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.

Hepatitis A

hepatitis a in العربية (المملكة العربية السعودية)

Related Terms

  • HAV
  • Infectious Hepatitis
  • Viral Hepatitis Type A

Differential Diagnosis

Specialists

  • Gastroenterologist
  • Infectious Disease Internist

Comorbid Conditions

  • Blood-clotting disorders (e.g., hemophilia)
  • Chronic liver disease
  • Immunosuppression
  • Liver transplant

Factors Influencing Duration

In some individuals, fatigue may persist for months even after liver function tests have returned to normal. Commercial food handlers, daycare workers, and healthcare workers should be off work as long as symptoms persist and for at least 1 week after symptoms have resolved in order to avoid spreading the virus. Duration may be extended in individuals with any other liver condition.

Medical Codes

ICD-9-CM:
070.0 - Hepatitis, Viral Type A with Hepatic Coma
070.1 - Hepatitis, Viral Type A without Mention of Hepatic Coma

Overview

Viral hepatitis type A, formerly called infectious hepatitis, is a highly contagious acute inflammatory liver disease caused by the hepatitis A virus (HAV). The virus is spread mainly by the fecal-oral route. Many cases can be traced to ingestion of contaminated water and food such as raw shellfish, milk, frozen raspberries or strawberries, and green onions. Personal contact with an individual infected with HAV is a confirmed transmission route, specially in situations of overcrowding and poor personal hygiene, although individuals spreading the infection may have no apparent symptoms. The disease also may be transmitted through certain sexual activities such as oral-anal contact. Rarely fatal, the disease typically runs its course in 2 months; about 10% to 15% of individuals have prolonged or relapsing disease for up to 6 months (Cheney). The disease is characterized by inflammation and enlargement of the liver that interferes with normal liver functions such as removing toxins from the blood, processing and storing nutrients, and handling the products of the decomposition of red blood cells. Individuals who have acute hepatitis A infection do not develop chronic hepatitis, and they develop immunity to HAV.

Because the virus is spread primarily by food or water contaminated with feces, type A hepatitis is common in developing countries with inadequate sanitation systems. Many cases occur among travelers who have recently returned from an area where the virus is prevalent and hygiene standards are low.

HAV infection may be spread in daycare centers where good hygiene such as hand washing is absent or in restaurants by food handlers with poor hygiene. Such high-exposure locations are frequently is the source of epidemics.

Transmission period of HAV begins approximately 2 weeks before the onset of symptoms, and lasts about a week after the onset of jaundice.

Incidence and Prevalence: There has been a steady decline in the number of reported cases culminating in an 88% reduction from 13,397 in 2000 to 1,670 in 2010, the lowest rate ever reported ("Viral Hepatitis Surveillance"). However, when underreporting and asymptomatic cases are factored in, the estimated number of new HAV infections in 2010 was estimated to be about 17,000 ("Viral Hepatitis Surveillance"). Decreases are attributed to use of the hepatitis A vaccine among children.

Worldwide, hepatitis A virus is responsible for approximately 1.4 million cases of hepatitis each year ("Hepatitis A"). European countries have reported marked decreases in the number of HAV cases recorded annually. Africa, South-East Asia, the Middle East and South America have the highest reported rates of HAV infection ("Hepatitis A").

Source: Medical Disability Advisor



Causation and Known Risk Factors

Travelers to countries where HAV is prevalent, healthcare workers, those who engage in sexual anal-oral contact, and users of injected illegal drugs are at higher risk than the general population. In rare instances, before new regulations were implemented in 1992 governing donor testing, HAV was transmitted by blood transfusion and the use of blood products. Acute HAV infection can affect individuals of any age or race, male or female.

Source: Medical Disability Advisor



Diagnosis

History: The incubation period ranges from 15 to 50 days (about 28 days); symptoms develop within 3 to 6 weeks after exposure ("Viral Hepatitis Surveillance"). Individuals may report an abrupt onset of the disease accompanied by fatigue, nausea, body aches, and loss of appetite. Fever is common but rarely higher than 102° F (38.9° C). Dark urine (choluria) and light-colored stools (acholia) also may be reported, along with yellowing of the eyes and skin (jaundice or icterus). Itching of the skin may accompany jaundice, or a rash may appear. Abdominal pain may be reported by some. Individuals may be involved in a foodborne outbreak, report recent travel to an underdeveloped country or may report close contact with an individual infected with HAV. Many may not know the route of transmission of their infection.

Physical exam: Even when an individual is infected, the physical examination may reveal few clinical signs. The liver may be enlarged (hepatomegaly) and tender. Occasionally, the spleen is also enlarged (splenomegaly). Jaundice may be present. About 75% of infected adults are symptomatic ("Hepatitis A").

Tests: Blood tests of liver function show significantly elevated levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase, and bilirubin. Positive results on a test specific for HAV (antibodies to HAV [anti-HAV] mainly of the IgM class) are necessary for a definitive diagnosis. Blood tests for hepatitis B and hepatitis C viruses also may be performed. Coagulation tests (prothrombin time [PT], partial thromboplastin time [PTT]) may be abnormal in some individuals and may require frequent monitoring. A complete blood count (CBC) may reveal both an abnormal increase in a specific type of white blood cells (lymphocytosis), with some evidence of destruction of red blood cells (hemolysis). Imaging studies rarely are indicated but may be done to evaluate underlying chronic liver disease if suspected.

Source: Medical Disability Advisor



Treatment

Rest usually is the only treatment for HAV infection. The duration of recommended rest depends on the severity of symptoms. Appropriate fluid and food intake are also recommended. Alcohol and other substances toxic to the liver should be avoided. In the unlikely event that abnormalities persist for more than 6 months, a liver biopsy may be indicated.

Individuals who are not previously immune to HAV who are in close contact with a HAV infected person may be advised to receive a protective injection of immune globulin, which is effective for about 3 to 6 months. Hepatitis A vaccines are available for those in high-risk occupations (e.g. healthcare workers) or those traveling to high-risk countries, but to be effective, vaccination must occur before exposure to HAV. The vaccine offers longer-term protection and consists of an initial shot followed by a booster shot in about 6 to 18 months. Routine hepatitis A vaccination is recommended for all children in the United States. The vaccine is often given in combination with Hepatitis B. Serious reactions to the vaccine are rare, but local reactions including pain, redness, tenderness, and warmth, are common at the vaccination site. Fever, abdominal pain, headache, fatigue, and allergic reactions also may occur. Preventive measures include washing hands frequently before handling food and after using the toilet or changing diapers. Travelers should avoid drinking untreated tap water and eating peeled fruit, raw vegetables, and raw shellfish when traveling in high-risk areas.

Source: Medical Disability Advisor



Prognosis

Most people with HAV infection recover; in 1 to 2 months, the liver is completely healed. The first signs of recovery are the disappearance of nausea, and the return of appetite. Mortality associated with hepatitis A is 2.0%, death occurring primarily in elderly or immunocompromised individuals ("Viral Hepatitis Surveillance").

Source: Medical Disability Advisor



Complications

Individuals with HAV infection seldom develop complications. Recovery usually begins within 3 weeks. Rarely, jaundice and other symptoms can last for 2 to 6 months or more (prolonged cholestatic jaundice). Chronic liver disease does not occur, but rarely relapsing hepatitis is possible, with recurrence of acute symptoms during several months.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Absence of jaundice is not required before returning to work, but employees who have significant social interaction may need to limit their contact with the public. Good hygiene is crucial. Customers at a restaurant or other place of business may be wary of employees who are jaundiced for fear of exposure to a contagious disease. Employees required to perform strenuous tasks may need to limit their job-related activities temporarily after returning to work.

For information on risk, capacity, and tolerance as they relate to chronic liver disease, a possible comorbidity, refer to "Work Ability and Return to Work," pages 363-364.

Risk: If a coagulopathy is present, then there would need to be restrictions from use of machinery where the risk of accidental lacerations is high, from working at unprotected heights, and from the use of firearms.

Source: Medical Disability Advisor



Maximum Medical Improvement

60 days.

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:

  • Did individual travel to a country where contaminated food or water is prevalent?
  • Is individual an intravenous drug user?
  • Is individual a healthcare worker or working or living in a situation where contact with individuals who have HAV infection may occur?
  • Was diagnosis of viral hepatitis type A confirmed by testing for hepatitis A IgM antibody?
  • Were other conditions such as other types of viral hepatitis (hepatitis B, C, and E), infectious mononucleosis, cytomegalovirus, or jaundice caused by prescription drugs, poisons, alcohol, or gallstones ruled out?

Regarding treatment:

  • Has individual been compliant with prescribed treatment plan?
  • Has individual been allowed sufficient time to rest and recover from the disease?
  • Has individual avoided substances toxic to the liver such as alcohol?

Regarding prognosis:

  • If symptoms have persisted past the expected duration, should diagnosis be revisited?
  • Does individual have an underlying condition such as other liver disease or blood clotting disorder that might affect recovery?
  • Does individual's condition demonstrate a relapsing pattern?
  • If abnormalities persist, is a liver biopsy indicated?

Source: Medical Disability Advisor



References

Cited

"Hepatitis A." Hepatitis A. 2000. World Health Organization. 3 Oct. 2013 <http://www.who.int/csr/disease/hepatitis/HepatitisA_whocdscsredc2000_7.pdf>.

"Viral Hepatitis Surveillance United States, 2010." Centers for Disease Control and Prevention. 2010. U.S. Department of Health and Human Services. 3 Oct. 2013 <http://www.cdc.gov/hepatitis/Statistics/2010Surveillance/PDFs/2010HepSurveillanceRpt.pdf>.

Cheney, Catherine P. "Overview of Hepatitis a Virus Infection in Adults." Up to Date. Ed. Martin S. Hirsch. 2 Oct. 2012. Wolters Kluwer Health. 3 Oct. 2013 <http://www.uptodate.com/contents/overview-of-hepatitis-a-virus-infection-in-adults>.

Talmage, J. B. , J. M. Melhorn, and M. H. Hyman, eds. Work Ability and Return to Work, AMA Guides to the Evaluation of. Second ed. Chicago: AMA Press, 2011.

Source: Medical Disability Advisor






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