the bacteria invade the lymph system and drain into the lymph nodes.

病毒侵入淋巴系统并流进淋巴结
A couple of days later a so-called bubo--

几天后被称为炎性淋巴
which gives the symptom

依据腺鼠疫的名字
that gives the disease its name, bubonic plague--

而命名的症状
the plague of buboes appears.

炎性淋巴腺肿出现
This is an infected swelling of the lymph nodes,

它的表现是淋巴结受感染肿大
a hard mass the size of an orange beneath the skin.

在皮肤下出现桔子般大小的硬块
The site of the bubo varies,

炎性淋巴腺肿的位置不定
according to the location of the infective bite.

依据传染源咬伤的位置而有所不同
If a flea bites the legs,

如果跳蚤咬在腿上
the bubo is usually in the groin, and would look like that.

淋巴腺肿一般出现在腹股沟像这样
If the fleas instead were to bite the arms,

如果跳蚤咬在上肢