Facial cleanliness indicators by time of day: results of a cross-sectional trachoma prevalence survey in Senegal.

BACKGROUND: The World Health Organization-recommended strategy for trachoma elimination as a public health problem is known by the acronym "SAFE", where "F" stands for facial cleanliness to reduce transmission of ocular Chlamydia trachomatis infection. Accurately and reliably measuring facial cleanliness is problematic. Various indicators for measuring an unclean face exist, however, the accuracy and reliability of these indicators is questionable and their relationship to face washing practices is poorly described. METHODS: Clean face indicator (ocular or nasal discharge, flies on the face, and dirt on the face), trachoma clinical sign, and ocular C. trachomatis infection data were collected for 1613 children aged 0-9 years in 12 Senegalese villages as part of a cross-sectional trachoma prevalence study. Time of examination was recorded to the nearest half hour. A risk factor questionnaire containing Water, Sanitation and Hygiene (WASH) questions was administered to heads of compounds (households that shared a common doorway) and households (those who shared a common cooking pot). RESULTS: WASH access and use were high, with 1457/1613 (90.3%) children living in households with access to a primary water source within 30 min. Despite it being reported that 1610/1613 (99.8%) children had their face washed at awakening, > 75% (37/47) of children had at least one unclean face indicator at the first examination time-slot of the day. The proportion of children with facial cleanliness indicators differed depending on the time the child was examined. Dirt on the face was more common, and ocular discharge less common, in children examined after 11:00 h than in children examined at 10:30 h and 11:00 h. CONCLUSIONS: Given the high reported WASH access and use, the proportion of children with an unclean face indicator should have been low at the beginning of the day. This was not observed, explained either by: the facial indicators not being reliable measures of face washing; eye discharge, nose discharge or dirt rapidly re-accumulated after face washing in children in this population at the time of fieldwork; and/or responder bias to the risk factor questionnaire. A high proportion of children had unclean face indicators throughout the day, with certain indicators varying by time of day. A reliable, standardised, practical measure of face washing is needed, that reflects hygiene behaviour rather than environmental or cultural factors.

Impact of a single round of mass drug administration with azithromycin on active trachoma and ocular Chlamydia trachomatis prevalence and circulating strains in The Gambia and Senegal.

BACKGROUND: Mass drug administration (MDA) with azithromycin is a cornerstone of the trachoma elimination strategy. Although the global prevalence of active trachoma has declined considerably, prevalence persists or even increases in some communities and districts. To increase understanding of MDA impact, we investigated the prevalence of active trachoma and ocular C. trachomatis prevalence, organism load, and circulating strains at baseline and one-year post-MDA in The Gambia and Senegal. METHODS: Pre- and one-year post-MDA, children aged 0-9 years were examined for clinical signs of trachoma in six Gambian and 12 Senegalese villages. Ocular swabs from each child's right conjunctiva were tested for evidence of ocular C. trachomatis infection and organism load (ompA copy number), and ompA and multi-locus sequence typing (MLST) was performed. RESULTS: A total of 1171 children were examined at baseline and follow-up in The Gambia. Active trachoma prevalence decreased from 23.9% to 17.7%, whereas ocular C. trachomatis prevalence increased from 3.0% to 3.8%. In Senegal, 1613 and 1771 children were examined at baseline and follow-up, respectively. Active trachoma prevalence decreased from 14.9% to 8.0%, whereas ocular C. trachomatis prevalence increased from 1.8% to 3.6%. Higher organism load was associated with having active trachoma and severe inflammation. Sequence typing demonstrated that all Senegalese samples were genovar A, whereas Gambian samples were a mix of genovars A and B. MLST provided evidence of clustering at village and household levels and demonstrated differences of strain variant frequencies in Senegal, indicative of an "outbreak". MLST, including partial ompA typing, provided greater discriminatory power than complete ompA typing. CONCLUSIONS: We found that one round of MDA led to an overall decline in active trachoma prevalence but no impact on ocular C. trachomatis infection, with heterogeneity observed between villages studied. This could not be explained by MDA coverage or number of different circulating strains pre- and post-MDA. The poor correlation between active trachoma and infection prevalence supports the need for further work on alternative indicators to clinical signs for diagnosing ocular C. trachomatis infection. MLST typing has potential molecular epidemiology utility, including better understanding of transmission dynamics, although relationship to whole-genome sequence variability requires further exploration.

Diagnostic accuracy of a prototype point-of-care test for ocular Chlamydia trachomatis under field conditions in The Gambia and Senegal.

BACKGROUND: The clinical signs of active trachoma are often present in the absence of ocular Chlamydia trachomatis infection in low prevalence and mass treated settings. Treatment decisions are currently based on the prevalence of clinical signs, and this may result in the unnecessary distribution of mass antibiotic treatment. We aimed to evaluate the diagnostic accuracy of a prototype point-of-care (POC) test, developed for field diagnosis of ocular C. trachomatis, in low prevalence settings of The Gambia and Senegal. METHODOLOGY/PRINCIPAL FINDINGS: Three studies were conducted, two in The Gambia and one in Senegal. Children under the age of 10 years were screened for the clinical signs of trachoma. Two ocular swabs were taken from the right eye. The first swab was tested by the POC test in the field and the result independently graded by two readers. The second swab was tested for the presence of C. trachomatis by Amplicor Polymerase Chain Reaction. In Senegal, measurements of humidity and temperature in the field were taken. A total of 3734 children were screened, 950 in the first and 1171 in the second Gambian study, and 1613 in Senegal. The sensitivity of the prototype POC test ranged between 33.3-67.9%, the specificity between 92.4-99.0%, the positive predictive value between 4.3-21.0%, and the negative predictive value between 98.0-99.8%. The rate of false-positives increased markedly at temperatures above 31.4°C and relative humidities below 11.4%. CONCLUSIONS/SIGNIFICANCE: In its present format, this prototype POC test is not suitable for field diagnosis of ocular C. trachomatis as its specificity decreases in hot and dry conditions: the environment in which trachoma is predominantly found. In the absence of a suitable test for infection, trachoma diagnosis remains dependent on clinical signs. Under current WHO recommendations, this is likely resulting in the continued mass treatment of non-infected communities.

Active trachoma among children in Mali: Clustering and environmental risk factors.

BACKGROUND: Active trachoma is not uniformly distributed in endemic areas, and local environmental factors influencing its prevalence are not yet adequately understood. Determining whether clustering is a consistent phenomenon may help predict likely modes of transmission and help to determine the appropriate level at which to target control interventions. The aims of this study were, therefore, to disentangle the relative importance of clustering at different levels and to assess the respective role of individual, socio-demographic, and environmental factors on active trachoma prevalence among children in Mali. METHODOLOGY/PRINCIPAL FINDINGS: We used anonymous data collected during the Mali national trachoma survey (1996-1997) at different levels of the traditional social structure (14,627 children under 10 years of age, 6,251 caretakers, 2,269 households, 203 villages). Besides field-collected data, environmental variables were retrieved later from various databases at the village level. Bayesian hierarchical logistic models were fit to these prevalence and exposure data. Clustering revealed significant results at four hierarchical levels. The higher proportion of the variation in the occurrence of active trachoma was attributable to the village level (36.7%), followed by household (25.3%), and child (24.7%) levels. Beyond some well-established individual risk factors (age between 3 and 5, dirty face, and flies on the face), we showed that caretaker-level (wiping after body washing), household-level (common ownership of radio, and motorbike), and village-level (presence of a women's association, average monthly maximal temperature and sunshine fraction, average annual mean temperature, presence of rainy days) features were associated with reduced active trachoma prevalence. CONCLUSIONS/SIGNIFICANCE: This study clearly indicates the importance of directing control efforts both at children with active trachoma as well as those with close contact, and at communities. The results support facial cleanliness and environmental improvements (the SAFE strategy) as population-health initiatives to combat blinding trachoma.

Trichiasis and geoclimatic factors in Mali.

Several trachoma surveys conducted in sub-Saharan countries showed different geographical distributions of active trachoma and trichiasis. Trichiasis is more common in southern regions. We analysed the role of geoclimatic factors in determining the distributions of active trachoma and trichiasis in Mali. In each region a random sample of 30 clusters was examined. The prevalence of active trachoma among children and of trichiasis among women was compared, and geographical, environmental and social risk factors were assessed. Logistic regression models were constructed. Multiple regression analysis was applied and models were used to map the probability of active trachoma and trichiasis. The highest prevalence rates of active trachoma (TF/TI) were found in the northern part of Mali reaching 41.1% among children living north of the 15th parallel. Surprisingly, prevalence rates of trichiasis (TT) among women regularly increased from north to south (1.0% north of the 15th parallel vs. 2.8% south; OR=2.91, 95% CI 2.01-4.24). The two related predictive maps showed a gradient SSE/NNW for TF/TI very different from the gradient NS/SW for TT. These opposite spatial distributions could be explained by differences in the pathogenic agent, the natural history of the disease, population susceptibility, grading process or vulnerable group behaviour.

Mapping xerophthalmia in Mali: results of a national survey on regional distribution and related risk factors.

BACKGROUND: Vitamin A deficiency is recognized to be a severe public health problem in most of the sahelian countries. In Mali, several surveys had been performed at the district or regional level. Unfortunately, they did not cover the entire territory. In the aim of getting a general picture, we collected information on the frequency and presentation of xerophthalmia among the children under 10 years old population recruited in the setting of a national survey planned in 1996 and 1997 to evaluate the prevalence and determinants of trachoma in Mali. METHODS: In each of the seven regions (with the exception of Bamako district), a random sample of thirty villages was taken from the general population. In a subsample of those villages, children under 10 years of age were examined by an ophthalmologist and their related mothers interviewed. Diagnosis of night blindness and Bitot spot occurrence was used for data gathering. Information was collected on village's infrastructures and familial socioeconomic condition. Multiple logistic regression analyses were performed to purpose the best model to describe the relationship between each outcome variable and the various risk factors assessed. RESULTS: The prevalence of night blindness was estimated to be 1.95% (95% Confidence Interval [CI]: 1.58-2.39) and Bitot spots frequency to be 1.10% (95% CI: 0.83-1.45) among children between 2 and 6 years of age. Xerophthalmia prevalence was 2.51% (95% CI: 2.09-3.00) and nearly similar according to gender (2.68% among boys and 2.32% among girls). By region of the country and for the same age group, the prevalence ranged from 0.26% in the Kayes region to 7.02% in the Timbuktu region. In Mali, in four regions out of seven, the WHO thresholds defining a serious public health problem have been exceeded. The higher prevalence rates were found in Timbuktu, Mopti and Segou. After adjustment to season, the main risk factors were latitude, village size and poor sanitary coverage. The main protective determinants were education and rice culture. CONCLUSIONS: This presentation illustrates a public health problem concerning vitamin A deficiency among young children in the general population and allows considering the effectiveness of substitutive intervention with vitamin A capsule distribution along with the improvement of vitamin A rich food production and consumption.

Blindness and low vision in Cape Verde Islands: results of a national eye survey.

AIMS: Prior to establishing a national prevention of blindness program a population based survey was conducted in Cape Verde Islands in1998. The objectives of the survey were to estimate the overall and age-specific prevalence of blindness and low vision, to identify the main disorders causing blindness and low vision, and to estimate the population need for basic eye care services. METHODS: A two-level cluster random sampling procedure was used, selecting 30 clusters from the nine inhabited islands and 3,803 persons of all ages were included in the sample. RESULTS: 3,374 persons were examined (coverage 88.7%). The prevalence of bilateral blindness (visual acuity in the better eye less than 3/60) was 0.8% (95% confidence interval [CI] 0.5-1.1), of bilateral low vision (6/18 to 3/60 in the better eye) 1.7% (95% CI: 1.3-2.2) and of monocular blindness 1.5% (95% CI: 1.2-2.0). The major causes of blindness were age related cataract and glaucoma (57.7% and 15.4%, respectively, of blind people recruited). The major causes of bilateral low vision were cataract, refractive errors, and macular disorders (46.2%, 26.8%, and 8.9%, respectively, of persons with low vision). Nontrachomatous corneal opacities accounted for 7.7% of bilateral and for 11.5% of monocular blindness. Vascular retinopathy was responsible for 7.7% of bilateral and for 9.6% of monocular blindness. Trachoma is not a public health problem as only 2.3% of children less than 10 years of age were suffering from active trachoma. Palpebral or limbal vernal conjunctivitis were encountered in 4.5% of persons under 25. CONCLUSION: More than half of the visual impairments are treatable by provision of cataract surgery and cataract has been indicated as a priority target in the recently designed National Blindness Program of the Cape Verde Republic. Pathologic conditions such as diabetes are emerging as serious burden for ageing populations and account for most of the retinal vascular disease.

A new condition specific quality of life measure for the blind and the partially sighted in Sub-Saharan Africa, the IOTAQOL: methodological aspects of the development procedure.

In Mali, blind and partially sighted people represent 1.2% of the population. Good quality and low cost ophthalmologic care is available, but, unfortunately, is insufficiently taken advantage of. In order to contribute to the analysis of this situation a valid and reliable questionnaire was needed to take the patient's perspective into account. Because of face validity concerns, it was not possible to merely translate an existing questionnaire. Thus we decided to develop a new questionnaire directly in one of the main languages of Mali: Bambara. This involved the setting of a study team composed of social and health science specialists, the majority of whom were native Bambara speakers. The overall project consisted in the iteration of three main steps (1) Conceptual clarification and operationalization of this concept. (2) Qualitative steps: qualitative interviews, focus groups and content analysis. (3) Quantitative steps: statistical analysis of an initial try-out survey (143 participants) and a validation survey (420 participants). This approach yields satisfying results. Indeed, the final version of the IOTAQOL has good psychometric properties. Thus, this interviewer administered instrument can be used to measure health-related quality-of-life in Mali and the methodology that we used could serve as a basis for similar projects.

Ocular lesions associated with malaria in children in Mali.

This study sought to estimate the frequency of ocular complications in malaria and its prognostic value in Mali. A total of 140 children (aged 6 months to 9 years) with severe malaria (105 with cerebral malaria, 35 without neurological complications) were compared with 34 children with mild malaria and 82 children with nonmalarial fever. Ocular lesions were rare in the mild malaria group (5.8%). Retinal hemorrhages occurred in 11.8% of the children in the severe noncerebral malaria group. Cerebral malaria was associated with retinal hemorrhages (22.9%) and retinal edema (10.5%). No association was found between ocular signs such as retinal hemorrhages or retinal edema and mortality. Exudates, papilledema, and the presence of cottonwool spots were associated with an increased risk of death. Coma score and convulsions were significantly associated with death but not with ocular signs. The presence of retinal signs in a child in a malaria-endemic area may signal a case of severe malaria.

Prevalence of undernutrition and vitamin A deficiency in the Dogon Region, Mali.

OBJECTIVES: A representative sample of 1510 preschool children living in the Bandiagra circle (Mopti Region, Mali) was examined between March and April 1997 to determine the level of vitamin A deficiency. METHODS: Using a randomized two level cluster sampling, 20 clusters of 75 children aged six months to six years were selected for evaluating xerophthalmia (XN night blindness and/or X1B Bitot spot). Concurrently stature and weight were determined. A semiquantitative seven-day dietary questionnaire was applied to the mothers of 484 infants to assess consumption of vitamin A rich foodstuffs. The prevalence of biochemical deficiency was attested using the Modified Relative Dose Response test (MRDR) on a sub-sample of 192. RESULTS: Of the studied children, 4.3% (95% Confidence interval [CI]: 3.2-5.3) reported night blindness and 2% (95% CI: 1.3-2.7) had Bitot spots. Prevalence of xerophthalmia attested by at least one of these signs was 5.4% (95% CI: 4.2-6.5). The prevalence reached 10.5% at three years of age. The MRDR test proved abnormal in 77.1% of the subjects (95% CI: 70.3-82.7). Serum retinol was lower than 0.35 micro mol/L in 43.8% (95.6% CI: 36.9-51.3) and less than 0.70 micro mol/L in 92.7% of the children (95% CI: 87.8-95.8). Weekly consumption of vitamin A rich food was rare: 75.8% had not eaten any animal vitamin A rich food, and 22.1% had consumed less than seven times a vitamin A rich food of either vegetable or animal origin. CONCLUSIONS: These data define vitamin A deficiency as a severe public health problem in the Bandiagara area of Mali.

From visual function deficiency to handicap: measuring visual handicap in Mali.

BACKGROUND/AIMS: Blindness is a major public health problem in developing countries, even though most could be prevented by relatively simple hygienic and medical interventions. Relatively few patients use the quality health care services available, despite their low cost, due to problems of access or socio-cultural barriers. This health services research project stressed the need for measurement of subjective self-perceived health. The objectives of this study were twofold: a) To translate, adapt and integrate the cultural context found in Mali and validate two instruments for measuring, respectively, perceived vision and quality of life. b) To study the relationship between these variables and visual deficiencies by gender. METHODS: The perceived vision and quality of life questionnaires were based on a translation of the Aravind questionnaire, adapted to Mali. The resulting perceived vision questionnaire comprises 13 questions, grouped according to five subscales (global vision, visual perception, sensory adaptation, visual field and depth perception). Furthermore, the 13 questions on quality of life were grouped into four subscales (personal care, mobility, social life and psychological). For both questionnaires, a global score could be computed. These two questionnaires were administered to a representative sample of 203 subjects with impaired vision, aged over 40, in a rural area in Mali. RESULTS: The acceptability of the questionnaires was good (1% missing data). The convergent validity was adequate for all but one subscale (psychological). The discriminate validity is acceptable for three of the six subscales where measurement can be made (visual perception, personal care, mobility). The Cronbach alpha coefficients indicate good reliability for the global scores. CONCLUSIONS: Analysis of mean results confirms the validity of the International Classification of Disease (ICD) definition of blindness (seeing less than 0.05 results in a steep decrease in quality of life). Moreover, blindness affects the quality of life of women more severely than that of men; this may be related to the availability of social support.