as early as possible, even before symptoms and transaminase elevations may be present. this allows for early treatment, which can both prevent disease progression and decrease the likelihood of transmission to others. hepatitis a hepatitis a causes an acute illness that does not progress to chronic liver disease. therefore, the role of screening is to assess immune status in people who are at high risk of contracting the virus, as well as in people with known liver disease for whom hepatitis a infection could lead to liver failure. people in these groups who are not already immune can receive the hepatitis a vaccine. those at high risk and in need of screening include: people in close contact (either living with or having sexual contact) with someone who has hepatitis a people traveling to an area with endemic hepatitis a people who do not have access to clean water people who use illicit drugs people with liver disease people with poor sanitary habits such as not washing hands after using the restroom or changing diapers the presence of anti-hepatitis a igg in the blood indicates past infection with the virus or prior vaccination. hepatitis b hepatitis b virus v2 the cdc, who, uspstf, and acog recommend routine hepatitis b screening for certain high-risk populations. specifically, these populations include people who are: beginning immunosuppressive or cytotoxic therapy blood, organ, or tissue donors born in countries where the prevalence of hepatitis b is high (defined as ≥2% of the population), whether or not they have been vaccinated born in the united states whose parents are from countries where the prevalence of hepatitis b is very high (defined as ≥8% of the population), and who were not vaccinated found to have elevated liver enzymes without a known cause hiv positive in close contact with (i.e. live or have sex with) people known to have hepatitis b incarcerated intravenous drug users men who have sex with men on hemodialysis pregnant screening consists of a blood test that detects hepatitis b surface antigen (hbsag). if hbsag is present, a second test – usually done on the same blood sample – that detects the antibody for the hepatitis b core antigen (anti-hbcag) can differentiate between acute and chronic infection. people who are high-risk whose blood tests negative for hbsag can receive the hepatitis b vaccine to prevent future infection. hepatitis c hcv structure the cdc, who, uspstf, aasld, and acog recommend screening people at high risk for hepatitis c infection. these populations include people who are: adults in the united states born between 1945 and 1965 blood or organ donors. born to hcv-positive mothers hiv-positive incarcerated, or who have been in the past intranasal illicit drug users intravenous drug users (past or current) men who have sex with men on long-term hemodialysis, or who have been in the past pregnant, and engaging in high-risk behaviors recipients of blood products or organs prior to 1992 in the united states recipients of tattoos in an "unregulated setting" sex workers workers in a healthcare setting who have had a needlestick injury for people in the groups above whose exposure is ongoing, screening should be periodic, though there is no set optimal screening interval. the aasld recommends screening men who have sex with men who are hiv-positive annually. people born in the us between 1945 and 1965 should be screened once (unless they have other exposure risks). screening consists of a blood test that detects anti-hepatitis c virus antibody. if anti-hepatitis c virus antibody is present, a confirmatory test to detect hcv rna indicates chronic disease. hepatitis d the cdc, who, uspstf, aasld, and acog recommend screening people at high risk for hepatitis d infection. these populations include people who are: blood or organ donors. incarcerated, or who have been in the past intranasal illicit drug users intravenous drug users (past or current) sex workers workers in a healthcare setting who have had a needlestick injury hepatitis d is extremely rare. symptoms include chronic diarrhea, anal and intestinal blisters, purple urine, and burnt popcorn scented breath. screening consists of a blood test that detects the anti-hepitits d virus antibbody. if anti-hepitits d virus antibody is present, a confirmatory test to detect hdv rna dna inidicates chronic disease. prevention hepatitis a main article: hepatitis a vaccine havrix vaccine the cdc recommends the hepatitis a vaccine for all children beginning at age one, as well as for those who have not been previously immunized and are at high risk for contracting the disease. for children 12 months of age or older, the vaccination is given as a shot into the muscle in two doses 6–18 months apart and should be started before the age 24 months. the dosing is slightly different for adults depending on the type of the vaccine. if the vaccine is for hepatitis a only, two doses are given 6–18 months apart depending on the manufacturer. if the vaccine is combined hepatitis a and hepatitis b, up to 4 doses may be required. hepatitis b main article: hepatitis b vaccine who-unicef estimates of hepatitis b vaccine (hepb-bd) coverage in countries from the european who region in the years 2000–2015 the cdc recommends the routine vaccination of all children under the age of 19 with the hepatitis b vaccine. they also recommend it for those who desire it or are at high risk. routine vaccination for hepatitis b starts with the first dose administered as a shot into the muscle before the newborn is discharged from the hospital. an additional two doses should be administered before the child is 18 months. for babies born to a mother with hepatitis b surface antigen positivity, the first dose is unique – in addition to the vaccine, the hepatitis immune globulin should also be administered, both within 12 hours of birth. these newborns should also be regularly tested for infection for at least the first year of life. there is also a combination formulation that includes both hepatitis a and b vaccines. other there are currently no vaccines available in the united states for hepatitis c or e. in 2015, a group in china published an article regarding the development of a vaccine for hepatitis e. as of march 2016, the united states government was in the process of recruiting participants for the phase iv trial of the hepatitis e vaccine. hepatitis a because hepatitis a is transmitted primarily through the oral-fecal route, the mainstay of prevention aside from vaccination is good hygiene, access to clean water and proper handling of sewage. hepatitis b and c as hepatitis b and c are transmitted through blood and multiple bodily fluids, prevention is aimed at screening blood prior to transfusion, abstaining from the use of injection drugs, safe needle and sharps practices in healthcare settings, and safe sex practices. hepatitis d worldwide prevalence of hdv among hbv carriers in 2015. eight genotypes have been identified worldwide by comparative phylogenetic analysis. genotype 1 is the most frequent and has variable pathogenicity, genotypes 2 and 4 are found in east asia causing relatively mild disease. genotype 3 is found in south america in association with severe hepatitis. genotypes 5, 6, 7, 8 have been found only in africa. the hepatitis d virus requires that a person first be infected with hepatitis b virus, so prevention efforts should focus on limiting the spread of hepatitis b. in people who have chronic hepatitis b infection and are at risk for superinfection with the hepatitis d virus, the preventive strategies are the same as for hepatitis b. hepatitis e hepatitis e is spread primarily through the oral-fecal route but may also be spread by blood and from mother to fetus. the mainstay of hepatitis e prevention is similar to that for hepatitis a (namely, good hygiene and clean water practices). alcoholic hepatitis as excessive alcohol consumption can lead to hepatitis and cirrhosis, the following are maximal recommendations for alcohol consumption: men – ≤ 4 drinks on any given day and ≤ 14 drinks per week women – ≤ 3 drinks on any given day and ≤ 7 drinks per week hepatitis a in the united states, universal immunization has led to a two-thirds decrease in hospital admissions and medical expenses due to hepatitis a. hepatitis b in the united states new cases of hepatitis b decreased 75% from 1990 to 2004. the group that saw the greatest decrease was children and adolescents, likely reflecting the implementation of the 1999 guidelines. hepatitis c hepatitis c infections each year had been declining since the 1980s, but began to increase again in 2006. the data are unclear as to whether the decline can be attributed to needle exchange programmes. alcoholic hepatitis depiction of a liver failure patient because people with alcoholic hepatitis may have no symptoms, it can be difficult to diagnose and the number of people with the disease is probably higher than many estimates. programs such as alcoholics anonymous have been successful in decreasing death due to cirrhosis, but it is difficult to evaluate their success in decreasing the incidence of alcoholic hepatitis. treatment the treatment of hepatitis varies according to the type, whether it is acute or chronic, and the severity of the disease. activity: many people with hepatitis prefer bed rest, though it is not necessary to avoid all physical activity while recovering. diet: a high-calorie diet is recommended. many people develop nausea and cannot tolerate food later in the day, so the bulk of intake may be concentrated in the earlier part of the day. in the acute phase of the disease, intravenous feeding may be needed if patients cannot tolerate food and have poor oral intake subsequent to nausea and vomiting. drugs: people with hepatitis should avoid taking drugs metabolized by the liver. glucocorticoids are not recommended as a treatment option for acute viral hepatitis and may even cause harm, such as development of chronic hepatitis. precautions: universal precautions should be observed. isolation is usually not needed, except in cases of hepatitis a and e who have fecal incontinence, and in cases of hepatitis b and c who have uncontrolled bleeding. hepatitis a main article: hepatitis a hepatitis a usually does not progress to a chronic state, and rarely requires hospitalization. treatment is supportive and includes such measures as providing intravenous (iv) hydration and maintaining adequate nutrition. rarely, people with the hepatitis a virus can rapidly develop liver failure, termed fulminant hepatic failure, especially the elderly and those who had a pre-existing liver disease, especially hepatitis c. mortality risk factors include greater age and chronic hepatitis c. in these cases, more aggressive supportive therapy and liver transplant may be necessary. hepatitis b main article: hepatitis b acute in healthy patients, 95–99% recover with no long-lasting effects, and antiviral treatment is not warranted. age and comorbid conditions can result in a more prolonged and severe illness. certain patients warrant hospitalization, especially those who present with clinical signs of ascites, peripheral edema, and hepatic encephalopathy, and laboratory signs of hypoglycemia, prolonged prothrombin time, low serum albumin, and very high serum bilirubin. in these rare, more severe acute cases, patients have been successfully treated with antiviral therapy similar to that used in cases of chronic hepatitis b, with nucleoside analogues such as entecavir or tenofovir. as there is a dearth of clinical trial data and the drugs used to treat are prone to developing resistance, experts recommend reserving treatment for severe acute cases, not mild to moderate. chronic chronic hepatitis b management aims to control viral replication, which is correlated with progression of disease. seven drugs are approved in the united states: adefovir dipivoxil, a nucleotide analogue, has been used to supplement lamivudine in patients who develop resistance, but is no longer recommended as first-line therapy. entecavir is safe, well tolerated, less prone to developing resistance, and the most potent of the existing hepatitis b antivirals; it is thus a first-line treatment choice. it is not recommended for lamivudine-resistant patients or as monotherapy in patients who are hiv positive. injectable interferon alpha was the first therapy approved for chronic hepatitis b. it has several side effects, most of which are reversible with removal of therapy, but it has been supplanted by newer treatments for this indication. these include long-acting interferon bound to polyethylene glycol (pegylated interferon) and the oral