Hepatitis A

from Wikipedia, the free encyclopedia
Classification according to ICD-10
B15.- Acute viral hepatitis A
B15.0 Viral hepatitis A with coma hepaticum
B15.9 Viral hepatitis A without coma hepaticum
ICD-10 online (WHO version 2019)

The Hepatitis A is an infectious disease caused by the hepatitis A virus. The main symptom is acute inflammation of the liver ( hepatitis ). Hepatitis A is never chronic and usually heals spontaneously without complications. It is transmitted through contaminated drinking water, contaminated food (e.g. mussels) or as a smear infection and occurs in temperate latitudes mostly as an imported disease after a stay in risk areas. A vaccination provides secure protection against hepatitis A.

Pathogen

Hepatitis A virus
Hepatitis A virus 01.jpg

Hepatitis A virus virion
Systematics
Classification : Viruses
Area : Riboviria
Empire : Orthornavirae
Phylum : Pisuviricota
Class : Pisoniviricetes
Order : Picornavirales
Family : Picornaviridae
Genre : Hepatovirus
Type : Hepatitis A virus
Taxonomic characteristics
Genome : (+) ssRNA linear
Baltimore : Group 4
Symmetry : icosahedral
Cover : no
Scientific name
Hepatovirus A
Short name
HAV, HVA
Left
NCBI  Taxonomy: 12092
ICTV Taxon History: 201852003

The hepatitis A virus (HAV, scientifically hepatovirus A , HVA) belongs to the Picornaviridae family , genus hepatovirus . It has an icosahedral nucleocapsid with 27  nm in diameter without envelope membrane , into which incorporated a single-stranded RNA - genome in positive strand orientation is. The genome has a total length of 7.5  kb . Due to the positive strand orientation, the genome is infectious per se, that is, under certain circumstances, the purified nucleic acid alone can cause an infection. The 3 'end of the genome is polyadenylated and has a non-translated region ( NTR ). The 5 'end has an additional NTR with a complex secondary structure which Internal ribosomal entry site ( IRES ), which the cap mediated -independent initiation of translation and additionally a covalently bound, virus-encoded protein VPg ( English associated genome virus protein ) .

The genome is from a single open reading frame ( English Open Reading Frame formed ORF) corresponding to a single precursor protein of 251  kDa in size and about 2225 amino acids encoded . This polyprotein cannot be determined experimentally because it is proteolytically cleaved into individual structural and non-structural proteins by the viral protease 3C during the actual synthesis . The structural proteins VP1, VP2, VP3 and VP4, which arise from the polypeptide P1, represent the basis of the viral capsid . They each consist of 60 units of the said proteins, only VP1 to VP3 being found on the surface. VP4, however, cannot be captured in the case of HAV. The non-structural proteins result from the polypeptides P2 and P3. They include, for example, protein 2A, which plays a role in virus assembly (assembly of virus particles ), as well as protease 3C and polymerase 3D. This virus is rarely found in countries with high hygienic standards. The virus is very resistant to high temperatures, acids and alkalis (for example soaps and other cleaning agents).

distribution

Hepatitis A - spread in the world (as of 2005)
  • High: prevalence higher than 8%
  • Medium: between 2% and 7%
  • Low: less than 2%

    • The HAV occurs in Southeast Asia, Russia, the Middle East, the Mediterranean , Africa, Central and South America and is often brought back from these countries when traveling. This occasionally leads to local outbreaks in hepatitis A-free regions. The number of cases reported to the RKI for Germany has developed as follows since 2000 (1994 for comparison):

    year reported case numbers
    1994 5484
    2000 2780
    2001 2274
    2002 1479
    2003 1368
    2004 1916
    2005 1217
    2006 1229
    2007 939
    2008 1073
    2009 926
    2010 788
    2011 831
    2012 832
    2013 779
    2014 682
    2015 830
    2016 737
    2017 1217
    2018 1044
    2019 874

    transmission

    The hepatitis A virus is transmitted fecally - orally (e.g. feces / urine  - hand - mouth) by smear infection . There is a high risk of transmission from corresponding sexual contacts.

    In countries with a high standard of hygiene, transmission occurs primarily through small children, whose infection is usually symptom-free. This means that the viruses can be transmitted through close personal contact as well as through contaminated drinking water, juices or insufficiently cooked food. Vegetables fertilized with faeces (e.g. salads) or seafood (e.g. mussels) pose an increased risk. In some mussel species, HAV can persist for several months.

    diagnosis

    The diagnosis is made clinically, laboratory evidence is provided by determining the anti-HAV IgM in the serum in the case of positive HAV total immunoglobulin or IgG . Direct detection of the pathogen by HAV antigen or virus RNA using RT-PCR in stool is unusual . Antigen or RNA are only detectable in the blood serum for a few hours.

    Clinical course

    The incubation period of this virus is 15 to 50 days. Hepatitis A can be acute over several weeks to months. Compared to other hepatitis, this disease is relatively mild. In children in particular, it is usually harmless and often quite asymptomatic. It never becomes chronic and therefore does not lead to permanent damage to the liver. The time of highest infectivity is about one to two weeks before the outbreak. However, patients are infectious for up to a week after the outbreak. Although most of the sick recover well, one in ten have to be treated in hospital. The healing usually takes four to eight weeks (rarely up to 18 months).

    HAV infection can lead to a critical impairment of liver function in patients with previously damaged liver or with chronic HBV or HCV infection.

    Several, but very rare cases have been described worldwide in which an HAV infection resulted in an acute breakdown of stem cells in the bone marrow ( agranulocytosis ) with fatal outcome. The immunological effects of HAV are discussed here. Almost every HAV infection has a small and transient decrease in peripheral immune cells.

    Symptoms

    After a period of about 28 days, nausea, vomiting, abdominal pain, fever, diarrhea, fatigue develop, often anicteric rarely severe (without jaundice), jaundiced (severe jaundice) with dark urine , pale stool and possible cholestatic .

    therapy

    Pediatric guidelines do not recommend causal therapy. Physical rest is recommended symptomatically. There are no guidelines for adults.

    Vaccination and prevention

    A vaccine is possible and recommended people "with a sexual behavior with an increased exposure risk; z. B. Men who have sex with men (MSM) ”,“ People with frequent transmission of blood components, e. B. haemophiles , or with diseases of the liver / with liver involvement ”and“ residents of psychiatric facilities or comparable care facilities for people with behavioral disorders or cerebral damage ”, as well as“ travelers to regions with high hepatitis A prevalence. "Likewise" People with an increased occupational exposure risk, including trainees, interns, students and volunteers with a comparable exposure risk in the following areas:

    Passive and active immunization is possible. Hepatitis A-only vaccines are injected intramuscularly twice . The second vaccination takes place after six to twelve months and ensures long-term protection, with protection already in place 14 days after the first vaccination at the latest. Children can be vaccinated from twelve months. The protective effect of the vaccination lasts for at least ten years.

    There are also combination vaccines, in addition to hepatitis B protection. These require a total of three vaccinations with follow-up vaccinations four weeks and six months after the first vaccination. Sometimes longer distances are used. A faster vaccination schedule can be used for faster immune formation. Re-vaccinations are recommended after seven days, 21 days and a fourth vaccination after twelve months.

    Further precautionary measures in risk areas against infection are:

    • Avoid seafood, especially mussels, raw meat and fish, if possible
    • only drink tap water that has been boiled beforehand
    • no ice cubes in drinks (as these are often made from tap water that has not been boiled)

    Reporting requirement

    Every acute viral hepatitis (including hepatitis A) must be reported by name under German law in accordance with Section 6 of the Infection Protection Act (IfSG) . In addition, evidence of the hepatitis A virus according to § 7 IfSG is also subject to reporting by name if it indicates an acute infection. The first obligation to notify primarily concerns the diagnosing physicians, the second primarily the management of laboratories ( § 8 IfSG).

    In Austria, after § 1 1 para. 1950 Epidemics Act of suspicion, illness and deaths from infectious hepatitis (hepatitis A, B, C, D, E) (including hepatitis A) notifiable . Doctors and laboratories, among others, are obliged to report this ( Section 3 Epidemics Act).

    Also in Switzerland is subject to hepatitis A the reporting requirement for physicians, hospitals, etc., and indeed after the Epidemics Act (EpG) in connection with the epidemic Regulation and paragraph 19 of Appendix 1 of the Ordinance on the reporting of observations of communicable diseases of man . In addition, the positive and negative laboratory analysis results for the hepatitis A virus must be reported to laboratories in accordance with the standards mentioned and Annex 3 of the EDI ordinance.

    Individual evidence

    1. ↑ Horst Kremling : Historical considerations on preventive medicine. Würzburg medical history reports 24, 2005, pp. 222–260, here p. 236 f.
    2. ↑ ICTV Master Species List 2018b.v2 . MSL # 34, March 2019
    3. ↑ a b c d ICTV: ICTV Taxonomy history: Enterovirus C , EC 51, Berlin, Germany, July 2019; Email ratification March 2020 (MSL # 35)
    4. ↑ Epidemiological Bulletin No. 3 of the RKI , January 23, 1996.
    5. ↑ Epidemiological Bulletin No. 3 of the RKI , January 18, 2002.
    6. ^ Epidemiological Bulletin No. 3 of the RKI , January 17, 2003.
    7. ↑ Epidemiological Bulletin No. 2 of the RKI , January 16, 2004.
    8. ↑ Epidemiological Bulletin No. 2 of the RKI , January 14, 2005.
    9. ↑ Epidemiological Bulletin No. 3 of the RKI , January 20, 2006.
    10. ↑ Epidemiological Bulletin No. 3 of the RKI , January 19, 2007.
    11. ↑ Epidemiological Bulletin No. 3 of the RKI , January 18, 2008.
    12. ↑ Epidemiological Bulletin No. 3 of the RKI , January 19, 2009.
    13. ↑ Epidemiological Bulletin No. 3 of the RKI , January 25, 2010.
    14. ↑ Epidemiological Bulletin No. 3 of the RKI , January 24, 2011.
    15. ↑ Epidemiological Bulletin No. 3 of the RKI , January 23, 2012.
    16. ↑ Epidemiological Bulletin No. 3 of the RKI , January 21, 2013.
    17. ↑ Epidemiological Bulletin No. 3 of the RKI , January 20, 2014.
    18. ↑ Epidemiological Bulletin No. 3 of the RKI , January 19, 2015.
    19. ↑ Epidemiological Bulletin No. 3 of the RKI , January 25, 2016.
    20. ↑ Epidemiological Bulletin No. 3 of the RKI , January 19, 2017.
    21. ↑ Epidemiological Bulletin No. 3 of the RKI , January 18, 2018.
    22. ↑ Epidemiological Bulletin No. 3 of the RKI , January 18, 2018.
    23. ↑ a b Epidemiological Bulletin No. 3 of the RKI , January 16, 2020.
    24. ↑ Hepatitis A: On a current accumulation in Munich. Increased risk of infection for homosexually active men again proven . In: Epidemiological Bulletin . No. 29/2003, July 18, 2003, ISSN  1430-0265 , ISSN  1430-1172 , pp. 223-224 ( PDF file; 114.8 kB ).
      Hepatitis A . In: www.aidshilfe.de . German AIDS Aid e. V., accessed and received on March 2, 2018.
    25. ↑ rki.de
    26. ↑ PM Matricardi: Infections preventing atopy: facts and new questions. In: Allergy. (1997); 52 (9), pp. 879-882.
    27. ↑ uni-duesseldorf.de ( Memento of the original from December 15, 2007 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / www.uni-duesseldorf.de
    28. ↑ Standing Vaccination Commission : Recommendations of the Standing Vaccination Commission (STIKO) at the Robert Koch Institute - 2017/2018 . In: Epidemiological Bulletin . No. 34/2017, August 24, 2017, doi: 10.17886 / EpiBull-2017-044.1 , ISSN  1430-0265 , pp. 333–380, here: 337–339 ( PDF file; 1.11 MB ).
    29. ↑ In exceptional cases, such as in patients with an increased bleeding tendency (hemophilia or treatment with vitamin K - antagonists such as warfarin or in Anglo-Saxon warfarin ), some of approved vaccines may also subcutaneously be given, and this with an increased risk normally harmless local side effects associated is.
    30. ↑ fit-for-travel.de .
    31. ↑ Technical information TWINRIX.

    literature

    Web links