1976 — July-Aug, Legionella pneumophila (Legionnaires Disease), Philadelphia, PA–29-34

–29-34 History.com. This Day in History, Disaster, July 23, 1976. “Legionnaires Gather in…”
— 34 Klein. “Remembering the Legionnaires’ Outbreak.” History.com. 11-13-2020 update.
— 34 O’Connor and Friedman. “Jul 23 1976. First Known Outbreak of Legionnaires Disease.”
— 29 Kohn. Encyclopedia of Plague and Pestilence…(Revised). 2001, p. 261.
— 29 Valley Independent, Monessen, PA. “Year that was,”12-31-1976, p. 3.
— 29 Winn. “Legionnaires Disease: Historical Perspective.” Clin. Microbiol. Rev., Jan 1988, 62.
— 28 Kohn. Encyclopedia of Plague and Pestilence…(Revised). 2001, p. 261.
— 26 Kohn. Encyclopedia of Plague and Pestilence…(Revised). 2001, p. 260.
— >25 OSHA, U.S. DOL. “Legionellosis (Legionnaires’ Disease and Pontiac Fever).”

Narrative Information

History.com: “On this day [July 23] in 1976, members of the American Legion arrive in Philadelphia to celebrate the bicentennial of U.S. independence. Soon after, many began suffering from a mysterious form of pneumonia. Their ailment would come to be known as Legionnaires’ disease.

“About 4,000 delegates from the Pennsylvania chapter of the American Legion met at the Bellevue-Stratford Hotel in Philadelphia for a four-day gathering. While at the hotel, built in 1900, the Legionnaires did not notice anything unusual. However, several days after the event ended, many attendees became sick. By August 2, 22 people were dead and hundreds connected to the gathering were experiencing pneumonia-like symptoms.

“The Center for Disease Control immediately launched an investigation, but it took four months to identify the culprit. Joseph McDade, a CDC research microbiologist, finally isolated the bacteria that caused the disease: an aquatic microorganism, found in watery places like pipes and air conditioning units, which caused a low fever and mild cough in most people who were exposed to it, but could affect other people in far worse ways. In a small, but significant, minority of people, vomiting, diarrhea and pneumonia developed, following an incubation period of between two and 10 days. Smokers, very old people and those suffering from pulmonary disease were most at risk.

“From the American Legion event in Philadelphia, about 250 cases were identified, which resulted in between 29 and 34 deaths. Researchers estimate that there are about 20,000 cases of Legionnaires’ disease annually in the United States, but only about 1,000 are correctly identified and diagnosed, as its symptoms can be similar to regular pneumonia. Antibiotics are usually effective against the disease.

“Scientists are still unclear as to how long Legionnaires’ bacteria had been striking victims before it was finally identified in 1976.” (History.com. This Day in History, Disaster, July 23, 1976. “Legionnaires Gather in Philly.”)

Klein: “In the midst of a star-spangled summer in which the United States celebrated its bicentennial, more than 4,000 members of the Pennsylvania chapter of the American Legion gathered… While Philadelphia sweltered on July 21, 1976, the military veterans discovered an icy refuge inside the air-conditioned quarters of the elegant Bellevue-Stratford Hotel as they kicked off the organization’s annual convention. For four days Legion members mixed and mingled… before returning home…

“Within days, however, the phone at the American Legion’s Pennsylvania headquarters began to ring with the distressing news of the deaths of a number of convention-goers. By August 2, however, it was clear that this was no string of bad luck as 12 members had died and three dozen more had been hospitalized with a mysterious respiratory illness. The pneumonia-like symptoms were nearly the same in every case—muscle aches, headaches, severe coughs, diarrhea, muscle and chest pains and fevers as high as 107 degrees. Many of the dead were older men and smokers, but the ages of the victims ranged from 39 to 82.

“As news spread, it was revealed that not all the afflicted were American Legion members or their wives. The victims included a bank teller who worked across the street from the Bellevue-Stratford Hotel and a bus driver who had transported a group of young cadets who marched in the convention’s parade.

“Although baffled as to the cause, public health officials urged calm as fears of a flu pandemic spread around Pennsylvania even more quickly than the mystery illness itself. Swine flu, which had struck a New Jersey army base earlier in the year, and parrot fever, spread by sick pigeons, were among the leading theories. The good news for investigators, however, was that it quickly became evident that the disease was not contagious. One convention-goer, for instance, exhibited no symptoms although the two men he shared a hotel room with had died suddenly. Antibiotics also proved effective in treating the sick.

“In response to the medical mystery, the federal Centers for Disease Control and Prevention (CDC) launched the largest investigation in its history. ‘No previous scientific detective effort in history has approached the scale and intensity of the campaign now under way to track down the course, source and pattern’ of the disease, reported the Boston Globe. A team of 20 CDC epidemiologists joined state health workers in scouring hospital records and poring through autopsy findings. Laboratories remained open throughout the night as helicopters flew in the latest blood and tissue samples. In hospitals across Pennsylvania, the medical sleuths interviewed patients about their every move in Philadelphia, from whether they ate the hotel’s go-getters’ breakfast to how many times they rode its elevators.

“Investigators even checked into the Bellevue-Stratford Hotel and combed the premises for clues. They examined everything from the hotel’s ice machines to its toothpicks, and they crawled into its heating and cooling systems to take samples. They considered causes ranging from food poisoning to foul play by anti-war protestors who had previously threatened violence against military veterans. The only common threads the investigators could find, however, were the disease’s symptoms and the fact that the afflicted appeared to have spent some time either in the hotel lobby or outside on the sidewalk.

“The outbreak of the mystery disease generated intense media coverage. Newsweek called it the ‘Killer Fever,’ while Time dubbed it the ‘Philly Killer’ on its front cover. Most of the media, however, settled on another name for the strange respiratory illness — ‘Legionnaires’ disease.’ As months progressed without the identification of a cause, the medical investigators themselves came under the microscope of public scrutiny—even being forced to testify before Congress.

“One frustrated CDC microbiologist, Joseph McDade, decided to redouble his efforts in the days after Christmas. Having cancelled his vacation plans, McDade spent hour upon hour in his laboratory scouring slides that had only been examined in five-minute bursts in the initial rush to find the cause. ‘It’s like looking for a contact lens on a basketball court with your eyes four inches above the ground,’ McDade told the New York Times. After spending a half-hour examining tissue taken from the lung of one of the victims, McDade found the culprit for the disease—a previously unknown bacterium that the CDC dubbed Legionella.

“Nearly six months after the outbreak, the CDC announced that it had cracked the case. The Legionella bacteria thrived in hot weather and in water such as the air-conditioning system perched on the roof of the 19-story Bellevue-Stratford Hotel. Although Legionella wasn’t found in the hotel’s cooling system because it had been cleaned by the time of its discovery, investigators surmised that the system’s powerful fans emitted a mist of contaminated water that fell on pedestrians on the sidewalk below and were sucked into the lobby through a ground-floor vent where victims breathed in the tiny, infected water droplets. Ultimately, 34 people died and more than 200 became ill from the outbreak during the American Legion convention, and the discovery led scientists to document earlier outbreaks of Legionnaires’ disease, including one that killed three members of the Independent Order of Odd Fellows who attended a convention in the same Philadelphia hotel in 1974.

“Although the medical case had been solved, Legionnaires’ disease has not been confined to the history books. In fact, it has made a resurgence in recent years. According to the CDC, the number of people diagnosed has increased nearly fourfold from 1,127 in 2000 to 5,166 in 2014, with the disease proving fatal in about seven percent of cases. Just last year, an outbreak in the Bronx killed 16 while another in Flint, Michigan, claimed the lives of a dozen more. Most of the 20 outbreaks averaged each year occur in buildings with large water systems and poorly maintained air-conditioning equipment.” Klein, Christopher. “Remembering the Legionnaires’ Outbreak.” History Stores. History.com. 7-21-2016, updated 11-13-2020.).

Kohn: “Philadelphia ‘Legionnaires’ Disease’ Epidemic.
“Alarming outbreak of a mysterious flulike illness that killed 26 out of 260 persons who attended an American Legion state convention at the Bellevue Stratford Hotel in Philadelphia in July 1976. Called ‘the greatest medical mystery of the century,’ the disease’s causative agent was later identified as a previously unknown bacterium which was named Legionella pneumophila.

“On July 20, 1976, the eve or the American Legion convention, the air conditioner repairman at the Bellevue Stratford Hotel became ill with flulike symptoms; he was never hospitalized and recovered. On July 24, the last day of the convention, a number of legionnaires suffered the same symptoms, and three of them were hospitalized as supposed typhoid cases by July 30. Meanwhile 14 other legionnaires, who had returned to their hometowns in Pennsylvania, became ill with the same symptoms; swine flue was first suspected. During the first week of August, epidemiologist at the U.S. Centers for Disease Control (CDC), U.S. Public Health Service, and the Pennsylvania State Health Department began studying the baffling ailment, which had alarmed inhabitants of he Philadelphia area, fearful of contagion. At first the CDC suspected the disease to be lassa fever (an acute viral illness first described in Nigeria in 1969) or pneumonic plague. In addition, the disease was even linked to theories of conspiracy by various militant groups and germ warfare, further alarming the public.

“One hundred seventy-nine cases of so-called legionnaires’ disease or legion fever were reported by August 31, 1976, and 28 of them had been fatal (two of the deaths were a nun and a priest, members of a Eucharistic Congress at the Bellevue Stratford Hotel on August 1-8.None of the hotel staff (with the exception of the air conditioner repairman), who dealt directly with the legionnaires, had become infected. A prostitute at the hotel during the convention became infected but recovered; later a researcher nonfatally contracted the disease in October while examining tissue specimens from victims.

“Health officials first thought pigeon droppings might have spread the infection through the hotel’s air-conditioning system and might have fouled the water supply; this was never proven. The CDC finally concluded that the disease was airborne transmitted and that the causative agent’s most likely habitat was the hotel’s rooftop water tower, which fed the air-conditioning system. The agent was thought to have emerged into the Bellevue through the vent above the registration desk; lobby employees may have become immune to its effect over a period to time.

“Due to bad publicity, many bookings for the Bellevue were canceled, and on November 18, 1976, the hotel closed. Scientists finally announced (January 19, 1977) the cause of the mysterious disease and later said that erythromycin, an antibiotic, was effective in treating it. Twenty-nine persons (26 American Legion members and three others) perished from legionnaires’ disease before the discovery of Legionella pneumophilia, which proved to be the same bacterium responsible for an earlier strange outbreak of fatal pneumonia at St. Elizabeth’s Hospital, a federal mental institution in Washington, D.C. The new bacterium was also found in water from a cooling tower at a hospital in Vermont in May 1977 and was the cause of an outbreak there. Since then, cases of legionnaires’ disease have occurred in the United States, Canada, and Europe.

“Further reading: Fraser et al., “Legionnaires’ Disease: Description of an Epidemic of Pneumonia”; Thomas and Morgan-Witts, Anatomy of an Epidemic.” (Kohn. Encyclopedia of Plague and Pestilence From Ancient Times to the Present (Revised). 2001, p. 260-261.)

Sources

Armstrong, Dennis. “A Look Back: 1976, and How Legionnaires’ Disease Got Its Name.” Legionnaires’ Disease News. 7-26-2017. Webpage accessed 3-24-2021 at: https://www.legionnairesdiseasenews.com/2017/07/look-back-1976-legionnaires-disease-got-name/

History.com. This Day in History, Disaster, July 23, 1976. “Legionnaires Gather in Philly.” At: http://www.history.com/this-day-in-history.do?action=tdihArticleCategory&displayDate=07/23&categoryId=disaster
This link is now inoperable (3-24-2021 attempt).

Klein, Christopher. “Remembering the Legionnaires’ Outbreak.” History Stores. History.com. 7-21-2016, updated 11-13-2020 Accessed 3-24-2021 at: https://www.history.com/news/the-discovery-of-legionnaires-disease

Kohn, George Childs (Ed.). Encyclopedia of Plague and Pestilence From Ancient Times to the Present (Revised Edition). NY: Checkmark Books, 2001.

O’Connor, John; added to by Carla Friedman. “Jul 23 1976. First Known Outbreak of Legionnaires Disease.” World History Project. Accessed 3-24-2021 at: https://worldhistoryproject.org/1976/7/23/first-known-outbreak-of-legionnaires-disease

OSHA (Occupational Safety and Health Administration), United States Department of Labor. “Legionellosis (Legionnaires’ Disease and Pontiac Fever).” Website accessed 3-24-2021 at: https://www.osha.gov/legionnaires-disease/background

Valley Independent, Monessen, PA. “Year that was,”12-31-1976, p. 3. Accessed 3-24-2021 at: https://newspaperarchive.com/monessen-valley-independent-dec-31-1976-p-1/

Winn, Washington C. Jr. “Legionnaires Disease: Historical Perspective.” Clinical Microbiology Reviews, Jan 1988, pp. 60-81. Accessed 3-24-2021 at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC358030/?page=1