Worldwide variations in prevalence of symptoms of allergic rhinoconjunctivitis in children: the International Study of Asthma and Allergies in Childhood (ISAAC).

BACKGROUND: As part of the International Study of Asthma and Allergies in Childhood (ISAAC), prevalence surveys were conducted among representative samples of school children from locations in Europe, Asia, Africa, Australia, North and South America. SUBJECTS: 257,800 children aged 6-7 years from 91 centres in 38 countries, and 463,801 children aged 13-14 years from 155 centres in 56 countries. METHODS: Written symptom questionnaires were translated from English into the local language for self-completion by the 13-14-year-olds and completion by the parents of the 6-7-year-olds. Rhinitis was described as a problem with sneezing, or a runny, or blocked nose when you (your child) DID NOT have a cold or the flu. Additional questions were asked about rhinitis associated with itchy-watery eyes, interference with activities and a history of hay fever ever. RESULTS: The prevalence of rhinitis with itchy-watery eyes ("rhinoconjunctivitis") in the past year varied across centres from 0.8% to 14.9% in the 6-7-year-olds and from 1.4% to 39.7% in the 13-14-year-olds. Within each age group, the global pattern was broadly consistent across each of the symptom categories. In centres of higher prevalence there was great variability in the proportion of rhinoconjunctivitis labelled as hay fever. The lowest prevalences of rhinoconjunctivitis were found in parts of eastern Europe, south and central Asia. High prevalences were reported from centres in several regions. CONCLUSION: These results suggest substantial worldwide variations in the prevalence and labelling of symptoms of allergic rhinoconjunctivitis which require further study. These differences, if real, may offer important clues to environmental influences on allergy.

Shigellosis in the United States: ten-year review of nationwide surveillance, 1964-1973.

In the 10 years 1964-1973, 105,832 isolations of shigellae were reported to the Center for Disease Control through a nationwide surveillance system. The number reported increased by approximately 13% annually, from 5852 in 1964, when only 17 centers reported all 4 quarters; to 16,797 in 1973, when 52 centers reported each quarter. The rate of reported isolations varied from 4.6 per 100,000 persons in 1965 to 9.1 per 100,000 in 1973. Shigella sonnei accounted for 64% of all these isolates and for more than 80% of isolates in 1973. The majority of reported cases of shigellosis occurred in young children and in women of childbearing age. During the 10-year surveillance period, 35 epidemics in 25 states were investigated. Two-thirds of these outbreaks were the result of person-to-person spread; investigations of common-source outbreaks showed the importance of both water and foodstuffs, especially salads, as potential vehicles of contamination. Indian reservations, custodial institutions, and day-care centers were identified as special high-risk settings for the transmission of shigellosis. The emergence of R-factor-mediated antimicrobial-resistance patterns in recent years has necessitated antibiotic sensitivity testing to determine the drug of choice for treatment of individual cases. Initial testing of oral vaccines suggests these vaccines will have only limited usefulness in protecting certain high-risk populations. Public health education coupled with improvements in water and sewerage systems remains the most satisfactory means of control.