by Alison Bowler

Created on: November 17, 2009   Last Updated: April 27, 2010

At the beginning of August 2009, the Chinese government announced a fatal case of pneumonic plague in the town of Ziketan. This remote town, of about 10,000 residents, is situated in Xinghai in the Qinghai Province of North Western China. As soon as the announcement was made, the World Health Organization (WHO) began monitoring the situation.

To prevent the plague’s spread, China restricted movement in and out of Ziketan. They also started tracing contacts of the fatal case. Teams of medical personnel started disinfection procedures and the killing rats and insects responsible for the spread of plague. The WHO stated that the control methods were adequate to prevent its spread.

By 4 August, a third person had died of the illness and about ten other cases were identified. These cases occurred among the first case’s family and neighbors. Since then no other cases have been reported. So, one can fairly confidently state that, the pneumonic plague will not come to America from this outbreak!

The use of quarantine procedures to prevent the spread of plague is well known. In 1665, the Great Plague inflicted a horrendous death toll on London. A conservative estimate of the total numbers of deaths is set at 100,000. A shipment of clothes carrying the deadly infection, probably infested with infected fleas, arrived from London at the village of Eyam in Derbyshire. With the plague established in their village the villagers set up a self-imposed quarantine, successfully preventing the spread of plague to surrounding towns and villages. While not able to save themselves, they did save many others. Of a village population of 292, eventually 252 people died of the infection

So what is pneumonic plague?

Both pneumonic and bubonic plagues are caused by the same bacterium, Yersinia pestis. Bubonic plague is transmitted by the bite of an infected flea. Pneumonic plague occurs when someone breaths in the bacteria contained in the aerosols produced by someone with the disease coughing.

According to the WHO, pneumonic plague is the rarest form of plague. A person with bubonic plague who does not obtain prompt antibiotic therapy may develop pneumonic plague if the bacteria spread to the lungs via the bloodstream. Once one case of pneumonic plague arises, person-to-person transmission occurs. Not all patients with bubonic plague develop pneumonic plague some develop septicemic plague, giving the classic symptoms of Black Death, while others just exhibit the symptoms bubonic plague.

Untreated pneumonic or septicemic plagues have fatality rates approaching 100%. Even with treatment, death rates during outbreaks of plague of 20% occur.

While many think of plague as belonging in the history books between 1000 and 3000 cases occur annually worldwide. Africa, India, China, Asia, South America   and even the USA are endemic for the infection.

The CDC estimates that about fifteen cases of bubonic plague occur in rural areas of the USA annually. Most of the cases of bubonic plague in the USA occur in residents or visitors to the desert areas of Arizona, California, Colorado, New Mexico and Utah. If one of these cases fails to seek proper treatment in time, America may have its homegrown outbreak of pneumonic plague.

Resource sources

CDC Plague home page

BBC News

Britain express

World Health Organization

Everyday Health.com

eMedicine from WebMD

Center for Biosecurity University of Pittsburgh Medical Center

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