrupt the transmission of ocular C. trachomatis infection.

Adolescent↗
PubMed2004

Diagnosis and assessment of trachoma.

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.

Chlamydia Infections↗
PubMed2003

Strategies for control of trachoma: observational study with quantitative PCR.

BACKGROUND: Antibiotics are an important part of WHO's strategy to eliminate trachoma as a blinding disease by 2020. At present, who needs to be treated is unclear. We aimed to establish the burden of ocular Chlamydia trachomatis in three trachoma-endemic communities in Tanzania and The Gambia with real-time quantitative PCR. METHODS: Conjunctival swabs were obtained at examination from 3146 individuals. Swabs were first tested by the qualitative Amplicor PCR, which is known to be highly sensitive. In positive samples, the number of copies of omp1 (a single-copy C trachomatis gene) was measured by quantitative PCR. FINDINGS: Children had the highest ocular loads of C trachomatis, although the amount of pooling in young age groups was less striking at the site with the lowest trachoma frequency. Individuals with intense inflammatory trachoma had higher loads than did those with other conjunctival signs. At the site with the highest prevalence of trachoma, 48 of 93 (52%) individuals with conjunctival scarring but no sign of active disease were positive for ocular chlamydiae. INTERPRETATION: Children younger than 10 years old, and those with intense inflammatory trachoma, probably represent the major source of ocular C trachomatis infection in endemic communities. Success of antibiotic distribution programmes could depend on these groups receiving effective treatment.

Adolescent↗
PubMed2003

Trachoma.

Trachoma is the most common infectious cause of blindness. It is caused by ocular serovars of Chlamydia trachomatis. Transmission is favoured in poor communities, where crowding is common and access to water and sanitation inadequate. Repeated reinfection over many years causes dense scarring of the upper eyelid. The resultant inversion of the lashes abrades the eyeball, and the abrasion leads to corneal opacification and visual impairment. The host immune response is probably at least partly the cause of this process. The "SAFE" strategy is used for the control of trachoma: surgery for in-turned lashes, antibiotics for active disease, facial cleanliness, and environmental improvement. The demonstration that a single oral dose of the antibiotic azithromycin is as effective as 6 weeks of topical tetracycline was an important advance in trachoma control. By means of the SAFE strategy, WHO and its partners aim to eliminate trachoma as a public-health problem by the year 2020.

Chlamydia trachomatis↗
PubMed2003

A critical review of the SAFE strategy for the prevention of blinding trachoma.

Trachoma is an ocular disease caused by repeated infection with Chlamydia trachomatis. It is the leading cause of infectious blindness globally, responsible for 5.9 million cases of blindness. Although trachomatous blindness is untreatable, it is eminently possible to prevent and the World Health Organization promotes the use of the SAFE strategy (surgery to treat end-stage disease, antibiotics to reduce the reservoir of infection, facial cleanliness, and environmental improvement to reduce transmission of C trachomatis) for this purpose. In this review we have assessed the evidence base supporting the elements of the SAFE strategy. We find strong support for the efficacy of the surgery and antibiotics components, although the optimal antibiotic regimens have not yet been established. The evidence for an effect of health education and environmental improvement is weaker, and depends mostly on cross-sectional observational studies.

Anti-Bacterial Agents↗