Analysis on features of acute hemorrhagic conjunctivitis and interventions in an enterprise in Shenzhen, 2007

ObjectiveTo analyze the features of a acute hemorrhagic conjunctivitis (AHC) outbreak, discuss the outbreak cause and evaluate the effect of interventions, and provide scientific evidence for the control of the outbreak. MethodsThe data of reported cases were analyzed, the outbreak cause was investigated by cross sectional study and the interventions were conducted. ResultsA total of 11 118 AHC cases were reported and isolated in an enterprise from July 20 to November 26, 2007, the attack rate was 2957.80/lakh, which was significantly higher than 433.72/lakh in 2006 (IP/I＜0.0001). The incidence peaked during August 14-September 4. The attack rate (5146.32/lakh) in Guanlan factory was significantly higher than that (2080.38/lakh) in Longhua factory (IP/I＜0.0001). The difference on the attack rate among the staff at different working sites and dormitories was significant. Before the intervention, 37.47% of cases were not found and isolated in 2 days, the terminal disinfection rate at working sites and dormitories where cases occurred were 38.43% and 43.22% respectively. Only 26.42% of staffs knew that AHC could be spread by air. After intervention for active case finding/isolation, terminal disinfection and health education, the outbreak ended. ConclusionThis AHC outbreak peaked in summer with the intensity greater than in 2006. Non-timely finding and isolation of the cases were the risk factors for the outbreak. Interventions were essential for the early finding and isolation of the cases and the control of the outbreak.