OBJECTIVETo study an epidemic of human lung plague fulminant from September to October, 2004 in Nangqian county, Qinghai province.

METHODSCases were diagnosed through data from epidemiological, clinical, bacteriological, serological and autopsy studies.

RESULTS14 patients were identified, ending up with 6 deaths and 8 cured. The first case was diagnosed as primary pesticemia late progressed to lung plague. 4 cases were transformed from pesticemia out of 13, leaving the 9 cases as primary lung plague. Situation was under complete control through routinely handling the plague focus.

CONCLUSIONThe first case was bitten by the infected fleas which parasitized the marmota preyed on a dog but later these fleas were brought into the tent by the dog. The others cases were infected through droplets or dust. Programs on monitoring and controling the amount of marmotas and fleas should to be strengthened to prevent the epidemics of plague in the area.