Serodiagnosis of Helicobacter pylori infection by Cobas Core ELISA in adults from Minas Gerais, Brazil

We evaluated the accuracy of a 2nd generation ELISA to detect Helicobacter pylori infection in adults from a developing country in view of variations in sensitivity and specificity reported for different populations. We studied 97 non-consecutive patients who underwent endoscopy for evaluation of dispeptic symptoms. The presence of H. pylori was determined in antral biopsy specimens by culture, by the preformed urease test and in carbolfuchsin-stained smears. Patients were considered to be H. pylori positive if at least two of the three tests presented a positive result or if the culture was positive, and negative if the three tests were negative. Sixty-five adults (31 with peptic ulcer) were H. pylori positive and 32 adults were H. pylori negative. Antibodies were detected by Cobas Core anti-H. pylori EIA in 62 of 65 H. pylori-positive adults and in none of the negative adults. The sensitivity, specificity and positive and negative predictive values of the test were 95.4, 100, 100 and 91.4 per cent, respectively. The Cobas Core anti-H. pylori EIA presented high sensitivity and specificity when employed for a population in Brazil, permitting the use of the test both to confirm the clinical diagnosis and to perform epidemiologic surveys.

Indirect immunofluorescence determination of the frequency of anti-H. pylori antibodies in brazilian blood donors

The accuracy of an indirect immunofluorescence (IIF) test for the serodiagnosis of Helicobacter pylori infections was evaluated in adult patients and compared with culture, preformed urease test and smears stained with carbolfuchsin. We studied 80 consecutive patients submitted to gastroduodenioscopy (17 of whom were found to have duodenal ulcer) plus 57 patients with duodenal ulcer. H. pylori was identified by microbiological mehtods in 65 of the 80 consecutive patients and in all 57 patients with duodenal ulcer. Among the 74 patients with duodenal ulcer, 71 presented antibody titers *1:20 and 46 of the 48 H. pylori-positive patients without duodenal ulcer presented antibody titers *1:20. Thirteen of the 15 H. pylori-negative patients presented antibody titers *1:10. The sensitivity,m specificity and positive predictive value of the IIF test were 95.9%, 88.8% and 98.4%, respectively. The seroprevalence of H. pylori in 380 asymptomatic Brazilian was also studied by the IIF teset. The presence of IgG antibodies against H. pylori was observed in 62.1% of the individuals. The prevalence of H. pylori infection increased with age and no difference was observed between males (60.3%) and females (66.6%)