Introduction 1 2 3 2 H. pylori 2 Helicobacter pylori 4 5 H. pylori 2 H. pylori H. pylori 6 7 H. pylori cagA vacA 6 8 10 VacA H. pylori 10 12 13 14 VacA 15 16 CagA 17 H. pylori H. pylori H. pylori Methods H. pylori cagA vacA 18 cagA vacA Results A total of 30 patients were included of whom nine were women. The average age was 65 years, varying between 40 and 87. Ten patients (33.3%) were operated laparoscopically. The perforation was found prepyloric in 11 patients, at the site of the pylorus in eight patients and postpyloric in 11 patients. A total of five (16.7%) patients had a history of PUD. Ten patients (33.3%) used NSAID’s, two patients (6.7%) used steroids, three patients (10.0%) used acid reducers, and one patient (3.3%) used a proton pump inhibitor (PPI) before admission to the hospital. The average hospital stay was 11.9 days, varying between 3 and 37 days. 1 Table 1 Helicobacter pylori  H. pylori The β-globin determination was performed as a control. In nine samples of nasogastric tube fluid and in two samples of lavage fluid it was negative, rendering these results as unreliable. Therefore, these results were excluded from further analysis. 2 Table 2 Frequencies of Individual Genes and Allelic Types Genotype Fluid from Naso-Gastric Tube Lavage Fluid Gastric Tissue Biopsy Control Non-Ulcer No. % No. % No. % % VacA 10 90.9 14 77.8 7 77.8 46.9 VacA 0 0 1 5.5 1 11.1 38.4 VacA 1 9.1 3 16.7 1 11.1 14.7 Total 11 100 18 100 9 100 100 VacA 6 54.5 9 50.0 5 55.6 29.4 VacA 4 36.4 8 44.4 3 33.3 55.9 VacA 1 9.1 1 5.6 1 11.1 0 (14.7 % incomplete) Total 11 100 18 100 9 100 100 CagA 9 81.8 14 77.8 5 55.6 47.1 Total 11 100 18 100 9 100 100 VacA vacA vacA 3 Table 3 vacA VacA Fluid from Naso-Gastric Tube Lavage Fluid Gastric Tissue Biopsy Control Non-Ulcer No. % No. % No. % % S1a 8 80.0 13 92.9 5 71.4 81.3 S1b 2 20.0 1 7.1 2 28.6 18.7 S1c 0 0 0 0 0 0 0 Total 10 100 14 100 7 100 100 The s1a subtype is predominant in all sample types. The “Control non ulcer” column represents the frequencies, found by van Doorn et al., in a population without PUD and is added to allow easy comparison. vacA 1 2 H. pylori H. pylori H. pylori p H. pylori 1 4 Table 4 Calculation of Sensitivity and Specificity of Lavage Fluid Analysis   Biopsy Lavage fluid  + – Total + 8 2 10 – 0 4 4 Total 8 6 14  Sens 8/8 = 1 Spec 4/6 = 0.67  H. pylori Discussion H. pylori H. pylori 19 21 H. pylori 5 H. pylori H. pylori 1 VacA vacA vacA cagA cagA vacA cagA vacA cagA 6 10 vacA 2 3 vacA cagA 3 H. pylori H. pylori p H. pylori H. pylori H. pylori H. pylori Overall, these results are positive, however they should be confirmed in a larger population. Conclusion vacA cagA vacA cagA H. pylori