The first paratyphoid early clinical symptoms were mainly fever, dizzy, headache, pharyngoxerosis, pharynx-ache and dry-cough with 7-27 days of incubation period, average 15 days.

甲型副伤寒早期临床症状以发热、头晕、头痛、咽干、咽痛、干咳为主，潜伏期7 ~ 27天，平均15天。

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The results show that there was an obvious incubation period of crack forming, at first some pits appeared on the verge of the sample notch;

结果表明：此过程存在明显的裂纹萌生孕育期：首先在缺口边缘上出现凹坑；

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The incubation period, the time from when you're first exposed to the time you express symptoms, is usually 1-5 days, but can be as long as 60 days.

CNN: "The Secret Life of Germs" author Philip Tierno

Therefore the first causality was probably at the beginning of March 2009 taking into account the incubation period.

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