Prevalence of Helicobacter pylori and parasites in symptomatic children examined for Helicobacter pylori antibodies, antigens, and parasites in Yemen.

OBJECTIVES: To estimate the prevalence of Helicobacter pylori (H. pylori) and parasites in symptomatic children examined for H. pylori antibodies, antigens, and parasites in Yemen.
METHODS: A record-based study was carried out at Specialized Sam Pediatric Center in Sana'a, Yemen for 3 years between 2011-2013. Out of the 43,200 patients seen for different causes through that period, 1008 (2.3%) (females: 675 [67%]; males: 333 [33%]) had gastric complaints, and were subjected to an examination of blood and stool for H. pylori and parasites. Data regarding age and gender was also collected.
RESULTS: The age of the patients ranged from 3-15 years. The prevalence of H. pylori among children examined for H. pylori was 65%, 30% of them were males, and 35% were females (chi square [I2]=142, p<0.01]). The prevalence in the 6-8 years age group was 83%, and it was 52% in the age group of 12-15 years. The prevalence of giardiasis was 10%, and amoebiasis was 25%.
CONCLUSION: Prevalence of H. pylori infection among children was high, and was more prevalent in the age group of 6-8 years than in the other age groups. Females were more affected than males. Parasites (amoebiasis and giardiasis) infestation was less prevalent.

In countries with low socioeconomic status, co-infections involving several different pathogens commonly occur. Several studies from different locations have reported a possible connection between Giardia intestinalis and Helicobacter pylori (.1,2 Both organisms inhabit the gastrointestinal tract (GI) in their human hosts within a close proximity, and both organisms are recognized to infect children at a high rate in low-income countries.3,4 The H. pylori is a common bacterial infectious disease whose manifestations predominately have an effect on the GI tract, a gram negative, spiral-shaped pathogenic bacterium residing in the mucosa overlying the epithelium of the gastric antrum was first isolated by Warren and Marshall in 1982.3 At first, this bacterium was classified as Campylobacter pylori but in 1989 it was included in a new genus, Helicobacter, and renamed Helicobacter pylori. It is among the most common bacterial infections in the world, and thousands of articles have been written regarding H. pylori.5

The H. pylori is capable to live in the stomach acid because it releases enzymes that neutralize the acid; this allows H. pylori to make its way to the “safe” area - the protective mucous lining, which permits acid to get through to the sensitive layer below. Both the acid and bacteria irritate the lining, and cause abdominal pain, or ulcer.6 The method of acquisition and transmission of H. pylori is uncertain, even though the most probable method of transmission is fecal-oral, or oral-oral. Risk factors, such as low-income in childhood, or affected family members also influence the prevalence. All children infected with H. pylori develop histologic chronic active gastritis but often asymptomatic. Manifestation of H. pylori infection in children is abdominal pain or vomiting, less often, refractory iron deficiency anemia, or growth retardation. Chronic colonization with H. pylori will prompt children to a notably augmented risk of developing duodenal ulcer, or gastric cancer. The H. pylori is classified as a group 1 carcinogen by the World Health Organization (WHO).7 The prevalence and rate of acquisition of H. pylori infection in children from developing countries is higher than in developed countries.8 The prevalence is 3-10% of the population each year in developing countries, while in developed countries it is 0.5%.8 In a very attractive longitudinal study from the US-Mexican border, Cervantes et al9 demonstrated that a younger sibling was 4 times more liable to become infected with H. pylori if the mother was infected with H. pylori in contrast with an uninfected mother. Younger siblings were 8 times more liable to become infected if their older index sibling had persistent H. pylori infection.9 Crowding, poor living conditions, and poor personal hygiene may play a role as well.10 In Saudi Arabia, they found that there was a significant relation between H. pylori infection, and recurrent abdominal pain among students.11 Similarly, in Oman they found that H. pylori associated with active chronic gastritis is the most common form of stomach diseases. Particularly females, young, and middle ages group had the highest frequency of H. pylori organisms in gastric antrum.12 Regardless of the success in numerous diagnostic methods for the detection of H. pylori, such as endoscopy, urea breath test, stool and blood samples, and the enhancement in socioeconomic status, infection with H. pylori is still on rise, and physicians in many developing countries are facing the issues of availability and cost, to establish the diagnosis of H. pylori infection. Worldwide, non-invasive tests for active infection are preferred (such as, urea breath test, stool antigen test, and blood antibody test).13

The results from many researchers depend on one or 2 tests only for the diagnosis of H. pylori, and any test that would give positive result for H. pylori was regarded positive for final diagnosis. However, every diagnostic method has a percentage of false positive or negative result, therefore, if at least 2 methods for H. pylori indicates positive result at the same time for the same patient, this indicates that the patient has really been infected with H. pylori.14,15 The aim of this study is to determine the prevalence of H. pylori, and parasites among symptomatic Yemeni children, and to identify the possible cause of the acquisition and transmission of H. pylori.

Methods

A record-based study was carried out at the Specialized Sam Pediatric Center (SPC) in Sana’a, Yemen between January 2011 to December 2013. The SPC provide services to community through the outpatient clinic and receive patients from the city of Sana’a, its surrounding areas, and at times, from other governorates. Out of the 43,200 patients seen for different causes through this 3-year period, 1,008 (2.3%) was included in the study. There were 675 (67%) females, and 333 (33%) males, and had different types of gastric complaints (recurrent, chronic abdominal pain, gastritis, dyspepsia, nausea, vomiting, and chronic diarrhea) and were subjected to blood examination for H. pylori antibody and stool examination for H. pylori antigen. For rapid chromatographic immunoassay for the qualitative detection of antibodies to H. pylori in serum or plasma, one step H. pylori test device (serum/plasma) (EUGENE®, Shanghai Eugene Biotech Co., Ltd, Shanghai, China) was used, and Chemtrue® One-Step H. pylori test (Shanghai Chemtron Biotech Co., Ltd., Shanghai, China), a rapid, visual immunochromatographic test for the qualitative detection of H. pylori antigen in fecal samples was used. Formalin ether concentration methods were used to test the prevalence of intestinal parasites (amoebiasis, giardiasis, intestinal roundworms, and tapeworms). Patients were considered to be infected with H. pylori if they were positive in both blood and stool, or one of the 2, either blood or stool test if there is a relevant complaint related to the abdomen. Also data regarding age and gender were collected and processed manually. Chi square test was performed using the Statistical Package for Social Sciences program version 20 for Windows (IBM Corp, Armonk, NY, USA). The study was approved by the Specialized Sam Pediatric Center Corporation.

Results

The total number of patients seen during the 3 years was 43,200. A total of 1,008 patients (2.3%) (females: 675 [67%], and males: 333 [33%]) with age ranging from 3-15 years, and had gastric symptoms were subjected to H. pylori and parasites examination. Of the 652 (65%) examined patients with H. pylori, 30% of them were males, and 35% were females. Chi square for H. pylori by gender was 142 (p=<0.01) (). There were 83% who had H. pylori in the age group from 6-8 years, 64% from the 9-11 years, and 52% from the 12-15 years age range ().

Discussion

In general, the prevalence of H. pylori is considered to be the most prevalent infectious disease known to occur in humans. Individuals living in countries with low-income had high incidence rates of H. pylori acquired at an early age.8 It is generally accepted that H. pylori infection is the major etiological factor for gastritis and peptic ulcer. Its eradication is connected with curing of these diseases, and important decrease of ulcer recurrence, and rebleeding. Some studies16 have verified that inflammations caused by H. pylori infection may lead to the development of adenocarcinoma of the stomach. The current study found that the prevalence of H. pylori infection was high among children complaining of chronic, or recurrent abdominal pain compared with other causes of abdominal pain. This agrees with other studies in many countries, such as Saudi Arabia,11 Oman,12 and Iraq.17

In this study, the prevalence of H. pylori was higher in the age group 6-8, and 9-11 years than in the age group 12-15 years. This finding is in agreement with other studies that revealed a higher incidence of H. pylori in a younger age than an older age.8,17 This may be attributed to low socioeconomic condition of the families, and some patients of the age group (12-15 years) consulted the adult clinics, instead of the pediatric clinics.

The findings in this study revealed that there was a significant difference between genders in the incidence of abdominal complaints and H. pylori infection; females (67%) were more affected than males (33%). This result agrees with a study conducted in Oman,12 which showed that females, young, and middle age group had the highest frequency of H. pylori organisms, but it does not agree with many other studies, which found that there was no significant difference between genders regarding infection by H. pylori.17 In the present study, we found that the parasites (amoebiasis and giardiasis) infestation was less prevalent compared with H. Pylori infection. This result disagrees with other studies that found a significantly higher frequency of giardial infection in cases where infected children also harbored the bacterial pathogen H. pylori.2 The results of this finding shows that H. pylori infection is more prevalent in the older than the younger age group (in our study, the age ranged from 3-15 years), while in giardial infection the prevalence is more in younger age group (<5 years).18

In conclusion, the prevalence of H. pylori infection among children examined for H. pylori antibody and antigen was high. Females were more affected than males. The prevalence of H. pylori in the age group 6-8 and 9-12 years was higher than the other age groups. Parasites (amoebiasis and giardiasis) infestation were less prevalent compared with H. pylori infection. A possible way of eliminating H. pylori from the population would be via early treatment of the infected mothers and children, and health measures, such as sanitation and the standard of living should be improved.

Table 1

Prevalence of Helicobacter pylori ( and parasite in children according to gender in a study among Yemeni children.

Table 2

Prevalence of abdominal pain and Helicobacter pylori ( according to age in a study among Yemeni children.