Generally patients with Legionnaires' disease develop fever, chills, and cough that may be dry or produce sputum [6]. In some patients muscle aches, headaches, loss of appetite, diarrhea and tiredness may also be seen.

Legionnaires' disease can also lead to severe pneumonia with dyspnea in some patients. In some cases it may lead to the development of adult respiratory distress syndrome. Bradycardia may also occur as a result of the fever that accompanies this condition.

The presentation for Legionnaire’s pneumonia is not distinctive as it closely relates to what is obtainable with other forms of pneumonia like Chlamydia pneumonia and Mycoplasma pneumonia.

In people with Pontiac fever, a self-limiting influenza-like illness with fever, chills, headache and muscle aches is seen but pneumonia is rare. Individuals affected often recover within 5 days without receiving any treatment.

• Fever

  Table summarizes key clinical differences between Legionnaires’ disease and Pontiac fever Legionnaires’ disease Pontiac fever Clinical features Fever, myalgia, and cough (according to the CSTE* case definition ) These symptoms are typical but not required [cdc.gov]

  […] for the long-term health effects of Q-fever. [ncbi.nlm.nih.gov]

• Chills

  People with Legionnaires' disease develop fever, chills and cough as the disease progresses. In its most advanced state, the disease can lead to severe pneumonia and respiratory failure. [symptoma.com]

  Symptoms for Legionnaires' include fever, cough, chills and muscle aches. "We are concerned about this unusual increase in Legionnaires’ disease cases in the South Bronx," Health Commissioner Mary Bassett said in a statement. [web.archive.org]

  Symptoms for Legionnaires’ include fever, cough, chills and muscle aches. “We are concerned about this unusual increase in Legionnaires’ disease cases in the South Bronx,” Health Commissioner Mary Bassett said in a statement. [reuters.com]

  The bacteria don't spread from person to person.symptoms of legionnaires' disease include fever, chills, a cough and sometimes muscle aches and headaches. Other types of pneumonia have similar symptoms. [icd9data.com]

  Symptoms of Legionnaires' disease include fever, chills, and a cough that may or may not produce sputum. Other symptoms include abdominal pain, diarrhea, and confusion. [ehso.com]

• High Fever

  A male neonate was admitted to our hospital with high fever and dyspnea, which had started 5 days after birth, and died due to severe pneumonia at 10 days old. [ncbi.nlm.nih.gov]

  fever, malaise, muscle aches, respiratory disorders and headache. [icd9data.com]

  Symptoms are high fever, chills, coughs, muscle aches and headaches. Chest x-rays are needed to find the pneumonia caused by the bacteria, as well as blood or urine to find evidence of the bacteria in the body. [grundfos.com]

  The most common symptoms of Legionnaires' disease include: Cough Shortness of breath High fever Muscle aches Headaches These symptoms usually begin 2 to 10 days after being exposed to the bacteria, but it can take longer so people should watch for symptoms [web.archive.org]

• Fatigue

  A large proportion of the two patient groups was negatively affected on many of the subdomains, especially 'Fatigue', 'General Quality of Life' and 'Role Physical'. [ncbi.nlm.nih.gov]

  […] required; additional symptoms (e.g., shortness of breath, headache, confusion, nausea, diarrhea) may be present A milder illness without pneumonia (according to the CSTE* case definition ) A flu-like illness, often with fever, chills, headache, myalgia, fatigue [cdc.gov]

  Clinical description LD has an incubation period of 2-10 days with fatigue and weakness often being the first signs of the disease. It manifests as pneumonia characterized by fever, cough, sputum production and shortness of breath. [orpha.net]

  A study of outbreak survivors showed persistence of fatigue (75%), neurologic symptoms (66%) and neuromuscular symptoms (63%) in months after an outbreak. See Share Your Story for a first-hand account of the severity of this disease. [legionella.org]

  Legionnaires’ Disease, which does not spread from person-to person, causes pneumonia-like symptoms including fever, cough, fatigue, confusion, aches and lung inflammation. It develops when water mist contaminated with Legionella bacteria is inhaled. [foodpoisoningbulletin.com]

• Malaise

  Abstract The cases of two elderly patients who complained of general malaise after they had undergone ward transfer (due to rationalisation of the rehabilitation service) are discussed. Both were pyrexial and had signs of pneumonic consolidation. [ncbi.nlm.nih.gov]

  482.84 converts directly to: 2015/16 ICD-10-CM A48.1 Legionnaires' disease Approximate Synonyms Legionnaires disease Legionnaire's disease Clinical Information An acute, sometimes fatal, pneumonia-like bacterial infection characterized by high fever, malaise [icd9data.com]

  […] additional symptoms (e.g., shortness of breath, headache, confusion, nausea, diarrhea) may be present A milder illness without pneumonia (according to the CSTE* case definition ) A flu-like illness, often with fever, chills, headache, myalgia, fatigue, malaise [cdc.gov]

  […] naires' disease | \ ˌlē-jə-ˈnerz- \ variants: or less commonly Legionnaire's disease Definition of Legionnaires' disease : pneumonia that is caused by a bacterium (Legionella pneumophila), is characterized initially by symptoms resembling influenza (as malaise [merriam-webster.com]

  Typically, but not uniformly, the first symptoms of Legionnaire disease are general malaise and headache, followed by high fever, often accompanied by chills. [web.archive.org]

• Cough

  Table summarizes key clinical differences between Legionnaires’ disease and Pontiac fever Legionnaires’ disease Pontiac fever Clinical features Fever, myalgia, and cough (according to the CSTE* case definition ) These symptoms are typical but not required [cdc.gov]

  "If you've got that cough, if you've got a headache, if you got achy muscles, please seek immediate medical attention," Kallos said. [ny1.com]

  Symptoms may include: Chest pain Cough that does not produce much sputum or mucus (dry cough) Coughing up blood Diarrhea, nausea, vomiting, and abdominal pain Fever General discomfort, uneasiness, or ill feeling ( malaise ) Headache Joint pain Loss of [web.archive.org]

  Symptoms may include: General discomfort, loss of energy, or ill feeling (malaise) Headache Fever, shaking chills Joint pain, muscle aches and stiffness Chest pain, shortness of breath Cough that does not produce much sputum or mucus (dry cough) Coughing [nlm.nih.gov]

• Dry Cough

  Abstract Two male patients ages 54 and 58 years had persisting pneumonia with dry cough, dyspnea, weight loss, and fever up to 39 degrees C that did not respond to erythromycin treatment. [ncbi.nlm.nih.gov]

  Symptoms may include dry coughing, high fever, chills, diarrhea, shortness of breath, chest pains, headaches, excessive sweating, nausea, vomiting, and abdominal pain. Occasionally, bloody sputum is produced. [healthcentral.com]

  This is followed by a dry cough and breathing difficulties that may progress to a severe pneumonia. Some people also develop diarrhoea or may become confused. [hse.ie]

  Symptoms may include: Chest pain Cough that does not produce much sputum or mucus (dry cough) Coughing up blood Diarrhea, nausea, vomiting, and abdominal pain Fever General discomfort, uneasiness, or ill feeling ( malaise ) Headache Joint pain Loss of [web.archive.org]

• Dyspnea

  Abstract Two male patients ages 54 and 58 years had persisting pneumonia with dry cough, dyspnea, weight loss, and fever up to 39 degrees C that did not respond to erythromycin treatment. [ncbi.nlm.nih.gov]

  Shortness of breath Other names Dyspnea, dyspnoea, breathlessness, difficulty of breathing, respiratory distress Pronunciation Dyspnea: /dɪspˈniːə/ Specialty Pulmonology Shortness of breath (SOB), also known as dyspnea, is a feeling of not being able [en.wikipedia.org]

  If you have Legionnaires’ disease, you may experience: Coughing Dyspnea, or shortness of breath Chills Fever or muscle aches Headache Nausea or diarrhea Confusion Most people see symptoms start a few days up to a week after being exposed to the Legionella [my.clevelandclinic.org]

• Pleural Effusion

  Pleural effusion is relatively common in Legionnaires' disease but is usually clinically insignificant. [ncbi.nlm.nih.gov]

  Chest x-ray should be done; it usually shows patchy and rapidly asymmetrically progressive infiltrates (even when effective antibiotic therapy is used), with or without small pleural effusions. [msdmanuals.com]

• Painful Cough

  Symptoms may include: Chest pain Cough that does not produce much sputum or mucus (dry cough) Coughing up blood Diarrhea, nausea, vomiting, and abdominal pain Fever General discomfort, uneasiness, or ill feeling ( malaise ) Headache Joint pain Loss of [web.archive.org]

  Other symptoms include nausea, loose stools or watery diarrhea, abdominal pain, cough, and joint pain. People may have difficulty breathing, and breathing may be painful. They may cough up blood. [msdmanuals.com]

• Diarrhea

  Cough Shortness of breath Fever Muscle aches Headaches Legionnaires’ disease can also be associated with other symptoms such as diarrhea, nausea, and confusion. [cdc.gov]

  Other symptoms include abdominal pain, diarrhea, and confusion. This list of symptoms, however, does not readily distinguish Legionnaires' disease from other types of pneumonia. [ehso.com]

  CASE: A 53-year-old Japanese male visited our hospital with symptoms of fever, vomiting, diarrhea, and altered mental status, but not with respiratory manifestations. [ncbi.nlm.nih.gov]

  Other symptoms can include diarrhea, myalgia, headaches, confusion/delirium and nausea. [orpha.net]

• Vomiting

  Symptoms include fever, chillls, headaches and muscle pain, which can progress to coughing, chest pain, nausea, vomiting and difficulty breathing. Between 5% and 30% of patients with Legionnaires' die, according to the CDC. [eu.usatoday.com]

  CASE: A 53-year-old Japanese male visited our hospital with symptoms of fever, vomiting, diarrhea, and altered mental status, but not with respiratory manifestations. [ncbi.nlm.nih.gov]

  Other symptoms include feeling nauseous, vomiting, diarrhoea and loss of appetite. Diarrhea is seen in 25–50% of cases and vomiting and nausea in 10–30% of cases. There may be a general weakness. [news-medical.net]

  Symptoms may include dry coughing, high fever, chills, diarrhea, shortness of breath, chest pains, headaches, excessive sweating, nausea, vomiting, and abdominal pain. Occasionally, bloody sputum is produced. [healthcentral.com]

• Nausea

  Pontiac fever Legionnaires’ disease Pontiac fever Clinical features Fever, myalgia, and cough (according to the CSTE* case definition ) These symptoms are typical but not required; additional symptoms (e.g., shortness of breath, headache, confusion, nausea [cdc.gov]

  Symptoms of the disease closely resemble the flu and include cough, fever, nausea and stomach discomfort. Ben Kallos, the City Councilman who represents the area, was handing out fliers to warn people about the disease. [ny1.com]

  Symptoms include fever, chillls, headaches and muscle pain, which can progress to coughing, chest pain, nausea, vomiting and difficulty breathing. Between 5% and 30% of patients with Legionnaires' die, according to the CDC. [eu.usatoday.com]

• Chest Pain

  A 32-year-old man presented with a five-day history of cough, dyspnea and chest pain. Chest radiography revealed patchy opacities in both lungs suggestive of bilateral pneumonia, and a urinary antigen test for Legionella pneumophila was positive. [ncbi.nlm.nih.gov]

  Symptoms include fever, chillls, headaches and muscle pain, which can progress to coughing, chest pain, nausea, vomiting and difficulty breathing. Between 5% and 30% of patients with Legionnaires' die, according to the CDC. [eu.usatoday.com]

  Health officials are telling people to watch for symptoms of pneumonia, such as chest pains when coughing or chills. But officials say there’s no reason to worry if you did visit the store. [kiro7.com]

  Symptoms may include dry coughing, high fever, chills, diarrhea, shortness of breath, chest pains, headaches, excessive sweating, nausea, vomiting, and abdominal pain. Occasionally, bloody sputum is produced. [healthcentral.com]

• Tachycardia

  On admission, he was febrile, toxic looking, dehydrated with hypotension and tachycardia. No clinical signs of respiratory infection were detected on admission. [ncbi.nlm.nih.gov]

  Cardiac tamponade presents with dyspnea, tachycardia, elevated jugular venous pressure, and pulsus paradoxus.[15] The gold standard for diagnosis is ultrasound.[15] Anaphylaxis typically begins over a few minutes in a person with a previous history of [en.wikipedia.org]

  Physical examination on admission showed a normal body temperature and blood pressure, tachycardia, tachypnea, decreased arterial oxygen saturation, and diminished breath sounds in the left lung field. [jamanetwork.com]

  Physical examination findings that are most common include pulmonary rÉles and other evidence of lung consolidation, tachypnoea and tachycardia. Confusion and memory loss are also relatively common findings. [web.archive.org]

• Cyanosis

  Inspection of the hands for signs of cyanosis or clubbing, chest wall, and respiratory rate. Palpation of the cervical lymph nodes, trachea and chest wall movement. Percussion of the lung fields for dullness or hyper-resonance. [en.wikipedia.org]

• Myalgia

  Table summarizes key clinical differences between Legionnaires’ disease and Pontiac fever Legionnaires’ disease Pontiac fever Clinical features Fever, myalgia, and cough (according to the CSTE* case definition ) These symptoms are typical but not required [cdc.gov]

  Presenting clinical features were similar to those reported for community-acquired pneumonia, with headache, myalgia and diarrhoea being common. Elevated C-reactive protein, hyponatraemia and abnormal liver function tests were also common. [ncbi.nlm.nih.gov]

  Other symptoms can include diarrhea, myalgia, headaches, confusion/delirium and nausea. [orpha.net]

  The disease presents as a rapidly progressive, severe, necrotizing pneumonia, accompanied by fever, nonproductive cough, and myalgias. The onset is abrupt, after an incubation period of 2 to 10 days. [histopathology-india.net]

• Hematuria

  Laboratory data may include an abnormal liver function test, low phosphorus in the blood (hypophosphatemia), blood in the urine (hematuria), and low blood sodium (hyponatremia). [rarediseases.org]

  […] levels Highly elevated erythrocyte sedimentation rate (ESR) Highly elevated ferritin levels Increased C-reactive protein (CRP) levels (>30 mg/L) Hypophosphatemia (specific to Legionnaires' disease excluding other causes of hypophosphatemia) Microscopic hematuria [symptoma.com]

  […] following: Hypophosphatemia Hyponatremia (sodium less than 130 mEq/L) secondary to the syndrome of inappropriate antidiuretic hormone is more common in Legionnaires disease than in most cases of pneumonia that are secondary to other pathogens Microscopic hematuria [ncbi.nlm.nih.gov]

• Headache

  The bacteria don't spread from person to person.symptoms of legionnaires' disease include fever, chills, a cough and sometimes muscle aches and headaches. Other types of pneumonia have similar symptoms. [icd9data.com]

  The symptoms of Pontiac Fever usually last for 2 to 5 days and may also include fever, headaches, and muscle aches. However Pontiac fever is not lethal. [grundfos.com]

  confusion, nausea, diarrhea) may be present A milder illness without pneumonia (according to the CSTE* case definition ) A flu-like illness, often with fever, chills, headache, myalgia, fatigue, malaise; less often with symptoms such as cough or nausea [cdc.gov]

  Pontiac fever may also include fever, headaches, and muscle aches, but tends to have a shorter duration — usually two to five days — and symptoms do not include pneumonia. [epi.dph.ncdhhs.gov]

  He became critically unwell during the hospital admission, with headache, uncontrolled fever, breathlessness, decreasing oxygen saturations and increasing oxygen requirements. [ncbi.nlm.nih.gov]

• Confusion

  Abstract A case of Legionnaires' disease is described in a 63 year old man who presented with pneumonia and confusion. Eleven days after admission he became acutely hypotensive and attempts at resuscitation failed. [ncbi.nlm.nih.gov]

  Cough Shortness of breath Fever Muscle aches Headaches Legionnaires’ disease can also be associated with other symptoms such as diarrhea, nausea, and confusion. [cdc.gov]

  Other symptoms can include diarrhea, myalgia, headaches, confusion/delirium and nausea. [orpha.net]

  […] disease : pneumonia that is caused by a bacterium (Legionella pneumophila), is characterized initially by symptoms resembling influenza (as malaise, headache, and muscular aches) followed by high fever, cough, diarrhea, severe pneumonia, and mental confusion [merriam-webster.com]

• Seizure

  Microcystins can cause fever, headaches, vomiting, and—in rare cases—seizures. [theatlantic.com]

  Symptoms The cancer cells in the covering of the brain can cause a range of symptoms, including: headaches changes to your sight such as double vision or loss of sight confusion weakness seizures (fits) feeling sick (nausea) vomiting hearing changes facial [cancerresearchuk.org]

  The most common symptoms include: a fever above 104°F chills a cough, with or without mucus or blood Other symptoms may include: shortness of breath headaches muscle aches a loss of appetite chest pain fatigue nausea and vomiting diarrhea confusion seizures [healthline.com]

• Lethargy

  Lethargy and confusion can occur in progressive, serious cases. [healthcentral.com]

  Abdominal pain, diarrhea, neurological signs such as headache, confusion, lethargy or agitation may also be present. [rarediseases.org]

• Altered Mental Status

  CASE: A 53-year-old Japanese male visited our hospital with symptoms of fever, vomiting, diarrhea, and altered mental status, but not with respiratory manifestations. [ncbi.nlm.nih.gov]

  There may be confusion and altered mental status. Complications Respiratory failure can occur, in which the body does not get enough oxygen from the lungs to function properly. [medicalnewstoday.com]

  Complications See the list below: Decreased pulmonary function Fulminant respiratory failure Dehydration, septic shock Respiratory insufficiency, hypoxic respiratory failure Endocarditis Neurologic symptoms: Including lethargy, headache, altered mental [emedicine.com]

Diagnostic tests are the backbone of diagnosis as these points out bacteria in sputum, presence of Legionella antigens in urine samples as a result of renal fibrosis and the presence of Legionella antibody levels in blood samples [7]. A urine antigen test is the most successful diagnostic test. This is because it detects Legionella pneumophila serogroup 1 which accounts for 70% of disease.

Other laboratory findings seen in patients with Legionnaires' disease include the following [8]:

• Elevated liver enzyme levels
• Highly elevated erythrocyte sedimentation rate (ESR)
• Highly elevated ferritin levels
• Increased C-reactive protein (CRP) levels (>30 mg/L)
• Hypophosphatemia (specific to Legionnaires' disease excluding other causes of hypophosphatemia) [9]
• Microscopic hematuria
• Proteinuria (40%)

• Pulmonary Infiltrate

  Histologic examination of the basal pulmonary infiltrates showed fibrosing alveolitis. Serologic titers indicated that the patients had suffered from Legionella pneumophila infection. [ncbi.nlm.nih.gov]

  Findings on an initial radiograph of the chest may be normal, but eventually a pulmonary infiltrate will develop [ 2, 3 ]. [casesjournal.biomedcentral.com]

• Hyponatremia

  ADH levels as the causal pathway to hyponatremia. [ncbi.nlm.nih.gov]

  Laboratory data may include an abnormal liver function test, low phosphorus in the blood (hypophosphatemia), blood in the urine (hematuria), and low blood sodium (hyponatremia). [rarediseases.org]

  Laboratory abnormalities often include hyponatremia, hypophosphatemia, and elevated aminotransferase levels and C-reactive protein. [msdmanuals.com]

• Hypophosphatemia

  (specific to Legionnaires' disease excluding other causes of hypophosphatemia) Microscopic hematuria Proteinuria (40%) Use of antibiotics and some of the newer macrolides are the current treatment of choice. [symptoma.com]

  Laboratory data may include an abnormal liver function test, low phosphorus in the blood (hypophosphatemia), blood in the urine (hematuria), and low blood sodium (hyponatremia). [rarediseases.org]

  Laboratory abnormalities often include hyponatremia, hypophosphatemia, and elevated aminotransferase levels and C-reactive protein. [msdmanuals.com]

• Hypophosphatemia

  (specific to Legionnaires' disease excluding other causes of hypophosphatemia) Microscopic hematuria Proteinuria (40%) Use of antibiotics and some of the newer macrolides are the current treatment of choice. [symptoma.com]

  Laboratory data may include an abnormal liver function test, low phosphorus in the blood (hypophosphatemia), blood in the urine (hematuria), and low blood sodium (hyponatremia). [rarediseases.org]

  Laboratory abnormalities often include hyponatremia, hypophosphatemia, and elevated aminotransferase levels and C-reactive protein. [msdmanuals.com]

• Hypoalbuminemia

  […] the patient in the present report was administered this regimen and incurred jaundice two weeks after the chemotherapy, consistent with hepatocellular jaundice, and the subcutaneous metastatic lesion significantly progressed with signs of anemia and hypoalbuminemia [bmccancer.biomedcentral.com]

• Legionella Pneumophila

  The antibody response indicated that his disease was due to Legionella pneumophila serogroup 2. [ncbi.nlm.nih.gov]

  • disease, which is caused by Legionella pneumophila, is seen on a frontal chest x-ray. [mysanantonio.com]

• Pleural Effusion

  Pleural effusion is relatively common in Legionnaires' disease but is usually clinically insignificant. [ncbi.nlm.nih.gov]

  Chest x-ray should be done; it usually shows patchy and rapidly asymmetrically progressive infiltrates (even when effective antibiotic therapy is used), with or without small pleural effusions. [msdmanuals.com]

Use of antibiotics and some of the newer macrolides are the current treatment of choice. The antibiotics that are used the most frequently are levofloaxacin and azithromycin [9]. The antibiotics are very effective as they have excellent intracellular penetration in cells that are infected with Legionella pneumophila.

As mentioned above, majority of people that become exposed to Legionella pneumophila do not go beyond the Pontiac fever phase. However, the condition can be life-threatening [5]. The risk of dying is highest in patients who have chronic conditions and those that get infected while on admission in a hospital.

The chief cause of death in patients is progressive respiratory failure. However, mortality rate is dependent on the patient’s comorbid conditions as well as the choice of antibiotics and the amount of time taken to begin treatment.

The legionellosis condition is chiefly caused by the bacterium Legionella pneumophila [2]. There are two distinct stages of this disease.

Pontiac fever is a milder illness which develops between a few hours and two days after initial infection. It generally resolves spontaneously.

Legionnaires' disease stage is the main stage of the infection and may involve pneumonia. This form of the disease generally kicks in two to 10 days after initial infection but its onset may be delayed by over two weeks. The disease got its name in 1976 following a pneumonia outbreak that hit individuals attending an American Legion convention of that year.

Legionnaires' disease is not rare but it is not uncommon either. Over 4% of all community-acquired pneumonia is as a result of it [3]. The number of people that develop Pontiac fever is also unknown as majority of such individuals only develop very mild symptoms.

Individuals likely to develop Legionnaires' disease after a Pontiac fever episode are those aged 50 and above, those that smoke or have chronic lung disease and immunosuppressed individuals.

Legionnaires' disease is generally acquired by inhalation [4]. In some cases, it can be acquired by microaspiration of water that has been contaminated. In the lungs, the causative organism is phagocytosed by macrophages in the alveoli. This leads to the release of virulent factors that makes it possible for them to no just survive but also replicate in the individual. In individuals with this disease, the alveoli are filled with bacteria, neutrophils, microphages as well as erythrocytes.

The pathogenesis for Pontiac fever is not clear but it is equally caused by the inhalation of Legionella pneumophila. 

To prevent outbreaks of Legionnaires' disease, pools, spas and other water systems have to be cleaned meticulously [10].

To further lower risk of infection, it is important for individuals to avoid smoking. Smoking increases chances of developing Legionnaires' disease as soon as the human body is exposed to Legionella pneumophila.

Legionnaires' disease is a condition also known as legionellosis. It is caused by a bacterium which lives mostly in the mist found typically in air-conditioned spaces [1]. This is why the bacterium has been able to infest entire buildings in many cases.

Another variation of the condition is Pontiac fever but Legionnaires' disease is more severe and if neglected, is ultimately fatal. People with Legionnaires' disease develop fever, chills and cough as the disease progresses. In its most advanced state, the disease can lead to severe pneumonia and respiratory failure. Antibiotics are useful in combating the condition but prevention is the most useful approach.

Legionnaires’ disease is an infection, often accompanied by pneumonia. Pneumonias refer to the inflammation of the lungs and in the case of Legionnaires’ disease it is caused by a bacterium known as Legionella pneumophila.

It is not possible to contact this disease from person-to-person contact. As majority of people get this disease by inhaling the bacteria. Older individuals, smokers and people with weak body defences have the highest risk of contracting the disease.

Another disease caused by the Legionella pneumophila is Pontiac fever. Pontiac fever is a milder illness and can occur separately or in combination with the Legionnaires’ disease in people infected with the bacteria. Pontiac fever often clears up on its own without treatment but Legionnaires' disease left untreated may be fatal.

Prompt treatment with antibiotics often cures the disease but follow up is required in some patients as problems may continue after treatment.

1. Kozak-Muiznieks NA, Lucas CE, Brown E, Pondo T, Taylor TH Jr, Frace M, et al. Prevalence of sequence types among clinical and environmental isolates of Legionella pneumophila serogroup 1 in the United States from 1982 to 2012. J Clin Microbiol. Jan 2014;52(1):201-11. 
2. Nguyen TM, Ilef D, Jarraud S, Rouil L, Campese C, Che D. A community-wide outbreak of legionnaires disease linked to industrial cooling towers--how far can contaminated aerosols spread?. J Infect Dis. Jan 1 2006;193(1):102-11. 
3. Woo AH, Goetz A, Yu VL. Transmission of Legionella by respiratory equipment and aerosol generating devices. Chest. Nov 1992;102(5):1586-90.
4. Brandsema PS, Euser SM, Karagiannis I, DEN Boer JW, VAN DER Hoek W. Summer increase of Legionnaires' disease 2010 in The Netherlands associated with weather conditions and implications for source finding. Epidemiol Infect. Jan 24 2014;1-12. 
5. Halsby KD, Joseph CA, Lee JV, Wilkinson P. The relationship between meteorological variables and sporadic cases of Legionnaires' disease in residents of England and Wales. Epidemiol Infect. Jan 9 2014;1-8. 
6. Fang GD, Fine M, Orloff J, et al. New and emerging etiologies for community-acquired pneumonia with implications for therapy. A prospective multicenter study of 359 cases. Medicine (Baltimore) 1990; 69:307.
7. Stout JE, Yu VL. Legionellosis. N Engl J Med 1997; 337:682.
8. Yu VL, Greenberg RN, Zadeikis N, et al. Levofloxacin efficacy in the treatment of community-acquired legionellosis. Chest 2004; 125:2135.
9. Fraser DW, Tsai TR, Orenstein W, et al. Legionnaires' disease: description of an epidemic of pneumonia. N Engl J Med 1977; 297:1189.
10. Kirby BD, Snyder KM, Meyer RD, Finegold SM. Legionnaires' disease: report of sixty-five nosocomially acquired cases of review of the literature. Medicine (Baltimore) 1980; 59:188.