The 1976 Legionnaires' disease outbreak, occurring in the late summer in Philadelphia, Pennsylvania, United States was the first occasion in which a cluster of a particular type of pneumonia cases were determined to be caused by the Legionella pneumophila bacteria. Previous outbreaks were retroactively diagnosed as being most probably caused by Legionella bacteria. [1] [2]
On July 21, 1976, the American Legion opened its annual three-day convention at the Bellevue-Stratford Hotel in Philadelphia, Pennsylvania. More than 2,000 Legionnaires, mostly men, attended the convention. The date and city were chosen to coincide with America's celebration of the 200th anniversary of the signing of the US Declaration of Independence at Philadelphia in 1776. [3]
On July 27, three days after the convention ended, Legionnaire Ray Brennan, a 61-year-old retired US Air Force captain and an American Legion bookkeeper, died at his home of an apparent heart attack. Brennan had returned home from the convention on the evening of July 24 complaining of feeling tired. On July 30, another Legionnaire, Frank Aveni, aged 60, also died of an apparent heart attack, as did three other Legionnaires. All of them had been convention attendees. Twenty-four hours later, on August 1, six more Legionnaires died. They ranged in age from 39 to 82, and, like Ray Brennan, Frank Aveni, and the three other Legionnaires, all had complained of tiredness, chest pains, lung congestion, and fever. [3]
Three of the Legionnaires had been patients of Ernest Campbell, a physician in Bloomsburg, Pennsylvania, who noticed that all three men had been at the Legionnaires convention in Philadelphia. He contacted the Pennsylvania Department of Health. Officials at the American Legion also began getting notices of the sudden deaths of several members, all at the same time. Within a week, more than 130 people, mostly men, had been hospitalized, and 25 had died. [3]
In total, there were 149 Legionnaires who became sick and 33 other persons associated with the hotel or in the area who also became sick. Of these 182 cases, 29 persons died. [1] [4]
The U.S. Center for Disease Control mounted an unprecedented investigation and, by September, the focus had shifted from outside causes, such as a disease carrier, to the hotel environment itself. In January 1977, the Legionella bacterium was finally identified and isolated and was found to be breeding in the cooling tower of the hotel's air conditioning system, [5] which then spread it through the building. [6] [7] This finding prompted new regulations worldwide for climate control systems. [8]
Complicating the situation was a fear among the public that the original cluster of 14 cases, six of whom died within a few days of each other, represented an outbreak of swine flu. The total number of cases reached 211, and of those, 29 had died. [9] At the time of the outbreak, epidemiological investigation protocols did not include active participation by both laboratory specialists and investigators. No effective communication existed between scientists in the field interviewing patients, and those in the laboratory testing specimens. [10]
While the Centers for Disease Control responded rapidly, as did the Pennsylvania Health Department, it took six months for the CDC microbiologist Joseph McDade to discover the cause of the outbreak. He initially thought the cause was viral because blood and tissues from the patients failed to grow bacteria when incubated in culture medium. His subsequent attempts to isolate the viral agent in eggs included antibiotics to kill off "contaminating" bacteria. It was only when he omitted the antibiotics that the bacteria grew in eggs. Attempts to reproduce the disease in mice, the standard laboratory animal model, also failed. The disease was finally produced in guinea pigs. The CDC announced the discovery at a press conference on January 18, 1977. [11] [12] [4] [13] The bacterium was later named Legionella pneumophila . [14]
Legionella pneumophila is the most common cause, but sometimes other species of Legionella bacteria also cause Legionnaires' disease. [15] [16] The terms "Philadelphia fever" and "Legion fever" appear to have been used at the time of the outbreak and for shortly thereafter, [17] although at least one 2008 source which covers disease in a historical narrative sense also included "Legion Fever" as alternate name. [18] Both the World Health Organization in 2018 and the United States Center for Disease Control and Prevention (CDC) in 2017 only use the term Legionnaires' disease to refer to the serious version with pneumonia. [15] [16]
CDC investigators quickly discovered outbreaks of respiratory disease caused by L. pneumophila dating back to 1959.
Pneumonia is an inflammatory condition of the lung primarily affecting the small air sacs known as alveoli. Symptoms typically include some combination of productive or dry cough, chest pain, fever, and difficulty breathing. The severity of the condition is variable.
Pontiac fever is an acute, nonfatal respiratory disease caused by various species of Gram-negative bacteria in the genus Legionella. It causes a mild upper respiratory infection that resembles acute influenza. Pontiac fever resolves spontaneously and often goes undiagnosed. Both Pontiac fever and the more severe Legionnaire's disease may be caused by the same bacteria, but Pontiac fever does not include pneumonia.
Legionella is a genus of pathogenic gram-negative bacteria that includes the species L. pneumophila, causing legionellosis including a pneumonia-type illness called Legionnaires' disease and a mild flu-like illness called Pontiac fever.
Atypical pneumonia, also known as walking pneumonia, is any type of pneumonia not caused by one of the pathogens most commonly associated with the disease. Its clinical presentation contrasts to that of "typical" pneumonia. A variety of microorganisms can cause it. When it develops independently from another disease, it is called primary atypical pneumonia (PAP).
Bacterial pneumonia is a type of pneumonia caused by bacterial infection.
Legionella pneumophila is an aerobic, pleomorphic, flagellated, non-spore-forming, Gram-negative bacterium of the genus Legionella. L. pneumophila is the primary human pathogen in the genus Legionella. In nature, L. pneumophila infects soil amoebae of the genus Acanthamoeba and freshwater amoeboflagellates of the genus Naegleria. This pathogen is thus found commonly near freshwater environments and invades the unicellular life found in these environments, using them to carry out metabolic functions.
The Legionellales are an order of Pseudomonadota ("Proteobacteria"). Like all Pseudomonadota, they are Gram-negative. They comprise two families, typified by Legionella and Coxiella, both of which include notable pathogens. For example, Q fever is caused by Coxiella burnetii and Legionella pneumophila causes Legionnaires' disease and Pontiac fever.
Legionella longbeachae is one species of the family Legionellaceae. It was first isolated from a patient in Long Beach, California. It is found predominantly in potting soil and compost. Human infection from L. longbeachae is particularly common in Australia, but cases have been documented in other countries including the United States, Japan, Greece and the UK.
The Bellevue-Stratford Hotel is a landmark building at 200 S. Broad Street at the corner of Walnut Street in Center City Philadelphia, Pennsylvania. Constructed in 1904 and expanded to its present size in 1912, it has continued as a well-known institution for more than a century and is still widely known by that original, historic name. In 1988, the building was converted to a mixed-use development. It has been known since then as The Bellevue. The hotel portion is currently managed by Hyatt as The Bellevue Hotel.
Charles C. Shepard was a microbiologist, and former director of the Centers for Disease Control’s Laboratory Division. It was the diligent efforts of Shepard, and cohort microbiologist Joseph McDade, which led to the 1977 discovery of the initially elusive bacterium Legionella pneumophila, the etiologic agent that causes ‘Legionnaires' disease’. In 1963, he was presented with the Gorgas Medal from the Association of Military Surgeons of the United States (AMSUS).
The Bovenkarspel legionellosis outbreak began on 25 February 1999 in Bovenkarspel, the Netherlands, and was one of the largest outbreaks of legionellosis in history. With at least 32 dead and 206 severe infections, it was the deadliest legionellosis outbreak since the original 1976 outbreak in Philadelphia, United States.
Legionella anisa is a Gram-negative bacterium, one of more than 40 species in the family Legionellaceae. After Legionella pneumophila, this species has been isolated most frequently from water samples. This species is also one of the several pathogenic forms of Legionella having been associated with rare clinical cases of illness including Pontiac fever and Legionnaires' disease.
Legionella cherrii is an aerobic, flagellated, Gram-negative bacterium from the genus Legionella. It was isolated from a heated water sample in Minnesota. L. cherrii is similar to another Legionella species, L. pneumophila, and is believed to cause major respiratory problems.
Legionella jordanis is a Gram-negative bacterium from the genus Legionella which was isolated from the Jordan River in Bloomington, Indiana and from the sewage in DeKalb County, Georgia. L. jordanis is a rare human pathogen and can cause respiratory tract infections.
Legionnaires' disease is a form of atypical pneumonia caused by any species of Legionella bacteria, quite often Legionella pneumophila. Signs and symptoms include cough, shortness of breath, high fever, muscle pains, and headaches. Nausea, vomiting, and diarrhea may also occur. This often begins 2–10 days after exposure.
In 2015, there were two outbreaks of Legionnaires' disease in the Bronx, New York City, United States. Between January and August 2015, one hundred and thirty people in New York City were infected with Legionnaires', but the majority of them were in the Bronx.
Legionella clemsonensis was isolated in 2006, but was described in 2016 by Clemson University researchers. It is a Gram-negative bacterium.
The 2022 Tucumán legionellosis outbreak refers to an epidemic that originated in San Miguel de Tucumán, Argentina. It was first identified on Saturday, 20 August 2022, when 7 people arrived at the Tucumán Hospital with fever, malaise, shortness of breath, and headache.
Sheila Sue Moriber Katz was an American pathologist and writer, dean of the Hahnemann University School of Medicine, and co-founder of the School of Public Health at Drexel. She is sometimes described as the first person to see the bacterium Legionella pneumophila, which causes Legionnaires' disease.
By early August, news organizations across the country were reporting that 6 to 14 of the men in Pennsylvania had died.