PREVALENCE OF HELICOBACTER PYLORI AMONG ASYMPTOMATIC POPULATIONS IN SANA'A, YEMEN

Objective: Helicobacter pylori consider the most important cause of chronic gastritis and also the most important etiological factor responsible for the duodenal and gastric ulcer and have an important role in the pathogenesis of gastric cancer. The aim of the present study to know the prevalence of H. pylori among the khat chewing adults in compared to non-khat chewing among asymptomatic populations. Methods: A total of 82 healthy subjects were screened to find out the prevalence of Helicobacter pylori using stool antigen card test during the period started in 16 April 2018 and ending in 8 May 2018 in Sana'a, Yemen. Predesigned questionnaire was used to collect information such as age, sex, education status, khat chewing, smoking, tobacco chewing, occupation, and tests results all above data were recorded for each subject. Results: Patients who had taken proton pump inhibitors or antibiotic for a month prior to study were excluded. Out of these 82 asymptomatic individuals, 36 were found positive for Helicobacter pylori by the test, giving a prevalence of 43.9 %. A prevalence of 26.9 % (62.9 % of khat chewing) was khat chewing individuals and it had statistically significant difference. A prevalence of 14.6 % was seen among cigarette smoking participants. Conclusion: The present study revealed substantial prevalence of Helicobacter pylori in khat chewing healthy subjects. A higher prevalence of Helicobacter pylori seen in these subjects may be contributed to khat chewing. Identification of khat chewing populations, who do not show symptoms of Helicobacter pylori infection, is essential for controlling the infection and it still remains a challenge for the clinicians.


INTRODUCTION
Helicobacter pylori, previously known as Campylobacter pylori, is a gram-negative, microaerophilic bacterium usually found in the stomach. It was identified in 1982 by Australian scientists Barry Marshall and Robin Warren. Over 80% of individuals infected with the bacterium are asymptomatic, and it may play an important role in the natural stomach ecology 1 . More than 50% of the world's populations have H. pylori in their upper gastrointestinal tract 2 . Infection is more common in developing countries than Western countries 3 . Helicobacter pylori consider the most important cause of chronic gastritis and also the most important etiological factor responsible for the duodenal and gastric ulcer and have an important role in the pathogenesis of gastric cancer 4 . In a case control study in Nairobi country the prevalence of H. pylori infection was found to be higher among khat chewers, indicating that Khat chewing could be a predisposing factor to gastrointestinal disorders 5 . Also In another study the prevalence of gastrointestinal disorders was found to be higher among khat chewers, indicating that khat chewing could be a predisposing factor to gastrointestinal disorders and H. pylori infection. Community-based awareness creation about the adverse effect of khat use is thus recommended 6 . Raja'a YA et al., revealed in his study that khat chewing is significantly associated with duodenal ulcer due to stress that follows khat chewing. This phenomenon is very common and is induced by the effect of amphetamine like action of cathine present in khat. Another possible factor can be due to Helicobacter pylori associated with khat chewing 7 . Khat is an evergreen plant found commonly grown in Yemen, Ethiopia, Kenya, Sudan, Madagascar and South Africa 8 . The plant is known by different names in different countries but in most of the literature it is known as Khat 9 . People chew the leaves and young bud of khat for social and psychological reasons 10, 11 . The psycho-stimulant effect of khat is due to the alkaloid chemical ingredient cathinone present in the fresh leaves of the khat plant 12,13 . Many people use khat for different purposes: for social recreation, to keep awake while driving long distances 14,15 , to reduce physical fatigue and to work hard for a long time 16 . It is believed that students in colleges and universities commonly use khat to improve their academic performance but the fact is the opposite. The result of one study showed that the mean cumulative Graded Point Average (GPA) of non-chewers was found to be significantly higher than that of chewers 17, 18 . The astringent characteristics of the tannins in khat accounts for periodontal disease, stomatitis, oesophagitis and gastritis 12 . Tannins and cathinone contribute to constipation, the most common medical complaint of the khat user. In a randomized controlled trial, Heymann et al., reported a delay in gastric emptying after chewing khat, which was attributed to the sympathomimetic action of the cathinone 19 . Moreover, Gunaid et al., 20 . found out that khat prolongs entire gut motility and Makonnen et al., reported that khat produced constipation in mice and an antispasmodic action on guinea-pig isolated ileum 21 .
The antispasmodic effect of khat extract was observed to be similar to that of d-amphetamine.
Khat is abundantly available in Yemen and is a highly valued export commodity in the country. The number of khat chewers has significantly increased in this country and khat consumption has become popular in all segments of the Yemeni population 16, 22 . There were many previous studies reported a positive association between Khat chewing and gastrointestinal disorders such as dental problems, gastritis and constipation 12,19,20,21 . According to some researchers, hemorrhoids are also considered to have associations with khat chewing 21, 23 . In developing countries such as Yemen, there was no study conducted to assess the prevalence and the association between the khat chewing in compared to non-khat chewing in asymptomatic populations. Therefore, it is important to study prevalence of H. pylori infection and the associated risk factors among these subjects.

MATERIALS AND METHODS
A total of 82 healthy subjects were screened to find out the prevalence of Helicobacter pylori using Stool Antigen card test during the period started in 16 April 2018 and ending in 8 May 2018 at Sana'a, Yemen. Predesigned questionnaire was used to collect information such as age, sex, education status, khat chewing, smoking, tobacco chewing, occupation, and tests results all above data were recorded for each subject. Individuals who had taken proton pump inhibitors or antibiotic for a month prior to study were excluded. Data were analyzed by the chi-square test to compare the association between different variables and positive Helicobacter pylori rates. A value of P <0.05 was considered statistically significant. Calculations were done using the software package SPSS 21.0.    29 . Another major health concern is the concurrent use of tobacco and khat in countries where these substances are used in combination, as tobacco use is a well-known factor for the development of various diseases. It has been reported that up to 61% of khat chewers smoke cigarettes 30 and that smokers usually consume more cigarettes during khat chewing sessions 31 . In a recent study, approximately 42.9 % of khat users reported use of tobacco, implying that khat chewing might serve as a "gateway" to tobacco use. A recent systemic review also showed that the prevalence of tobacco use among   29 . Among the socio-demographic characteristics of the participants, statistically significant difference was not obtained for educational attainment which is in agreement to studies 38,39 and inconsistent to other studies 34, 40 . The absences of association in this study might be due to less number of non-educated subjects that cause difficulty to compute the association.

CONCLUSION
Based on the findings, it was concluded that khat chewing is a common practice among Yemeni adults. The result of this study depicts that H. pylori prevalence are significantly associated with khat chewing. Identification of khat chewing populations, who do not show symptoms of Helicobacter pylori infection, is essential for controlling the infection and it still remains a challenge for the clinicians The present study findings call for further research especially in a longitudinal study which is more costly and time-consuming to strengthen current current study findings. Regulatory bodies may need to devise strategies to counter the expansion of Khat chewing and other substance uses which pose continuing public health risks. Community based health education is also needed.

AUTHOR'S CONTRIBUTION
The manuscript was carried out, written, and approved in collaboration with all authors.