Effectiveness of a school district closure for pandemic influenza A (H1N1) on acute respiratory illnesses in the community: a natural experiment.

BACKGROUND: Following detection of pandemic influenza A H1N1 (pH1N1) in Dallas/Fort Worth, Texas, a school district (intervention community, [IC]) closed all public schools for 8 days to reduce transmission. Nearby school districts (control community [CC]) mostly remained open. METHODS: We collected household data to measure self-reported acute respiratory illness (ARI), before, during, and after school closures. We also collected influenza-related visits to emergency departments (ED(flu)). RESULTS: In both communities, self-reported ARIs and ED(flu) visits increased from before to during the school closure, but the increase in ARI rates was 45% lower in the IC (0.6% before to 1.2% during) than in the CC (0.4% before to 1.5% during) (RRR(During)(/Before) = 0.55, P < .001; adjusted OR(During/Before) = 0.49, P < .03). For households with school-aged children only (no children 0-5 years), IC had even lower increases in adjusted ARI than in the CC (adjusted OR(During/Before) = 0.28, P < .001). The relative increase of total ED(flu) visits in the IC was 27% lower (2.8% before to 4.4% during) compared with the CC (2.9% before to 6.2% during). Among children aged 6-18 years, the percentage of ED(flu) in IC remained constant (5.1% before vs 5.2% during), whereas in the CC it more than doubled (5.2% before vs 10.9% during). After schools reopened, ARI rates and ED(flu) visits decreased in both communities. CONCLUSIONS: Our study documents a reduction in ARI and ED(flu) visits in the intervention community. Our findings can be used to assess the potential benefit of school closures during pandemics.

Comparison of neonatal thyroid-stimulating hormone levels and indicators of iodine deficiency in school children.

OBJECTIVES: To compare thyroid-stimulating hormone (TSH) levels in neonatal cord blood between study sites in Bangladesh, Guatemala and the United States. Also, to compare neonatal TSH results with indicators of iodine deficiency in school children. DESIGN: Consecutive births and, in school children, cross-sectional surveys. SETTING: Savar, Bangladesh; San Pedro Sacatepequez, Guatemala; and Atlanta, United States. SUBJECTS: In each study site, cord blood was spotted on to filter paper and TSH levels determined using a sensitive monoclonal assay. In the USA, heel stick blood specimens from newborns spotted on to filter paper were also obtained as well as exposure to iodine-containing antiseptics during the birthing process. Urine specimens were collected from mothers of newborns and tested for iodine concentration. School children in the same areas were surveyed for thyroid size by palpation and ultrasonography, and urine specimens collected for iodine concentration. RESULTS: Between 141 and 243 cord blood specimens were collected from each study site. The prevalence of elevated cord blood TSH levels (> 5 mUl(-1)) was high in all study sites, from 58% to 84%. All sites would be categorised as having 'severe' iodine deficiency based on WHO/UNICEF/ICCIDD criteria. Iodine-containing antiseptics were used during 98% of the births in the USA but not in Bangladesh or Guatemala. The neonatal TSH classification indicated more severe iodine deficiency levels than classifications based on urinary iodine and goitre in school children. CONCLUSIONS: In the USA, elevated TSH levels may be partially attributed to use of beta-iodine-containing antiseptics prior to birth. We recommend the cautious interpretation of TSH results in newborns for the assessment of iodine deficiency disorders when iodine-containing antiseptics are used during the birthing process.