In 1894, Hong Kong had had the third plaque outbreak which kills more then 2000 people. This year a large scale outbreak is happening in Madagascar which kills more then 200 people by early December. This deadly disease is transmitted from rat to human through flea bites so we need to be aware of rat control to prevent this disease.

Yersinia pestis is the causative agent of plaque. One entering the human bofy they can cause inflammation of the lymph node (causing bubonic plaque), or entering the blood stream and lead to multiple organ failure (septicaemia plaque), or affacting the lung (causing pneumonic plaque). Most of the time infection is limited to bubonic plaque and early antibiotic treatment can help in disease control, but fatality ratio still reach 30-60% (data from CHP, HKSAR). When it is the pneumonic plaque, the disease can be transmitted among human through respiratory droplets and this type of infection is always fatal. The best way to prevent the disease is to have proper rat control. Household rrfuse should be stored and treated properly. Refuse from restaurant should be covered well and cleared everyday, and have the permisis thoroughly cleaned. Beware not to leave any food leftover or refuse on the pipe which can attract rats. Good rat control is the best way to prevent this deadly disease.