3.5 Pilot study
3.5.2 Stage two: Interviews
Helicobacter pylori associated histological gastritis was observed in 70 (51.5%) dyspeptic patients in Ilorin. This rate of 51.5% is similar but higher than the rate of 49.1% obtained from an earlier study of the histomorphology of H. pylori associated chronic gastritis in Ilorin.161 This rate can also be compared to the H. pylori associated histological gastritis rate of 57.2%
reported in a retrospective study of 603 antral biopsies in Maiduguri.172 It is however lower than the prevalence rate of 89.1% reported in another study from Maiduguri which may be due to the higher prevalence rate of 78.5% recorded in that study when compared to the 47.3% prevalence rate obtained in my study.156 H. pylori infection in the subjects was significantly associated with chronic gastritis, neutrophil inflammatory activity, glandular atrophy and intestinal metaplasia with p< 0.001. However, its association with chronic gastritis was stronger (p= 0.0006) than with neutrophil activity (p< 0.001), glandular atrophy (p< 0.001) and intestinal metaplasia (p= 0.003).
The observed association of H. pylori infection with chronic gastritis also showed causality and that the presence of histological gastritis is a predictor of H. pylori infection. The association between H. pylori infection and the degrees of chronic inflammation, neutrophil activity, glandular atrophy and intestinal metaplasia was statistically significant with p-values less than 0.05. The association was stronger for chronic gastritis, neutrophil activity and glandular atrophy (p< 0.001) than for intestinal metaplasia (p= 0.009). These findings were consistent with those from previous studies.165,172
99
In a study from China,173 where the predictive value of neutrophil infiltration as a marker of H.
pylori infection was evaluated using UBT for detection of the organism, the sensitivity, specificity, positive predictive value and negative predictive value of neutrophil infiltration/activity in the diagnosis of H. pylori infection were 92.3%, 83.5%, 77.4% and 94.7%, respectively. Neutrophil infiltration of gastric mucosa in the histological analysis was strongly associated with H. pylori infection (77.4% in the neutrophil infiltration positive group vs 5.3% in the neutrophil infiltration negative group, p< 0.001). A similar strong association with H. pylori infection was found in this study (75.6% in the neutrophil infiltration positive group vs 8.0% in the neutrophil infiltration negative group, p< 0.001). Furthermore, in the same study, moderate neutrophil infiltration was observed to occur more frequently with H. pylori infection when compared to mild neutrophil infiltration (81.8% and 75.0%, respectively). This, however, did not reach statistical significance.173_ENREF_180_ENREF_180_ENREF_179 The findings in this study are similar with moderate neutrophil infiltration occurring more frequently with H. pylori infection when compared to mild neutrophil infiltration (80.9% and 52.8% respectively).
Surprisingly, none of the 16 patients with histological diagnosis of gastric adenocarcinoma had H. pylori infection. This may be due to the poor sensitivity of histology in the setting of gastric cancer since H. pylori does not colonize gastric cancer epithelium.174 Perhaps, the use of other methods of H. pylori detection such as UBT or serology in this subset of patients might have revealed the presence of H. pylori infection as one would expect considering the established role the organism is known to play in the aetiology of gastric cancer.
100
CHAPTER SEVEN
LIMITATIONS, CONCLUSIONS AND RECOMMENDATIONS LIMITATIONS OF THE STUDY
1. The addition of at least one other method of H. pylori detection such as PCR or FISH to the one used in this study perhaps may have increased the diagnostic yield of the organism.
2. The hospital-based cross sectional design of this study may not give a true reflection of the prevalence rate of H. pylori in the community.
101
CONCLUSIONS
1. The H. pylori prevalence rate of 47.3% obtained from this hospital-based study from Ilorin is moderately high.
2. Gastroduodenitis was recorded in 42 (28.4%) patients at endoscopy and the association between H. pylori infection and its occurrence was statistically significant.
3. Gastric and duodenal polyps were found in 4 (2.7%) patients who were all infected by H.
pylori and a significant association was found between the organism and their presence in the upper GI tract.
4. The number of cases of gastric adenocarcinoma 11 (7.4%) encountered in this study over a period of 9 months is quite high.
5. There is significant association between H. pylori infection and the histological findings of chronic gastritis, neutrophil activity, glandular atrophy and intestinal metaplasia as well as with the severity of these findings.
6. The presence of chronic gastritis and neutrophil activity on histology strongly predicts the presence of H. pylori infection.
102
RECOMMENDATIONS
1. Screening for H. pylori infection should remain a key component of the evaluation of patients with dyspepsia since the prevalence of this organism among these patients remains high.
2. A large multicenter prevalence study with the use of a combination of both endoscopy and non-endoscopy based diagnostic tests for H. pylori should be carried out in order to obtain a better and more current estimate of the true prevalence of this organism among dyspeptic patients in Nigeria.
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