Sandie R Thomson

A comparison of Clostridium difficile diagnostic methods for identification of local strains in a South African centre.

Accurate diagnosis of Clostridium difficile infection is essential for disease management. A clinical and molecular analysis of C. difficile isolated from symptomatic patients at Groote Schuur Hospital, South Africa, was conducted to establish the most suitable clinical test for the diagnosis and characterization of locally prevalent strains. C. difficile was detected in stool samples using enzyme-based immunoassays (EIA) and nucleic acid amplification methods, and their performance was compared with that of C. difficile isolation using direct selective culture combined with specific PCR to detect the C. difficile tpi gene, toxin A and B genes and binary toxin genes. Toxigenic isolates were characterized further by ribotyping. Selective culture isolated 32 C. difficile strains from 145 patients (22 %). Of these, the most prevalent (50 %) were of ribotype 017 (toxin A- B+) while 15.6 % were ribotype 001 (toxin A+B+). No ribotype 027 strains or binary toxin genes (cdtA and cdtB) were detected. The test sensitivities and specificities, respectively, of four commercial clinical diagnostic methods were as follows: ImmunoCard Toxins A & B (40 % and 99.1 %), VIDAS C. difficile Toxin A & B (50 % and 99.1 %), GenoType CDiff (86.7 % and 88.3 %) and Xpert C. difficile (90 % and 97.3 %). Ribotype 001 and 017 strains had a 100 % detection rate by Xpert C. difficile, 100 % and 93.3 % by GenoType CDiff, 75 % and 53.3 % by ImmunoCard and 75 % and 60 % by VIDAS, respectively. The overall poor performance of EIA suggests that a change to PCR-based testing would assist diagnosis and ensure reliable detection of locally prevalent C. difficile 017 strains.

Endoscopic management of bile leaks after laparoscopic cholecystectomy

BACKGROUND A bile leak is an infrequent but potentially serious complication after biliary tract surgery. Endoscopic intervention is widely accepted as the treatment of choice. This study assessed the effectiveness of endoscopic retrograde cholangiopancreatography (ERCP), sphincterotomy and biliary stenting in the management of postoperative bile leaks. METHODS An ERCP database in a tertiary referral centre was reviewed retrospectively to identify all patients with bile leaks after laparoscopic cholecystectomy. Patient records and endoscopy reports were reviewed. RESULTS One hundred and thirteen patients (92 women, 21 men; median age 47 years, range 22 - 82 years) with a bile leak were referred for initial endoscopic management at a median of 12 days (range 2 - 104 days) after surgery. Presenting features included intra-abdominal collections with pain in 58 cases (51.3%), abnormal liver function tests (LFTs) in 22 (19.5%), bile leak in 25 (22.1%), and sepsis in 8 (7.1%). Twenty-nine patients (25.7%) were found to have either major bile duct injuries without duct continuity, vascular injuries or other endoscopic findings requiring surgical or radiological intervention. Of 84 patients managed endoscopically, 44 had a cystic duct (CD) leak, 26 a CD leak and common bile duct (CBD) stones, and 14 a CBD injury amenable to endoscopic stenting. Of the 70 patients with CD leaks (group A), 24 underwent sphincterotomy only (including 8 stone extractions), 43 had a sphincterotomy with stent placement (including 18 stone extractions) and 1 had only a stent placed, while 2 patients with previous sphincterotomies required no further intervention. The average number of ERCPs in group A was 2.3 (range 1 - 7). Of the 14 patients with bile duct injuries treated endoscopically (group B), 7 had a class D, 5 an E5 and 2 a class B injury; 13 patients underwent sphincterotomy and stenting, and 1 had a sphincterotomy only. Group B required an average of 3.6 ERCPs (range 2 - 5). The 113 patients underwent a total of 269 ERCPs (mean 2.4, range 1 - 7). Seven patients had one or more complications related to the ERCP: 3 acute pancreatitis, 2 cholangitis, 2 sphincterotomy bleeds, 1 duodenal perforation and 1 impacted Dormia basket, the latter 2 requiring operative intervention. CONCLUSIONS Three-quarters of bile leaks after laparoscopic cholecystectomy were due to CD leaks (with or without retained stones) or lesser bile duct injuries and were amenable to definitive endoscopic therapy. Nineteen patients (16.8%) had major injuries that required operative intervention.

The efficacy of endoscopic therapy in bleeding peptic ulcer patients

BACKGROUND Endotherapy is the primary modality for the control of bleeding from peptic ulceration. OBJECTIVE To assess the efficacy of endoscopic intervention for high-risk bleeding peptic ulcer disease and to benchmark our surgical and mortality rates. METHODS Two hundred and twenty-seven patients with peptic ulcers stratified by Rockall and Forrest scores as at high risk for re-bleeding underwent therapeutic intervention (adrenalin injection) between January 2004 and December 2009. The median age of the patients was 57 years (range 19 - 87 years); 60% were males. Results. Primary endoscopic haemostasis failed in 51/227 patients (22.5%); 18 patients (7.9%) required surgery for bleeding not controlled at initial or second endoscopy; and 29 patients (12.8%) died, 12 by day 3 and 17 by day 30. Fifteen patients, all with significant medical co-morbidity, died after successful primary endotherapy, and 4 died after surgery. Surgical patients required more blood (odds ratio (OR) 1.45, p=0.0001) than those not undergoing surgery, but had similar mortality. Rebleeding was the only predictor of death in patients who died by day 3 (OR 18.77). A high Rockall score was the only predictor of death by day 30 (OR 1.98). CONCLUSION The overall surgical and mortality rates were 7.9% and 12.8%, respectively. Over half the deaths resulted from medical co-morbidity, despite successful primary endotherapy. This finding is supported by the use of the Rockall score as a predictor of mortality at day 30. Improving the technical success of primary endoscopic haemostasis, currently 77.5%, has the potential to reduce rebleeding after primary endotherapy, a predictor of death at day 3 in this study.

The rise and fall of CA 19-9.

Tumour markers abound in the field of gastroenterology. One of the most ubiquitous is carbohydrate antigen 19-9 (CA 19-9), which was first described by Koprowski et al. in 1979 as an abnormal glycoprotein, expressed on the surface of colorectal cell lines. Also referred to as sialyl Lewis-a CA 19-9, it is formed as a result of an aberrant pathway during production of its normal counterpart disialyl Lewis-a. The latter is a glycoprotein predominantly expressed in non-malignant epithelial cells. The abnormal form can be measured in serum by a specific monoclonal antibody. Ten per cent of the white population lack the Lewis blood group antigen and are unable to produce CA 19-9, even in the presence of malignant disease.

The shifting epidemiology of colorectal cancer in sub-Saharan Africa

The perception that colorectal cancer is rare in sub-Saharan Africa is widely held; however, it is unclear whether this is due to poor epidemiological data or to lower disease rates. The quality of epidemiological data has somewhat improved, and there is an ongoing transition to western dietary and lifestyle practices associated with colorectal cancer. The impact of these changes on the incidence of colorectal cancer is not as evident as it is with other non-communicable diseases such as diabetes. In this Viewpoint, we discuss the epidemiology of colorectal cancer in sub-Saharan Africa. Colorectal cancer in this region frequently occurs at an early age, often with distinctive histological characteristics. We detail the crucial need for hypothesis-driven research on the risk factors for colorectal cancer in this population and identify key research gaps. Should colorectal cancer occur more frequently than assumed, then commensurate allocation of resources will be needed for diagnosis and treatment.

The incidence and histo-pathological characteristics of colorectal cancer in a population based cancer registry in Zimbabwe.

BACKGROUND Data on colorectal cancer (CRC) in sub-Saharan Africa is mainly based on hospital series which suggest low incidence and frequent early onset cancers. This study characterises colorectal cancer in a population-based cancer registry in Zimbabwe. METHODS Cases of CRC recorded by the Zimbabwe National Cancer Registry between 2003 and 2012 were analysed. Demographic and pathological characteristics were compared according to ethnicity and age. Trends in age standardised incidence rates (ASR) were determined. RESULTS There were 886 and 216 cases of CRC among black Africans and Caucasians respectively, and 26% of the black Africans were younger than 40 years. Signet ring cell carcinomas were more common among black Africans compared to Caucasians (4% vs 1%, p=0.027). ASR increased by 1.9%/year and 3.9%/year among black African males and females respectively. CONCLUSION CRC incidence is rising among black Africans and has unique demographic and pathological characteristics.

Laparoscopic splenectomy for immune thrombocytopenic purpura.

BACKGROUND Laparoscopic splenectomy has become the preferred method of splenectomy for refractory immune thrombocytopenic purpura (ITP). We present our experience with the introduction of laparoscopic splenectomy for ITP. METHODS Over a 2-year period, retrospective and prospective data were collected on all patients undergoing laparoscopic splenectomy for ITP at our institution. We analysed demographic data, peri-operative courses, platelet count responses and complications. RESULTS Twenty laparoscopic splenectomies were performed. There were 2 conversions to an open procedure. The average operating time was 100 minutes (range 30 - 170 minutes), and mean blood loss was 106 ml (range 50 - 200 ml). There were no deaths or major complications. The mean follow-up period was 7 months. Ninety-five per cent of patients had a complete or partial response to splenectomy. CONCLUSION Laparoscopic splenectomy can be introduced safely with an acceptable conversion rate, and is an effective treatment for ITP on short-term follow-up.

Differentiating Crohn’s disease from intestinal tuberculosis at presentation in patients with tissue granulomas

BACKGROUND Overlapping clinical, endoscopic, radiographic and histological features, coupled with poor microbiological yield, make differentiating Crohns disease (CD) from intestinal tuberculosis (ITB) challenging. Granulomas are present in both diseases; in CD they predict the need for immunosuppressive therapy that requires ITB to be excluded before initiation. OBJECTIVES To compare granuloma-positive CD and ITB, to identify factors that may aid in diagnosis. METHODS This was a retrospective cohort study evaluating granuloma-positive CD and ITB identified from a pathology database. RESULTS Sixty-eight ITB and 48 CD cases were identified. Patients with ITB were more likely to be male, and to have HIV infection, isolated colitis, night sweats and tachycardia. ITB was also associated with lower serum albumin and haemoglobin and higher C-reactive protein levels, a chest radiograph showing active tuberculosis, and lymph nodes >1 cm on imaging. Extraintestinal manifestations (EIMs) were predictive of CD. There were no significant differences in smoking status, symptom duration or perianal disease. On multivariate analysis, HIV positivity (odds ratio (OR) 29.72, 95% confidence interval (CI) 2.15 - 410.96; p=0.01), isolated colitis (OR 6.17, 95% CI 1.17 - 32.52; p=0.03) and the absence of EIMs (OR 0.10, 95% CI 0.01 - 0.65; p=0.02) remained significant risk factors for ITB. CONCLUSION This is the first study to identify clinical and biochemical factors to aid in differentiating granuloma-positive ITB from CD. EIMs support a diagnosis of CD, while isolated colitis and HIV are predictors of ITB.

Breast cancer and HIV

BACKGROUND Biliary mucinous cystic neoplasms (BMCNs) are uncommon neoplastic septated intrahepatic cysts which are often incorrectly diagnosed and have the potential for malignant transformation. OBJECTIVE To assess the outcome of surgical resection of BMCNs. METHOD A prospective liver surgery database was used to identify patients who underwent surgery at Groote Schuur Hospital Complex for BMCN from 1999 to 2015. Demographic variables including age and gender were documented as well as detailed preoperative imaging, location and size, operative treatment, extent of resection, histology, postoperative complications and outcome. RESULTS Thirteen female patients (median age 45 years) had surgery. Eleven were diagnosed by imaging for symptoms. Two were jaundiced. One cyst was found during an elective cholecystectomy. Five cysts were located centrally in the liver. Before referral three cysts were treated with percutaneous drainage and two were treated with operative deroofing. Six patients had anatomical liver resections and seven patients had non anatomical liver resections of which two needed ablation of residual cyst wall. One patient needed a biliary-enteric reconstruction to treat a fistula. Median operative time was 183 minutes (range: 130-375). No invasive carcinoma was found. There was no operative mortality. One surgical site infection and one intra-abdominal collection were treated. Two patients developed recurrent BMCN after 24 months. CONCLUSION BMCNs should be considered in middle aged women who have well encapsulated multilocular liver cysts. Treatment of large central BMCNs adjacent to vascular and biliary structures may require technically complex liver resections and are best managed in a specialised hepato-pancreatico-biliary unit.

Dietary patterns and colorectal cancer risk in Zimbabwe: A population based case-control study

Highlights • Three main dietary patterns in Zimbabwe; traditional African, urban and processed foods.• Traditional African diet associated with a reduced risk of colorectal cancer.• No association between colorectal cancer and the urban or processed food patterns.