Viral hepatitis
is the inflammation of the liver caused by one of the five hepatotropic
viruses, which are hepatitis A, hepatitis B, hepatitis C, hepatitis D and
hepatitis E.
Besides these
viruses, other viruses that can cause hepatitis are herpes simplex,
Epstein-Barr virus, cytomegalovirus and virus causing yellow fever. However,
the liver inflammation caused by these viruses is not termed as viral hepatitis
The elderly are increasingly predisposed to the threat of developing viral
hepatitis owing to the increase in life expectancy. Elderly people with viral
hepatitis have high rates of mortality than their younger counterparts. Factors
that contribute to viral hepatitis in the elderly are presence of co-morbid
conditions, aging, environmental hepatotoxins and growing exposure to hepatotropic
viruses.
Andres Carrion
and colleagues published a paper in the American
Journal of Gastroenterology regarding the increasing prevalence of viral
hepatitis in the elderly.
The researchers
stated in the paper, "The age-related decline of liver regeneration has been
described in animal models in which the mitogenic capacity of hepatocytes is
reduced with aging (up to 70% lower than in younger animals). This finding has
also been recently corroborated in humans with significant reductions in liver
regeneration noted in individuals older than 50 years compared with younger
adults undergoing living donor liver transplantation."
Hepatitis A
Due to
implementation of vaccination against hepatitis A virus (HAV) in children and
adults, the prevalence of hepatitis A has declined considerably. However, the
authors state that "The seroprevalence of anti-HAV immunoglobulin (Ig) G, a
marker of prior infection with HAV, increases proportionally with age
reflecting a cumulative risk of HAV infection throughout life."
It is noted that
the severity of clinical cases of HAV in elderly people are reflected in high
rates of mortality and hospitalization.
On the whole,
the reasons for poor outcomes of HAV infection in the older population are
multifactorial and related to high prevalence of co-morbid conditions, lowered
regenerative capacity of liver and declining immune function especially
cell-mediated immunity with increasing age.
Hepatitis B
The third
National Health and Nutrition Examination Survey (NHANES III) revealed the
prevalence of chronic hepatitis B virus (HBV) is 0.42% in the United States.
The paper also
reported, "The NHANES (1999-2006) showed an overall seroprevalence of
past/present HBV infection in the United States of 4.7%."
The clinical
presentation of acute HBV infection is quite different in the elderly than the
younger individuals. During an outbreak of acute hepatitis B infection, most of
the affected elderly people were asymptomatic and only few of them presented
with jaundice and symptoms such as nausea, vomiting and anorexia.
The paper
revealed an important point-"The risk of progression to chronic hepatitis B is
inversely related to age at the time of infection."
Immunization
against HBV is advised for all elderly who are at the risk for infection
especially in nursing and healthcare centers as these individuals are exposed
to contamination with blood and other body fluids.
The prophylactic
use of antiviral agents in HBV carriers irrespective of age is advised in case
of initiation of immunosuppressive therapy. The commonly used drugs for short
term treatment (≤12 months) are telbivudine and lamivudine and for long term
treatment are entecavir and tenofovir.
Hepatitis C
The incidence of
hepatitis C Virus (HCV) infection in the United States is declining, especially
in the younger population.
In the elderly
population, the possible risk factors for HCV infection are military services,
tattoos, injection drug use, blood transfusions (prior to 1992), hemodialysis
and employment as a health care worker. After making adjustments for alcohol
intake, sex, diabetes, body mass index and HIV status, advancing age at the
time of onset of infection is also an important factor associated with advanced
hepatic fibrosis.
It is seen that
older individuals have low acceptance of antiviral therapy, and low doses and
discontinuation of antiviral therapy is quite common in elderly people as
compared to younger generation.
The paper
suggested, "Current practice guidelines recommend not withholding antiviral
therapy based purely on advanced age but suggested that special attention
should be paid to co-morbid conditions and tolerance for potential side
effects."
Hepatitis E
The hepatitis E
virus (HEV) is sporadic in USA while endemic and epidemic in Africa, Asia and
Mexico.
Very limited data
is available for HEV and exposure to HEV is rare. In elderly, it should be
regarded as a potential etiology of acute hepatitis.
With increasing
advancement in health care, an increase in elderly population is noticed across
the globe. This elder population is exposed to high risk of acute and chronic
liver complications and prevalence of high co-morbid conditions. Andres Carrion
highlighted the need for broadening and revising the indications for
immunization of the elderly against hepatitis A ands B to prevent these
infections and protect the elderly against potential complications.
Reference:
Viral Hepatitis in the Elderly; Andres Carrion et al;
The American Journal of Gastroenterology 2012
Source-Medindia