Legionnaire's Disease


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Legionnaire’s Disease is a deadly severe form of pneumonia. It is the cause of nosocomial pneumonia. This disease can be fatal. Legionnaire’s disease is a lung infection. It is a disease caused by a bacteria, known as Legionella. This disease is often screened for whenever a person is diagnosed with pneumonia because of the close resemblance Legionnaire’s has to pneumonia. Legionnaire’s disease is commonly from inhaling the bacteria.
Legionnaire's Disease
The history of Legionnaire's Disease, can be viewed below under History of Disease.

The bacteria, Legionella, in Legionnaire’s disease can also lead to Pontiac Fever, which is like a milder version of Legionnaire’s disease. Pontiac Fever resembles the flu. If a person is diagnosed with both illnesses, then the term is Legionellosis. Unlike Legionnaire’s disease, Pontiac Fever usually clears on it own1.


History of Disease: Legionnaire’s disease first came about in 1967 when a group of people in Philadelphia, attending an American Legion convention meeting became exposed to this disease.  View Legionnaire's Disease video below or please visit http://www.youtube.com/watch?v=8oTf2bGCt-Y.  


Accurate data reflecting the true incidence of disease are not available because of underutilization of diagnostic testing and under-reporting. It is a common cause of severe pneumonia requiring hospitalization10.


  • Responsible for ~ 5% of all pneumonias4
  • 12,000 people affected yearly in the U.S.4
  • Severe, sometimes fatal disease4
  • Each year an estimated 8,000-18,000 hospitalized cases occur in the U.S.10
  • The majority of reported cases are sporadic10
  • Travel-associated outbreaks, outbreaks in community settings, and nosocomial and occupational outbreaks are common10
  • More than 20% of all cases are thought to be associated with recent travel10
  • Difficult to detect among travelers because of the low attack rate, long incubation period, and the dispersal of persons  from the source of the outbreak10
  • Present rate is that 80% of those contracting the disease die26


For recent breaking news on Legionnaire's Disease regarding California health officials investigating a mystery illness at the Playboy mansion possibly caused by a fog machine, please visit http://www.youtube.com/watch?v=xk5dEOYtPbw&feature=fvsr.

♦ Legionnaire's Disease is not only found in the United States, but it is worldwide. ♦

            Image:World_images.jpg                                                      Images3.jpg


Characteristics/Clinical Presentation

For patient stories on contracting Legionnaire's Disease, visit http://www.youtube.com/watch?v=n5tL69KVTZg.


Many patients report having the following symptoms: Images4.jpg 

S/S: Fevers, chills, dry or productive cough, fatigue, anorexia, headache, myalgia, diarrhea, muscle aches, & gastrointestinal symptoms4

Associated Co-morbidities

People at risk:

  • Smokers (esp. Middle-aged/older adults who smoke cigarettes)
  • Chronic lung disease
  •  Advanced age
  • Alcohol abuse
  • Surgery
  • Recent travel with an overnight stay outside of the home
  • Exposure to whirlpool spas
  • Recent repairs or maintenance work on domestic plumb
  • Immune system compromised by

          o DM
          o Renal Failure
          o Cancer (esp. hematological or pulmonary malignancy)
          o AIDS


Erythromycin (the drug of choice for prolonged period) - given early

Rifampin is also a benefit

Newer Effective Therapeutic Options Include Antibiotics (Macrolides)4:



Diagnostic Tests/Lab Tests/Lab Values

Legionnaire’s disease is diagnosed by growing bacteria on a special medium and silver staining. The bacteria is identified in the sputum and the Legionella antigen is seen in the urine4.

          Images6.jpg                Images8.jpg
What diagnostic tests can confirm Legionnaires' disease? (http://www.cdc.gov/legionella/faq.htm9)

Diagonostic Tests




Culture - Clinical & Environmental isolates can be compared
- Detects all species & serogroups
- 100% specific
- Technically difficult
- Slow (>5 days to grow)
- Sensitivity highly dependent on technical skill
- May be affected by antibiotic treatment
Urine Antigen - >99% specific...
- Rapid (same day)
- ...but only for L. pneumophila serogroup 1 (Lp1) [ which may account for up to 80% of cases]
- Limited utility when compared to environmental isolates
Serology - Not affected by antibiotic treatment
- 70-80% sensitive; >90% specific
- Must have paired sera
- 5-10% of population has titer 1:≥256
Single acute phase antibody titers of 1:≥256 do not discriminate between cases of Legionnaires' disease and other causes of community-acquired pneumonia.
DFA - Can be performed on pathologic specimens
- 95% specific
- 25-75% sensitive


Legionnaire’s disease is the cause of nosocomial pneumonia4.

Common places that allow Legionella transmission10:
1. Potable (drinking) water systems
2. Whirlpool spas
3. Cooling towers 

Conditions for Legionella transmission10:
1. Heat
2. Stasis
3. Aerosolization

Systemic Involvement

Gastrointestinal symptoms include nausea, vomiting, diarrhea, and anorexia.

Neurologic symptoms include headache, lethargy, altered mental status, and rarely, focal symptoms.

Musculoskeletal symptoms include arthralgias and myalgias.

Nonpulmonary symptoms are prominent early in the disease.

Medical Management (current best evidence)

Patients diagnosed with Legionnaire's Disease are prescribed to take the various medications see above under Medications

For patients with Pontiac fever: it is a self-limited illness that does not benefit from antibiotic treatment. Complete recovery usually occurs within 1 week10.

Physical Therapy Management (current best evidence)

Screening Questions:

    - Have you traveled recently? (Patient could have traveled-associated Legionnaire’s disease (http://www.cdc.gov/legionella/faq.htm9)

Top 10 Things Every Clinician Needs to Know About Legionellosis (http://www.cdc.gov/legionella/top10.htm10)

What does the diagnosis of Legionnaire’s disease include? Two clinical syndromes:

Legionnaire's Disease vs. Pontiac Fever
Legionnaires' disease Pontiac fever
Clinical Features Pneumonia: cough, fever, chest pain Flu-like illness (fever, chills, malaise) without pneumonia
Radiographic pneumonia Yes No
Incubation period 2-14 days after exposure 24-48 hours after exposure
Etiologic agent Legionella species Legionella species
Attack rate* < 5% > 90%
Isolation of organism Possible Virtually never
Outcome Hospitalization common
Case-fatality rate: 5-40%**
Hospitalization uncommon
Case-fatality rate: 0%
Additional Below*

  * Percent of persons who, when exposed to the source of an outbreak, become ill.
** Percent of persons who die from Legionnaires' disease or Pontiac fever.

Tests In Relationship to Snout/Spin
Test Sensitivity (%) Specificity (%)
Culture 80 100
Urine antigen 70 100
Paired serology* 70-80 >90
Direct fluorescent antibody stain 25-75% 95
*Note: A single antibody titer of any level is not diagnostic of legionellosis


Patient Care: Respiratory Therapists/PTs: O2 therapy, repositioning, postural drainage, suctioning4

Monitor: Chest wall expansion, depth/pattern of ventilations, cough, chest pain, restlessness, & hypoxemia4

Signs of Shock: ↓ blood pressure, tachycardia w/weak thread pulse, diaphoresis, clamy skin, & cold4

Patient Education: Pulmonary hygiene, deep breathing and coughing exercises, chest physiotherapy, postural drainage, disposal of solid tissues to prevent disease transmission4

Alternative/Holistic Management (current best evidence)

Treatment:  Natural Encyclopedia recommends following remedies for Pnuemonia &  Bronchitis.

•You will want to use essentially the same treatment as outlined for bronchitis; except that, because the person's illness is so much more serious, he must be given much rest and intensified care.
•Rinse out the nose with saltwater, gently taking it in and blowing it out. Gargle with saltwater. Then repeat the rinsing and gargling with a goldenseal and myrrh mixture. This will help keep a cold or flu from going down into the lungs.
•But if the lungs are already affected, do the above treatment. Also give hot footbaths and a high herb enema at least once a day. Drink plenty of water. Take laxative herbs, to keep the bowels working properly. Give short, hot fomentations to the chest and upper back, with short cold between each hot application.
•Only give liquids the first few days. These should consist of fruit juices (diluted pineapple juice or orange juice) or lemon and water (without sugar), etc. Continue this until the high fever abates. Then give strained vegetable broths, whole grains (best in dry form, so it will be chewed well).                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             •

•Stop smoking and get tobacco out of the house. If you have chronic bronchitis, do not expect much improvement as long as tobacco smoke is in the home.
•Do not use milk; it produces a thick phlegm which complicates healing. White-flour products and sugar foods should not be used until bronchitis is past.
•Drink plenty of fluids: pure water, soups, and herb teas. Vitamin C is important! Take it to bowel tolerance.
•Anise tea and almond milk are helpful in bronchitis. Make the almond milk by blending 6 tbsp. of almonds in a pint of water.
•Cayenne and lobelia will help break up the congestion.
•Add moisture to the air with a vaporizer or humidifier or heat a pan of water on the stove.
•Remain in bed as long as fever is present. Bronchitis often hangs on because people think it is about over and begin going about their everyday duties. Go to bed and get well.
•Deep breathing exercises should be taken 3-4 times a day. Take a deep breath, hold it a few seconds, and exhale. Do this 10-20 times. This will help air out of the infected area.
•Breathe deep. Blow up a balloon several times every day. This helps open up and enlarge the airways.
•Apply a heating compress at night.
•A hot footbath will help pull the blood away from the chest and reduce congestion.
•Hot drinks help you cough out the phlegm. Coughing is the only way the phlegm can come out. Do not use cough suppressants while you have bronchitis.
•Apply warm, moist heat or a hot water bottle over the chest and back before bedtime. This will help relieve congestion and aid in sleep.
•Avoid fatigue and chilling. Do not walk barefoot on cold floors while you are trying to get well.
•If the coughing gets worse, there is a high fever, wheezing sounds, lethargy, and weakness. Chest pains develop and very difficult breathing. Contact a health professional; the condition may be developing into pneumonia.
•If the condition persists over too long a time, there is the possibility of tuberculosis or lung cancer.
•A professional can use bronchoscopy instruments to examine the bronchial tubes and suction out phlegm.
•In recent years, a new type of bronchitis has arisen, which is contracted primarily by women. Difficult to treat, it often continues for 3 weeks to 5 months. Drinking goldenseal tea is helpful with this condition, as well as with other types of bronchitis.
•Other helpful herbs include pau d'arco, chickweed, ginkgo biloba, burdock, lobelia, slippery elm bark, echinacea, and wild cherry bark.

Data taken from Natural Encyclopedia26.

Differential Diagnosis25

  • Adult Respiratory Distress Syndrome (ARDS)
  • Bronchitis
  • Congestive heart failure
  • Gastroenteritis
  • HIV infection and AIDS
  • Inflammation of the rib cartilage (costochondritis)
  • Meningitis
  • Non-Legionnaire's pneumonia
  • Pleural effusion
  • Pneumonia caused by other organisms
  • Prostatitis
  • Septic shock
  • Tuberculosis

Case Reports/ Case Studies

Atypical Presentation of Legionnaire’s Disease: A Case Report and Review [5]

(Abstract Only): A case of a 62-year-old man with Legionella pneumonia complicated with multisystem organ failure is presented, and English-language literature on Legionnaire’s disease is reviewed. Clinical spectrums of this patient include not only respiratory involvement, but also abdominal complaints, encephalopathy, rhabdomyolysis with renal failure, hepatic dysfunction and myocarditis. Our patient experienced severe mutilobar pneumonia and respiratory failure requiring mechanical ventilation in the intensive care unit and underwent hemodialysis for acute renal failure. Even though Legionnaire’s disease is implicated in systemic manifestations with multiple organ involvement, nonspecific signs and symptoms of the disease and difficulties in isolating Legionella pneumophila from specimens make the diagnosis of this disease very difficult. Despite a delay in diagnosing with positive serology, this patient was successfully treated with erythromycin and levofloxacin. Review of published articles showed that delay in starting adequate therapy is shown to be a key factor associated with poor outcome in many cases. Thus, Legionellosis should be considered in the differential diagnosis of patients presenting with neurologic, cardiac and gastrointestinal symptoms in the setting of pneumonia in immunocompromised or critically ill patients, and treatment for Legionnaire’s disease should be initiated as soon as possible. [For full case report, please view report in New York Medical Journal]

Severe Legionnaires disease complicated by multi-organ dysfunction in a previously healthy patient: a case report [7]

 A 58-year-old white Caucasian British lady, came to the emergency department with a 2 day history of high fever (38.6°C) shortness of breath, productive cough and diarrhoea 3 days after she had arrived from New Jersey.
In the emergency department, her respiratory rate was 21/min, blood pressure 88/57 mmHg, and heart rate 116/min and regular and Arterial oxygen saturation was 77% on room air and increased to 90% on 100% oxygen via a face mask. Rales were present in one third of the lung fields bilaterally and Percussion revealed dullness at the base of the right lung, with poor air entry in the right lower base. Additionally, her blood gas results were her blood gas results were, pH: 7.49, PaO2: 4.9 mmHg, PaCO2: 3.8 mmHg, HCO-3: 24 mM, BE: -0.5 mM and SaO2 77%. Her CURB score surprisingly was 1, one point for Low blood pressure.

A chest radiograph showed extensive consolidation present throughout the right lung (Figure 1) and there was also a little patchy consolidation in the left mid and lower zones.


Figure 1:Chest X-ray on admission which showed RLL consolidation7. Kassha et al. Cases Journal 2009 2:9151 doi:10.1186/1757-1626-2-9151

Due to septic shock, acute respiratory distress syndrome and disseminated intravascular coagulation The patient was admitted to the ITU and she was placed on CPAP initially and inotropes were started. The patient's hypoxemia increased, and there was marked progression of the bilateral shadows on chest X-ray, suggestive of ARDS. Hence, the patient was placed on mechanical ventilation, steroid infusion and an antibiotic regime of clarithromycin, ceftriaxone, rifampicin and clindamycin commenced. Because she did not show any signs of improvement, she was transferred to another hospital for ECMO (Extracorporeal membrane oxygenation), which she had for 5 days. On hospital day 6, her urine output was low and so she was put on RRT (Renal replacement therapy).

On the seventh day after admission, Legionella antigen was detected in the urine, the diagnosis of Legionella pneumonia was confirmed. Also, Bacteriological examination of sputum disclosed Legionella pneumophila. All her antibiotics were stopped except ceftriaxone, and she was continued on prednisolone for 3 more weeks.
After the 21st hospital day, the radiographic findings gradually improved, the patient was taken off the ventilator and placed on CPAP. Moreover, her kidney functions recovered and RRT was stopped and she was moved to a respiratory ward, where she remained for another 4 weeks during which she had nutritional and physiotherapy support. The lady was discharged with almost full range of mobility and independency in day 70th. Table 1 shows the clinical course of the present case. [For full case report and lab values, please view report in Cases Journal]

Legionnaires Disease: A Case Study [6]

A 28-year-old man, N.C., came to the emergency department because he had shortness of breath, fatigue, a cough, diarrhea, and arthralgias. The shortness of breath was associated with minimal exertion (1 flight of stairs) and resolved after several minutes of rest. He did not have pain on inspiration or chest pain. He described the fatigue as overwhelming, and his activities were restricted to essential activities of daily living. The cough was nonproductive and did not have a pattern or aggravating or relieving factors. It was not associated with pain, positioning, or time of day. One day before admission, he had had fever and chills, with a maximum body temperature of 38.6°C (101.4°F). Watery, brown diarrhea occurred without other gastrointestinal distress and was intermittent, approximately 7 to 8 times a day. No treatments had been instituted at home.

N.C. had had idiopathic dilated cardiomyopathy in 1990 and had received an orthotopic heart transplant in 1994. Other notable abnormalities and previous interventions included transplant arteriopathy, biventricular heart dysfunction, placement of a pacemaker, recurrent right-sided pleural effusions, pleurodesis, posttransplant hypertension, hypercholesterolemia, treatment with antibodies to cardiolipin, a thoracotomy, chronic renal insufficiency, and coronary artery disease. His name was again on the list for a heart transplant, status 1B. At the time of admission, he was taking intravenous milrinone, warfarin, furosemide, antihypertensives, and drugs to prevent rejection of his heart transplant. He had a brother who also had received a heart transplant because of idiopathic dilated cardiomyopathy.

N.C. did not use alcohol or tobacco. He lived in an apartment with 2 roommates and worked at home as an editor. He had no pets and he had not traveled recently, but both roommates had had an upper respiratory infection within the preceding week.
In the emergency department, N.C. was afebrile and mildly short of breath, with respirations 18/min, blood pressure 90/40 mm Hg, and heart rate 110/min. Cardiac rhythm was sinus tachycardia. Arterial oxygen saturation was 84% when he was breathing room air and increased to 95% when he was breathing 50% oxygen via a face mask. Jugular venous distension was present at the angle of the jaw. Rales were present in one third of the lung fields bilaterally. Percussion revealed dullness at the base of the right lung. Cardiac assessment revealed a regular rhythm with a hyperdynamic point of maximum impulse; S1, S2, and S3 heart sounds; and a grade III/VI tricuspid murmur. He had 1+ edema in the lower extremities and 2+ pedal pulses. Neurologically, he had no focal deficits, and he followed commands appropriately. The results of an abdominal assessment were unremarkable. He had no clubbing of the fingers or cyanosis.

Tests of blood samples obtained in the emergency department indicated the following serum levels: sodium 131 mmol/L, potassium 4.6 mmol/L, chloride 107 mmol/L, urea nitrogen 7.1 mmol/L (20 mg/dL), and creatinine 115 µmol/L (1.3 mg/dL). A complete blood cell count was as follows: white blood cell count 16.8 x 109/L and platelet count 319 x 109/L. His hemoglobin level was 88 g/L, and his hematocrit was 0.26. The serum level of thyrotropin was 2.45 mIU/L. Blood levels of digoxin, cyclosporine, and mycophenolate (CellCept) were appropriate. A chest radiograph showed bilateral diffuse basilar infiltrates, otherwise unchanged from findings on previous radiographs. All cultures of blood, stool, and sputum; tests to detect acid-fast bacilli; assays of nasal swabs for detection of influenza viruses A and B; and urine test for Legionella antigen were pending.

N.C. was admitted to the cardiac intermediate care unit for further observation and treatment. Small doses of diuretics were given for fluid overload, previous medications were continued, and administration of levofloxacin was started.
On hospital day 3, N.C. was less short of breath than before, but he continued to have a nonproductive cough. His vital signs were body temperature 37.8°C (99.9°F), heart rate 78/min, blood pressure 96/50 mm Hg, and respirations 16/min. He was weaned from 50% oxygen via a face mask to 2 L of oxygen by nasal cannula; oxygen saturation by pulse oximetry was 96%. The diarrhea had improved. His electrolyte levels were unremarkable, but his white blood cell count increased to 26.0 x 109/L. The cultures for influenza A and B viruses were negative as were stool cultures for ova and parasites and blood cultures for bacteria and fungus. The urine test for Legionella antigen was positive. The infectious disease team recommended that levofloxacin 500 mg orally once a day be continued for a total of 14 days. Samples of material from a humidifier from N.C.’s apartment were cultured as a potential source of the Legionella.

N.C. showed clinical improvement and was discharged on hospital day 8. He was taking all of his previous medications and would continue to take levofloxacin to complete the 14-day course of treatment. His white blood cell count had decreased to 15.2 x 109/L, and his final chest radiograph showed bilateral patchy infiltrates compatible with pneumonia. He was afebrile and had stable vital signs, including an oxygen saturation of 99% when he was breathing room air.
The patient was scheduled to have a follow-up appointment, as well as another chest radiograph and laboratory tests (including a complete blood cell count, blood chemistries, and measurement of levels of immunosuppressant medications) 10 days after discharge. He was not to return to his home until the cultures of the samples from the humidifier were known to be negative for Legionella. The culture was negative, and the source of Legionella was not ascertained. [view study in American Journal of Critical Care]


1.http://www.cdc.gov/legionella/patient_facts.htm 2. http://www.osha.gov/SLTC/legionnairesdisease/index.html 3. OSHA eTool: http://www.osha.gov/dts/osta/otm/legionnaires/index.html 4. Taber’s Cyclopedic Medical Dictionary. F.A. Davis Company. Phildelphia. Edition 19. 2001. Pg.121 5. Atypical Presentation of Legionnaire’s Disease: A Case Report and Review. Sophie Kay1, DO, Christopher Grantham2, MD, Michelle Dahdouh3, MD. http://newyorkmedicaljournal.org/index.php/articles/atypical_presentation_of_legionnaires_disease_a_case_report_and_review 6. Legionnaires Disease: A Case Study. By Melinda Cramer, RN, BSN. From School of Nursing, University of Pennsylvania, Philadelphia, Pa. American Journal of Critical Care. 2003;12: 234-238. http://ajcc.aacnjournals.org/content/12/3/234.full 7. Severe Legionnaires disease complicated by multi-organ dysfunction in a previously healthy patient: a case report. Kays Kassha1, Issam Abuanza2, Samer A Hadi3 and Roy Hilton2. http://casesjournal.com/content/2/1/9151 8. Legionnaires' Disease with Facial Nerve Palsy. Case Reports in Medicine. Volume 2011 (2011), Article ID 916859, 4 pgs. Shailesh R. Basani, Salwa Mohamed Ahmed, and Eyassu Habte-Gabr. Received 20 September 2010; Accepted 16 January 2011. http://www.hindawi.com/journals/crim/2011/916859/ 9. http://www.cdc.gov/legionella/faq.htm
10. http://www.cdc.gov/legionella/top10.htm

Recent Related Research (from Pubmed)

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17. http://www.suntimes.com/news/nation/4080689-418/legionnaires-disease-found-at-playboy-mansion.html
18. http://www.nbcchicago.com/news/local/Bacteria-that-Causes-Legionnaires-Disease-Found-at-Playboy-Mansion-117204503.html
19. http://www.dailymail.co.uk/news/article-1361964/Playboy-Mansion-illness-Legionnaires-disease-bacteria-water-source.html
20. http://www.mayoclinic.com/health/legionnaires-disease/DS00853
21.http://www.nlm.nih.gov/medlineplus/legionnairesdisease.html & picture
22. http://www.nlm.nih.gov/medlineplus/ency/article/000616.htm
23. http://www.legionella.org/
24. http://emedicine.medscape.com/article/783656-overview
25. http://www.mdguidelines.com/legionnaires-disease/differential-diagnosis
26. http://www.naturalencyclopedia.com/Legionnaire's_Disease