Response to Drs. Luzza et al. and Furuta et al.

Abstract

To the Editor: We acknowledge the papers of Luzza et al. (1) and Furuta et al. (2), which were published after our manuscript. The present study focused on the risk of infection with Helicobacter pylori (H. pylori) and hepatitis A virus (HAV) in different groups of hospital workers, but not on the mode of transmission of these agents (3). As outlined, infection with H. pylori or HAV can be avoided, if general hygienic procedures are carefully observed. Based on the overall seropositivities of 33.0% and 25.8% for H. pylori and HAV respectively, a theoretical probability for seropositivity to both H. pylori and HAV could have been expected in only 8.5% of all study participants. However, 15.4% of the subjects were positive for H. pylori and HAV antibodies suggesting a possible association. As noticed by Luzza et al., this association appears low, but was statistically significant (p < 0.001). Moreover, the -coefficient was higher than that in the study of Hazell et al. (4). The high number of subjects negative for both H. pylori and HAV antibodies indicates that the risk of infection in hospital workers can be ignored, but does not allow any conclusion about the mode of transmission. As outlined in our paper and mentioned by Furuta et al. and Luzza et al., seroprevalences for H. pylori and HAV increased with age. Because this is the case for both infections, a positive correlation might persist even if the age factor is considered in a multivariate analysis. Reanalysis of our data with the inclusion of age into a multivariate analysis confirmed the positive correlation between H. pylori and HAV seroprevalence. Unfortunately, there was no opportunity to evaluate other risk factors such as socioeconomic status or childhood conditions that might be important risk factors in H. pylori and HAV infection. However, consideration of these factors might explain differences in seroprevalences rather than provide information about the transmission of these infections. Because of the smaller number of subjects in group III (personnel in the gastroenterology and endoscopy unit), the lack of correlation of H. pylori and HAV in this group is not surprising. However, because there were no differences in seroprevalences between the three hospital staff groups, analysis of the total study population might result in more reliable data with respect to a possible association of H. pylori and HAV. We agree with Furuta et al. that transmission of HAV, but not H. pylori, is possible by consumption of shellfish. However, in the past few years, hospital staff involved in patient care were at higher risk of acquiring HAV infection (5). This suggests that HAV could also be transmitted directly by contact with feces or with feces-contaminated food. Moreover, the consumption of shellfish is less frequent in the area where the present study was conducted. It may be that regional differences in seroprevalences and association between H. pylori and HAV exist according to differences in eating habits such as the consumption of seafood. Therefore, our findings are consistent with the assumption that H. pylori could be transmitted via the fecal-oral route.