DESECRIPTION

Infectious Agent:
All types of VH are caused by RNA virus except HBV, which is caused by DNA virus . 

Water-related Diseases:
Hepatitis, a broad term for inflammation of the liver, has a number of infectious and non-infectious causes. Two of the viruses that cause hepatitis (hepatitis A and E) can be transmitted through water and food; hygiene is therefore important in their control.
The disease and how it affects people
Among the infectious causes, hepatitis A and hepatitis E are associated with inadequate water supplies and poor sanitation and hygiene, leading to infection and inflammation of the liver. The illness starts with an abrupt onset of fever, body weakness, loss of appetite, nausea and abdominal discomfort, followed by jaundice within a few days.
The disease may range from mild (lasting 1-2 weeks) to severe 
disabling disease (lasting several months). In areas highly endemic for hepatitis A, most infections occur during early childhood. The majority of cases may not show any symptoms; fatal cases due to fulminant acute hepatitis are rare. Nearly all patients recover completely with no long-term effects.
The cause:
Hepatitis A and E viruses, while unrelated to one another, are both transmitted via the fecal-oral route, most often through contaminated water and from person to person. Hepatitis A could also be transmitted via food contaminated by infected food-handlers, uncooked foods, or foods handled after cooking. Hepatitis A has also caused outbreaks transmitted through injecting or non-injecting drug use.

Distribution
Both hepatitis A and E are found worldwide. Hepatitis A is particularly frequent in countries with poor sanitary and hygienic conditions (in Africa, Asia, and Central and South America). Countries with economies in transition and some regions of industrialized countries where sanitary conditions are sub-standard are also highly affected, e.g.in southern and eastern Europe and some parts of the Middle East. Outbreaks of hepatitis E have occurred in Algeria, Bangladesh, China, Ethiopia, Indonesia, Iran, Libyan, Mexico, Nepal, Pakistan, Somalia .
Scope of the Problem
The mortality rate is low (0.2% of icteric cases) and the disease ultimately resolves. Occasionally, extensive necrosis of the liver occurs during the first 6-8 weeks of illness. In such cases, high fever, marked abdominal pain, vomiting, jaundice, and hepatic encephalopathy (with coma and seizures) are the signs of fulminant hepatitis, leading to death in 70-90% of the patients. In these cases mortality is highly correlated with increasing age, and survival is uncommon over 50 years of age. Among patients with chronic hepatitis B or C or underlying liver disease, who are super infected with hepatitis A virus, the mortality rate increases considerably.
Improved economic and sanitary conditions may lead to a higher disease incidence in older age groups, with higher reported rates of clinically evident hepatitis A. In countries with very low hepatitis A infection rates, the disease may occur among specific risk groups such as travelers.
 Hepatitis E:  is mainly found in young to middle-aged adults. Women in the third trimester of pregnancy are especially susceptible to acute fulminant hepatitis arising from hepatitis E infection.
Symptoms can return over the following 6–9 months and include:
Fatigue ,Fever, Abdominal pain ,Nausea ,Diarrhea ,Appetite loss ,Depression ,Jaundice, Sharp pains in the right-upper quadrant of the abdomen ,Weight loss ,Itching 
Bile is removed from blood stream and excreted in urine giving a dark amber color 
Feces tend to be light in color due to lack of bilirubin in bile 
Strong aversion to cigarette smoking 
Pathogenesis
Following ingestion, HAV enters the bloodstream through the epithelium of the oropharynx or intestine. The blood carries the virus to its target, the liver, and multiplies within hepatocytes and Kupffer cells (liver macrophages). 
Virions are secreted into the bile and released in stool. HAV is excreted in large quantities approximately 11 days prior to appearance of symptoms or anti-HAV IgM antibodies in the blood. 
The incubation period is 15–50 days and mortality is less than 0.5%. 
Diagnosis
Serum IgG, IgM and ALT following Hepatitis A virus infection
Although HAV is excreted in the feces towards the end of the incubation period, specific diagnosis is made by the detection of HAV-specific IgM antibodies in the blood. IgM antibody is only present in the blood following an acute hepatitis A infection. It is detectable from one to two weeks after the initial infection and persists for up to 14 weeks. 
The presence of IgG antibody in the blood means that the acute stage of the illness is past and the person is immune to further infection. IgG antibody to HAV is also found in the blood following vaccination and tests for immunity to the virus are based on the detection of this antibody.
During the acute stage of the infection, the liver enzyme alanine transferase (ALT) is present in the blood at levels much higher than is normal. The enzyme comes from the liver cells that have been damaged by the virus.
Hepatitis A virus is present in the blood, (viremia), and feces of infected people up to two weeks before clinical illness develops.
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 6–10% of people diagnosed with hepatitis A may experience one or more symptomatic relapse(s) for up to 40 weeks after contracting this disease.

 Prognosis
The United States Centers for Disease Control and Prevention (CDC) in 1991 reported a low mortality rate for hepatitis A 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. Death usually occurs when the patient contracts Hepatitis A while already suffering from another form of Hepatitis, such as Hepatitis B or Hepatitis C
Hepatitis E is a viral hepatitis (liver inflammation) caused by infection with a virus called hepatitis E virus (HEV). HEV is a positive-sense single-stranded RNA virus. HEV has a fecal-oral transmission route. Infection with this virus was first documented in 1955 during an outbreak in New Delhi, India
Epidemiology
The incidence of hepatitis E is highest in juveniles and adults between the ages of 15 and 40. Though children often contract this infection as well, they less frequently become symptomatic. Mortality rates are generally low, for Hepatitis E is a “self-limiting” disease, in that it usually goes away by itself and the patient recovers. However, during the duration of the infection (usually several weeks), the disease severely impairs a person’s ability to work, care for family members, and obtain food. Hepatitis E occasionally develops into an acute severe liver disease, and is fatal in about 2% of all cases
Clinically, it is comparable to hepatitis A, but in pregnant women the disease is more often severe and is associated with a clinical syndrome called fulminant hepatic failure. Pregnant women, especially those in the third trimester, suffer an elevated mortality rate from the disease of around 20%.
Although there is one serotype of this virus, four distinct genotypes have been reported. Genotypes 1 and 2 are restricted to humans and often associated with large outbreaks and epidemics in developing countries with poor sanitation conditions. Genotypes 3 and 4 infect humans, pigs and other animal species and have been responsible for sporadic cases of hepatitis E in both developing and industrialized countries.
   Patterns
Hepatitis E is prevalent in most developing countries, and common in any country with a hot climate. It is widespread in Southeast Asia, northern and central Africa, India, and Central America. It is spread mainly through fecal contamination of water supplies or food; person-to-person transmission is uncommon. Outbreaks of epidemic Hepatitis E most commonly occur after heavy rainfalls and monsoons because of their disruption of water supplies. Major outbreaks have occurred in New Delhi, India (30,000 cases in 1955-1956), Burma (20,000 cases in 1976-1977), Kashmir, India (52,000 cases in 1978), Kanpur, India (79,000 cases in 1991), and China (100,000 cases between 1986 and 1988).
Prevention
Improving sanitation is the most important measure, which consists of proper treatment and disposal of human waste, higher standards for public water supplies, improved personal hygiene procedures and sanitary food preparation. Thus, prevention strategies of this disease require large-scale international financing of water supply and water treatment projects. A vaccine based on recombinant viral proteins has been developed and recently tested in a high-risk population (military personnel of a developing country). The vaccine appeared to be effective and safe, but further studies are needed to assess the long-term protection and the cost-effectiveness of hepatitis E vaccination.

In Iraq 2005- 2006 :
Hepatitis A: is hyper-endemic in Iraq, with no gender differences. Serologic evidence of previous exposure to the infective agent is present in the majority of general population (96.4%). It is a disease of childhood. After the second decade of life no obvious increase in its prevalence is noticed.
. Hepatitis E: is endemic in Iraq with a prevalence of its serologic marker (IgG antibody) of 20.3%. Males have a slightly higher prevalence rate. A steady increase in prevalence is observed with advancing age.
Hepatitis A vaccines
Techniques for growing HAV in cell culture have made it possible to generate sufficient amounts of virus for vaccine production. Several inactivated or live attenuated vaccines against hepatitis A have been developed, but only four inactivated hepatitis A vaccines are currently available internationally. All four vaccines are similar in terms of efficacy and side-effect profile. The vaccines are given parenterally, as a two-dose series, 6-18 months apart. The dose of vaccine, vaccination schedule, ages for which the vaccine is licensed, and whether there is a pediatric and adult formulation varies from manufacturer to manufacturer. No vaccine is licensed for children younger than one year of age.
A combination vaccine containing inactivated hepatitis A and recombinant hepatitis B vaccines has been licensed since 1996 for use in children aged one year or older in several countries. The combination vaccine is given as a three-dose series, using a 0, 1, 6 month schedule. 
Hepatitis A vaccines are all highly immunogenic. Nearly 100% of adults will develop protective levels of antibody within one month after a single dose of vaccine. Similar results are obtained with children and adolescents in both developing and developed countries.