1. General Information

1. General Information

Among the 2,021 cases, 1,420 were male, accounting for 70.3%; 601 were female, accounting for 29.7%. Of these, 591 were under 15 years old, representing 29.2%; 709 were aged 16–30, accounting for 35.1%; 421 were aged 31–45, accounting for 20.8%; 224 were aged 46–60, accounting for 11.1%; and 76 were over 60, accounting for 3.8%. By occupation, 722 were workers, accounting for 35.7%; 678 were cadres, accounting for 33.5%; 326 were residents, accounting for 16.1%; 198 were students, accounting for 6.8%; and 97 were military personnel, accounting for 4.8%. By month of onset, 217 cases occurred in January–March, accounting for 10.7%; 458 cases occurred in April–June, accounting for 22.7%; 1,022 cases occurred in July–September, accounting for 50.7%; and 324 cases occurred in October–December, accounting for 16.0%. Among them, 721 had a family history of the disease, accounting for 35.7%; 1,136 had social contact history, accounting for 56.2%; and 164 had a history of blood transfusion (blood products), vaccination, or injection, accounting for 8.1%.