What is Hepatitis A?
The hepatitis A virus (HAV) is a common cause of acute hepatitis, an inflammation of the liver, all over the world. HAV is mostly spread through consuming contaminated food or water, or from close contact with someone who is already infected. As per the World Health Organization, the infection rates are low in developed countries. However, populations at high risk include drug users who inject, men who have sex with other men, people travelling to areas with high infection rates, and isolated communities.
Unlike hepatitis B or C, hepatitis A does not lead to long-term liver disease. Its symptoms, which include nausea, vomiting, abdominal pain, fatigue, feeling unwell, loss of appetite, and fever usually get better on their own. However, in rare cases, extremely severe hepatitis, also called fulminant hepatitis, may occur. There can also be different patterns of the disease, which include prolonged symptoms and relapsing disease.
There’s a vaccine against hepatitis A, which is recommended for children aged 12 months and older, and adults who are at risk. This includes individuals travelling to countries with high infection rates, men who have sex with other men, illicit drug users, those who due to their occupations could get exposed to the virus, and people with chronic liver disease.
Worldwide, hepatitis A infection rates have gone down thanks to improvements in public healthcare policies, sanitation, and education. On the other hand, the infection rates for other types of hepatitis seem to be on the rise.
What Causes Hepatitis A?
Hepatitis A virus (HAV) is a highly common cause of acute inflammation of the liver all over the world. Approximately 1.5 million people get infected with Hepatitis A every year, according to the estimates by the World Health Organization. Countries that struggle with low economic conditions and poor sanitation and hygiene practices have a higher rate of Hepatitis A infections. Most people in these developing countries get the virus when they are children. But in developed countries like the USA, Canada, and Western Europe, the infection rates are much lower.
However, even in these countries, some groups are more at risk for catching Hepatitis A. These include drug users who inject, men who have sex with men, people who visit high-risk places, and isolated groups like residents of nursing homes and daycare centers.
Interestingly, factors like income, housing conditions, sanitation, and water quality can predict how many people in a community get infected. After a vaccination against Hepatitis A was introduced in the USA, cases of the virus have gone down dramatically. From 1995 to 2007, the number of new infections fell by 92%, going from 12 out of 100,000 people to just 1 out of 100,000 people.
In most cases, Hepatitis A is passed from one person to another through close contact. It’s extremely rare to get the virus through blood transfusion. Being in an institutional setting like a hospital or a nursing home, having close personal contact with an infected person, traveling to foreign countries, certain occupations, using injected drugs, or engaging in homosexual activities are all risk factors for catching Hepatitis A.
Risk Factors and Frequency for Hepatitis A
Improved hygiene and sanitation have changed the age group most likely to contract hepatitis A, leading to a decrease in new infections in recent years.
- The United States has a low rate of ongoing hepatitis A infections.
- Mexico, on the other hand, has a higher number of people who have had the disease in the past, especially in states close to the U.S. border where acute hepatitis is more common.
- The incidence of hepatitis A in the U.S. has gone down by 90% to an average of 1.2 cases in every 100,000 people, with the biggest improvements seen in children and states that started regular vaccinations in 1999.
- Over the past 40 years, the average age of people with hepatitis A has increased.
The majority of hepatitis A infections occur in high-risk groups. These include travellers to developing countries, homosexual men, childcare workers, people living in institutions, and those living in poverty. Despite popular belief, individuals who handle food aren’t a frequent source of disease outbreaks in the U.S. However, essentially any food can be contaminated with the virus causing hepatitis A.
Internationally, hepatitis A is most prevalent in developing areas of the world like Africa, Asia, and South America, where just about everyone has evidence of a past infection. Children often acquire the disease in these regions, yet it typically doesn’t cause symptoms.
Hepatitis A doesn’t target any particular sex. It is commonly seen in aid workers, homosexual men, and people who spend time around sewage. As people age, they’re more likely to develop symptoms and adverse effects from the disease. The risk of suffering fatal liver failure from the disease also increases with age.
Signs and Symptoms of Hepatitis A
Acute Hepatitis A virus (HAV) infection is usually a temporary illness that clears up on its own. Some symptoms may include nausea, vomiting, discomfort in the upper right abdomen, feeling unwell, loss of appetite, muscle pain, fatigue, and fever. Within a week, patients may begin to produce dark urine and pale stools, followed by yellowing of the skin and eyes (jaundice) and itchiness. Blood tests usually show increased levels of specific liver enzymes and bilirubin. These test results return to normal typically between 1 to 6 weeks after the symptoms start. The time it takes for the virus to cause symptoms, the incubation period, is usually 14 to 28 days but can last up to 50 days. How severe the symptoms are can vary depending on the age of the patient and any other health conditions they have, particularly liver diseases. Children with acute HAV infection often don’t show any symptoms.
Sometimes, rare complications can occur that affect other than the liver. These can include inflammation of the pancreas, rash, sudden kidney damage, lung inflammation, inflammation of the lining of the heart, breakdown of red blood cells, and inflammation of the gallbladder. There have also been reports of nerve and brain-related complications. Two cases of autoimmune hepatitis caused by acute HAV infection were reported in 1991. Five clinical patterns are described in cases of acute HAV infection: silent infection, symptomatic infection with jaundice, a form of hepatitis where bile is not adequately eliminated by the body, recurring infection, and severe hepatitis which can be life-threatening.
- Silent infection
- Symptomatic infection with jaundice, dark urine, and pale stools
- Hepatitis where bile is not adequately eliminated by the body, causing prolonged increase in specific liver enzymes and bilirubin, and itchiness
- Recurring infection
- Severe, potentially life-threatening hepatitis
Testing for Hepatitis A
Acute hepatitis A is often identified through blood tests that look for specific antibodies known as immunoglobulin (IgM) in your blood, which show up when the hepatitis A virus (HAV) is present. Additional tests can also be conducted to detect the actual virus in the body. Another antibody, immunoglobulin G (IgG), also develops soon after infection and stays with you for life.
Common blood tests will typically show a mild increase in a type of white blood cell called lymphocytes. The time it takes for blood clotting – known as prothrombin time – should be normal. An elevated prothrombin time could indicate severe liver damage, including a risk for a condition called encephalopathy.
Hepatitis A usually increases the levels of a liver enzyme called aspartate aminotransferase, which should return to normal within 4-6 months. If a substance called bilirubin, which is produced when the liver breaks down old red blood cells, remains elevated, it might suggest a condition where the liver can’t properly remove bilirubin from the body, called cholestatic liver disease.
An ultrasound, a diagnostic imaging technique, is not generally conducted for routine cases of hepatitis A.
Treatment Options for Hepatitis A
For most people with a mild Hepatitis A Virus (HAV) infection, no specific treatment is necessary. Instead, these individuals just need to take care of themselves until they fully recover, which can take a few weeks to even months. However, in rare severe cases that lead to a condition called fulminant hepatitis, a liver transplant may be needed to save the individual’s life. Any complications outside of the liver are managed through regular treatments.
The World Health Organization (WHO) states that preventing HAV infection is best achieved by improving sanitation, food safety and immunization practices. Vaccines are available in the United States to protect against Hepatitis A. These include shots such as HAVRIX, VAQTA, and TWINRIX (which also works against Hepatitis B). The Centers for Disease Control and Prevention encourage vaccinations for certain groups. This includes children who are a year old or older, travelers going to places where the virus is common, gay individuals, those who use illegal drugs, individuals at risk due to their jobs, and people with certain health conditions. Adults are usually given two doses of the vaccine, with the shots given 6 to 12 months apart.
Previously, a treatment called immunoglobulin was the only option for protecting people who had been exposed to HAV. More recent studies, though, have shown that an inactivated HAV vaccine can also be effective. This is now the recommended option for healthy individuals between the ages of 1 and 40 who have been exposed to HAV. However, for individuals who are 41 and older, immunoglobulin is still the preferred option because this age group can have more serious symptoms and there isn’t enough evidence to show that the vaccine is effective for them. Also, immunoglobulin is advised for children under 12 months, people with long-term liver disease, and those with weak immune systems.
What else can Hepatitis A be?
- Hepatitis caused by excessive alcohol consumption
- Other forms of viral hepatitis, such as Hepatitis B, C, D, and E
- Hepatitis caused by the body’s immune system attacking its own liver (Autoimmune hepatitis)
What to expect with Hepatitis A
Most people with Hepatitis A virus (HAV) have positive outcomes. After being infected, it’s common for people to develop long-term immunity, and unlike other types of viral hepatitis, it’s rare for symptoms to occur again. Death due to HAV is infrequent, but it can occur in older people or those with pre-existing liver disease. Each year in the US, there are around a hundred deaths from HAV.
In rare cases, children who develop fulminant liver disease due to HAV might require a liver transplant. Age is a crucial factor that affects the prognosis; the older a person is, the higher the likelihood of experiencing an adverse reaction or event. Long-term complications from HAV are extremely rare.
Possible Complications When Diagnosed with Hepatitis A
- Long-term obstruction of the bile duct
- Sudden kidney failure
- Autoimmune liver disease
