In May 2009, one of the earliest outbreaks of 2009 pandemic influenza A virus (pH1N1) infection resulted in the closure of a semi-rural Pennsylvania elementary school. Two sequential telephone surveys were administered to 1345 students (85% of the students enrolled in the school) and household members in 313 households to collect data on influenza-like illness (ILI). A total of 167 persons (12.
View Article and Find Full Text PDFObjectives: To characterize illness and identify the etiology for two nursing home outbreaks of respiratory illness.
Design: Multisite outbreak investigations; cohort.
Setting: Two nursing homes in Pennsylvania.
Objectives: We investigated a measles outbreak that began in March 2003 in a Pennsylvania boarding school with >600 students to identify all cases, including the source; implement outbreak control measures; and evaluate vaccine effectiveness.
Methods: Measles was suspected in any person at the school with a generalized rash and fever during March 21 to May 28, 2003 and investigated with serologic testing. We reviewed vaccination history from school records and conducted a survey to determine country of measles vaccination.
Background: Legionella species are abundant in the environment and are increasingly recognized as a cause of severe pneumonia. Increases in cases of community-acquired legionellosis in the greater Philadelphia metropolitan area (GPMA) led to concern that changing environmental factors could influence occurrence of disease.
Methods: We evaluated the association between weather patterns and occurrence of legionellosis in the GPMA, using both traditional Poisson regression analysis and a case-crossover study approach.
Background: Necrotizing enteritis associated with Clostridium perfringens type C ("pigbel") is a well-known syndrome in severely protein-deprived populations in the Pacific. It is exceedingly rare in the developed world. C perfringens type A is a common cause of acute gastroenteritis and, in a handful of infections, has been reported in association with a syndrome resembling necrotizing enteritis.
View Article and Find Full Text PDFTo determine vaccine effectiveness (VE), a varicella outbreak in a highly vaccinated day-care center (DCC) population in Pennsylvania was investigated. In Pennsylvania, proof of immunity is required for children >or=12 months old for DCC enrollment. Questionnaires were administered to parents of children who had attended the DCC continuously during the study period (1 November 1999-9 April 2000) to determine history of varicella disease or vaccination and for information about any recent rash illnesses.
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