While contemplating on writing about AMOEBIC LIVER ABSCESS and dysentery, two people came to my mind. The first is my very good neighbour who we fondly call Mama. She will come to me and say: “Doctor, you are my doctor and me I am your doctor,” pointing fingers to me and herself as she says so. Then comes the real thing. She will hand me a straw coloured liquid with some roots in it and say: “E good for belle. Na AGBO JEDI JEDI.
Mama will not stop there: “Oya drink am.” Oh my gush. I must be a good boy. I will use my two fingers to close my nose as I gulp this thing. The smell and the taste are just awful.
The second person that came to my mind was my good old teacher Prof. Jide Gbadamosi. As medical students in those days, we used to call him Baba Stuff or Baba Guru. He had walked in during a ward round being conducted by the Senior Registrar in his unit, took a glance at the patient and asked in just three words: “AMOEBIC LIVER ABSCESS?” The Senior Registrar was stunned and asked him back: “Sir how did you know?” He laughed and simply said: “Once you have seen one, you have seen all. Good for the experience.”
These two incidents were more than 30 years apart, which tells you that Amoebic Dysentery has remained stubborn to this day.
For starters, an ABSCESS is an enclosed COLLECTION OF DEAD CELLS in liquid form. The commonest type is that BOIL that when cut open, milky fluid flows out. This fluid in common parlance is known as PUS. It is composed of dead WHITE BLOOD CELLS and the offending organism. In case of amoebic liver abscess, the causative organism is ENTAMOEBA HISTOLYTICA and the disease process AMOEBIASIS or in common parlance DYSENTERY. The abscess contains mainly dead liver cells known as HEPATOCYTES, TROPHOZOITE stage of Entamoeba hystolytica in degenerating state and dead white cell and in some cases BILE.
Entamoeba histolytica is a PROYOZOAN (a single cell that can survive on its own) parasite. This organism can survive in an environment of low oxygen concentration and are aptly described as ANAEROBES. They exist in two forms, the TROPHOZOITE stage and CYST. The trophozoite stage is the form that causes the symptoms of amoebic dysentery and liver abscess. The cyst is the form of hibernation of this parasite. It is easily destroyed by heat and conditions of low temperature. When swallowed from food item contaminated by faeces it causes the infection.
These cysts, having four NUCLEI in each cell are digested in the intestine to release the trophozoites, which migrate to invade the cells of the large intestine. Here the organisms cause tissue destruction, hence the name HISTO-LYTIC (cell lysis). The bloody stool seen in amoebic dysentery is as a result of this tissue destruction. The parasites can invade the blood vessels and transported to distant organs like brain, lungs and the liver, the commonest site, to cause abscesses.
In the liver, with the destruction of cells the channels through BILE flow are also affected. With invasion of the blood vessels, the bile now leaks into them and eventually enters the systemic circulation resulting in JAUNDICE. This phenomenon is often described as BILIOVASCULAR fistula.
The Diagnosis of amoebic liver abscess to the experienced physician can be very straightforward. Quite commonly one gets a history of loose stool mixed with mucus and blood prior to the patient presenting severe pains on the right side of the upper abdomen where the liver is located. There will be fever, rigours and sweating, which can be very profuse. Many of the patients with amoebic liver abscess would have significant loss of weight. This is because the patient must have been having loose stool with blood for at least one week before developing metastatic abscess in the liver. The liver would be enlarged and easily PALPABLE or rather felt by the caregiver.
Blood counts would have to be done because of losses during the disease progression. The stool would have to be examined for the presence of the cysts and the trophozoites. Medical imaging has revolutionised the diagnosis of amoebic liver abscess. Ultrasonography is almost the gold standard these days with the technology being readily available and practitioners becoming more proficient in using it. COMPUTERIZED TOMOGRAPHIC scanning makes it even easier for those who can afford it.
SERUM BILIRUBIN and the liver enzymes are also tested because in severe forms of the disease the liver may fail with catastrophic consequences. There could be life-threatening bleeding from the rectum during the disease process. This would require an instrument to be passed through the ANUS to view the lumen of the large bowel. With this, bleeding points are visualised and coagulated, through a procedure known as SIGMOIDOSCOPY.
Luckily, in most cases of amoebic liver abscess, the location is commonly the RIGHT LOBE of the liver and they are usually SOLITARY. The advantage of this is that in case the need arises for ULTRASOUND GUIDED aspiration or drainage, the caregiver is in a comfort zone. Sometimes you may find the abscess occurring in more than one place. This multi foci abscesses are not aspiration friendly and are better left alone.
Irrespective of the mode of presentation in this environment, the treatment of amoebic liver disease is MEDICAL using ORAL or INTRAVENOUS METRONIDAZOLE. Other drugs also used in the management of this condition include CHLOROQUINE, NIRIDAZOLE, TINIDAZOLE and EMETIN. Emetine is the most potent of the drugs, but METRONIDAZOLE is the safest, the most cost effective and is the gold standard in our environment.
In large cavity abscess with a possibility of rupture, the option is ultrasound guided surgical aspiration/drainage. Classically, the aspirate is often described as being chocolate or dark brown in colour. After this, the treatment is continued with metronidazole. In some climes, one of the treatment objectives is to also completely eliminate the parasite from the lumen in the intestine in order to curtail spread.
It must be stated that amoebiasis is one protozoan infection that can be eliminated or the prevalence drastically reduced. The reasons are simple. First, the disease causing stage is the trophozoite, which to date has not developed resistance to any of the anti-microbial substance used against it. Secondly, the cystic stage is very vulnerable to heat and cold. Thus both boiling and refrigeration readily have them destroyed.
What had remained a challenge to this scourge is our attitude to the environment and handling of faecal waste. In some of our surrounding, faeces are dumped with reckless abandon.
In a particular area (name withheld) where road construction works is going on; by the side of the road being constructed is what can only be described as OPEN LATERINE! Not quite a distance of 25 metres from this site are numerous eateries, apples being hawked openly and houseflies all over the place. People just passed by, grabbed and munched.