Learning Points from a Case of Severe Amoebic Colitis
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Le Infezioni in Medicina, n. 3, 281-284, 2017 CASE REPORT 281 Learning points from a case of severe amoebic colitis Christina Petridou1, Adnan Al-Badri2, Anjana Dua1, Matthew Dryden1, Kordo Saeed1 1Microbiology Department, Hampshire Hospitals NHS Foundation Trust, Royal Hampshire County Hospital, Winchester, United Kingdom; 2Pathology Department, Hampshire Hospitals NHS Foundation Trust, Royal Hampshire County Hospital, United Kingdom SUMMARY A case of amoebic colitis and liver abscess is described learning points including the importance of taking a in a previously fit 59-year old man who had been given lifelong travel history, the difficulties in telling ulcer- the incorrect diagnosis of ulcerative colitis. His symp- ative colitis and amoebic colitis apart both clinically toms were so severe that a colectomy was being con- and histopathologically, and the importance of send- sidered. The patient had a significant travel history in- ing multiple stool samples for parasitological micros- cluding trips to Morocco, the Gambia and Cape Verde, copy analysis in patients being investigated for inflam- putting him at risk of acquiring amoebic disease. How- matory bowel disease. ever, this history was not ascertained until much later on in the disease process. The case highlighted crucial Keywords: amoebic colitis, liver abscess. n CASE REPORT 8 times a day, his inflammatory markers were markedly raised and he had deranged liver func- 59-year-old man was admitted to Royal tion tests with a C-reactive protein of 263 mg/L, a white cell count of 25.6 109/L, an ALT of 102 U/L A Hampshire County Hospital, a district gener- al hospital in the United Kingdom, directly from and an ALP of 336 U/L. He was tachycardic but the Inflammatory Bowel Disease (IBD) clinic on other bedside observations were normal. He was 15 January 2017 with worsening of his long-stand- diagnosed as having a flare-up of UC and start- ing bloody diarrhoea, abdominal pain and weight ed on intravenous hydrocortisone with a view to loss. He had previously been diagnosed with ul- repeat sigmoidoscopy and starting infliximab. A cerative colitis (UC) in September 2016 following stool sample sent on admission was culture neg- a flexible sigmoidoscopy and biopsy showing ative, polymerase chain reaction (PCR) negative active chronic colitis. His symptoms at the time for Campylobacter, Salmonella, Shigella and Esch- included gradually worsening bloody diarrhoea erichia coli 0157 and negative for intestinal para- and abdominal pain and he was started on mesal- sites on direct wet film microscopy and ethyl-ace- azine in December 2016. His symptoms continued tate concentration. and on 7 January 2017 he began a reducing course His condition deteriorated with ongoing bloody of steroids. He had no additional medical history diarrhoea and 5 days after admission a CT scan and was on no other medication. was performed due to his lack of improvement On admission he was passing loose, bloody stools and deranged liver function. Imaging showed a large, septated liver abscess measuring 15 cm x 15 cm in his right lobe with pancolitis, and he was started on intravenous co-amoxiclav (Figure 1). A Corresponding author drain was inserted under ultrasound and no or- Christina Petridou ganisms were seen on microscopy of the pus and E-mail: [email protected] it was culture negative and pan-bacterial 16S PCR 282 C. Petridou, et al. negative. Due to the septated nature of his abscess strongly positive. Hydatid serology was negative. only 250 mls was drained prompting a further at- Following the serology results, Entamoeba cysts tempt to re-site the drain on 24 January. He was were seen on a third stool sample using ethyl-ac- transferred to the Intensive Care Unit 2 days lat- etate faecal concentration and PCR for Entamoeba er for on-going monitoring and total parenteral histolytica was positive on the BD MAX Enteric nutrition where he remained symptomatic with Parasite Panel which is able to detect nuclei ac- raised inflammatory markers. Repeat stool sam- ids from Giardia lamblia, Cryptosporidium and E. ples and hydatid and amoebic serology were ad- histolytica. Although not validated PCR was also vised by the Microbiology team and intravenous performed on his pus sample and was strongly metronidazole added. By 25 January, the patient positive for E. histolytica. The metronidazole was became agitated and confused and was intubated increased to 800 mg TDS and was followed by and ventilated and antibiotic therapy broadened paromomycin. He continued on co-amoxiclav for to meropenem. A CT brain and lumbar puncture 2 weeks as there was concern of super-added bac- were unremarkable. terial infection. A liver biopsy was planned to assess whether On repeat imaging 2 weeks after diagnosis the there was an underlying malignancy and he was size of the liver abscess had improved significant- under consideration for a colectomy as he was not ly (Figure 2). He was transferred to the ward af- responding to mesalazine and steroids. Immuno- ter 9 days in ICU and his drain removed 2 weeks suppressive therapy was not recommended due later. His mesalazine was stopped following to his liver abscess. the diagnosis of amoebic colitis and his steroids 16 days after admission the amoebic indirect im- weaned. His symptoms slowly improved and he munofluorescent antibody test was reported as was discharged after 9 weeks in hospital. Figure 1 - CT scan shows a large, septated liver abscess measuring 15 cm x 15 cm in his right lobe with pancolitis. Figure 2 - CT scan two weeks after diagnosis. The size of the liver ab- scess had improved sig- nificantly. A case of severe amoebic colitis 283 n DISCUSSION the variable shedding of organisms. For patients with presumed IBD three stool samples should Amoebiasis is common in tropical countries and ideally be collected on alternate days to exclude is caused by the parasitic protozoan E.histolytica. the diagnosis of parasitic disease such as amoebi- Humans become infected through the oro-faecal asis. Hydatid and amoebic serology should also route. Presentations vary from asymptomatic to be performed. The first stool sample ever sent for severe invasive amoebic colitis. Liver abscesses this patient was following his hospital admission are the most common extra-intestinal complica- and only one of three samples was positive for tion and a delay in diagnosis may be life threat- E. histolytica cysts. For complex patients such as ening [1]. these the early involvement of infection special- This case highlighted many important learning ists is important to help guide appropriate micro- points. biological investigations. Firstly, due to similarities in clinical presentations, PCR for E. histolytica is not performed routinely amoebiasis needs to be considered as a differential in many diagnostic laboratories however if avail- for IBD, especially if not responding to conven- able, in-house testing for such patients could be tional therapy. This patient had been treated with an invaluable tool allowing rapid diagnosis in steroids and mesalazine and had not improved, patients where amoebic disease is suspected or with immunosuppression and a life changing col- warrants excluding. ectomy being considered. This case highlighted Apart from the clinical similarities between amoe- how severe amoebic colitis can be and how diffi- bic colitis and IBD, they can also be difficult to cult it can be to tell the conditions apart clinically. distinguish histologically. This patient had bi- Secondly, it is crucial to obtain a travel history. opsies taken from the colon and rectum. These In industrialised countries E. histolytica is main- showed non-specific patchy active chronic colitis. ly restricted to returning travellers, immigrants, There was no ulceration, granuloma formation or institutionalised settings where sanitary condi- neoplasia seen. The histological changes in amoe- tions may be poor and men who have sex with biasis are non-specific and can be difficult to dif- men [1]. Entamoeba infections accounted for only ferentiate from other types of active colitis includ- 1% of laboratory-confirmed cases of travel-asso- ing IBD, drug-related inflammation, ischaemic ciated gastrointestinal disease in the UK in recent colitis and other types of infections. The diagno- years, with 14 confirmed cases in 2008. The main sis of ameobiasis relies on the identification of the countries of travel were India and Pakistan how- trophozoites, which may or may not be present ever there was one case imported from Europe in the surface exudate as round globules with a (Greece) [2]. Once the patient was extubated, a full foamy cytoplasm but are difficult to differentiate travel history was taken and he reported visiting from other surface debris like macrophages and Cape Verde in November 2016, Morocco in 2015 sloughed epithelial cells. Amoebiasis is not a com- and Gambia in 2014. He stated that his symptoms mon cause of colitis in industrialised countries started after his return from Gambia although and if the number of trophozoites is small they they were mild and he developed coping strat- can easily be missed. The histological detection of egies. They progressed over the years becoming the infection depends on a high degree of clinical significantly worse in January, possibly coincid- suspicion and on being given a thorough clinical ing with the introduction of steroids, which are and travel history. known to be associated with more severe disease, In uncomplicated amoebic liver abscesses of less culminating in his admission. An initial travel than 10 cm diameter in the right lobe, amoebi- history may have prompted amoebiasis to be con- cidal drugs alone should be adequate treatment sidered and appropriate microbiology samples to [3-5]. This differs from pyogenic liver abscesses be sent. When amoebiasis is suspected clinicians where surgery/drainage alongside antibiotics is need to be mindful that the patient’s life long optimal, however it can be difficult to distinguish travel history is explored.