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 C


Related Terms

  • HCV
  • Non-A Non-B Hepatitis
  • Viral Hepatitis Type C

Differential Diagnosis

Specialists

  • Gastroenterologist
  • Hepatologist
  • Infectious Disease Internist

Comorbid Conditions

  • Alcoholism
  • Blood-clotting disorders
  • Chronic liver disease
  • Drug addiction

Factors Influencing Duration

Although recent progress has been made in the diagnosis and description of HCV infection, many factors influencing the severity of the disease have not yet been determined.

Medical Codes

ICD-9-CM:
070.41 - Hepatitis, Viral Type C with Hepatic Coma, Other Specified
070.44 - Chronic Hepatitis C with Hepatic Coma
070.5 - Hepatitis, Viral Type C without Mention of Hepatic Coma, Other Specified
070.51 - Hepatitis, Viral Type C
070.54 - Chronic Hepatitis C without Mention of Hepatic Coma
070.7 - Viral Hepatitis C, Unspecified
070.70 - Viral Hepatitis C without Hepatic Coma, unspecified; Unspecified Viral Hepatitis C NOS
070.71 - Viral Hepatitis C with Hepatic Coma, Unspecified

Overview

Hepatitis C is a viral infection that results in liver inflammation, formation of scar tissue (fibrosis) in the liver (cirrhosis) and chronic liver disease. Patients who develop cirrhosis have a 20% increased risk of hepatocellular carcinoma. It is the most common blood-borne infection worldwide. Transmission of the hepatitis C virus (HCV) is by exposure to infected blood, primarily through sharing intravenous drug paraphernalia.

Identified for the first time in the late 1980s, the HCV is considered to be the most insidious of the various hepatitis viruses (hepatitis A, B, C, D, and E) because symptoms tend to occur only in late stages of the disease. The virus also undergoes mutations that help it evade immune responses. An infection may go undetected for decades until a seropositive individual finally experiences symptoms that may indicate extreme liver damage or outright liver failure. The disease becomes chronic in 54% to 86% of all cases (Seeff).

Transmission period of acute HCV infection begins approximately a week or longer before the onset of symptoms and encompass all the acute clinical course of the disease. In the chronically ill, the period is indefinite. All persons who test positive should be considered potentially contagious.

Incidence and Prevalence: Although the number of new HCV cases has declined precipitously over the years, the burden of chronic infection remains. Rates have dramatically declined from 5.2 cases per 100,000 in 1995 to 0.5 cases per 100,000 persons age 25 - 39 in 2007. This decline has been largely ascribed to better hygiene practices among injection drug users. Since 2003, the HCV incidence has plateaued and is similar among all racial/ethnic groups except for American Indians and Alaskan Natives (AI/AN), whose rates have fluctuated. In 2007, 849 cases of confirmed HCV were reported in the US.; new HCV infections were estimated at 17,000 after factoring in asymptomatic individuals and underreporting (Daniels). An estimated 3.2 million individuals are chronically infected with HCV, the most common blood borne infection in the US (Daniels).

Source: Medical Disability Advisor



Causation and Known Risk Factors

Only 38% of all reported cases of HCV identify a known or suspected exposure source (CDC). Exposure to HCV-infected blood is the primary risk factor. Known risk factors include primarily shared use of intravenous needles. The Centers for Disease Control and Prevention (CDC) have identified the following additional risk categories: having sexual contact with a suspected or confirmed HCV patient, being a man who has sex with men (MSM), having multiple sex partners concurrently, having sexually transmitted diseases (STD), having household contact with a suspected or confirmed HCV patient, having had occupational exposure to blood, being a hemodialysis patient, having received a blood transfusion, having sustained a percutaneous injury, or having undergone surgery especially among those 40 or older ("Viral Hepatitis Surveillance").

The implementation of HCV screening in donated blood and blood products has almost eliminated the risk of transmission in blood transfusion recipients (1 in 2.3 million transfusions). Before 1992, when new regulations required more stringent donor testing, HCV was transmitted through blood transfusions; in 2010 only 6 of the 1,378 cases of HCV infection with information about blood transfusions reported having had a blood transfusion ("Viral Hepatitis Surveillance"). Nevertheless, individuals who received clotting factor concentrates before 1987, as well as blood or blood products, or who had organ transplantation before 1992, are at risk of having been infected. Rare infection by transfusion may lead to a higher incidence of chronic liver disease and cirrhosis, possibly indicating viral dose dependence. Hospitalized patients are at risk of transmission via receipt of blood not screened for HCV, and of patient-to-patient transmission through unsafe injections and other health care procedures, mainly in developing countries (Ward).

Healthcare workers may be exposed to infected blood via accidental needle-stick; accidental needle sticks among healthcare workers was documented in 2% of cases in 2007 (Daniels). The average risk of HCV transmission from an infected needle-stick exposure is 1.8% (0 – 7%). Other potential exposure routes include treatment with poorly sterilized medical instruments, contact with open cuts or wounds, and tattooing or body piercing. Risk also is increased in children born to a mother with HCV infection.

Individuals with alcoholism or cirrhosis, those over age 40, and those who have been infected with the virus for many years are more susceptible to developing HCV-related liver cancer (hepatocellular carcinoma). Alcohol use has been shown to accelerate progression of HCV-associated liver disease, which may lead to cirrhosis and hepatocellular carcinoma. Men are at a higher risk than women of developing this cancer, and women have better outcomes generally (Ghany). Hepatitis C progresses more rapidly in individuals with HIV infection (Perz). HIV-positive individuals are more likely to die from end-stage liver disease if co-infected with HCV.

Source: Medical Disability Advisor



Diagnosis

History: The incubation period ranges from 15 to 160 (mean 50) days; the onset of symptoms is insidious. Although early symptoms of the disease often are absent, individuals may report fatigue, fever, muscle and joint aches, headaches, weight loss, and weakness. Other reported symptoms may include loss of appetite, nausea, and mild right-upper-quadrant discomfort or tenderness. In more advanced stages of the disease, an individual may develop dark urine (choluria), itching, abdominal pain, and bloating. Because laboratory tests are not always definitive, the individual's clinical and social histories are important for diagnosis in the early stages of the disease.

Physical exam: The exam may show enlargement of the liver (hepatomegaly) and spleen (splenomegaly). Progressive liver disease may be indicated by visible branching capillaries on the skin (spider nevi), redness of the palms of the hand (palmar erythema), and a liver that is firm on examination. The skin and the white part of the eyes (sclerae) may appear yellowish (jaundice). Muscle wasting, accumulation of free fluid within the abdominal cavity (ascites), ankle swelling (edema), and skin abrasions (excoriations) from scratching also may be apparent.

Tests: Although anti-HCV antibodies are routinely detected by enzyme immunoassay (EIA), false-positive results occur occasionally (1%); false negative results may occur in individuals with compromised immune systems (e.g., HIV infection) (Ghany). EIA does not differentiate between acute and chronic infection. A highly sensitive qualitative assay such as polymerase chain reaction (PCR) or transcription-mediated amplification (TMA) is the preferred method of confirming this diagnosis and predicting the response to treatment. The presence of HCV RNA as detected with PCR or TMA indicates active infection. Antibodies to HCV are present in almost all individuals by 1 month after onset of acute illness. Recombinant immunoblot assays (RIBA-2) also can be used to confirm anti-HCV reactivity in individuals with active infection.

If available, HCV genotyping is an important tool in the clinical management of HCV infected patients. The genotype will inform the clinician about the severity and aggressiveness of the liver infection, and is useful for predicting the required duration of therapy and its efficacy. There are 6 main genotypes of HCV: genotype 1 (the most common in the United States, with about 70% of cases) is less responsive to treatment than genotypes 2 (about 20% of cases) or 3, and it typically requires longer therapy (48 weeks versus 24 weeks for genotypes 2 or 3) (Qiu). Genotypes 3-6 account for about 1% of cases each.

Diagnostic lab testing also includes a complete blood count (CBC) with differential leukocyte count, liver function tests, and thyroid stimulating hormone (TSH or thyrotropin) level, as well as HIV, and hepatitis B virus (HBV) screening. Progressive liver disease may be indicated if elevated results of liver function tests are found, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase, and bilirubin. Other tests, such as serum albumin or the platelet count, also may have abnormal values. In this case, a small piece of the liver may be removed for microscopic examination (liver biopsy). Biopsy usually is performed if the diagnosis is uncertain, if other liver disease may be present, or if the individual is immunocompromised. Some specialists recommend that liver biopsy be performed to rule out liver damage in all cases in which hepatitis C has been identified. Ultrasound imaging may be performed to evaluate liver tissue.

Source: Medical Disability Advisor



Treatment

The American Association for the Study of Liver Diseases has recommended that therapy for HCV be limited to those individuals who have histological evidence of progressive disease (viremia). Drugs are administered only to individuals with anti-HCV antibodies, HCV RNA, elevated serum ALT levels, and evidence of chronic hepatitis on liver biopsy. The current drug treatment regimen consists of a 24- to 48-week use of the combination of pegylated interferon (peginterferon) alpha, and ribavirin. In 2011, 2 new agents, boceprevir and telaprevir, were licensed for treatment of HCV, representing the first direct-acting agents (DAAs) with specific activity against HCV infection. Compared with pegylated interferon/ribavirin therapy alone, the addition of telaprevir or boceprevir to this regimen increases sustained virologic response (SVR) rates from 38% to 63% and 44% to 75%, respectively (Ward). Treatment also is administered in cases in which fibrosis or moderate to severe degrees of inflammation and tissue death (necrosis) are indicated by liver biopsy. Individuals with acute viremia or lower quantitative HCV RNA levels typically are managed on a case-by-case basis. Individuals with pre-existing cirrhosis may not show improvement with standard drug therapy. In HIV-infected individuals, standard drug therapy is administered as long as there are no contraindications.

In extreme cases, a liver transplant may be performed, depending on organ availability and prognosis for the individual. Unlike for hepatitis A and B, a preventive vaccine has not yet been developed for hepatitis C (Ghany).

Source: Medical Disability Advisor



Prognosis

In most individuals, HCV infection does not develop into a life-threatening condition but does progress to chronic disease. Many individuals with this form of hepatitis have few, if any, symptoms, particularly in the early stages of the disease. The virus may be present without active infection developing.

Approximately 75% to 85% of individuals with active HCV infection will progress to chronic hepatitis, 15% to 35% of these will develop cirrhosis, and 1% to 3% will develop liver cancer (Ward). One of the most common reasons for liver transplants in the US is liver failure from chronic hepatitis C.

Genetic testing can reveal individuals infected with a viral genotype that predicts a less successful response to treatment (Qiu). Progression of disease is accelerated among persons who are older, who are obese, who are immunosuppressed (e.g., HIV co-infected), and who consume more than about 50 g of alcohol per day (Ghany).

Source: Medical Disability Advisor



Complications

Chronic hepatitis may develop into cirrhosis or, rarely, into hepatocellular carcinoma. Other complications found to be associated with chronic hepatitis include thyroiditis, vasculitis, and various immune disorders.

More than 10% of those treated with standard drug therapy develop mild to moderate side effects from peginterferon alpha, including fatigue, muscle aches, headaches, nausea and vomiting, skin irritation at the injection site, low-grade fever, weight loss, irritability, depression, mild bone marrow suppression, and sometimes hair loss. Side effects from ribavirin may include anemia, fatigue and irritability, itching, skin rash, nasal stuffiness, sinusitis, and cough.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

The absence of jaundice is not required before returning to work; however, individuals with jaundice often do not work. Decisions about return to work may depend on the amount of contact the individual has with the public and the chances of blood-to-blood contact. Employees required to perform strenuous tasks may need to limit their job-related activities temporarily after returning to work. Company policy on medication usage should be reviewed to determine if medication use is compatible with job safety and function.

For more information on risk, capacity, and tolerance, 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, from the use of firearms.

Source: Medical Disability Advisor



Maximum Medical Improvement

Treatment regimens usually last 1 year.

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:

  • Was individual exposed to HCV-contaminated blood via intravenous drug use, acupuncture, tattooing, sharing razors, transfusion, surgery, dialysis, or accidental needle stick?
  • Is individual a healthcare worker?
  • Does individual engage in high-risk sexual activities?
  • Has diagnosis of viral hepatitis C been confirmed?
  • Have conditions with similar symptoms, such as other types of viral hepatitis, infectious mononucleosis, or cytomegalovirus, been ruled out?
  • Have blood tests (EIA, PCR, TMA, or RIBA-2) been done to identify HCV and HCV RNA to ensure proper diagnosis and predict response to and duration of treatment?
  • Has genetic testing been performed to identify strain of HCV?
  • Was active infection (viremia) confirmed?
  • Was ultrasound imaging done to evaluate liver tissue?
  • Was liver biopsy performed? Was chronic liver disease confirmed?

Regarding treatment:

  • Was individual treated with standard drug therapy appropriate for identified strain of HCV?
  • Is individual compliant with treatment recommendations? If not, what can be done to increase compliance?
  • Is individual being considered for a liver transplant?

Regarding prognosis:

  • If symptoms persist longer than expected, should diagnosis be revisited?
  • Does individual have a coexisting condition (e.g., alcohol or drug addiction, HIV infection, pre-existing liver disease) that may affect recovery?
  • Does individual continue to consume alcohol?
  • Would individual benefit from consultation with a specialist (gastroenterologist, hepatologist, infectious disease specialist)?
  • Does the individual have acute or chronic HCV?
  • Has liver disease progressed to permanent liver damage or liver cancer?
  • Is individual on local/national transplant lists?

Source: Medical Disability Advisor



References

Cited

"Viral Hepatitis Surveillance – United States, 2010." CDC. 26 Aug. 2013. Centers for Disease Control and Prevention. 3 Oct. 2013 <http://www.cdc.gov/hepatitis/Statistics/2010Surveillance/index.htm>.

Daniels, D. , S. Grytdal, and A. Wasley. "Surveillance for Acute Viral Hepatitis - United States, 2007." Morbidity and Mortality Weekly Report 58 (2009): 1-27.

Ghany, M. G. , et al. "Diagnosis, Management, and Treatment of Hepatitis C: An Update." Hepatology 49 (2009): 1335-1374.

Perz, J. F. , et al. "The Contributions of Hepatitis B Virus and Hepatitis C Virus Infections to Cirrhosis and Primary Liver Cancer Worldwide." Hepatology 45 (2006): 529-538.

Qui, P. , et al. "HCV Genotyping Using Statistical Classification Approach." Journal of biomedical science 16 (2009): 62.

Seef, L. B. "Natural History of Chronic Hepatitis C." Hepatology 36 (2002): S35-S46.

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.

Ward, J. W. "The Epidemiology of Chronic Hepatitis C and One-Time Hepatitis C Virus Testing of Persons Born During 1945 to 1965 in the United States." Clinics in Liver Disease 17 (2013): 1-11.

General

"Hepatitis C." World Health Organization. 7 2013. 3 Oct. 2013 <http://www.who.int/mediacentre/factsheets/fs164/en>.

Source: Medical Disability Advisor






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