Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Job Classification

In most duration tables, five job classifications are displayed. These job classifications are based on the amount of physical effort required to perform the work. The classifications correspond to the Strength Factor classifications described in the United States Department of Labor's Dictionary of Occupational Titles. The following definitions are quoted directly from that publication.

Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Legionnaire's Disease


Related Terms

  • Legionellosis
  • Legionnaire's Pneumonia

Differential Diagnosis

Specialists

  • Critical Care Internist
  • Infectious Disease Internist
  • Pulmonologist

Comorbid Conditions

  • Chronic lung disease
  • Immune system disorders

Factors Influencing Duration

If the individual is over 60, has poor underlying health, or has a compromised immune system, recovery time may be longer.

Medical Codes

ICD-9-CM:
482.84 - Pneumonia Due to Other Specified Bacteria, Legionnaires Disease

Overview

Legionnaires' disease is an acute respiratory infection caused by the bacterium Legionella pneumophila, which dwells in man-made and natural aquatic environments. Legionnaires' disease is not spread from person to person, but rather through contaminated water or ventilation systems, plumbing systems, air conditioners, humidifiers, hot tubs, whirlpools, ice machines, and potable water systems. Factors that are now known to enhance the growth of Legionella bacteria in man-made water environments include water temperatures between 77° F and 107° F (25° C and 41.7° C), stagnant water, and water with scale and sediment. Legionnaire's disease is a relatively common type of community-acquired pneumonia, accounting for up to 10% of cases.

An outbreak of serious pulmonary infections among individuals attending a convention of the American Legion in Philadelphia, Pennsylvania, during the US Bicentennial celebration in July 1976 prompted the name Legionnaires' disease. A nonpneumonic variant caused by the same species of bacteria is called Pontiac Fever, named for an outbreak of this disease that occurred in Pontiac, Michigan, in 1968.

Since its initial identification in 1976, Legionnaires' disease has become recognized as the most common cause of atypical pneumonia in hospitalized individuals and the second most common cause of community-acquired bacterial pneumonia.

Conditions that lead to increased risk for Legionnaires' disease include diabetes, pulmonary disease requiring ventilation, renal disease, immunosuppression, and cancer.

Incidence and Prevalence: Passive reports received by the Centers for Disease Control (CDC) indicate an incidence of 0.48 cases per 100,000 people. More active surveillance estimates upward of 20,000 cases annually in the US. Outbreaks have been recognized throughout North America, Africa, Australia, Europe, and South America.

Source: Medical Disability Advisor



Causation and Known Risk Factors

The elderly, smokers, and alcoholics are at increased risk for Legionnaires' disease. It is more common in the summer, especially in August, and is slightly more prevalent in the northern US.

Source: Medical Disability Advisor



Diagnosis

History: The classical presentation begins after an incubation period of 2 to 8 days. Individuals complain of high fever, shaking, chills, headaches, muscle aches and stiffness, chest pain, a dry cough, lethargy, weakness, and shortness of breath. As the disease progresses, individuals may complain of abdominal pain, diarrhea, and muscular discoordination (ataxia). Musculoskeletal symptoms include joint pain (arthralgia) and muscle pain (myalgia). Improvement begins 4 to 5 days after presentation.

Physical exam: Physical findings include a high fever, rapid breathing (tachypnea), and altered mental status. Relatively slow pulse (bradycardia) may occur in up to 66% of individuals. The absence of inflammation of the upper respiratory tract is common and is a clinically useful indicator. Chest sounds may be normal or may reveal crackling (rales), a musical pitch (rhonchi), or signs of diminished air entry into affected parts of the lung (consolidation). The individual may have blood-streaked sputum (hemoptysis). Inflammation of the covering of the heart (pericarditis) and inflammation of the inner portions of the heart (endocarditis) may be present. An enlarged liver (hepatomegaly) may be seen in rare cases. The neurological examination or the individual's mental status may be abnormal.

Tests: Laboratory tests may include chest x-ray and, infrequently, a CT scan, serologic (blood) testing for Legionella bacteria, a complete blood count (CBC), an electrolyte panel, blood urea nitrogen (BUN), and creatinine levels. The white blood cell count will be elevated (leukocytosis). A sedimentation rate may also be elevated. The urine and lung fluid will be examined for signs of the disease. Because the Legionella pneumophila bacteria does not show up in ordinary sputum cultures, a special sputum culture or stain test (sputum DFA-direct fluorescent antibody) will be necessary to identify it. Arterial blood gases may show low concentrations of oxygen, and liver function tests may be mildly elevated. Alkaline phosphatase and creatinine phosphokinase levels may be elevated, as well.

Source: Medical Disability Advisor



Treatment

Hospitalization is often required, during which time the individual is given intravenous (IV) antibiotics for several days. Some individuals require supplemental oxygen during this time, along with fluids and electrolyte replacement. More severely affected individuals may require mechanical ventilation. After the individual stabilizes, oral antibiotic therapy must be continued for an additional 14 to 21 days. Antibiotics for Legionnaires' disease include the macrolides (erythromycin, azithromycin and clarithromycin), doxycycline, and the fluoroquinolones (including gatifloxacin, and levofloxacin).

Source: Medical Disability Advisor



Prognosis

Recovery is variable. Most individuals with Legionnaires' disease recover with prompt treatment. However, some outbreaks have had mortality rates between 15% and 25%. Some individuals experience rapid improvement, whereas others have a much more protracted course despite treatment. The mortality rate approaches 50% with hospital-acquired infections and 80% among individuals with compromised immune systems.

Source: Medical Disability Advisor



Complications

Complications include lung abscess, respiratory failure, low blood pressure (hypotension), shock, and kidney failure. Prolonged dependence on mechanical ventilation may result from severe pneumonia, especially in the setting of underlying lung disease. In addition, any underlying lung disease or immunological problems may make Legionnaires' disease more resistant to treatment. An acute, quickly worsening (fulminating), potentially fatal disease of skeletal muscle that involves destruction of muscle (rhabdomyolysis) is occasionally seen in Legionnaires' disease. It may be so severe as to cause renal failure, dehydration, respiratory insufficiency, and inflammation of the inner portions of the heart (endocarditis).

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Relapses are not uncommon. Therefore, recovering individuals with physically demanding occupations should be careful to avoid overexertion until they are fully recovered. Buildings in which they work should be examined and the water and ventilation systems modified, cleaned, and repaired.

Source: Medical Disability Advisor



Failure to Recover

If an individual fails to recover within the expected maximum duration period, the reader may wish to consider the following questions to better understand the specifics of an individual's medical case.

Regarding diagnosis:

  • Has diagnosis of Legionnaires' disease been confirmed?
  • Have conditions with similar symptoms been ruled out?
  • Is the timing between exposure and clinical onset compatible with the known biologic facts about the illness?
  • Is the clinical illness, including the history, physical examination, and laboratory findings, consistent with the description of other cases?
  • Are the laboratory values and tests at or near the normal levels?
  • Has individual experienced any complications such as lung abscess, respiratory failure, hypotension, shock, kidney failure, dehydration, respiratory insufficiency, or endocarditis?

Regarding treatment:

  • Has individual been promptly started on appropriate antibiotics?
  • Do symptoms persist despite treatment?
  • Was culture and sensitivity done to identify the pathogen and determine the most effective antibiotic to use?
  • Have antibiotic-resistant organisms been ruled out?

Regarding prognosis:

  • Does individual have an underlying condition such as immune deficiency or underlying lung disease that may be affecting recovery?
  • Does individual smoke tobacco?
  • Are there special attributes of the particular individual that make it more or less likely that he or she would be so affected?
  • Because constant exposure to the organisms and the environment(s) in which they reside could lead to recurrences of the disease and a permanent state of disability, is there a positive history of exposure in the workplace?
  • Could exposure be occurring in the home, the community, or in recreational activities?
  • What can be done to prevent further exposure to pathogens?

Source: Medical Disability Advisor



References

General

"Legionellosis." MedicineNet.com. 24 Apr. 2002. MedicineNet, Inc. 20 May 2005 <http://www.medicinenet.com/legionnaire_disease_and_pontiac_fever/article.htm>.

Source: Medical Disability Advisor






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