Pneumonic plague overview

Jump to navigation Jump to search

Template:Pneumonic plague Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

Pneumonic plague, a severe type of lung infection, is one of three main forms of plague, all of which are caused by the bacterium Yersinia pestis. It is more virulent and rare than bubonic plague. The difference between the versions of plague is simply the location of the infection in the body; the bubonic plague is an infection of the lymphatic system, the pneumonic plague is an infection of the respiratory system, and the septicemic plague is an infection in the blood stream.

Pathophysiology

Pneumonic plague can be caused in two ways: primary, which results from the inhalation of aerosolised plague bacteria, or secondary, when septicemic plague spreads into lung tissue from the bloodstream. Pneumonic plague is not exclusively vector-borne like bubonic plague; instead it can be spread from person to person. There have been cases of pneumonic plague resulting from the dissection or handling of contaminated animal tissue. This is one type of the formerly known Black Death.[1] It could kill 90%–95% of a population if the victims coughed and passed on the bacteria.

Epidemiology and Demographics

Since 2002, the World Health Organization (WHO) has reported seven plague outbreaks, though some may go unreported because they often happen in remote areas. Between 1998 and 2009, nearly 24,000 cases have been reported, including about 2,000 deaths, in Africa, Asia, the Americas and Eastern Europe. 98 percent of the world's cases occur in Africa.

Natural History, Complications and Prognosis

The pneumonia progresses for two to four days and may cause respiratory failure and shock. Patients will die without early treatment, some within 36 hours. Pneumonic plague is a very aggressive infection requiring early treatment. The mortality rate from untreated pneumonic plague approaches 100%.

Treatment

Medical Therapy

Antibiotics must be given within 24 hours of first symptoms to reduce the risk of death.[2] Streptomycin, gentamicin, tetracyclines, and chloramphenicol are all effective against pneumonic plague. Antibiotic treatment for 7 days will protect people who have had direct, close contact with infected patients. Wearing a close-fitting surgical mask also protects against infection.

Future and Investigational Therapies

The main investigational technique being looked into is that of a vaccine to stop any possible plague outbreaks. Currently, there is not an available vaccine against the plague, particularly the pneumonic version. This all may be changing because there has been research conducted giving promising results for a vaccine against the pneumonic plague.

References

  1. Benedictow, Ole Jørgen (2004). The Black Death, 1346-1353: the complete history. Boydell & Brewer. pp. 27–28. ISBN 0-85115-943-5.
  2. Facts about Pneumonic Plague (Center for Disease Control, 2004)

Template:WH Template:WS