Everything has to start somewhere (just think about the Big Bang), so therefore pretty much everything has a history to speak of. Of course, certain histories are better documented than others. Like for instance the Bayeux Tapestry, which chronicles events directly preceding the Norman conquest of England, and culminating in the Battle of Hastings; albeit in embroidered cloth. Other histories are less graphically catalogued and re-told, with the history of Legionnaires’ disease being a point in question.

First noted in what we refer to as recent history, Legionnaires’ disease came to public prominence back in 1977, when it was first identified; and went on to what later became universally recognised as a potentially fatal strain of pneumonia. Systematic scientific and clinical scrutiny of what led to the death of 34 members of the public attending a convention in a Philadelphia hotel in July 1976, revealed that a bacteria which manifests in stored water assemblies found the world over was the culprit. And the rest as they say, is (Legionnaire’s disease) history.

But before we take a look at a more detailed timeline of how Legionnaires’ materialised and went on to be acknowledged as a significant threat to human health thereafter, we quickly recap as to what constitutes Legionnaires’ disease as we understand it today. Essentially a particularly dangerous lung infection with the capacity to render victims seriously ill - or in the most extreme cases - bring about their death, Legionnaires’ stems from contaminated water storage systems. In terms of the point of exposure in which humans can then find themselves susceptible to the individual extent of the disease, and largely it takes root if and when someone inhales droplets of water from showers, taps, hot tubs or even air conditioning units which have been unknowingly preyed on by legionella bacteria.

Legionnaires’ Disease Timeline: The When, Where, What, Who, Which and Why

• 1957 (United States of America) – This remains the first known (albeit somewhat belatedly) epidemic account of the illness which became referred to as Legionnaires’ disease some twenty years later; when 78 employees of Austin’s Hormel Foods Corporation meat packing plant developed symptoms consistent with pneumonia. Although the source of the Minnesota outbreak was never determined at the time, after the pivotal Philadelphia case which follows, it was found that there were significant levels of antibodies to L. pneumophila in the blood works of victims in Austin. The finger of guilt was pointed at the plant’s cooling tower, retrospectively.
• 1965 (United States of America) - A further 14 patients died (while 81 people in total contracted pneumonia, the cause of which was tracked back to water released from a lawn sprinkling system) at St Elizabeth’s Psychiatric Hospital in Washington D.C that year. The correlation with the Philadelphia outbreak came to light after analysis of stored serum specimens, in the aftermath of the more monumental case described beneath.
• July 1976 (United States of America) – This history-making outbreak of pneumonia claimed the lives of some 34 delegates attending the 58^th annual convention held by the American Legion, and hosted by Philadelphia’s Bellevue-Stratford Hotel. In total 234 (of the 4,000) members of the Pennsylvania State American Legion succumbed to illness, a figure which includes those who perished. At the time a cause of death wasn’t established. Indeed, theories which did the rounds in the immediate aftermath were wild and purely speculative, including an unprecedented act of chemical or microbiological terrorism, a CIA experiment gone wrong, a hoax (with the notion being to gain support for expanding swine flu vaccinations), nickel carbonyl poisoning, toxic fumes from photocopy machines and even an extra-terrestrial attack.
• December 1976 (United States of America) – Dr Joseph McDade - US Center for Disease Control (CDC) laboratory scientist – managed to isolate bacterium and positively ID it as Legionella pneumophila. Citing the hotel’s air conditioning system as the root cause of the outbreak, McDade explained that fine water vapours from the compromised water cooling tower had conspired to distribute the bacterium.
• April 1977 (United States of America) – The year in which Legionnaires’ disease was identified as such, and afforded the name by which it’s globally recognised today; which pays tribute to the Legionnaires in attendance at the abovementioned convention. This came on the back of far-reaching scientific and clinical research during the intervening year, conducted by teams of specialists in their fields, who had observed both the individual and collective circumstances of those attendees at the previous year’s conference to construct a broader picture of what was behind their contracting of what materialised as the legionella bug. This was later found to be the air-conditioning ventilator situated in the hotel’s lobby. N.B. The term Legionnaires’ disease was first published as the official name of the disease by the CDC.
• July 1973 (Spain) – No, this isn’t a mistake. We need to travel back to the future to determine what was later discovered to be amongst the very first instances of Legionnaires’ disease. And to travel back to Benidorm, to be precise. With cheaper flights and package tours riding the crest of a Mediterranean wave during the 1970s, increasing numbers of us Brits took full advantage of Costa holidays, and Spain’s coastal region around Benidorm was the destination everyone was heading for. Satisfying the demand of the holidaying hordes, new hotels were being built at a rate of knots; one of such was the Rio Park in Benidorm. And in July 1973, four holidaymakers staying there contracted what at the time was described as a ‘mysterious form of pneumonia’ and paid the ultimate price with their lives. Despite intensive investigations being conducted (including testing of all food and drinks at the hotel for traces of toxins), very little was revealed at the time to ascertain the root cause of the tourist’s (then) unexplained deaths.
• 1974 (United States of America) – Another spot of time-travelling required, as it later transpired that 1976’s episode wasn’t the first recorded case of suspicious events taking place at the Bellevue-Stratford. Not least because the Philadelphia hotel was the scene of another epidemic some two years earlier, when 20 members (2 of whom later died) of the Independent Order of Odd Fellows developed similar symptoms after attending a meeting in the hotel’s main ballroom.
• 1977 (Spain) – Four years after the first incident, the same hotel suffered a similar outbreak. This time however, those tasked with getting to the bottom of the unsolved health problem had been made aware of the events which had unfolded in America 12 months previously, which had resulted in the identification of the new legionella bacterium. Acting quickly, health investigators ensured blood samples from those Benidorm holidaymakers affected were sent to America to confirm whether or not the infection was Legionnaires’ disease. Once they had received confirmation of their suspicions, the 1973 outbreak at the same Spanish resort hotel was retrospectively determined.
• 1968 (United States of America) - We haven’t quite yet finished with the flashbacks, as in 1968 in Pontiac, Michigan, an undisclosed fever struck down a number of employees who had either worded at, or visited, the city’s health department. Post-legionella bacteria discoveries almost a decade on, allowed health officials to declare that the same bacterium causes both Legionnaires’ and (the so-called) Pontiac fever. For the record, the spread of the initial contamination was traced to a leak in the building’s air duct. This provided the means by which the infected water from the air-conditioning system could enter the building’s atmosphere.
• Early 1980s (globally) – Fast forward to the start of the decade, when the antibiotic known as erythromycin was championed as harvesting the best results when tackling the onset of Legionnaires’.
• March 1990 (Netherlands) – 318 people fall ill, of whom 32 later die, after contracting Legionnaires’ disease while attending a flower exhibition.
• 1985 (United Kingdom) – 28 people passed away when 103 cases of Legionnaires’ was confirmed at a Staffordshire hospital. It was clinically observed that those who suffered with underlying chronic diseases, smokers, heavy drinker and men (in terms of gender patterns) were considered more prone to the risk.
• 1996 (United States of America) – It was determined that a public display whirlpool spa (positioned in DIY store) in southwest Virginia was to blame for 23 lab-confirmed cases of Legionnaires’ coming to bear, after nearly all those diagnosed recalled walking past the assemblage in the weeks before.
• 1998 (United Kingdom) – Of all place, the Queen’s official residence, Buckingham Palace was the source of an outbreak of Legionnaires’ in the late 1990s, which triggered the entire building’s labyrinth-like water system being comprehensively flushed out. As a precautionary measure, all 335 members of the royal household staff were ordered to visit with their GP if they noted any of the symptoms.
• April 2000 (Australia) – 4 people succumbed to the disease in Melbourne, as it was reported that 125 cases of Legionnaires’ had presented.
• July 2001 (Spain) – A staggering 800 cases recorded in Murcia, which led to the deaths of 6 people, with Legionnaires’ disease being the culprit once again.
• 2002 (United Kingdom) – A total of 7 victims died, as 180 people became infected with Legionnaires’ in the Cumbrian town of Barrow-in-Furness. Rapid administering of the antibiotic, erythromycin (together with the development of a urine test), was hailed as the difference between survival and dying. A poorly maintained air-con unit at a nearby leisure centre (which vented over a busy alleyway in the town centre) was eventually found to be the cause.
• 2005 (Norway and Canada) – With 56 cases and 10 mortalities in Norway, while in Canada that year 21 residents of a nursing home also passed away. Both cases cited Legionnaires’ disease.
• 2012 (Spain) – On the Costa Blanca, 3 British Saga holidaymakers, all in their 70s, fell victim to another hotel outbreak. As a result, the four-star AR Diamante Beach Hotel in Calpe was forced to close.

N.B. Experts were partly baffled by the emergence of Legionnaire’ disease due to the underlying fact that it failed to respond to penicillin. Which around this time (the 1960s and 70s) was being hailed as a wonder drug which could conquer most clinical threats. Equally so, the legionella bug didn’t appear on routine microbiological test results performed at this time. Whilst many working in the areas of scientific and clinical research had moved on to explore alternative fields, the rapid evolution of deadly pathogens such as Lassa, Marburg and AIDS provided a timely wake-up call; so as to remind us not to forget about the threats still posed by infectious diseases.