China's Ministry of Health has revised an emergency response plan on the prevention of rat plague in line with the country's public health emergency response plan after rampant rats attacked flooded counties surrounding central China's Dongting Lake this June.

The new plan, made public via the State Council, requires relevant departments to set up a national plague emergency command with clear duty division and close cooperation among different agencies when facing an "extremely serious" rat plague incident.

The plan classifies the plague into four categories -- extremely serious, serious, moderate serious and ordinary -- based on a plague's location, type, infected case number, scope, tendency and harm so as to enhance prompt reporting and control. It also outlines logistic supports during plagues.

The rat plague in Dongting Lake began on June 23 and an estimated 2 billion rats invaded 22 counties after their homes on islands in the lake were flooded, causing six million yuan (US$789,000) in losses.

Rats have also thrived in woodlands, partly due to global warming, experts said. Efforts to develop farmland to grassland and forests also provide favorable conditions for rats, which causes fear that they may spread plague to people.

Rampant rats had caused damage to 1.4 million hectares of woodlands by the end of 2006, a sharp increase from previous years, statistics from the State Forestry Administration show.

Plague, a fatal bacterial disease transmitted by fleas from infected rats, can be contracted through breathing in airborne particles and through close contact with infected rodents.

The most common form, the bubonic plague, results in high fever, delirium and swollen lymph nodes.

Plague outbreaks have killed about 200 million people in the past 1,500 years. The most infamous epidemic, Europe's Black Death, which started in 1347, killed 25 million people in Europe and 13 million in the Middle East and China in the period of five years.

(Xinhua News Agency September 6, 2007)