<Li> Gangrene of the extremities such as toes, fingers, lips and tip of the nose . </Li> <P> Other symptoms include heavy breathing, continuous vomiting of blood (hematemesis), aching limbs, coughing, and extreme pain caused by the decay or decomposition of the skin while the person is still alive . Additional symptoms include extreme fatigue, gastrointestinal problems, lenticulae (black dots scattered throughout the body), delirium, and coma . </P> <P> Bubonic plague is an infection of the lymphatic system, usually resulting from the bite of an infected flea, Xenopsylla cheopis (the rat flea). In very rare circumstances, as in the septicemic plague, the disease can be transmitted by direct contact with infected tissue or exposure to the cough of another human . The flea is parasitic on house and field rats, and seeks out other prey when its rodent hosts die . The bacteria remained harmless to the flea, allowing the new host to spread the bacteria . The bacteria form aggregates in the gut of infected fleas and this results in the flea regurgitating ingested blood, which is now infected, into the bite site of a rodent or human host . Once established, bacteria rapidly spread to the lymph nodes and multiply . </P> <P> Y. pestis bacilli can resist phagocytosis and even reproduce inside phagocytes and kill them . As the disease progresses, the lymph nodes can haemorrhage and become swollen and necrotic . Bubonic plague can progress to lethal septicemic plague in some cases . The plague is also known to spread to the lungs and become the disease known as the pneumonic plague . </P>

Where did the fleas get the plague from
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