Legionella pneumophila Toxin, Isolation and Purification

We are all aware of the dramatic outbreak of what is now termed Legionnaires Disease that occurred in the city of Philadelphia, Pennsylvania, in the summer of 1976 in which 29 people died. Eight months following that outbreak a gram negative bacteria now termed Legionella pneumophila was isolated and identified as the etiologic agent by Drs. Fraser and McDade. Although Legionnaires Disease has been recognized in 43 states and the District of Columbia the disease is not restricted to the North American continent. In addition to Canada, cases have been reported in Australia, England, Israel, Scotland, Denmark, Spain and The Netherlands. The largest outbreak of legionellosis yet documented outside the United States occurred in Vasteras, Sweden from August 28 to September 21, 1979, and involved 67 cases. We now recognize two distinct clinical syndromes associated with this organism. The first termed Legionnaires Disease, involves patients ranging in age from 3 to 82 years. The symptoms include headaches, myalgia, and general malaise. Within one or two days there is a rapid temperature rise associated with chills. A moderate nonproductive cough is common. The symptoms then progress to include chest pain, abdominal pain, vomiting and mental confusion. Diarrhea is seen in one sixth of the patients. The disease is basically a rapidly progressive and fulminant pneumonia with chest X-rays initially showing patchy infiltrates that may have an interstitial or consolidated appearance which typically in the untreated case progress to nodular consolidation that may be unilateral or bilateral. The pneumonic form of the disease has a 16 percent lethality in normal individuals and a 54 percent lethality in immunologically compromised patients. Death is associated with respiratory failure or shock.