What Is Hepatitis A? Common Signs and Effective Prevention Tips - pharmacyteach

DISEASES OF THE LIVER

ACUTE HEPATITIS A

 

ESSENTIALS OF DIAGNOSIS

v Prodromal of anorexia, nausea, vomiting, malaise, aversion to smoking.

v  Fever, enlarged and tender liver, jaundice.

v  Normal to low white cell count; markedly elevated aminotransferases.

 

General Considerations

The hepatitis A virus (HAV) causes hepatitis A, an inflammation of the liver. The virus spreads mainly through the consumption of food or water contaminated with an infected person's excrement by an uninfected (and unvaccinated) person. Oral-anal sex, poor personal hygiene, inadequate sanitation, and contaminated food or water are all strongly linked to the disease.

The five hepatotropic viruses (A, B, C, D, and E), as well as numerous medications and toxic substances, can cause hepatitis; the clinical signs and symptoms may be similar regardless of the source. The 27-nm RNA hepatovirus known as the Hepatitis A virus (HAV) is a member of the picornavirus family and can cause hepatitis in epidemics or in isolated individuals. The fecal-oral pathway is how the virus is disseminated, and crowded conditions and inadequate cleanliness contribute to its transmission. International travel has become the primary risk factor, accounting for more than 40% of cases, and the incidence rate of HAV infection has decreased from 14 to 1.3 cases per 100,000 people since the introduction of the HAV vaccine in the United States in 1995. This has resulted in a 32% decrease in the mortality rate.

According to WHO estimates, 7134 people died from hepatitis A globally in 2016 (which represents 0.5% of the deaths from viral hepatitis). With a propensity for cyclical recurrences, hepatitis A occurs both sporadically and in epidemics around the globe. As demonstrated by the 1988 pandemic in Shanghai that afflicted over 300,000 people, epidemics linked to tainted food or water can explode. They can also spread from person to person, impacting communities for months at a time. Hepatitis A viruses can survive food production procedures that are frequently employed to inactivate or eliminate bacterial diseases because they are persistent in the environment [1].

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Distribution by geography

Hepatitis A virus infection levels can be classified as high, intermediate, or low in geographic distribution areas. However, since infected young infants do not exhibit any obvious symptoms, infection does not always equate to disease.

 

In low- and middle-income nations with inadequate sanitation and hygiene standards, infection is prevalent, and 90% of children have contracted the hepatitis A virus before turning ten years old, usually with no symptoms (2). High-income nations with clean and sanitary conditions have low infection rates. Adolescents and adults in high-risk groups, such as injecting drug users (PWID), men who have sex with men (MSM), travelers to high-endemicity areas, and secluded populations, like closed religious groups, may contract the disease. There have been significant epidemics among homeless people in the United States of America.

An additional 18% of cases are linked to exposure to foreign visitors. Contaminated food or water, especially undercooked seafood, can still cause common source outbreaks. HAV has been identified as a reemerging food-borne public health concern in Europe, and an epidemic in the United States in 2013 was caused by frozen pomegranate arils imported from Turkey. There have also been documented incidences among international adoptees and their connections, as well as outbreaks among injecting drug users.

On average, the incubation phase lasts 30 days. Rarely, HAV is eliminated in feces beyond the first week of sickness, but it can occur up to two weeks before the onset of clinical illness. Hepatitis A has a low death rate, and fulminant hepatitis A is rare, except a few unusual cases where it develops in a patient who already has chronic hepatitis C. A chronic carrier status does not exist. Approximately 30% of people in the US have serologic indications of prior HAV infection.

Clinical Findings

 

A. Symptoms and Signs

 

 While clinical disease is typically asymptomatic in youngsters, but more severe in adults. The symptoms, which include anorexia, upper respiratory symptoms, myalgia, arthralgia, easy fatigability, and malaise, might appear suddenly or gradually. Similar to anorexia, a dislike of smoking may develop early. In addition to diarrhea or constipation, nausea and vomiting are common. Except in rare instances where systemic toxicity may develop, fever is typically low-grade but prevalent. Jaundice frequently begins with effervescence and a decrease in pulse rate.

Abdominal pain is usually mild and constant in the right upper quadrant or epigastrium, often aggravated by jarring or exertion, and rarely may be severe enough to simulate cholecystitis.

 

Jaundice could appear concurrently with the early symptoms, but it usually takes 5–10 days to appear. Jaundice never appears in a large number of patients. Prodromal symptoms frequently get worse when jaundice first appears, and then there is a gradual improvement in the condition. During this stage, alcoholic stools may be present.

 

Usually, the acute illness goes away in two to three weeks, and by nine weeks, all clinical and laboratory symptoms have recovered. Recovery is common, but in few instances, one or two relapses may occur after clinical, biochemical, and serologic recovery. Sometimes the course of acute hepatitis A is complicated by acute cholecystitis.

 

Hepatomegaly-rarely marked-is present in over half of cases. Liver tenderness is usually present. Splenomegaly is reported in 15% of patients, and soft, enlarged lymph nodes especially in the cervical or epitrochlear areas-may occur.

 

Who is in danger?

Hepatitis A can infect someone who has not had a vaccination or has already contracted the virus. The majority of hepatitis A infections in regions with high epidemics happen in young children. Risk factors consist of:

 

Ø Living in a home with an infected person,

Ø using recreational drugs,

Ø having sex with someone who has an acute hepatitis A infection,

Ø having inadequate sanitation,

Ø not having access to safe water,

Ø Visiting high-endemicity areas without getting vaccinated.

 

B. Laboratory Findings

 

During the preicteric period, the white blood cell count is typically low to normal. There may occasionally be large atypical lymphocytes seen. Bilirubinuria frequently occurs before jaundice manifests, and mild proteinuria is usual. Elevations of bilirubin and alkaline phosphatase accompany remarkably high ALT or AST values, and in a small percentage of cases, the latter continue to rise after aminotransferase levels have returned to normal. Sometimes cholestasis is noticeable. Early in the illness, anti-body to hepatitis A (anti-HAV) develops (Figure 16-1). Serum levels of IgM and IgG anti-HAV can be found shortly after the beginning. The first week of clinical illness is when peak IgM anti-HAV titers arise, and they go away in three to six months. Although IgM anti-HAV detection is a great test for identifying acute hepatitis A, it is not advised for evaluating asymptomatic individuals with consistently high blood aminotransferase levels due to the possibility of false-positive results. One patient receiving rituximab for rheumatoid arthritis has reported experiencing false-negative results. IgG anti-HAV titers increase one month into the illness and can last for years. IgG anti-HAV (without IgM anti-HAV) signifies immunity, noninfectivity, and prior HAV exposure.

Differential Diagnosis

Other viruses that cause hepatitis, especially hepatitis B and C, as well as illnesses like infectious mononucleosis, cytomegalovirus infection, herpes simplex virus infection, Middle East respiratory syndrome, and infections from numerous other viruses, such as influenza and Ebola virus, are included in the differential diagnosis. Other illnesses include brucellosis, rickettsia diseases, such as Q fever and drug-induced liver injury, and ischemic hepatitis (shock liver). Sometimes the acute onset of autoimmune hepatitis can be mistaken for acute viral hepatitis. Rarely, leukemia, lymphoma, or liver cancer that has spread may show symptoms similar to hepatitis.

The prodromal phase of viral hepatitis must be distinguished from another infectious diseases, such as the exanthematous diseases. Cholestasis may mimic obstructive jaundice.

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Prevention

Strict isolation of patients is not necessary, but hand washing after bowel movements is required. Unvaccinated per-sons who are exposed to HAV are advised to receive post exposure prophylaxis with a single dose of HAV vaccine or immune globulin (0.02 mL/kg) as soon as possible. The vaccine is preferred in healthy persons ages 1 year to 40 years, whereas immune globulin is preferred in those who are younger than I year or older than 40 years or who are immunocompromised or who have chronic liver disease.

 

In the United States, there are two effective inactivated hepatitis A vaccines that are advised for everyone who lives in or visits endemic areas (including military personnel), people with chronic liver disease after being prescreened for immunity (though it has been questioned whether it is cost-effective to vaccinate all patients with concurrent chronic hepatitis C), people with clotting-factor disorders receiving concentrate treatment, men who have sex with men, people who handle animals, people who use illegal drugs, people who work in sewage systems, people who handle food, close personal contacts of international adoptees, and children and caregivers in daycare facilities and institutions. A single dose of the vaccine given at any point prior to departure can offer sufficient protection for healthy travelers. The Centers for Disease Control and Prevention's (CDC) Advisory Committee on Immunization Practices has approved the routine vaccination for use in all children in the United States between the ages of one and two, and it is recommended for all children in states where the incidence of hepatitis A is at least twice the national average. The HAV vaccination is also successful in preventing secondary transmission to primary cases' home contacts. One milliliter (1440 ELISA units) of Havrix (GlaxoSmithKline) or one milliliter (50 units) of Vaqta (Merck) should be administered intramuscularly to adults, with a booster dose at six to eighteen months. There is a vaccination called Twinrix, made by GlaxoSmithKline, that combines the hepatitis A and B viruses. The response to the HAV vaccine is hampered by HIV infection, particularly in those whose CD4 count is less than 200/mcLl.

 

Treatment

Bed rest is advised only in cases where symptoms are noticeable. Intravenous 10% glucose is recommended if there is significant nausea and vomiting or if oral intake is significantly reduced.

The goal of dietary control is to eat tasty meals as directed without going overboard; breakfast is typically the meal that is most tolerated. Avoid hepatotoxic substances, alcohol, and strenuous physical activity. Because oxazepam metabolism is not hepatic, small doses are safe; morphine sulfate should be avoided.

Patients with viral hepatitis, even those with fulminant illness, do not benefit from corticosteroids.

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Prognosis

 

In most patients, clinical recovery is generally complete within 3 months. Laboratory evidence of liver dysfunction

may persist for a longer period, but most patients recover completely. Hepatitis A does not cause chronic liver dis-ease, although it may persist for up to 1 year, and clinical and biochemical relapses may occur before full recovery.

The mortality rate is less than 0.6%.

 

When to Admit

 

Ø Encephalopathy is present.

Ø INR greater than 1.6.

Ø The patient is unable to maintain hydration.

 

References

1.     Collier MG et al; Hepatitis A Outbreak Investigation Team. Out-break of hepatitis A in the USA associated with frozen pome-granate arils imported from Turkey: an epidemiological case study. Lancet Infect Dis. 2014 Oct;14(10):976-81. [PMID: 25195178]

2.     Wenzel JJ et al. Hepatitis A as a foodborne infection. Lancet Infect Dis. 2014 Oct;14(10):907-8. [PMID: 25195177]

3.     WHO, Hepatitis A report 12 February 2025 .