Nodding disease in southern Sudan

In January 2008, an advisor on school health and nutrition working for Save the Children [USA] observed several cases of children suffering from "nodding disease", while on a visit to southern Sudan. The affected children were from the districts of Mvolo and Wulu in Western Equatoria and Lakes states respectively. A quick assessment among the community for data of children infected with the disease revealed more than 100 cases in a population of 3-5,000 people. Save the Children USA requested WHO/HQ to assist in investigating this disease, identify risk factors and help prevent and/or find cure for this disease. On 14 January WHO/HQ notified WHO/EMRO. Verification through WHO offices in Sudan and the government health authorities did not yield any additional information about the disease. The two districts border Mundri County, where in 2001/2 WHO researchers investigated an outbreak of nodding disease but did not identify the etiology

Onchocerciasis in Sundus area: skin and eye manifestation

Onchocerciasis is known in Sudan since 1933. It, now, prevails in three foci: southern, northern and eastern focus [Sundus area]. Sundus area was studied last time in mid 1980s. The actual status of the disease in Sundus area was not clear, because some villages to be hyper-endemic at that time, were abandoned and the population resettled in other areas. This study was designed to provide the actual information of skin and eye lesions due to onchocerciasis, in Sundus area, eastern Sudan. Methodology Two clinics were setup in the area, and all individuals coming to these clinics were included in the study. They were subjected to physical examination for dermatological changes and ophthalmic examination using slit lamp biomicroscope and direct ophthalmoscope. Total number of 302 individuals was examined, of which 87 individuals [28.8%] were found to have onchocercal skin disease. The commonest type was lichenified onchodermatitis [18.5%] and chronic papular onchodermatitis [11.6%]. The localized onchodermatitis [Sowda] was seen in 19 subjects. No case of blindness was recorded; however, ocular changes were seen in 43 individuals [14.2%] including corneal opacity and cataract. Results of this study provide support for the still existence of the disease in Sundus area

Eye lesions and onchocerciasis in a rural farm settlement in Delta State, Nigeria.

Between December 1999 and September 2000, an investigation on 326 inhabitants who voluntarily participated in screening for eye lesions and onchocerciasis in a rural farm settlement in Aniocha North local government area of Delta State, Nigeria was carried out. Microfilariae were reported in the skin tissues of 134 (41.1%) inhabitants. Of these, males had more microfiladermia (49.9%) than their female counterparts (33.3%). The percentage prevalence of the clinical signs of onchocerciasis in the farm settlement was hanging groin 14.1%, onchocercal nodules 25.1%, onchocercal dermatitis 27.6% and scrotal enlargement 3.7%. The percentage prevalence of the eye lesions among the onchocerciasis infected inhabitants was cataract 7.4%, glaucoma 3.7%, optic atrophy 0.6% and uveitis 18 (5.5%). Impaired vision occurred among 80 (24.5%) inhabitants and blindness was reported among 2 (0.6%) inhabitants.

Insecticide resistance in the Simulium damnosum S. L. vectors of human onchocerciasis: distributional, cytotaxonomic and genetical studies

Human onchocerciasis is a debilitating disease caused by the filarial parasite Onchocerca volvulus (Leukart). The parasite is transmitted by dipterous insects of the family Simuliidae. ln West Africa, transmission is by members of lhe Simulium damnosum (Theobald) species complex. The manifestations of the disease are mainly dermal, lymphatic and ocular, the most severe of which is blindness hence the common name 'river blindness'. The disease is found in parts of Latin America, the Yemen and Sub-Sahara Africa. lt affects some 17.7 million people world-wide with 500,000 severely visually disabled and some 27O,00O blind. ln West Af rica, which is the most affected area, there are over 5 million infected with onchocerciasis and about 148,000 blind. ln view of this, the Onchocerciasis Control Programme in West Africa (OCP), one of the biggest vector control operations covering parts of 11 countries was started in 1975 by the World Health Organization to control onchocerciasis as a disease of public health and socio-economic importance. The initial strategy of the OCP was the application of insecticides to the breeding sites of the insect vectors. ln the OCP, temephos an organophosphate insecticide (OP) was the only chemical used for the initial five years due to its selective mode of action. Resistance to temephos first appeared in 1980 in a population of S. soubrense/S.sanctipauli on the Bandama river in Southern Côte d'lvoire. Later, similar resistant populations of the same species were identified in other river basins in the C6te d'lvoire. ln 1981 Chlorphoxim, also an OP, was used as a replacement for temephos in areas where resistance to temephos had been detected but a similar pattern of resistance was soon detected against chlorphoxim Careful monitoring of resistance to temephos has shown that it has spread to all river basins and different species of the S. damnosum complex at one time or another within the OCP area. Resistance to insecticides demands that large quantities and more novel and toxic chemicals have to be used in the fight against insects and other arthropod pests. This has important economic, operational and environmental demands. ln the West African vector control programme mentioned above, a rotation of 6 insecticides is used to manage insecticide resistance. This strategy places a major constraint on the operations of the Programme (OCP) due to the logistic need of stocking insecticides in the field

Health and nutritional determinants of school failure

Education is associated with wide-ranging benefits to both the individual and society. Lockheed and colleagues reviewed the literature on primary education in developing countries and found that education had a positive effect on economic growth...It has been recognised for some time that both the quality of the school and the child's home background have marked effects on school attainment levels. There is now increasing concern that poor health and nutrition might detrimentally affect children's school achievement. This publication addresses to what extent children's health and nutrition contribute to school failure. The conditions considered to be potentially important are the following: protein energy malnutrition; iron and iodine deficiency; hunger; sensory impairment due to hearing or visual deficits from any cause including vitamin A deficiency, otitis media, and onchocerciasis; and infections, particularly parasitic infections such as malaria, geohelminth infections such as diarrhea and respiratory infections may also be important. This chapter will briefly review studies that have examined associations between children's school performance or ability and their health and nutrition. Then it will describe two studies we have conducted in Jamaica, one in primary-school children and one in adolescent girls

Apoc impact assessment study Onchocerciasis: baseline ophthalmological Survey in southwestern Sudan

A cross-sectional survey of eye disease supported by the African Programme for Onchocerciasis Conffol (APOC) was carried out in October 1998, in Raja, Sudan, a Savanna ecological zone to determine the prevalence and distribution of onchocercal eye disease. Detailed eye examination including measurement of visual field using the Wu-Jones computerized Motion Sensitivity Screening Test (MSST) were carried out. A total of 481 individuals were examined, of which 379 underwent detailed eye examination. A high prevalence of blindness (8.1%) from all causes was recorded. Onchocerciasis-induced eye disease was responsible for blindness in 56.40/o of all blind persons. Of the 38 persons who had visual impairment, 13 (2.7%) were severely affected. As many as 91 (24.0%) persons had microfilariae (mfs) in the anterior chamber (AC) and /or cornea with the highest prevalence of 29.3Yo and 28.8% respectively, recorded among the young and active individuals. This age group (15-24yeus) also had the highest prevalence (15.3%) of flufff corneal opacities. Sclerosing keratitis was present in 46 (12.1%) subjects while iridocyclitis was diagnosed in 9.0% with the highest prevalenc e of 25 .0o/o noted in the 45 - 54 age group. Prevalence of blinding cataract was 54.1% while that of glaucoma was12.2%. Presumed optic nerye disease, a known pathway to onchocercal blindness was observed in 19.6% with one third of this percentage already at the advanced stage. Another common pathway to blindness, chorioretinitis, affected 15.2% of the subjects of which 7.2% had reached advanced stages.Prevalence of abnormal visual fields was 6.6Yo. Posterior segment oncho disease was found to be the main ocular pathology in 15.6% subjects followed closely by 13.5% whose main cause was anterior segment oncho lesion. Both sexes were almost equally affected. Ocular findings in this area particularly among the young conform to high intensity levels of onchocerciasis infection and therefore require urgent effective intervention to forestall further devastating oncho-induced blindness and alleviate the socio-economic burden imposed on this population.

Sitios apropiados para el desarrollo de etapas inmaduras del simulium ochraceum en Guatemala

Se realizaron dos estudios en diferentes regiones del foco central de Oncocercosis. En ambos estudios hubo buena relación de datos. Se determinó que el 80 por ciento de los ríos con aforo entre 1 y 10 litros por segundo son apropiados para el desarrollo de las etapas inmaduras de S. ochraceum, teniendo como límite una distancia de 140 metros de longitud. Así mismo el 87 por ciento de los ríos positivos con S. onchraceum se encontraron en el rango de 0.1 a 5.0 litros por segundo de descarga de agua y el 11 por ciento en el rango de 5.1 a 10.0 litros/segundo. En el rango de 0.1 a 3.0 l/s se encontró el mayor número de ríos positivos para la misma especie. Las especies metallicum, callidum y horacioi, fueron las más comunes conviviendo con ochraceum