Inter-observer and intra-observer variability in the diagnosis of dysplasia in patients with inflammatory bowel disease: correlation of pathological and endoscopic findings.

AIM: Colonic epithelial dysplasia is deemed the precursor lesion of cancer arising in inflammatory bowel disease (IBD). It has been suggested that many dysplastic lesions could be endoscopically detected to obtain target biopsies, leading to better yield. However, the clinical impact of a diagnosis of dysplasia may be hampered by a significant degree of histological and endoscopic intra-observer and inter-observer variability. This study aimed to evaluate intra-observer and inter-observer variability in the microscopic diagnosis of dysplasia in IBD and correlate endoscopic and histological findings. METHOD: In total, 158 cases of ulcerative colitis and 14 of Crohn's disease with dysplasia were selected from a pathology database. Slides were blindly reviewed twice by two expert gastrointestinal pathologists. Results of endoscopic examinations were extracted from the reports. The degree of intra-observer and inter-observer variability was determined by kappa statistics. RESULTS: Overall, there was an excellent degree of histopathological inter-observer agreement (κ = 0.786). The lowest level of agreement in the dysplasia group was for indefinite dysplasia (κ = 0.251). Negative and high grade dysplasia diagnosis reached the highest level of agreement with κ values of 0.822 [95% confidence interval (CI) 0.673-0.971] and 1.00 (95% CI 0.850-1.149), respectively. Intra-observer agreement was good and increased during the latter period of the study (κ = 0.734, 95% CI 0.642-0.826). Endoscopic-histological correlation was poor among the negative endoscopies, as up to 43% of cases were diagnosed with at least focal high grade dysplasia. The endoscopic-histological correlation improved when evaluating suspicious endoscopic lesions. CONCLUSION: Dysplasia is reliably diagnosed by expert gastrointestinal pathologists but has poor correlation with an endoscopic diagnosis of dysplasia.

Descriptive and spatial epidemiology of Rift valley fever outbreak in Yemen 2000-2001.

Rift valley fever (RVF) is an arboviral disease produced by a bunyavirus belonging to the genus Phlebovirus. Several species of Aedes and Culex are the vectors of this virus that affects sheep, goats, buffalos, cattle, camels and human beings. The human disease is well known, especially during periods of intense epizootic activity. The initial description of the disease dates back to 1930, when animals and human outbreaks appeared on a farm in Lake Naivasha, in the Great Rift Valley of Kenya. Until 2000, this disease was only described in Africa, and then outbreaks were also declared in the Kingdom of Saudi Arabia (2000-2001 and 2004) and in Yemen (2000-2001). Animal and human cases were recorded. This work presents a retrospective summary of the data collected on animal RVF cases during this epidemic in Yemen. Results from several RVF surveys were gathered from the Yemeni vet services and FAO experts. Geographical data (topographic maps and data freely available on internet) were used for the location of outbreaks. After cleaning and standardization of location names, all the data were introduced into a GIS database. The spatial distribution of outbreaks was then studied at two scales: at the national level and at a local scale in the particular area of Wadi Mawr in the Tihama plain, Western coast of Yemen.