2. The liver serves as the initial site of filtration of absorbed intestinal
luminal contents and is particularly susceptible to contact
with microbial antigens of all varieties.
The liver can be affected by :
(1) Spread of bacterial or parasitic infection from outside the liver;
(2) Primary infection by Spirochetal, Protozoal, Helminthic, or
Fungal organisms;
(3) Systemic effects of bacterial or granulomatous infections.
4) Viruses
4. Pyogenic Liver Abscess
Pyogenic liver abscess is a pus filled area within the liver.
Causes:
Infection in the blood( Hematogenous spread) Staphylococcus aureus
or Streptococcus milleri.
An infection of biliary tract ;enteric gram – bacilli and enterococci .
Pelvic or colonic source: mixed flora incl. Aerobic and anaerobic
especially B. fragilis.
5. Toxic Shock Syndrome
It is a multisystem disease .
Staphylococcus aureus or Group A Streptococci.
Hepatic involvement - Jaundice and extensive necrosis.
Toxic shock syndrome toxins (superantigens ) cause T cell activation
and massive cytokine release.
7. Enteric fever
Salmonella typhi
Hepatic damage by S. typhi
Mediated by bacterial endotoxin
Mesenteric adenitis
Yersinia enterocolitica
The subacute septicemic form of the
disease result in abscess.
8. Fitz hugh curtis syndrome
Neisseria gonorrhae
Hepatic complication of gonococcal infection.
Perihepatitis- Direct spread of the infection
from the pelvis.
Brucellosis
Brucella suis, Brucella abortus,
Brucella melitensis,Brucella ovis
Jaundice , hepatosplenic abscesses.
10. Oroya Fever
Bartonella bacilliformis
Jaundice, hepatosplenomegaly and
Centrilobular necrosis of the liver .
Bacillary Angiomatosis
Bartonella henselae, Bartonella quintana
Peliosis hepatis or blood-filled cysts
(immunodeficiency states).
Infection frequently is associated with
exposure to cats.
11. Ehrlichiosis
Ehrlichia Chaffeensis,
Ehrlichia Ewingii
( obligately intracellular pathogens
belongs to rickettsiaceae family).
Focal necrosis, fibrin ring granulomas, and cholestatic hepatitis.
Liver injury is attributable to proliferation of organisms within
hepatocytes and provocation of an immune response.
12. Leptospirosis
Leptospira interrogans
Icteric leptospirosis-hepatic involvement.
Severe form with multi-organ involvement- Weil's disease.
( hepatorenal damage)
Lyme Disease
Borrelia burgdorferi(Tick-borne spirochete).
Acute hepatitis as a manifestation of reactivation
13. Syphilis
Treponema pallidium
Hepatic lesions are common.
Hepatic Tuberculosis
Mycobacterium tuberculosis
Mycobacterium avium intracellulare ( AIDS )
Tubercle bacilli reach the liver by way of
hematogenous dissemination .
15. Hepatic sinusoidal lymphocytosis
(malaria)
P. falciparum
Mixed infection with P. vivax
Repeated exposure to malaria (aberrant immunologic Response)
Overproduction of B lymphocytes
Circulating malarial antibody
An increased levels of circulating immune complexes.
Visceral leishmaniasis
Leishmania donovani
Infective form- flagellated promastigotes
Hepatocyte necrosis
Complications of chronic liver disease are rare.
16. Amoebic liver abscesses
Entamoeba histolytica
Infective form - cyst
Definitive host - man
Source of infection- cyst passing chronic patient or asymptomatic carrier.
Mode of transmission-oral-fecal route
Intestinal lesions can metastasize to various other organs,commonest
being liver(hepatic amoebiasis).
Necrosis of liver cells leading to abscess formation which is typical
anchovy sauce in appearance.
18. Toxoplasmosis
Toxoplasma gondii
Primary host - cat
Intermediate host - human
Uptake of cyst by inhalation, followed by ingestion .
Disseminated infection of liver occurs resulting in hepatomegaly.
19. Hyperinfection syndrome
Strongyloides stercoralis
Common - immunocompromised patients.
Infective form - filariform larvae.
Route of entry - intact skin,lungs,intestine.
Dissemination of filariform larvae into tissues(liver) that usually are not
infected.
20. Trichinosis
Trichinella spiralis
Mode of transmission - raw or undercooked pork bearing larvae
Route - in the small intestine, penetrate the mucosa, and disseminate
through the systemic circulation to other organs and liver resulting in
jaundice.
21. Hepatic Capillarias
Capillaria hepatica
Mode of infection - ingesting soil, food, or water contaminated with
embryonated eggs.
Larvae released in the ceacum penetrate the intestinal mucosa, enter the
portal venous circulation, and lodge in the liver.
Adult worms disintegrate, releasing eggs into the hepatic parenchyma
and producing an intense inflammatory reaction.
22. Ectopic Ascariasis
Ascaris lumbricoides
Mode of infection - contaminated food ,drink or fingers.
Definitive host - man
Infective agent - embryonated egg
Site of localisation - small intestine
Migration of adult worm to liver causes liver abscess
23. Viseral larva Migrans
Toxocara canis,Toxocara catis
Mode of transmission - contaminated food or soil.
Route of transmission - intestine,penetrate the wall ,carried in blood to
liver forming nodules.
24. Echinococcosis (hydatid cyst)
Echinococcus granulosus
Definitive host - dog
Intermediate host – man
Mode of infection - contaminated food and drink
Infective agent - embryonated eggs.
The eggs hatch in the small intestine and liberate oncospheres that
penetrate the mucosa and migrate via vessels or lymphatics to distant
sites, liver being the most common destination (70%) and forms cyst
known as hydatid cyst.
25. The early stage of infection is generally asymptomatic. As the cyst
enlarges, symptoms of a space-occupying lesion develop.
The great danger lies in the rupture of the cyst causing the escape of
hydatid fluid and hydatid sand
anaphylactic shock
escaped
protoscolices can form new hydatid cysts.
E. multilocularis is highly invasive
Infection leads to formation of solid masses in the liver .
E. vogeli has clinical features intermediate between those of infections
caused by the other two species and is characterized by multiple fluid
filled cysts.
Superinfection of the hepatic cysts can lead to pyogenic liver
abscesses in up to 20% of patients with hepatic disease.
26. Schistosomiasis (Bilharziasis)
Schistosoma mansoni, S. haematobium,S.japonicum.
Infective form - cercariae
Source of infection - contaminated freshwater
Intermediate host-Snail
Definitive host -humans
Hepatic granulomas
Its due to immunologic reactions to Schistosoma eggs trapped in tissues.
Antigens released from the egg stimulate a granulomatous reaction
involving T cells, macrophages, and eosinophils
27. Clonorchiasis
Clonorchis sinensis
Source of infection - raw or inadequately cooked fresh fish infected with
metacercariae of clonorchis.
Definitive host - man
First intermediate host - snail
Second intermediate host - crypinoid fish
Hepatic parenchymal damage
28. Fasciolosis
Fasciola hepatica,Fasciola gigantica
Definitive host - humans
Intermediate host - freshwater snails
Infective form - metacercaria
Reservoir host - sheep
Source of infection - raw aquatic vegetation contaminated with encysted
metacercaria such as lettuce and green salad.
Painful enlargement of liver, obstruction and inflammation of bile duct .
31. Disseminated histoplasmosis
Histoplasma capsulatum
Portal of entry - respiratory tract .
Predisposing factor- Severely immunocompromised persons .
The liver can be invaded in both acute and chronic progressive
disseminated histoplasmosis
33. Hepatitis A
RNA Virus
Source of infection - Faeces
Route of transmission - Fecal-oral
Infects the liver, causing inflammation. Although it may cause acute
symptoms, it rarely results in severe or chronic liver disease.
34. Hepatitis B
DNA Virus
Source of infection-Blood/blood derived body fluid
Route of transmission- :
parenterally, low vertical and sexual transmission
Hepatocellular necrosis occurs due to the body’s reaction to the virus
rather than due to the virus itself
35. Hepatitis C (the silent epidemic)
RNA virus
Source of infection-Blood/blood derived body fluid
Route of transmission- Parenterally, low vertical and sexual transmission
Cirrhosis
Hepatocellular carcinoma
36. Hepatitis D
Defective virus which requires hepatitis B as a helper virus in order to
replicate.
Infection therefore only occurs in patients who are already infected with
hepatitis B.
Increased severity of liver disease in hepatitis b carriers.
37. Hepatitis E
RNA virus similar to hepatitis A
Source of infection - faeces
Route of transmission-Fecal-oral
Cause of enterically transmitted non-a,non-b hepatitis(acute).
Fulminant hepatitis in pregnant women.
Hepatitis G
RNA virus
0.2% acute hepatitis
Exact role not known, probably not a pathogen
