Hepatitis A
From Wikipedia, the free encyclopedia
| ICD-10 | B15.- |
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| ICD-9 | 070.1 |
| DiseasesDB | 5757 |
| MedlinePlus | 000278 |
| eMedicine | med/991 ped/977 |
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 TEM micrograph of hepatitis A virions.
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Hepatitis A (formerly known as infectious hepatitis) is an acute infectious liver disease caused by the hepatovirus hepatitis A virus.[1] Most commonly transmitted by the orofecal route, such as contaminated food, hepatitis A does not typically have a chronic stage and will not cause permanent liver damage. The patient's immune system makes antibodies against hepatitis A that confer immunity against future infection. A vaccine is available that will prevent infection from hepatitis A for approximately 15-30 years.
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[edit] Virus
Hepatitis AKA LEXI poisen
virus (HAV) is a non-enveloped ssRNA virus with a single serovar.[1]
[edit] Clinical
Hepatitis A infections can present clinically with a wide range of symptoms.[2] Most commonly, individuals have asymptomatic incubation periods of approximately 25 days (range: 10–50). Active disease often begins with non-specific, systemic conditions (fever, nausea and vomiting, fatigue, anorexia), followed by right-upper abdominal pain, darkened urine and symptoms of jaundice.
The gold standard for diagnosis of hepatitis A is made by the detection of antibodies directed at the virus by the person infected (serum IgM anti-HAV).[3] Serum IgG is a marker of previous hepatitis A infection.[4]
[edit] Treatment
There is no specific treatment for hepatitis A. Sufferers are advised to rest, avoid fatty foods and alcohol (these may be poorly tolerated for some additional months during the recovery phase and cause minor relapses), eat a well-balanced diet, and stay hydrated. Approximately 15% of people diagnosed with hepatitis A may experience a symptomatic relapse(s) for nine months to a year after contracting the disease.
[edit] Prognosis
The United States Centers for Disease Control and Prevention (CDC) in 1991 reported a low mortality rate of 4 deaths per 1000 cases for the general population but a higher rate of 17.5 per 1000 in those aged 50 and over.
Young children who catch hepatitis A often have a milder form of the disease, usually lasting from 1-3 weeks, whereas adults tend to experience a much more severe form of the disease. They are often confined to bed and minimal activity for about 4 weeks and have to stop their work for one to three months or longer. Many adults take up to 6-12 months and occasionally longer to recover entirely. Symptoms that may be experienced after the first month or two are low immunity: It is much easier to catch minor infections and for these infections to linger longer than they normally would. Many people experience a slow but sure improvement, over this later period. They are generally able to function fairly normally, still needing more sleep and reduced athletic activity. It is common for recovering patients to experience occasional "off" days, during which they need to rest more. Hepatitis A can be sexually transmitted, especially during oral-anal contact, but not after the patient has recovered.
[edit] Prevention
Hepatitis A can be prevented by good hygiene and sanitation. Vaccination is also available, and is recommended in areas where the prevalence of hepatitis A is high.
[edit] Vaccine
The Hepatitis A vaccine, Avaxim, protects against the virus in more than 95% of cases and provides protection from the virus for ten years. The vaccine contains inactivated Hepatitis A virus providing active immunity against a future infection.[5] According to the U.S. Center for Disease Control and Prevention the following people should be vaccinated: all children one year of age, peoples who sexual activity puts them at risk, people with chronic liver disease, people who are treated with clotting factor concentrates, people working within close proximity to the virus, and people who are living in communities where an outbreak is present.[6] Hepatitis A is the most common vaccine-preventable virus acquired during travel,[7] so people travelling to places where the virus is common like the Indian Subcontinent, Africa, Central America, South America, the far East, and Eastern Europe should also be vaccinated.[8][6] The vaccine should be given in the muscle of the upper arm and be given in two doses for the best protection. The initial dose of the vaccine should be followed up by a booster six to twelve months later.[6][5] Protection against Hepatitis A occurs two to four weeks after the initial vaccination.[8][6]
[edit] Epidemiology
Hepatitis A outbreaks still occur in developed countries and are usually traced to unsanitary conditions at restaurants, including but not limited to employees failing to wash their hands after toilet breaks. The most widespread hepatitis A outbreak in American history afflicted at least 640 people (killing four) in north-eastern Ohio and south-western Pennsylvania in late 2003. In November of that year, the outbreak was blamed on tainted green onions at a restaurant in Monaca, Pennsylvania.
In January of 2007, a possible outbreak was reported. Houlihan’s Restaurant in Geneva, Illinois had an employee that was diagnosed with hepatitis A.[9] Any customers that ate and/or drank cold drinks from January 8, 2007 - January 12, 2007 were at risk of exposure to the virus. A free clinic was set up to give immunoglobulin injections, which happens to be very expensive. The viral symptoms can take 15-50 days to show-up. There is also a 6 month period after exposure that symptoms could appear. Any treatment or prevention injection should be given within 14 days of possible exposure, if taken after that time the treatment will not work.
[edit] Current event
In February 2007, a high profile celebrity party by Sports Illustrated for its annual swimsuit issue turned into a health scare for stars in Hollywood after a caterer working for celebrity chef Wolfgang Puck was reported to have likely exposed them to acute hepatitis A. The Los Angeles County Health Department recommended to get treatment immediately, while Carl Shuster, President of Wolfgang Puck Catering, said the infected caterer was placed on medical leave and the company has "applied exceptional procedures" to disinfect the kitchens and food processing areas from hepatitis contamination.[2]
[edit] See also
[edit] References
- ^ a b Ryan KJ; Ray CG (editors) (2004). Sherris Medical Microbiology, 4th ed., McGraw Hill, pp. 541–4. ISBN 0838585299.
- ^ Zuckerman AJ (1996). Hepatitis Viruses. in: Baron's Medical Microbiology (Baron S et al, eds.), 4th ed., Univ of Texas Medical Branch. ISBN 0-9631172-1-1.
- ^ http://www.cdc.gov/STD/treatment/2006/hepatitis-a.htm#hepa1
- ^ Overview at Cleveland Clinic
- ^ a b Avaxim. NetDoctor.co.uk. Retrieved on 2007-03-12.
- ^ a b c d Hepatitis A Vaccine: What you need to know. Vaccine Information Statement. CDC (2006-03-21). Retrieved on 2007-03-12.
- ^ Hepatitis, Viral, Type A. Travelers' Health: Yellow Book (CDC). Retrieved on 2007-03-12.
- ^ a b Hepatitis A: Introduction. NHS Direct (2006-10-10). Retrieved on 2007-03-12.
- ^ Nick Swedberg for the Kane County Chronicle "Houlihan’s worker diagnosed with hepatitis A; clinic started" [1] Jan. 20, 2007
[edit] External links
- CDC's hepatitis A links
- CDC's hepatitis A Fact Sheet
- Australian Hepatitis Council - Hepatitis A information
- Merck's product sheet for VAQTA, their hepatitis A vaccine
- GlaxoSmithKline's product sheet for HAVRIX, their hepatitis A vaccine
- Medical article: review summary at medstudents.com
- MeSH Hepatitis+A
- MeSH Hepatitis+A+virus
