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 Table of Contents  
ORIGINAL ARTICLE
Year : 2018  |  Volume : 17  |  Issue : 1  |  Page : 41-46

Prevalence and risk factors for helicobacter pylori infection in gastroduodenal diseases in Kano, Nigeria


1 Department of Medicine, Ahmadu Bello University, Ahmadu Bello University Teaching Hospital, Zaria, Nigeria
2 Department of Pathology, Bayero University Kano, Aminu Kano Teaching Hospital, Kano, Nigeria
3 Department of Medicine, Bayero University Kano, Aminu Kano Teaching Hospital, Kano, Nigeria

Date of Web Publication2-Jul-2018

Correspondence Address:
Ahmad Kumo Bello
Department of Medicine, Ahmadu Bello University Teaching Hospital, P. M. B. 06, Shika - Zaria, Kaduna State
Nigeria
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/ajmhs.ajmhs_36_17

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  Abstract 


Background: Helicobacter pylori (H. pylori) has been well noted as a causative agent of many diseases in the gastrointestinal (GI) tract notably, gastritis, peptic ulcer disease, and gastric adenocarcinoma. Determining the burden and the risk factors for acquiring this infection may be crucial to containing it and its sequelae in Kano, Nigeria. Methodology: The study was cross-sectional in design. Questionnaires were administered in dyspeptic patients to obtain the relevant clinical, and sociodemographic data. Upper GI endoscopy was performed in the patients, and gastric biopsy specimens were taken and sent to the histopathology laboratory for assessment and H. pylori identification. Results: Of the 306 participants, 136 (44.4%) were males, while 170 (55.6%) were females, with male: female ratio of 1:1.3. The ages of the participants ranged from 18 to 84 years with a mean of 41.2 ± 15.3 years. Of the 306 samples, 250 (81.7%) were positive for H. pylori. This gives H. pylori prevalence of 81.7%. Only 4 (1.3%) of the participants belonged to the higher social class, out of which 25% had positive H. pylori, while 230 (75.2%) participants belonged to the lower socioeconomic class with 87.8% H. pylori prevalence. The lower social class had a significant association (P < 0.0001) with increased H. pylori infection. A total of 290 subjects (94.8%) shared a room with three or more other siblings in childhood, out of which 233 (80.3%) had H. pylori. Only 80 subjects (26.1%) used pipe-borne water in childhood, while 226 (73.9%) sourced their water from either well, pond or stream during childhood. Conclusion: This study showed a high prevalence of H. pylori in Kano, and low socioeconomic status, unclean water source, overcrowding, and cigarette smoking were significant risk factors for H. pylori infection.

Keywords: Histology, prevalence of Helicobacter pylori in Kano, risk factors, water source


How to cite this article:
Bello AK, Umar AB, Borodo MM. Prevalence and risk factors for helicobacter pylori infection in gastroduodenal diseases in Kano, Nigeria. Afr J Med Health Sci 2018;17:41-6

How to cite this URL:
Bello AK, Umar AB, Borodo MM. Prevalence and risk factors for helicobacter pylori infection in gastroduodenal diseases in Kano, Nigeria. Afr J Med Health Sci [serial online] 2018 [cited 2018 Dec 17];17:41-6. Available from: http://www.ajmhs.org/text.asp?2018/17/1/41/235736




  Introduction Top


Helicobacter is motile, Gram-negative, microaerophilic bacteria which is endemic in Africa and Asia; the two continents contributing two-thirds of the world's disease burden. Barry Marshall and Robin Warren who isolated and identified Helicobacter pylori (H. pylori) from the human stomach also drew attention to the association of H. pylori with gastritis; and much evidence showed that H. pylori causes peptic ulcers, and is also involved in the development of gastric mucosa-associated lymphoid tissue lymphoma.[1],[2] Infection with this bacterium has been established as the etiologic factor in the development of gastric cancer, thus, H. pylori was designated a Class 1 carcinogen by the WHO.[3],[4]

In developing countries, 70%–90% of the population harbor H. pylori which is mostly acquired during childhood, while in the developed countries, the prevalence is lower ranging from 30% to 40%.[5] Studies from Nigeria by Bashir and Ali [6] in Kano reported an H. pylori prevalence of 81%, Malu et al. in Jos, found a prevalence of 87%,[7] while Aboderin et al. reported 73% in South-West.[8] Studies from many African countries reported similar prevalence rates of 91.7% in Egypt,[9] 97% in Gambia,[10] and 75.4% in Ghana.[11] Similarly, in Asia, prevalence rates of 92% have been reported in Bangladesh [12] and 62% prevalence was found in Chinese.[13]

Studies have shown that low socioeconomy was a major risk factor in H. pylori acquisition.[14] Allaker et al.[15] noted that transmission of H. pylori is largely by the oral–oral or fecal–oral routes. This may have been encouraged by poor environmental sanitation, crowding, and fecal contamination of water source used for irrigation of vegetables in farms or domestic use. Jemikajah and Okogunand Etukudo et al. in separate studies showed that sourcing water from well and borehole confers a higher risk of H. pylori infection than pipe-borne water.[16],[17] Studies also by Bateson in Glasgow and Ogihara et al. in Jiangsu [18],[19] showed that there is increased prevalence of H. pylori in subjects who smoked cigarettes than in those who never smoked. Understanding the risk factors for acquiring H. pylori infection in Kano, Nigeria is therefore critical if we are to reduce the prevalence and thus the burden of the diseases caused by this infection.

The aim of our study, therefore, was to determine the prevalence and risk factors for H. pylori infection in gastroduodenal diseases in Kano, North-West, Nigeria.


  Methodology Top


The study was carried out from August 2011 to April 2013 in Aminu Kano Teaching Hospital (AKTH), a tertiary hospital in Kano, the most populous state in Nigeria. AKTH is the only public hospital in the North-West with a functioning endoscopy and endoscopic retrograde cholangiopancreatography facility and thus receives referrals from many hospitals. The study was cross-sectional in design, and the ethical approval for the study was obtained from the research ethics Committee of AKTH before the commencement of the study. Dyspeptic patients referred for upper gastrointestinal endoscopy constituted the study population. Dyspeptic patients 18 years and above who consented to participate in the study were randomly recruited to meet the required sample size. Excluded from participating were patients on antibiotics, proton pump inhibitors, or bismuth salts in the preceding 4 weeks, and those with medical conditions such as congestive cardiac failure and cardiac arrhythmias. Written informed consent was sought and obtained from each patient before commencing the procedure.

With the aid of interviewer-administered questionnaire, relevant clinical, and sociodemographic data was obtained from the recruited patients. Social class of the participants was determined using the National statistics socioeconomic classification.[20] which assigns people to social class based on standard occupation classification. The three-class version of the classification was adopted here for convenience as follows: Higher social class (Class 1): Higher managerial administrative and professional occupations (company Chief Executive Officer, Directors; Doctors, Lawyers Senior Army and Police officers, etc.,); middle social class (Class 2): Intermediate occupations (Musicians, Nurses, Journalists, actors, etc.,); and lower social class (Class 3): Routine and manual occupations (Artisans, Publicans, Farmers, laborers, etc.). Patients were then booked for oesophagogastroduodenoscopy and asked to fast overnight, at least 8–10 h before the endoscopy. The process of the endoscopy procedure was explained to the patients, then 10% xylocaine pharyngeal spray was administered to the patient's pharynx to paralyze the gag reflex. The patient was then placed on his left lateral position on the endoscopy couch, and a forward viewing fiber-optic Pentax FC-38 LW 2008 endoscope was used to examine the esophagus, stomach, and duodenum of the patients. During the procedure, four biopsy specimens, two each from the body of the stomach and antrum were taken and fixed in 10% formaldehyde and sent to the histopathology laboratory for histologic assessment and identification of H. pylori.

In the histopathology laboratory, the paraffin-embedded tissue blocks were sectioned at 4 μm thickness and stained with the routine H and E stain for morphology while modified Giemsa and Warthin-Starry stains were used for the identification of H. Pylori. Sections found to show spiral bacteria in the mucosal layer or on the surface of the gastric epithelial cells were considered positive for H. pylori as assessed independently by two consultant histopathologists who were blinded to the endoscopic findings. Gastritis was evaluated according to the updated Sydney system,[21] i.e., inflammation (mononuclear cell infiltration), activity (neutrophil infiltration), atrophy and intestinal metaplasia.

Data were analyzed using Statistical Package for Social Sciences, version 16.0 (SPSS Inc., 2009, Chicago Illinois, USA). Quantitative variables were summarized using range, means, and standard deviation while qualitative variables were summarized using ratios, proportions, and percentages. P < 0.05 was regarded as statistically significant. Determinants and predictors were explored using univariate and multivariate analyses with logistic regression.


  Results Top


Of the 320 samples sent to the histology laboratory for analysis, 14 (4.4%) were lost during processing. The remaining 306 samples were analyzed as follows.

Out of the 306 samples examined by the pathologist, a total of 250 (81.7%) were positive for H. pylori, while 56 (18.3%) were negative. This gave H. pylori prevalence of 81.7% at histology.

[Table 1] shows 136 (44.4%) participants were males, while 170 (55.6%) were females, with a male: female ratio of 1:1.3. The ages of the subjects ranged from 18 to 84 years with a mean age of 41.2 ± 15.3 years. Univariate analysis on demographic factors in this study showed that there is an increased prevalence of H. pylori in male subjects which is statistically significant (P< 0.0041) when compared with that of females. Of the 306 participants, 230 (75.2%) participants belonged to the lower socioeconomic class with 87.8% of them being H. pylori positive. [Table 3] reveals that lower social class had a statistically significant association (P< 0.0001) with H. pylori infection. We noted that of the 290 participants who lived in a room with two or more other siblings in childhood, 233 (80.4%) had positive H. pylori on histology. This shows that living in crowded condition is association with increased risk of H. pylori infection (P = 0.0001). [Table 4] shows that sourcing water from well or stream increases the risk of H. pylori infection P < 0.0001. Only 7 (2.2%) subjects had a history of cigarette smoking out of which 5 (71.4%) were found to have H. pylori. Statistical analysis [Table 3] revealed a significant association between cigarette smoking and increased prevalence of H. pylori infection (P< 0.0001).
Table 1: The prevalence of Helicobacter pylori according to gender of the study subjects

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Table 3: Univariate analysis of risk factors for Helicobacter pylori infection (histology)

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Table 4: Multivariate analysis using binary logistic regression to determine independent predictors of histologically defined Helicobacter pylori infection

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  Discussion Top


The prevalence of H. pylori in this study was 81.7% using histology, as seen in [Figure 1], which is the gold standard for the detection of H. pylori in our environment. This prevalence is consistent with H. pylori prevalence rates as reported in other Nigerian studies. An earlier study in 2009 from the same center by Bashir and Ali [6] reported 81% prevalence. In another study from Gombe [22]H. pylori prevalence was found to be 77.1%, while Ndububa et al.[23] in Ile-Ife reported prevalence rates of 73%. Nigerian prevalence rates are similar to those reported in studies in South Africa [24] and Kenya [25] which reported, respectively, rates of 66% and 94%. Woodward et al.[26] in a study in Glasgow, UK reported a prevalence of 66% which they noted was more typical of prevalence in developing countries and thus concluded that the high degree of social deprivation in Glasgow at that time was the explanation for the high prevalence of H. pylori found in the study.
Figure 1: Modified giemsa stain of gastric tissue from the study subject showing Helicobacter pylori in the glandular crypts and lumina (×400)

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In our study, as shown in [Table 1], the prevalence of H. pylori infection is higher in males (82.4%) than females (81.6%). Univariate analysis [Table 3] on demographic factors in this study showed that there is an increased prevalence of H. pylori in male subjects which is statistically significant (P< 0.0041) when compared to that of females. Similarly Omosor et al.[27] revealed that the prevalence of H. pylori infection was also higher in males (55%) than females (51.4%). Woodward et al. also reported a higher prevalence of H. pylori in men than in women.[26] Ford and Axonobserved that male gender is a risk factor for H. pylori infection.[28] In contrast, a study from Warri, Nigeria [16] reported a higher H. pylori prevalence in females than in males.

Our study, as seen in [Table 2], revealed that 87.83% of the subjects in lower socioeconomic class and 76.4% of those in the middle class have H. pylori when compared to only 25% of those in higher social class. Univariate analysis [Table 3] showed that lower social class is significantly association (P< 0.0001) with increased H. pylori infection. Multivariate logistic regression analysis [Table 4] in our study showed that belonging to a lower social class increases the risk of infection with H. pylori (P< 0.0043). A study by Malaty and Grahamin the USA also reported the prevalence of H. pylori infection was 82% in the lower social class, 52% in the middle class, and 11% in the higher social class.[29] Similarly, in Denmark, Steffen et al.[30] found an increase in the risk of chronic H. pylori infection with decreasing socioeconomic status. Individuals from low socioeconomic class are more likely to be associated with low level of education, including poor health education and more tendency to living in an environment that predisposes to fecal contamination of food and water.
Table 2: Relationship between Helicobacter pylori positivity and risk factors for infection

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[Table 2] shows that more than 80% of subjects who shared a room with three or more other siblings during childhood were found to have H. pylori on histology. Univariate analysis [Table 3] showed that crowding is a major risk factor for H. pylori infection and is statistically significant in our study subjects (P< 0.0001). Multivariate binary logistic regression [Table 4] showed that multiple occupants per room (crowding) is strongly associated with H. pylori infection (P< 0.043). Similarly, several studies in Nigeria by Etukudo et al.[17] and Olufemi et al.[31] showed that the higher the number of persons in the household, the higher the rate of H. pylori infection. Khalifa et al. also identified household crowding, sharing of bed, and increasing household contact as risk factors for H. pylori infection.[32] A study by Torres et al. found density of living conditions as a major determinant in the acquisition of H. pylori infection,[33]

We found in our study, as seen in [Table 2], a higher prevalence of H. pylori infection among subjects that sourced their drinking water from wells, stream, and ponds when compared to those who use tap water (P< 0.0001). Multivariate logistic regression [Table 4] shows that patients who sourced their drinking water from wells and ponds had higher prevalence of H. pylori than those who used pipe-borne water (P< 0.042). The reason for this could be attributed to the more likelihood of fecal contamination of well and surface water when compared to tap water which is usually treated before distribution. A similar study in Nigeria showed that sourcing water from well and borehole confers a higher risk of H. pylori infection than pipe-borne water.[16] Another study from Kazakhstan [34] found high prevalence of H. pylori infection among subjects who use the river and well water for drinking compared to those who use tap water. In another study Hegarty et al. found anti-H. Pylori antibody in surface and shallow groundwater samples tested in the USA and concluded that the route of transmission for H. pylori is also waterborne.[35]

As seen in [Table 3], there is a strong association between cigarette smoking (P< 0.0001) and increased prevalence of H. pylori infection. Multivariate logistic regression shows that cigarette smoking is significantly associated with increased risk of H. pylori infection (P< 0.038). This is consistent with the finding by Bateson which showed that there is a strong association between H. pylori infection and current cigarette smoking in his study subjects. Other studies that reported similar findings are those of Ogihara et al., and Halter et al.[18],[36] Similarly, a study in the UK also revealed a strong correlation between H. pylori infection and cigarette smoking (P< 0.01).[18] In contrast to our study, Shi et al. found no association between H. pylori prevalence and smoking. The likely reason for this difference may be due to the high prevalence of cigarette smoking in Jiangsu [37] their study area where close to 70% of the population smoke.


  Conclusion Top


This study showed that the prevalence of H. pylori infection is very high among patients with dyspepsia in Kano, Nigeria, and low socioeconomy, crowding, cigarette smoking, and using well or stream water are strongly associated with increasing risk of H. pylori infection.

Recommendation

Efforts should be made by Governments at all levels, together with well-meaning individuals in the community in making education accessible and affordable. Provision of clean potable water to the rural communities will significantly reduce the burden of this infection.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
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    Figures

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    Tables

  [Table 1], [Table 2], [Table 3], [Table 4]


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