RESUMO
In a community hepatitis A outbreak in the Rochester, New York area, 64 of 79 (81%) people with anti-hepatitis A IgM-antibodies and onset of symptoms from 9 April-31 May 1994, recalled eating food obtained from a retail buyer's club. Eleven (65%) of 17 households with cases contained club members compared with 7 (21%) of 34 neighbourhood-matched control-households (matched odds ratio 8.5; 95% CI 1.7-41.6). Club employees who ate sugar-glazed baked goods were at fourfold increased risk for hepatitis. The source of infection was an IgM-positive baker who contaminated baked goods while applying sugar glaze. Computer-generated purchase lists implicated 11-12 March and 21-24 March as the most likely dates when contamination occurred. This investigation demonstrates the importance of food workers adhering to established hygiene practices. Computer-generated commercial datasets can be useful in epidemiologic investigations.
Assuntos
Pão/virologia , Surtos de Doenças , Hepatite A/etiologia , Hepatite A/imunologia , Anticorpos Anti-Hepatite/sangue , Imunoglobulina M/sangue , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Manipulação de Alimentos , Humanos , Masculino , Pessoa de Meia-Idade , New York , Razão de Chances , Vigilância da População , Fatores de Risco , Estudos Soroepidemiológicos , Inquéritos e Questionários , Saúde da População UrbanaRESUMO
OBJECTIVE: To describe the epidemiologic features of an outbreak of influenza A that occurred in a skilled nursing home although over 90 percent of the resident population had previously received influenza vaccine. DESIGN: Retrospective cohort study. SETTING: Skilled nursing home facility in western New York State. PATIENTS: Nursing home residents and patient-care staff. MAIN OUTCOME MEASURE: Incidence of influenza-like illness among vaccinated versus unvaccinated nursing home residents and staff. RESULTS: Thirty-seven of 124 residents (attack rate = 30%) and 18 of 146 staff (attack rate = 12%) had an influenza-like illness. Staff illness began 16 days prior to onset among residents. Six cases of pneumonia and three influenza-related deaths occurred, all among the vaccinated residents. Ninety percent of the nursing home residents and 10% of the staff received the influenza vaccine prior to the outbreak. The calculated vaccine efficacies were minus 21% and plus 45% for residents and staff, respectively. CONCLUSION: While antigenic drift of the circulating influenza virus was the major factor in the apparent vaccine failure, the observed poor staff immunization rate (10%) and absence of surveillance which precluded the use of amantadine chemoprophylaxis suggest that the use of these strategies may be of importance in controlling influenza outbreaks in nursing homes.