Donald W. Spady

OBJECTIVE: We describe the frequency and patterns of injury affecting 96 359 children between 0 and 10 years old and living in Alberta, Canada. DESIGN: This population-based, longitudinal study involved children born in the 3 fiscal years of April 1, 1985 to March 31, 1988, recruited before age 1, and who remained in the study until at least age 5. We used the International Classification of Diseases, Ninth Revision, Clinical Modification chapter-17 diagnostic codes provided by physicians. Codes were grouped into 17 categories; injury episodes were calculated, and age- and gender-specific incidence rates for each category were calculated. The age, pattern, times of greatest risk, and the effect of gender on the type and incidence of injury were determined. SETTING: Health care administrative data were obtained from all fee-for-service health care venues in Alberta between April 1, 1985 and March 31, 1998 providing services to children registered with the Alberta Health Care Insurance Plan and otherwise meeting entrance criteria. RESULTS: Nearly 84% of children received care for an injury during the study period, and in any given year approximately 21% of the population studied had at least 1 injury. Repeat injury was common (73%), and boys were more likely than girls to be injured and to have repeat injury. The most common injuries were dislocations and sprains, open wounds, and superficial injuries and contusions. Burns, poisoning, intracranial injury, and foreign bodies were the next most common, and fractures were least common. Approximately 10% of injuries were multiple-category injuries. Rates varied greatly by injury category, age, and gender. Hospitalization rates varied in a similar manner and commonly accounted for approximately 10% of all services. Males were most likely to have an injury, and aboriginal children or children who had received welfare at some time were at greatest risk. CONCLUSIONS: Administrative data can be used to estimate the incidence of injury in a pediatric population. Distinct patterns of injury occur at different ages. Recurrent injury is common. Almost identical proportions of injury (46%) are treated in emergency departments and physicians' offices.

BACKGROUND: Swine outbreaks of pandemic influenza A (pH1N1) suggest human introduction of the virus into herds. This study investigates a pH1N1 outbreak occurring on a swine research farm with 37 humans and 1300 swine in Alberta, Canada, from 12 June through 4 July 2009. METHODS: The staff was surveyed about symptoms, vaccinations, and livestock exposures. Clinical findings were recorded, and viral testing and molecular characterization of isolates from humans and swine were performed. Human serological testing and performance of the human influenza-like illness (ILI) case definition were also studied. RESULTS: Humans were infected before swine. Seven of 37 humans developed ILI, and 2 (including the index case) were positive for pH1N1 by reverse-transcriptase polymerase chain reaction (RT-PCR). Swine were positive for pH1N1 by RT-PCR 6 days after contact with the human index case and developed symptoms within 24 h of their positive viral test results. Molecular characterization of the entire viral genomes from both species showed minor nucleotide heterogeneity, with 1 amino acid change each in the hemagglutinin and nucleoprotein genes. Sixty-seven percent of humans with positive serological test results and 94% of swine with positive swab specimens had few or no symptoms. Compared with serological testing, the human ILI case definition had a specificity of 100% and sensitivity of 33.3%. The only factor associated with seropositivity was working in the swine nursery. CONCLUSIONS: Epidemiologic data support human-to-swine transmission, and molecular characterization confirms that virtually identical viruses infected humans and swine in this outbreak. Both species had mild illness and recovered without sequelae.