[Japanese encephalitis]. / L'encéphalite Japonaise.

Japanese encephalitis is an arboviral disease due to a flavivirus transmitted by a mosquito of the genus Culex. It is a major public health problem in Southeast Asia where it is endemo-epidemic. The socio-economic impact of Japanese encephalitis is great since most cases occur in children and young adults and lead to death in 25 to 30 % and neurological sequelae in survivors. The tendency of Japanese encephalitis to spread geographically and the existence of imported cases are particularly important issues. The clinical features are the same as other viral encephalitis. Suspicion of imported Japanese encephalitis depends on awareness of the epidemiological setting (return from endemic areas). Diagnosis must be confirmed by serology using ELISA capture method to detect anti-viral antibodies in blood and cerebrospinal fluid. Unlike herpes encephalitis, there is currently no specific treatment for Japanese encephalitis. Only preventive measures can be effective against infection. At the present time the most widely used vaccine is Biken's lyophilized vaccine produced from a reference strain (Nakayama strain), but its high cost prevents mass vaccination in endemic areas. Recent progress in molecular biology has raised hope for the discovery of a genetically engineered vaccine to improve overall protection against Japanese encephalitis.

[Prevalence of exercise-induced asthma in school children]. / Prévalence de l'asthme d'effort en milieu scolaire.

BACKGROUND: Although asthma is the most common pulmonary condition in pediatrics, the incidence of exercise-induced asthma (EIA) in school children is not well documented and few studies have been devoted to the condition. There are considerable variations in morbidity and mortality between countries. This study was designed to evaluate the prevalence of EIA in children in the 6th grade (11-14 year-olds) in one French department (Haute-Vienne) and to identify undiagnosed cases. METHODS: The representative sample was obtained over a period of 28 days (February 2(nd) to April 10(th) 1998) by cluster sampling method, stratified by size of the schools. The number of subjects planned was 891. The selected children filled in a questionnaire on their asthma history and were subjected to an outdoor exercise test (6 minute run). Respiratory function was measured with a peak flow-meter. RESULTS: Seven hundred and eighty two school children were included in this survey. Participation rate was 87.8%. The prevalence of asthma from the questionnaire was 10.7% (CI 95%: 8.7 - 12.8). After exercise, 68 school children presented exercise-induced bronchospasm: the prevalence of the EIA was 8.7% (CI 95%: 6.9 - 10.5). Among these 68 school children, 27 were known asthmatics and 41 were not. With the 10 treated asthmatics, the overall prevalence of EIA was therefore estimated at 9.9% (CI 95%: 8.2 - 11.7). CONCLUSION: The prevalence of asthma and EIA was close to that found in other studies using a similar methodology. EIA remains under-diagnosed since 41 undeclared asthmatic school children were identified in our population. Nurses'information is necessary to initiate the use of systematically testing respiratory function (with a peak flow meter) at least once a year. Efficient management of the asthmatic child requires cooperation between the various professionals dealing with school children.

Role of drug exposure in aphthous ulcers: a case-control study.

BACKGROUND: Drug-induced aphthous ulcers have been the subject of several isolated and heterogeneous case reports for the last three decades. OBJECTIVES: To perform a case-control study to evaluate the risks linked to drug exposure in aphthous ulcers. METHODS: Eighty patients with typical clinical patterns of aphthous ulcers and 152 control patients who had had consultations for skin tumours were studied. A standardized questionnaire, concerning clinical features, life-style and medications taken during the last month, was completed for each patient. RESULTS: Case patients had a much higher intake of medications than control patients, respectively, 5.1 and 2. 8 medications per patient (P < 0.0001). Multivariate paired analysis showed an association between aphthous ulcers and two classes of drugs: non-steroidal anti-inflammatory drugs (P < 0.001) and beta-blockers (P = 0.002). Smoking could have a protective effect against aphthous ulcers (P < 0.001). CONCLUSIONS: Previous case reports and the results of this study suggest a real link between beta-blockers and aphthous ulcers. Our study did not confirm a role of other drugs but a few interesting case reports with positive reintroduction have to be considered. These results could be beneficial for patients, as healing may occur when the incriminated drug is discontinued.

Parkinson's disease and environmental factors. Matched case-control study in the Limousin region, France.

The study included 140 patients with Parkinson's disease (PD) and 280 non-Parkinson age-matched controls to evaluate environmental risk factors associated with PD. The effect of exposure to environmental and dietary factors was determined using conditional logistic regression. This multivariate analysis showed that PD in first-degree relatives and tea drinking were the main risk factors for PD. Smoking appeared to be a protective factor. Exposure to toxic compounds was not a significant risk factor. Further research is needed to validate that tea consumption increases the risk of PD.

Estimation of the amyotrophic lateral sclerosis incidence by capture-recapture method in the Limousin region of France.

Amyotrophic lateral sclerosis (ALS) is a rapidly fatal degenerative neurological disease categorized among motor neuron diseases. In the literature, the incidence of ALS varies between 0.7 and 2.4 per 100, 000 inhabitants. A study using the capture-recapture method (multiple records system analysis) was undertaken in Limousin (France) ascertaining all patients having onset of definite or probable ALS during the period 1994-1995. Three information sources able to identify these new ALS cases were selected: the first source was a computerized database of the Neurology Department of the University Hospital of Limoges; the second source consisted of the neurologists of the Limousin region and neighboring provinces (county-sized regions); the third source grouped the hospitals of the Limousin region and neighboring provinces (county-sized regions). During this period, 46 new cases of ALS were seen, corresponding to an observed mean annual incidence of 3.2 (+/-0.6) per 100,000 inhabitants. After standardization for age, the annual incidence was 2.5 per 100,000 inhabitants. The number of new cases estimated by the capture-recapture method was 70, corresponding to an estimated mean annual incidence of 4.9 (+/-1.0) for 100,000 inhabitants. Hence, statistical modeling utilizing partially overlapping information sources permitted a more exhaustive compendium of the new cases of ALS and may be a truer reflection of actual disease incidence than has been previously reported.

Estimation of the prevalence of epilepsy in the Benin region of Zinvié using the capture-recapture method.

BACKGROUND: The prevalence of epilepsy was estimated in two villages of 3134 inhabitants, in Benin, in April and May 1997 using the capture-recapture method. METHODS: Information was obtained from (i) a door-to-door cross-sectional study, (ii) a non-medical source consisting of key informants (traditional practitioners, teachers, village leaders, and religious representatives) and (iii) a medical source through evaluation of medical records in health centres. In all the three situations, the diagnosis of epilepsy was confirmed by a neurologist. RESULTS: The door-to-door survey found 50 epileptics, i.e. a prevalence of 15.9 per 1000. The non-medical source found 26 patients. The medical source found only four patients. In total, 66 epileptics were found by combining the three sources, giving a prevalence of 21.1 per 1000. After application of the capture-recapture method, the estimated number of cases from the door-to-door survey and non-medical source was 105, and 110 cases when the medical source was considered as well. The respective prevalences were 33.5 per 1000, and 35.1 per 1000. CONCLUSIONS: The door-to-door survey has been usefully improved by using key informants. The epilepsy prevalence estimate found by capture-recapture is clearly higher than that found by traditional cross-sectional methods, and could better depict the frequency of epilepsy in Africa.

[Epidemiology of cerebral cysticercosis in an Andean community in Ecuador]. / Epidémiologie de la cysticercose cérébrale dans une communauté des Andes en Equateur.

Taenia solium neurocysticercosis (NCC) has been documented to be an underlying cause of epilepsy, intractable headaches, hydrocephalus, dementia and other serious neurological conditions in many countries of Central and South America. However, methodological limitations had prevented the assessment of the true prevalence of this condition at the community level. We conducted a house-to-house neuroepidemiological survey of 6,118 residents of an Andean community. This information was used to target neuroimaging (CT-scan) and immunodiagnosis (enzyme-linked immunoelectrotransfer blot assay, EITB) tests in individuals suspected of harbouring Taenia solium NCC. In the rural population, NCC was confirmed in 8 out of 47 examined by CT-scan (17%) and in 6 of 42 examined by EITB (14%). In the urban population, NCC was confirmed in 35 of 147 examined by CT-scan (23.8%) and in 28 of 124 examined by EITB (22.6%). In a sample of relatives of patients with documented cerebral cysticercosis, 20 out of 81 examined by CT-scan (25%) and 12 of 79 (15%) examined by EITB had NCC. Finally, CT scans were performed for 83 school children from urban areas, and 9 (11%) were diagnosed as harbouring NCC. In a community-based study, cysticercosis appears to be much more frequent than initially thought, when CT examination is used as the "gold standard" for diagnosis.

[Sociocultural approach to epilepsy in Mauritania]. / Approche socioculturelle de l'épilepsie en Mauritanie.

In Black Africa, treatment of epilepsy is affected by sociocultural attitudes. The purpose of this report is to describe attitudes towards epilepsy in Mauritania and assess repercussions in 150 patients. Most patients were deprived of educational and occupational opportunities. Seventy-seven percent of patients were treated by traditional remedies. Regardless of ethnic origin, a widely held notion was that epilepsy was caused by djinns (evil spirits). An additional cause almost consistently cited by the Moorish population was diet. In these ethnic groups, the term iguindi refers to all clinical manifestations including seizures attributed to excessive eating. Traditional treatment involves ingestion of foods considered as antidotes for iguindi. These findings underline the need for information campaigns to enhance public awareness and understanding of epilepsy.

[HIV-1 cognitive and motor syndrome]. / Syndrome cognitif et moteur associé au VIH-1.

The central nervous system (CNS) is often affected by HIV-1 infection. Over 40% of AIDS cases present with neurological symptoms and CNS lesion are detected by anatomical and pathological studies in 80 to 90% of AIDS cases. There may be infections and tumors secondary to the immunodeficiency and pathologies may occur directly due to the neurotropism of the virus. Neurological problems associated with HIV-infection include encephalopathies, myelopathies, neuropathies and myopathies. HIV-1-induced encephalopathy may develop at any stages of HIV-1 infection and affects all risk groups equally. Its frequency worldwide is between 4 and 65% among individuals seropositive for HIV-1. The frequencies reported differ between studies due to differences in sampling methods, geographical factors, diagnostic criteria and investigative methods used. The pathogenesis of HIV-1-associated encephalopathy is not understood, but there are several hypotheses. The involvement of HIV-1 infected macrophages and microglial cells has been demonstrated. Indirect mechanisms such as release of lymphokines (tumor necrosis factor-TNF alpha- and interleukin-1) and neurotoxicity of the HIV envelope protein, gp 120, have also been suggested. This disorder is known as HIV-1-associated cognitive and motor syndrome. It presents clinically as a form of sub-cortical dementia with cognitive problems, motor deficits and behavioral disorders depending on the type and stage of HIV infection. The diagnosis can only be made after all other infections and tumors common in HIV-1 patients have been ruled out by appropriate investigations such as cerebrospinal fluid analysis, cerebral scan and magnetic resonance imaging. Electrophysiological studies, such as evoked responses and electroencephalograms, are particularly useful in its diagnosis. Anatomical examination shows diffuse paleness of the white matter, multi-nucleated giant cells and microglial nodes. Neuropsychological studies could be of value in diagnosis and in assessing the response to anti-retroviral treatment. There is currently no specific therapy for HIV-1-associated cognitive and motor syndrome. The use of new nucleoside analogue drugs in combination with existing drugs may provide new approaches to managing these patients.