Yellow Fever
什麼是Yellow Fever
Yellow fever is a serious infectious disease that varies in the severity of illness. It is caused by the yellow fever virus. There are three types of yellow fever. One involves mosquitoes and non-human primates (monkeys) and is called jungle yellow fever since it occurs in forested rural areas. An intermediate type involves humans, primates and various types of mosquitoes in savannah regions of Africa. The third type is called urban yellow fever and involves humans and mosquitoes that are adapted to urban areas. In all three types, infected mosquitoes are the agents that transmit the disease to humans.
It is difficult to assess the risk of contracting yellow fever in the traveller since it depends on many different factors such as the traveller’s destination, the season, the work and recreational activities, as well as the local activity of the virus.
您如何獲得Yellow Fever？
Yellow fever is transmitted to humans through the bite of an infected mosquito.
易感性和抵抗力
Any unvaccinated person is susceptible.
Recovery from yellow fever is followed by lasting life-long immunity. Immunity in nursing infants born to immune mothers may persist for up to 6 months. In natural infections, antibodies appear in the blood within the first week. Yellow fever vaccination provides immunity for 10 years or more.
有哪些症狀？
Yellow fever is usually characterized by sudden onset of fever, chills, headache, backache, generalized muscle pain, prostration, nausea and vomiting. Jaundice (yellow skin) can occur early in the disease and progressively worsens later (20 to 50 percent of jaundiced cases are fatal). Most of the illness goes away following the early stage. Some cases progress, after a brief remission of hours to a day, to a stage that includes haemorrhagic symptoms including nose bleeds, bleeding from the gums, vomiting blood, black excrement, and liver and kidney failure. Around 5 percent of infected local populations will die, but that rate can reach 20 to 40 percent in individual outbreaks.
預防措施
接種疫苗可以預防黃熱病。前往某些國家/地區需要接種證明書。如果旅行者要去或住在黃熱病發地區，則也需要此證明。避免被蚊子叮咬也會減少黃熱病的風險。
治療
Other than treatment of the symptoms, there is no specific treatment for yellow fever.
疫苗接種
通常在哪裡發生？
叢林黃熱病在非洲從撒哈拉沙漠向南延伸至安哥拉北部、薩伊、奈及利亞和坦尚尼亞的地區。最近，喀麥隆、剛果民主共和國、幾內亞和塞內加爾報告了病例。
在拉丁美洲熱帶森林地區，玻利維亞、巴西、哥倫比亞、厄瓜多爾、秘魯和委內瑞拉報告了黃熱病中間型病例。沒有證據表明自1942年以來，美洲曾出現過城市黃熱病。
沒有證據表明黃熱病在亞洲或非洲最東岸地區曾經出現過。
