The WHO estimates that Entameoba histolytica causes 50 million cases and 100,000 deaths annually, making this disease the second leading cause of death from protozoal diseases [1
]. Although infection with Entamoeba histolytica occurs world-wide, yet, liver abscess is the most common extraintestinal complication in 3% to 9% of patients [1
]. Diagnosis of amoebic liver abscess is usually straightforward on the basis of the clinical, epidemiological, serological and ultrasonographic findings.
Amoebic liver abscess arises from the hematogenous spread of the trophozoites of Entameba histolytica from the intestinal mucosa to the liver through the portal vein. The disease is suspected in endemic areas in persons presenting with fever, pain abdomen and liver tenderness [7
]. Compared to pyogenic liver abscesses, patients with amoebic abscesses are often younger, more acutely ill with fever and right upper quadrant pain, and are usually from high prevalence areas [11
]. The mean age of our patients with amoebic liver abscess was 40 years and was comparable to other studies [11
]. The frequency of fever and pain abdomen is 67-87% and 62-94% of patients with amoebic liver abscess respectively in different series [10
]. In our study, these two symptoms of fever and pain abdomen occurred in 94 and 90% respectively [10
]. From India, Sharma et al in a study of 70 cases of amoebic liver abscess found hepatomegaly in 84%, pleural effusion in 10% and ascites in 4% cases [8
]. In contrast, hepatomegaly (16%) was not a predominant feature of amoebic liver abscess in our study. Forty six percent cases in our study were consuming alcohol and this may account for the lesser occurrence of hepatomegaly. In our study, pleural effusion was seen in 14% and ascites in 5.7% cases respectively.
From India, earlier series showed jaundice in 45%-50% of cases of amoebic liver abscess, but, after the advent of invasive catheter drainage, coupled with effective anti-amoebic therapy, it has become less common [11
]. Jaundice occurred in 12.7% cases in our study. The pathophysiology of jaundice remains controversial and various explanations of jaundice are; pressure of abscess cavity on hepatic ducts [14
] and cholestasis [18
]. Recently, in 12 cases of amoebic liver abscess with jaundice, the formation of a bilio-vascular fistula was seen [21
]. Duration of symptoms longer than 2 weeks is seen in 14-41% in different series [11
]. In a study of amoebic liver abscess by Amarapurkar and colleagues of 131 patients, the duration of symptoms less than 2 weeks was seen in 83.9% of cases [22
]. In this study, 84% presented within 2 weeks and mild elevations of serum transaminases was seen in 19.8% cases. In our study, duration of symptoms less than 2 weeks was evident in 48% cases and raised liver enzymes more than 3 times the normal occurred in 35% cases. The lesser rise of serum transaminases seen in the study by Amarapurkar and colleagues could have been due to an earlier detection of ALA on abdominal ultrasonography [22
]. In our study, diarrhea occurred in 10.5% and cough in 3.5% cases whereas in other studies, these 2 symptoms occur in 14-40% and 8-24% cases respectively [11
Abdominal Ultrasound is the gold standard for diagnosing liver abscesses. Sonographically, in ALA, 4%-42% cases have multiple abscesses, 20%-35% have an abscess in the left lobe, and the remaining 49%-80% have a solitary abscess in the right lobe [9
]. Our study showed multiple abscesses in 22% cases, a solitary left lobe abscess in 13% cases and a single right lobe abscess in 65% of cases.
Atelectasis and pleural effusions are common complications of ALA. Pleural effusions occur mostly frequently in the right lobe and cause cough and chest pain. Respiratory distress can follow as a sequel to ALA rupturing through the diaphragm. Such a course has been shown to unravel in 7-20% of cases of ALA and in this study accounted for 14% of cases [11
]. Of all our patients, 9.3% required a chest tube insertion for pleural drainage. In 2-7% of cases of ALA, a peritoneal rupture can cause shock and peritonitis [23
]. A peritoneal rupture occurred in 4 cases, of which there was 1 case with both right pleural and peritoneal rupture. In recent years, with the advent of pigtail catheter drainage, the role of surgical exploration in ALA ruptured into the peritoneal cavity has been mainly confined to haemodynamically unstable patients [26
]. None of our patients underwent surgical exploration. Although, the in hospital stay of patients of ruptured ALA was more than those managed conservatively, yet, it did not reach statistical significance. This may be due the small size of the group of patients managed conservatively.
The overall mortality rate seen in ALA from various series ranges from 2-15% [11
]. In our study, the mortality rate was 5.8% and correlated to an increased number of pigtails catheters that were inserted in the ALA cavity. This fact is of particular concern and awaits further confirmation across a larger study.