Onchocerciasis in Ecuador: prevalence of infection on the Ecuador-Colombia border in the Province of Esmeraldas.

The prevalence of onchocerciasis infection was determined in communities on 7 rivers located in the northern area of the canton San Lorenzo, province of Esmeraldas. Diagnosis of the infection was obtained by skin biopsies and recombinant-antigen based-serology. No evidence of infection was detected in 9 communities studied along the Rio Mataje, which forms the frontier between Ecuador and Colombia, nor in 10 adjacent communities located on 5 interior rivers. Evidence for Onchocerca volvulus infection was found in 4 communities on the Rio Tululvi with the following prevalence: La Boca (3.5% by biopsy and 3.9% by serology), Guayabal (9.1% by both biopsy and serology), La Ceiva (51.5% by biopsy and 53% by serology), and Salidero (4% by biopsy and 7.7% by serology). A few individuals in these communities were seropositive for O. volvulus in the absence of detectable dermal microfilariae: these might harbor very light or prepatent infections. No clinical disease attributable to onchocerciasis was found. The infected communities will be included in the ivermectin-based National Control Program for the disease, with no evidence of the infection having extended north of the Ecuadorian-colombian border.

[Ocular manifestations of vitamin A deficiency and their prevention]. / Les manifestations oculaires de la carence en Vitamine A et leur prévention.

PIP: Vitamin A deficiency and xerophthalmia are among the most widespread human nutritional problems worldwide. High levels of vitamin A deficiency are seen especially among disenfranchised populations where young children are the most severely affected, leading to blindness and early mortality. Not seen in the industrialized countries since the 1950s, vitamin A deficiency still exists in Africa, Asia, and South America. There are approximately 10 million new cases of xerophthalmia per year, of which 280,000-500,000 are blinded. For 20 years, international organizations, governments, and private concerns have found such deficiency with some, but not complete, success. The authors describe the metabolism of vitamin A, analyze its ocular manifestations, and consider the epidemiology of vitamin A deficiency, its association with excess infant mortality, and the course of disease leading to blindness. The global distribution of vitamin A deficiency and xerophthalmia are described. All factors related to vitamin A level in the human body can be changed for the better. Food supplementation with vitamin A and the occasional administration of vitamin A are discussed as possible options to pursue.^ieng

Health and schooling: evidence and policy implications for developing countries.

PIP: Health and education are typically viewed as distinct topics from both the research and policy perspectives. Accordingly, the direct interactions between health status and education have been neglected in both research and policy making. The authors use survey data collected from students during the 1980s in Piaui, Ceara, and Pernambuco states as part of an evaluation of a major educational intervention program, EDURURAL, to investigate the complementarities of health with school attainment and cognitive achievement. A series of anthropometric measures for individual students in rural northeast Brazil are used in educational performance models. The promotion models and value-added achievement models both demonstrate the importance of students' visual acuity. Poor vision systematically leads to higher drop-out rates, more grade repetition, and lower achievement. The achievement models also point to the role of good nutrition.^ieng

Lens opacities, demographic factors and nutritional supplements in the Barbados Eye Study.

BACKGROUND: This study evaluated the association of age-related lens opacities with the use of nutritional supplements and demographic factors among 4314 black participants (> or = 40 years) in the population-based Barbados Eye Study. METHODS: Lenses were classified at the slit lamp by the Lens Opacities Classification System II (LOCS II); a score > or = 2 was used to define the presence of gradable lens opacities, by type. Lens changes also included prior cataract surgery or cataract too advanced to grade. Associations with risk factors were evaluated by logistic regression analyses. RESULTS: The study identified 1800 individuals with lens changes in at least one eye; 229 had nuclear opacities only; 851 had cortical opacities only. Older age and indicators of lower socioeconomic status (low education and/or non-professional occupation), were positively associated with both nuclear (odds ratio [OR] = 1.90) and cortical (OR = 1.47) opacities. Women had an increased risk of cortical opacities (OR = 1.41). Regular users of nutritional supplements were less likely to have lens changes (OR = 0.78) and, specifically, cortical opacities (OR = 0.77). The association with nutritional supplements was present in those < 70 years, but not at older ages. CONCLUSIONS: The study supports the association of lower socioeconomic status with lens changes, including nuclear and cortical lens opacities. The findings also suggest that regular users of nutritional supplements have a one-fourth lower risk of lens changes and particularly, of cortical opacities; a result seen at ages under 70 years. The associations with potentially modifiable factors indicate the need for further evaluations, given the high prevalence of lens opacities.

PIP: The associations between age-related lens opacities and nutritional supplementation and selected demographic factors were investigated in 4314 men and women 41-84 years of age enrolled in the Barbados Eye Study. The Lens Opacities Classification System II was used for grading. 1800 of these adults had lens changes (defined as any type of gradable lens opacities, a history of cataract surgery, or cataract too advanced to grade) in at least one eye; 229 had nuclear opacities only and 851 had cortical opacities only. In logistic regression analyses, older age and low socioeconomic status (assessed on the basis of educational and occupational status) were positively associated with both nuclear (odds ratio (OR), 1.90) and cortical (OR, 1.47) opacities. The average age of participants with lens changes was 68.2 years compared with 51.8 years among those without such opacities. Compared with men, women had an increased risk of cortical opacities (OR, 1.41). Regular use of nutritional supplements (primarily cod liver oil and multivitamins) was associated with a decreased risk of lens changes (OR, 0.78), especially cortical opacities (OR, 0.77). The association with nutritional supplements did not persist beyond 70 years of age, however. The potential of nutritional supplements to reduce cataract in adults under 70 years of age could have significant public health implications, but requires confirmation in controlled clinical trials.

Vitamin A supplementation and increased prevalence of childhood diarrhoea and acute respiratory infections.

There is uncertainty over whether vitamin A supplementation reduces morbidity among children with subclinical deficiency of the vitamin. Hence a double-blind, placebo-controlled trial of the effect of vitamin A supplementation on childhood morbidity was conducted among 11,124 children aged 6-83 months in the northwest of Haiti. After a random start, children were sequentially assigned by household units to receive either megadose vitamin A or placebo in three distribution cycles 4 months apart. 2 to 8 weeks after each administration of the vitamin A and placebo capsules, indicators of childhood morbidity were reassessed through interviews conducted in the homes of participating families. The vitamin A group was found to have an increased 2-week prevalence of all symptoms and signs of childhood morbidity assessed, including diarrhoea (rate ratio [RR] = 1.09, 95% confidence interval 1.05-1.14), rhinitis (RR = 1.02, 95% confidence interval 1.00-1.04), cold/flu symptoms (RR = 1.04, 95% confidence interval 1.01-1.06), cough (RR = 1.07, 95% confidence interval 1.03-1.11), and rapid breathing (RR = 1.18, 95% confidence interval 1.09-1.27). The study shows an increased 2-week prevalence of diarrhoea and the symptoms of respiratory infections after vitamin A supplementation.

PIP: In the late 1980s, 11,124 children 6-83 months old, living in the sparsely populated northwest of Haiti participated in a double-blind, placebo-controlled trial of the effect of vitamin A supplementation on child morbidity. An ophthalmic assistant and a supervising ophthalmologist examined all children 2 years old. 30 children had vitamin A deficient related corneal disease (20 with corneal xerosis and 10 with corneal ulceration, keratomalacia, and/or corneal scarring). The children received either a capsule containing 200,000 IU of vitamin A and 40.6 mg vitamin E or a capsule containing only 40.6 mg vitamin E (placebo) every 4 months. Field workers interviewed caretakers 2-8 weeks after the children received their capsules to gather data on signs and symptoms of illness. Children in the vitamin A group were more likely to have a higher prevalence of diarrhea and of respiratory infections than the placebo group (e.g., 1st cycle, 42 vs. 36% for diarrhea and 18 vs. 15% for rapid breathing, rate ratios = 1.6 and 1.19, respectively). The risk of morbidity was highest 8-17 weeks after receiving the megadose of vitamin A. These findings indicate that prevalence of diarrhea and respiratory infections increased 2 weeks after vitamin A supplementation. Mortality rates of the 2 groups were essentially the same. The mortality rate of nonparticipants was higher than that of participants (52/1000 vs. 23/1000), however, suggesting that the supplements may have had some benefit.

The prevalence of trachoma in preschool and school children in Olimpia, Guaraci and Cajobi, Sao Paulo, Brazil.

A school-based prevalence survey of trachoma was conducted in three rural municipalities in the state of Sao Paulo, Brazil, in 1989. A total of 950 children aged 4-11 years were examined. The prevalence of inflammatory trachoma was found to be 6.3%, peaking at 24.1% in the 4 year-old age group. The prevalence of trachomatous scarring was 2.7% and was more prevalent in older children. Risk factors included household sleeping arrangements and nasal discharge.

PIP: In December 1989, researchers gathered data on 950 4-11 year old children attending preschool or primary schools in the rural municipalities of Olimpia, Guaraci, and Cajobi in northwestern Sao Paulo State, Brazil to measure prevalence of active trachoma and to identify its risk factors. Overall prevalence of trachoma was 8.6%. Physicians treated all trachoma cases with topical 1% tetracycline twice daily for 6 weeks and examined them later at a local health care center. Prevalence of inflammatory trachoma stood at 6.3%. This was similar to its prevalence in an Olimpia's neighboring town called Bebedouro. Prevalence of trachomatous scarring was 2.7%. Thus the northwestern part of Sao Paulo state was an important focus of endemic trachoma infection. Inflammatory trachoma was highest among the 4 year olds (24.1%) and fell to 0 by age 11. On the other hand, trachomatous scarring was relatively rare in 4-5 year olds then increased to 7% in 10-11 year old children. In fact, the mean age for inflammatory trachoma was 6.6 years and for trachomatous scarring 8.5 years. Perhaps the recently implemented trachoma control activities in Olimpia explained the lowest prevalence of inflammatory trachoma (5.4%). Guaraci experienced the highest prevalence rate (9.6%), but did not have any cases of trachomatous scarring. Children who slept with others were significantly more likely to have inflammatory trachoma than were those who slept alone (p.005). Sleeping pattern was the only personal hygiene variable significantly associated with inflammatory trachoma. Not even face washing was significantly associated with it. The only clinical symptom significantly associated with inflammatory trachoma was nasal discharge (p.001). A considerable community-based epidemiological survey would qualify these results.

Joint Resolution MINED / MINSAP No. 1/89 of 2 February 1989.

PIP: This Cuban Resolution amends the Health Regulations for Nurseries to include rules on detection of strabismus and amblyopia by means of ophthalmological examinations carried out before a child enters a nursery and periodic examinations performed while the child is in the nursery.^ieng