潜伏期:一般为2～10天,个别病人可长达19天。临床表现:起初有前驱症状,包括不适、广泛性肌痛及头痛等。24～48小时后,体温快速上升,持续高热(40～40.5℃),反复寒战和严重衰弱。病程早期可有胃肠症状,如恶心、呕吐、水样腹泻(无血和粘液,不伴腹痛)。 Latency: usually 2 to 10 days, individual patients up to 19 days. Clinical manifestations: At first, there are prodromal symptoms, including discomfort, generalized muscular and headache. After 24 to 48 hours, the body temperature rose rapidly, sustained high fever (40 ~ 40.5 ℃), repeated chills and severe weakness. The early course of the disease may have gastrointestinal symptoms, such as nausea, vomiting, watery diarrhea (no blood and mucus, not accompanied by abdominal pain).