The Prevalence of Helicobacter Pylori Infection among Medical Science Students of Hodeidah University-Republic of Yemen

Background: The prevalence of Helicobacter pylori (H. pylori) infection worldwide varies greatly among countries and among population groups within the same country. Objective: The aim of this study was to evaluate the prevalence of H. pylori infection among Medical Sciences' students of Hodeidah University, Yemen. Methods: A total of 150 students were recruited (50 males [33.3%] and 100 females [66.7%]) with a mean age of 21.6±1.6 years (age varied from 19 to 27 years). General characteristics and other relevant information of the students in this study were collected using pre-designed questionnaire, which included information such as demographic data, clinical symptoms and socioeconomic status. Serum samples were collected from all volunteers and then blood rapid qualitative serologic test was used for the diagnosis of H. pylori by detecting H. pylori antibodies. Results: The prevalence of H. pylori was 68% (102 of the volunteers showed positive results). The higher infection rate was reported in females (69.6% of positive results= 71 female volunteers) with no significant difference between the positive and negative results. Conclusion: There was a high prevalence of H. pylori infection in our young university Medical Sciences' students' population This high prevalence in this young population may have both important clinical and economic implications.


INTRODUCTION
elicobacter pylori (formerly called Campylobacter pylori) are a spiral Gramnegative microorganism that is distributed worldwide.It is estimated that over 50% of the world's population are infected with H. pylori. (1). pylori associated infection is either usually clinically silent or its signs and symptoms are nonspecific.4) However, these symptoms are seen in many childhood illnesses.Younger children with peptic complaints may not have symptoms as clear as those of older children, and diagnosis of infection due to H. pylori is more difficult. (2,5,6) H pylori is recognized as the most important causative agent for chronic gastritis and is present in 90% of duodenal ulcers and 70% of gastric ulcers.It is also a cofactor for gastric cancer and mucosa-associated lymphoid tissue (MALT) lymphoma.(5,7) Definitive routes of transmission of H. pylori infection have not yet been characterized, and the principal reservoir appears to be family members.Person-to-person transmission via the faecal-oral and oral-oral routes have been proposed.(8,9) The epidemiology of H. pylori-associated infection

Research Article
is variable, since the prevalence is significantly higher and infection occurs in earlier ages in developing or poor countries compared to developed countries.The prevalence of infection seems to mostly depend on the rate of acquisition, in addition to the rate of loss of infection and the length of the persistence period between acquisition and loss. (10,11) 13) Epidemiological studies have demonstrated that the prevalence of infection is estimated to be about 50% of the adults in the developed countries, which increases with advancing age.(14) It reaches up to 90% of adults in developing countries and this high prevalence was found among low socioeconomic level populations, probably due to conditions that favor the acquisition of infection such as precarious hygiene, crowded living conditions, and absence or deficiency of sanitation.(2)(3)(4)(5)13) The aim of this study was to evaluate the prevalence of H. pylori infection and its relationship with the affecting factors (demographic and socioeconomic data) among Medical Sciences' students of Hodeidah University.

Study setting and design
This cross section study was carried out during the period from March 2011 to August 2013, in Faculty of Medical Sciences; Hodeidah University, Yemen.

Study population
A total of 150 Medical Sciences' students of Hodeidah University (50 males, and 100 females) who agreed to participate were included in the study.

Data collection
The data were collected by face-to-face interview using a pre-designed questionnaire which was filled out for every student under the study.The questionnaires included questions on age, sex, blood group, parents' education, socioeconomic status, (15) parents' occupation, Khat chewing (Khat is a chemical extract from a plant Catha Edulis, used as a natural stimulant in East Africa and bordering Arabic states mainly Yemen), smoking, alcohol and caffeine consumption, the presence of gastric symptoms, and hygienic behaviors.
-Each student consented to have a blood sample to perform the H. pylori serological test.

Diagnosis of H. pylori infection
Two ml of blood sample was collected from each student.Serum was separated and used for detection of H. pylori IgG antibodies by the Rapid Hp StAR (Dako Cytomation Ltd., United Kingdom) according to manufacturer's instructions.

Statistical analysis
Chi-square (χ 2 ) test was used to compare the prevalence of H. pylori infection in the different categories of the explanatory variables.The significance level was set at 0.05.

RESULTS
In the present study, a total of 150 students were recruited [50 males (33.3%) and 100 females (66.7%)] with a mean ±SD age of 21.6± years (age varied from 19 to 27 years).All volunteers were Yemeni living in Hodeidah governorate.
The prevalence rate of H. pylori infection was 68% (102 out of 150).Among H. pylori positive results, 31(30.4%)were males and 71(69.6 %) were females.The fathers were without stable or governmental work in 86.3% of those showing positive infection, while the fathers were working in 87.5% of those showing negative infection.Socioeconomic status was found to be one of the most important factors affecting the spread of H. pylori infection, where 80.39% of the positive samples were associated with low socioeconomic status.
About one third of the fathers of the students with positive infection were either illiterate (39.2%) or had primary level of education (33.3%).About two thirds (76.5%) of the mothers of the students with positive infection were illiterate.Most (67.6%) of the students who showed positive infection had blood group (O).There was no statistical significant difference between H. pylori infection and different characteristics of the studied students (Table 1).Table (2) illustrates the relationship between H. pylori with the drinking water source and some hygienic behaviors.It was found that about 60% of positive samples were taking their drinking water from tap.Approximately all studied subjects whether

DISCUSSION
The interest in rapid diagnosis of H. pylori has increased in recent years.To reduce costs, it has been proposed that endoscopy be reserved for patients with serious symptoms such as the weight loss, anemia suggestive of a bleeding ulcer or cancer and advanced age.On the other hand, it has been suggested that patients under the age of 45 years without serious symptoms be treated for their H. pylori infections and subjected to endoscopy only if still symptomatic after successful eradication therapy.Both of these approaches would benefit from a reliable rapid diagnostic test.For screening of dyspeptic patients, a test of high sensitivity is needed to ensure that positive individuals who should have endoscopies will not be missed.However, if treatment decisions are to be made on the basis of the test used, it is extremely important that the test is highly specific so that false-positive results and unnecessary antimicrobial therapy can be avoided.The Rapid Hp StAR (Dako Cytomation Ltd., United Kingdom) test is easy to perform; no special equipment is needed, the results are available generally within 10-30 min.18) Helicobacter pylori is one of the most common chronic bacterial infections of humans and has a worldwide distribution.In this study, H. pylori was detected in 68% of the studied samples.Epidemiological studies strongly suggested that more than 50% of the world's population is colonized by H. pylori. (19)However, the prevalence of H. pylori infection varies from 10% to 90%, depending on age, geographic location, and socioeconomic status of the populations. (20)n developing countries, the prevalence of H. pylori infection was found in more than 70% of the populations. (21)n the Middle East countries like Turkey, the prevalence was 63% in the university students. (2)In Arabian countries like Saudi Arabia, H. pylori was found in 31 % of the university students. (22)However, Yemen is one of the developing countries with a high incidence of gastrointestinal symptoms and a high reported rates of sero-prevalence of H. pylori infection. (23)6) In a study of the prevalence of H. pylori infection in a rural area of the state of Mato Grosso, Brazil, (27) there was significant relation between the presence of H. pylori infection and age .On other hand in the present study, this relation was not found.
A study about the prevalence of H. pylori in a district in Turkey, (2) found that most infected with H. pylori were living in an urban area.In this study, the samples were taken from the Faculty of Medical Sciences' students which is located in the urban district of Hodeidah Governorate irrespective of the origin of these students.
In the present study as well as in a study of Mansour-Ghannaei et al., (28) to evaluate the prevalence of H.pylori infection among children in Rasht, Northern Iran, there was no significant difference between the sero-positivity rates of H. pylori infection and individuals' ages, gender or socioeconomic levels.
(31) H.pylori exists in two forms: the spiral form and the coccoid form.
(34) Some researches have shown that H. pylori can survive water microcosms in coccoid form . (35,36) The coccoid H. pylori in water has therefore been suspected to contribute an important part to the transmission of the bacteria.In the present study, the main two water sources consumed by the studied students were either tap or well water that showed no relation with H. pylori infection.

CONCLUSION &RECOMMENDATIONS
In the present study, high prevalence rates of H. pylori infection (68%) were detected among Medical Sciences University students.Periodic screening for H. pylori among students and other target population should be done to detect the prevalence rates and to correlate them with different demographic variables.

Table 1 :
Relation between H. pylori infection and the general characteristics of students

Table 2 :
Relation between H. pylori with the drinking water source and some hygienic behaviors

Table 3 :
Relation between different habits and the H. pylori infection