Socioeconomic status and prevalence of allergic rhinitis and atopic eczema symptoms in young adolescents.

Environmental factors are known to influence the development of allergic rhinitis and atopic eczema in genetically susceptible individuals. Socioeconomic status (SES) may be an important indicator of risk for these conditions. The International Study of Asthma and Allergies in Childhood (ISAAC) Phase 1 written questionnaire was used to determine the prevalence and severity of allergic rhinoconjunctivitis and atopic eczema symptoms in 4947 pupils aged 13-14 years attending 30 schools in socioeconomically diverse areas of Cape Town. Home addresses were used to stratify participants into five SES bands. Relationships between symptom prevalence and severity, and SES, recent urbanization and upward socioeconomic mobility were examined. Logistic regression was used to generate odds ratios (OR) and 95% confidence intervals (CI) in order to assess overall trends by SES. The prevalences of self-reported allergic rhinitis symptoms and recurrent itchy rash in the past year were 33.2% and 11.9% respectively. Girls had a significantly higher prevalence of all symptoms than boys. The prevalence of allergic rhinitis symptoms increased from lowest to highest SES (overall OR for rhinitis symptoms in past year = 1.16, 95% CI 1.11-1.21). There was no significant trend in reported eczema symptoms by SES other than for the question, 'Have you ever had eczema' (OR = 0.88, 95% CI 0.83-0.93). Longer period of urbanization was weakly associated only with recurrent itchy skin rash (OR = 1.05, 95% CI 1.01-1.09). 'Socially mobile' pupils, i.e. those resident in the lowest SES areas but attending highest SES schools showed significantly higher prevalences of eczema and some rhinitis symptoms than pupils attending lowest SES schools. These findings may reflect differences in reporting related to language, culture and access to medical care rather than real differences in prevalence.

Identification of a novel Lymantria dispar nucleopolyhedrovirus mutant that exhibits abnormal polyhedron formation and virion occlusion.

In previous studies on the formation of Lymantria dispar nuclear polyhedrosis virus (LdMNPV) few polyhedra (FP) mutants, several polyhedron formation mutants (PFM) were identified that appeared to be unique. These viral mutants are being characterized to investigate the processes of polyhedron formation and virion occlusion. LdMNPV isolate PFM-1 is one of these mutants, and is described in this report. Genetic techniques were used to determine if isolate PFM-1 contained a mutation in the polyhedrin or 25K FP gene. Wild-type viruses were recovered after coinfection of Ld652Y cells with isolate PFM-1 and a FP mutant, and with isolates PFM-1 and PFM-C (isolate PFM-C contains a mutation in the polyhedrin gene). These viruses were analyzed by genomic restriction endonuclease digestion and found to be chimeras of the original PFMs used in the coinfections. Marker rescue studies mapped the mutation in isolate PFM-1 to a genomic region that does not include the polyhedrin or 25K FP genes. Isolate PFM-1 produced approximately 14-fold fewer polyhedra than LdMNPV isolate A21-MPV, an isolate that produces wild-type levels of polyhedra, and approximately 2-fold more polyhedra compared to the FP isolate 122-2. Polyhedra generated by isolate PFM-1 were normal in size and shape but contained very few viral nucleocapsids. The same amount of budded virus (BV) was released from cells infected with isolates PFM-1 and A21-MPV. In contrast, isolate 122-2 yielded significantly more BV than isolates PFM-1 and A21-MPV.

Clinical characteristics of childhood asthma.

A prospective study was undertaken of 298 asthmatic children attending a paediatric allergy clinic in Bloemfontein. A detailed history was obtained, and skin tests were performed. Male predominance and an early age of onset were confirmed. Symptomatic allergic rhinitis was an extremely common finding. A family history of allergy was obtained in over 90% of cases. Respiratory tract infections, changes in the weather and exercise were found to be the most common asthma-inducing factors. Common allergens were grass pollen (63%) and animal danders. House-dust mite (25%) and dietary allergens (less than 20%) were relatively uncommon. The failure to recognise the symptoms of asthma in children, particularly young children, was identified as an ongoing problem.