"Hepatitis E is" inflammation of the liver due to an RNA virus classified in the hepevirus family (HEV: hepatitis E virus) of which four genotypes have been identified, ie groups of viruses characterized by genetic affinity.
The infection is present in many areas of the world with a higher number of new cases (incidence) in the countries of Southeast Asia and Latin America, especially where there are many inhabitants and the hygienic conditions are inadequate. Approximately 20 million infections have been reported worldwide, of which approximately 3 million cause disorders (symptoms).
The age group most affected by the infection is between 15 and 40 years. In Italy, the cases reported to the SEIEVA surveillance system of the Istituto Superiore di Sanità are relatively few (just under 200 in the 2007-2016 period) but however, there is still a lack of knowledge of the ways of transmission of the infection and of the signals that indicate its presence.
The infection is mainly transmitted via the fecal-oral route, by drinking water contaminated with the feces of sick people or animals. Limited cases have been reported following the ingestion of inadequately cooked pork.
Hepatitis E tends to appear suddenly (acute form) 15-60 days after infection of the virus. The first symptoms (symptoms) of acute hepatitis are represented by:
- malaise and weakness
- low-grade fever
- nausea, vomiting
- abdominal pain
- itch, skin rashes
After a few days, the skin and eyes generally take on a yellowish color (jaundice).At this stage, the urine may appear darker than normal. The disorders (symptoms) caused by acute hepatitis can last for a variable period from two to six weeks and usually tend to spontaneously decrease. In rare cases, also documented in women during the third trimester of pregnancy, hepatitis it can present in a fulminant form with the risk of mortality due to insufficient functioning of the liver.
The hepatitis E virus (HEV), coming from the faeces of infected people or animals, can survive in an active form and contaminate the water used for food or agriculture. Furthermore, the virus is present in the meat of animals (pigs, wild boars ) untreated or not properly cooked.
For this reason, the infection is mainly transmitted through:
- ingestion of contaminated water, fruit and vegetables with fecal material from infected people, mainly in highly populated areas where there is no adequate management of sewer discharges. The preparation of meals by sick people can spread the infection in the home or collectively
Furthermore, albeit to a much lesser extent, transmission of the infection is possible through:
- pork intake not properly cooked
- maternal-fetal transmission, although it has only been documented in a small number of cases
The diagnosis of hepatitis E is based on the disorders (symptoms) present and on instrumental and laboratory investigations. The characteristic symptoms of acute hepatitis (jaundice, abdominal pain, nausea, vomiting and loss of appetite) can provide the doctor with indications for the prescription of laboratory tests able to identify the cause of the hepatitis.
An enlarged liver, with or without pain, may be seen during a medical examination or an abdominal ultrasound.
In laboratory tests, there is usually an increase in the blood of certain enzymatic proteins (transaminases GOT / AST and GPT / ALT, gamma-GT) which represent an index of the state of inflammation of the liver and elevated levels of bilirubin in the blood and in the urine.
The detection (diagnosis) of hepatitis E requires, however, the presence in the blood of antibodies against HEV. In particular, antibodies of the IgM class indicate an "infection in progress while those of the IgG class may be present in the acute phase or months or years after healing. There is also a molecular examination, called RT-PCR test, for the detection of viral RNA in the blood.
The disorders (symptoms) caused by hepatitis E generally last a few weeks and tend to decrease over time until they disappear. The treatment consists of adequate rest and a specific diet based on light and fat-free foods up to Complete healing of liver alterations. In more serious cases, the use of anti-viral drugs such as ribavirin has been experimented with moderate success.
Prevention of hepatitis E
Infection can be prevented:
- respecting the hygiene rules both collective (water control, sewage management, food production control and distribution) and individual (hand and food washing, cooking food)
- avoiding, in countries where the infection is present and widespread (endemic), the ingestion of non-bottled water (also in the form of ice), the intake of vegetables and fruit washed with running water or uncooked food
A vaccine against hepatitis E is available which confers effective protection against the virus and promotes the response of the body's defense system (immune).Its use is suggested by the World Health Organization (WHO) to people residing in countries where the infection is widespread (Southeast Asia, subtropical Latin America) or where there are limited epidemics, particularly if hygienic conditions are not adequate.
Hepatitis E, in most cases, occurs in an acute form, lasts for a few weeks and must be treated exclusively with rest and a specific diet, based on light foods, low in fat, and rich in fiber and vegetables. during this period it is important to prevent the spread of the infection to family members and cohabitants through frequent hand washing and careful preparation of food. In severe cases, in which the liver is compromised, hospitalization is indicated to receive the necessary treatment.
World Health Organization (WHO). Fact sheet on Hepatitis E (English)
World Health Organization (WHO). Hepatitis E vaccine: WHO position paper (English)
Khuroo MS. Discovery of hepatitis E: the epidemic non-A, non-B hepatitis 30 years down the memory lane [Summary]. Virus Research. 2011; 161: 3-14
Khuroo M, Khuroo MS, Khuroo NS. Hepatitis E: Discovery, global impact, control and cure. World Journal of Gastroenterology. 2016; 22: 7030–7045
EpiCentro (ISS). Viral hepatitis
Tosti ME, Mele A, Spada E, Marzolini F, Crateri S, Ferrigno L, Iantosca G, SEIEVA collaboration group (Ed.). X Workshop SEIEVA (Integrated Epidemiological System of Acute Viral Hepatitis). Bagno Vignoni (Siena) 13-15 December 2012. Proceedings. Rome: Higher Institute of Health; 2015 (ISTISAN Reports 15/29)