Liver infections
Viral hepatitis is a major world health
problem. In addition to the well-recognised acute and chronic liver diseases
produced by hepatitis A, B and C, other hepatitis viruses have been isolated
including hepatitis D, which is usually detected only in patients with hepatitis
B virus (HBV) infection, and hepatitis E, which produces a self-limiting
hepatitis due to faecal—oral spread similar to hepatitis A.
Hepatitis A presents with anorexia, weakness and general malaise for several weeks
prior to the development of clinical jaundice, often accompanied by tenderness
on palpation of an enlarged liver. The condition is spread by the faecal—oral
route and often spreads rapidly in closed communities. Liver function tests will
be compatible
Hepatitis B is a more serious condition in most respects than hepatitis A. Although it
can also produce an acute self-resolving hepatitis, the virus is often not
cleared and produces long-term liver damage with the development of liver
cirrhosis and primary liver cancers. Patients may therefore present acutely with
malaise, anorexia, abdominal pain and clinical jaundice due to active hepatitis
or may present at a late stage owing to the complications of cirrhosis, most commonly
ascites or variceal bleeding. Treatment for acute hepatitis is supportive. In
patients with cirrhosis, treatment is initially dictated by the specific
complication at presentation (see subsections on the treatment of ascites and
variceal bleeding earlier in this chapter). In established cirrhosis, liver
transplantation may be considered if viral eradication or suppression can be
achieved with antiviral agents (e.g. lamivudine). Without viral suppression
death from reinfection of the transplanted liver is common. The hepatitis
virus greatly increases the risk of primary liver cancers which usually appear
at the stage when the liver parenchyma has become cirrhotic. The assessment and
management of HBV cirrhosis with hepatocellular carcinoma (HCC) is discussed in
the section on ‘Liver turnouts.
Hepatitis C has become one of the commonest causes of chronic liver disease
world-wide and in many countries a large percentage of the population has been
exposed. One per cent of blood donors world-wide are hepatitis C virus (HCV)
positive. Transmission is often related back to blood transfusion and routine
screening of blood for HCV has only recently been introduced in many countries.
As with hepatitis B, it may present as an acute hepatitis or remain hidden until
the development of cirrhosis and the complications of portal hypertension. Acute
hepatitis C proceeds to cirrhosis in about 20 per cent of cases. Deterioration
in liver function, encephalopathy, ascites or bleeding in a patient with known
HCV cirrhosis necessitates an urgent assessment for liver transplantation, if
available. Although reinfection of the graft is common it
generally results in a mild hepatitis from which the graft and patient fully
recover and is associated with a good long-term outcome.
Ascending
cholangitis
Ascending bacterial infection of the biliary
tract is usually associated with obstruction, and presents with clinical jaundice,
rigors and a tender hepatomegaly. The diagnosis is confirmed by the finding of
dilated bile ducts on ultrasound, an obstructive picture of liver function tests
and the isolation of an organism from the blood on culture. The condition is a
medical emergency and delay in appropriate treatment
The aetiology of a pyogenic liver abscess is
unexplained in the majority of patients. It has an increased incidence in the
elderly, diabetics and the immunosuppressed, who usually present with anorexia,
fevers and malaise accompanied by right upper quadrant discomfort. The diagnosis
is suggested by the finding of a multiloculated cystic mass on ultrasound or CT
scan (Fig. 52.17) and is confirmed by aspiration for culture and sensitivity.
The most common organisms are Streptococcus milleri and Escherichia
coil but other enteric organisms such as Streptococcus faecalis, Klebsiella and Proteus vulgaris also occur and mixed growths are common.
Opportunistic pathogens include Staphylococci.
First-line antibiotics would be a penicillin, aminoglycoside and
metronidazole or a cephalosporin and metronidazole. Treatment is with
antibiotics and ultrasound-guided aspiration. Percutaneous drainage without
ultrasound guidance should be avoided as an empyema may follow drainage through
the pleural space. A source for the liver abscess should be sought, particularly
from the colon. Atypical clinical or radiological findings should raise the
possibility of a necrotic neoplasm.
Entamoeba
histolytica is
endemic in many parts of the world. It exists in vegetative form outside the
body and is spread by
This is a very common condition in countries
around the Mediterranean. The causative tapeworm, Echinococcus granulosus, is present in the dog intestine and ova
are ingested by humans and pass in the portal blood to the liver. Liver
abscesses are often large by the time of presentation with upper abdominal
discomfort or may present after minor abdominal trauma as an acute abdomen due
to rupture of the cyst into the peritoneal cavity. Diagnosis is suggested by the
finding of a multiloculated cyst on ultrasound and is further supported by the
finding of a floating membrane within the cysts on CT scan (Fig.
52.18). Active
cysts contain a large number of smaller daughter cysts (Fig.
52.19) and rupture
can result in these implanting and growing within the peritoneal cavity. Liver
cysts can also rupture through the diaphragm producing an empyema, into the
biliary tract producing obstructive jaundice or into the stomach. Clinical and
radiological diagnosis can be supported by serology for antibodies to hydatid
antigen in the form of an enzyme-linked immunosorbent assay (ELISA). Treatment
is indicated to prevent progressive enlargement and rupture of the cysts.