Prevalence and eradication rate of helicobacter pylori infection among the patient using the low dose of aspirin attending outpatient clinic at tertiary hospitals in Dodoma, Tanzania. A prospective longitudinal observational study

doi:10.21203/rs.3.rs-4950972/v1

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Research Article

Prevalence and eradication rate of helicobacter pylori infection among the patient using the low dose of aspirin attending outpatient clinic at tertiary hospitals in Dodoma, Tanzania. A prospective longitudinal observational study

https://doi.org/10.21203/rs.3.rs-4950972/v1

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Introduction:

Low-dose of aspirin has been widely used by health providers as primary prevention of major cardiovascular events, its benefit counterbalanced by side effects The synergistic interaction between H. pylori infection and LDA use has been identified as a significant risk factor for peptic ulcer disease, chronic gastritis, perforation, bleeding and gastric cancer with increase folds two to three times among H. pylori positive patient.

Methodology:

A prospective observational longitudinal study was carried out for patients using the low dose of aspirin attended outpatient clinic at Benjamin Mkapa Hospital and Dodoma Regional Referral Hospital in between September, 2023 to April, 2024.A sample size of 159 participants were recruited, aged 18 years or older met specified inclusion criteria. At baseline Demographic data, clinical characteristics were extracted from questionnaire form. Blood sample was collected for full blood picture and stool for H. pylori antigen test. Data analysis employing frequencies, chi-square test and binary logistic regression was done by using SPSS version 26. Statistical significance was ruled out for p < 0.05.

Results

Among 159 patients enrolled in this study, mean age was 57 (IQR 20–75), 57.7% were female. The prevalence was 74.8%. Variables which show significance in this study include use of alcohol [p value = 0.007, OR = 3.24, 95% CI (1.38–7.61)], non-adherence of medications [p value = 0.001, OR = 5.5, 95% CI (2.11–14.46)], smoking [p value < 0.001, OR = 13.61, 95% CI (2.30–56.30)].

Conclusion

H. pylori infection is frequently observed in patients using low dose of aspirin attending medical clinic to tertiary hospital in Dodoma. Factors which have significance with helicobacter pylori eradication failure were smoking, alcohol and non-adherence to medication during treatment period.

Helicobacter pylori infection

low dose of aspirin

eradication rate

risk factors

Globally it is estimated that about one billion people are taking a low-dose aspirin(LDA) for both primary prevention and secondary prevention of cardiovascular events(1). The use of low dose aspirin use varies widely across regions with different income groups with lower usage in low- and lower-middle-income countries accounting for 0.6% and 1.2% respectively. The prevalence is much higher in upper-middle-income countries at 11.7% and 17.7% in high-income countries (2).

In United states of America (USA) over 30% of adult population are using LDA for primary and secondary prevention of cardiovascular events, however the trend decreased from 32% in 2012 to 30% in 2015 (3). However, the trend of using low dose aspirin is reported to raise significantly in low-income countries because of increased prevalence of cardiovascular disease (4, 5). High prevalence reaching up to 47.2% was reported in sub-Saharan countries (6).

Helicobacter pylori infection is very prevalent among patients using low dose aspirin reaching up to 89.8% compared to 68.7% among non-users (Sostres & Lanas, 2018). This higher H. pylori infection in patients using LDA compared to non-users is a primary result of LDA effect on cyclooxygenase enzymes causing decreased protective prostaglandins in the gastric mucosa (7, 8).

This weakened mucosal barrier together with increased gastric acidity due to aspirin creates a favorable environment for H. pylori colonization and persistence among these patients (9, 10). Damage of gastric mucosal can be caused even with very low doses of aspirin (10 mg daily) because it is known to reduce the levels of gastric mucosal prostaglandins (11–14).

Several other risk factors for H. pylori infection in LDA users which are shared with non-users. Such factors include advanced age, concurrent use of corticosteroids or NSAIDs, smoking, alcohol consumption, poor dietary habits, and poor hygiene (15–17). These factors tend to compound the mucosal damage resulted from LDA, making the stomach even more susceptible to H. pylori colonization and persistence (1).

H. pylori eradication is potentially significant for preventing complications among LDA users (10). It is necessary to eradicate H. pylori infection because of its complications including peptic ulcers, gastric cancer, and MALT lymphoma due to chronic inflammation of the stomach lining (18–20). The test and treat for H. pylori strategy is reported to be mandatory among patients using LDA especially in settings with high prevalence of H. pylori (1).

The eradication rate of H. pylori infection is termed significant when reaches 90% successful as recommended by WHO (21). the eradication rate of H pylori is still low especially in developing countries where the prevalence is verry high. In Africa the pooled eradication rate was 79% being high in Ethiopia (90%) and lower in East Africa zone including Tanzania (69%) and Kenya (68%), and lowest in Ivory Coast (22.3%) (22).

Studies have shown the eradication failure to be higher among LDA users. This is explained mainly by mucosal damage caused by aspirin which creates conducive environment of H. pylori to persist (10, 23). Also, Aspirin tend to inhibit cyclooxygenase-1 (COX-1) resulting in raised acid production in the stomach hence reducing the effectiveness of some antibiotics like clarithromycin and Amoxicillin (24–26). Other factors associated with eradication failure includes alcohol consumption, smoking, poor adherence to medication, bacterial resistance, and dosage and timing of dosage (27–30).

Understanding the prevalence and eradication rate of H. pylori among LDA patient population is crucial, as it may shed light on the potential implications of H. pylori infection on gastrointestinal complications and its association with low dose aspirin use (14, 31). This study aimed to determine prevalence, eradication rate and risk factors for eradication failure of H. pylori among patients using LDA attending outpatient clinics at public tertiary hospitals in Dodoma, Tanzania.

Study design

Prospective longitudinal observational study

Study settings

This study was conducted at two hospitals which are Dodoma regional referral and Benjamin Mkapa hospitals. Dodoma is the capital city of Tanzania with rapidly growing population of 3,085,625 as per national data of 2022 (NBS, 2022). Both hospitals serve as consultancy, diagnostic and teaching hospital of the University of Dodoma. The hospitals offer a wide range of medical specialties including Internal medicine and have equipped laboratories with modern equipment for diagnosis. Benjamin Mkapa hospital and Dodoma regional referral hospital has a bed capacity of 400 and 420 respectively. These hospitals have specialized outpatient clinic of average of aspirin users of 1800 and 2160 at DRRH and BMH respectively per year.

Study duration

Study was conducted for eight (8) months from September, 2023 to April, 2024.

Study population

The study enrolled adult patients aged 18 years above who are using LDA attending outpatient clinic at department of internal medicine at Dodoma regional referral hospital and Benjamin Mkapa hospital during the study period

Inclusion criteria

The study included adult patients aged 18 years and above using low dose of aspirin > 3 months as prophylaxis for MACE, patients voluntarily signed the consent form to participate in the study.

Exclusion Criteria

All patients who were using antibiotics within 30 days

All patients who reported to be allergic to the regimen used in this study

All patients who were on (PPI, NSAIDS, Macrolides, Bismuth, Steroid, Penicillin

sampling technique

Simple random technique was used to enroll all study participants who met inclusion criteria giving equal chance of participate in this study. Until the sample size was reached.

Sample size estimation

The formula (Krejcie &Morgan) was used to calculate sample size as follows:

$$\:\text{s}=\frac{{x}^{2}*N*p\left(1-p\right)}{{d}^{2}\left(N-1\right)+\:{\text{x}}^{2}p\left(1-p\right)}$$

$$\:\text{s}=\frac{3.841*3960*0.085\left(1-0.085\right)}{{0.05}^{2}\left(3960-1\right)+\:3.841\text{*}0.085\left(1-0.085\right)}$$

$$\:\text{s}=\frac{1182.9857}{10.1627}=116.4046\:\approx\:116\:\text{L}\text{D}\text{A}\:\text{u}\text{s}\text{e}\text{r}\text{s}.$$

Where: $\:p$ = the expected population proportional based on previous studies: 8.5%(6)

$\:{x}^{2}$ = the value of chi-square for 1 degree of freedom at 95% confidence level: 3.841.

$\:\:\:\:d$ = the degree of accuracy expressed as a proportion: 5%

$\:\:\:\:N$ = the estimated population size of LDA patients served at BMH (1800) and DRRH (2160) per year. (according to BMH and DRRH routine report, 2022).

$\:s$ = required sample size

Therefore, a minimum sample size for this study with an attrition rate of 30% of the sample size calculated was 151 LDA users which were proportionally distributed based on the number of LDA users served annually at BMH and DRRH which is 69 (45.45%) and 82 (54.55%) respectively.

Data collection tools, methods and Procedure

Data collection tools and methods

Data were collected for the specified period of time by means of face-to-face interview using a structured questionnaire. Data collection was carried out by researcher and research assistant who asked questions to the study participants and explained the meaning of the question so as to ensure uniformity of data. A questionnaire included socio-demographic information, medication use, and factors associated with H. pylori eradication rates.

Study procedure

All patients using LDA who met inclusion criteria of the study were told the aim, safety and benefits of the study and were requested to sign a written informed consent form. For those who were un able to read and write, researcher or research assistants read for them and they signed form by using thumb sign. History taking, general examination and laboratory investigation commenced after they consent to participate in this study. Prevalence of H. pylori was established by using Stool antigen test as explained below and for those with positive test were then managed by using triple therapy as per STG and then followed up until eighth week post commencement of medication and be tested for H. pylori. All patients with SAT positive at 8 weeks were declared eradication therapy failure, and those with negative SAT were declared eradication therapy success.

During follow up phone number of the patients and close relative was used to reach the patients and remind them to come back continuation of treatment regimen and adherence assessment score using MMAS4 and for the stool antigen test. For the patients who did not bring stool sample and those who were not reachable in three consecutive days were considered lost to follow-up. However, in this study there were no lost to follow-up recorded making a response rate of 100% among study participants.

Laboratory procedure and data collection

Stool Antigen Testing (SAT)

this non-invasive diagnostic method was used for establishing prevalence of H. pylori and assessing eradication rate because it has sensitivity of 95–100% and specificity of 90%. The test was done first day of enrollment and at eight weeks from day one of treatment for assessing eradication rate. The patient was instructed to collect a small stool sample in a clean, dry, sealable container which was provided at hospital. They were instructed to avoid contamination with urine, water, or toilet paper to ensure clean samples. Stool collection tube must be sterile with built in spoon for collection of specimens, clean dry bed pan or a piece of dry plastic or piece of hard paper Don’t urinate on specimen tube container or mix the specimen with water The container was labeled with patients’ hospital identification number and was sent to laboratory immediately so as can be processed within 72 hours. The stool sample were then tested by immunochromatography assay (H. PYLORI QIUCK CHECK™ then laboratory technician assigned for this study and interpretation was sent to researcher for recording.

Full blood count

this was done mainly to assess the hematological parameters with the interest of assessing hemoglobin level and platelets. Blood samples were collected by experienced nurses and doctors who were available at the post during the study period by following all sterile guideline. The EDTA tube with sample was labelled with identification number of the patient and promptly sent to laboratory. The machines. The calibrated XN 2000 SYMEX machine. Made in India. The result was then interpreted by the qualified laboratory technician and then recorded by the researcher.

Definition of variables

Independent variables

Included demographic data and clinical characteristics which are, age, gender, place of residence, education level, body mass index. Blood pressure and indication of using low dose of aspirin.

Factors associated with H. pylori eradication rates including diagnosed HPI, treatment adherence to medication, medication regimen, symptoms duration, alcoholism, smocking, and chronic medical condition.

Dependent variable

was eradication of pylori infection at eighth week post commencement of medication. It was categorized into two groups which were eradication success and eradication failure when test was negative and positive respectively.

Validity and reliability

Study validity

Before gathering data, a comprehensive process was undertaken to ensure the questionnaire validity. Initially, pilot study was done at DRRH including 15 patients to assess the questionnaire's consistency and any potential issues were identified and corrected with aid from supervisors. Additionally, to maintain the quality of data collection, the research assistants were provided with comprehensive training and orientation by the principal researcher. This training equipped them with the necessary skills and knowledge to proficiently carry out their duties and responsibilities in the research process, ensuring the validity of the data collected for the study

Reliability

All laboratory procedures were conducted by the experienced laboratory technicians designated for the study under the standard guideline adapted by both hospitals. Also, all blood sample were collected by well experienced doctors and nurses by following the standard protocols.

Data analysis

Data was analyzed by using IBM SPSS version 26. Descriptive statistics were used to summarize demographic and clinical characteristics. All categorical variables were analyzed as frequency and percentages whereas continuous variables were analyzed as mean with standard deviation or medians with interquartile ranges according to distribution of data.

Inferential statistics included the use of Pearson’s chi-square test and binary logistic regression to assess association between independent and dependent variables. This was done to assess factors associated with eradication rate of H. pylori in such a way that; all variables with p value less than 0.2 in chi square test were taken into univariate regression where crude odds ratio was established. All variables with p value < 0.05 was then subjected into multivariable regression where adjusted odds ratio was established after controlling cofounders. 95% confidence interval was calculated and a p value < 0.05 were considered statistically significant.

Ethical consideration

Ethical approval

was obtained from the University of Dodoma’s IRREC with reference letter number MA.84/261/02/A/66/9. Letter was submitted to hospital directors of BMH and DRRH for data collection permit. Permit was released from both health facility and data collection exercise effectively started from October 2023.

Stringent measures were implemented to safeguard the confidentiality of participants and protect their sensitive information throughout the study. To maintain anonymity, participants were assigned unique identification numbers rather than using their real names. All study-related documents, both hard copies and electronic files, were stored in a highly secure location, accessible only to authorized personnel, including the principal investigator and research assistants. Electronic data were further fortified through the use of robust password protection. The utmost care was taken to ensure that all information collected from participants remained strictly confidential.

The participants were informed that they had a chance to withdraw from the study at any stage of the study, and were given an equal care with those who have remained in the study. Participants tested positive kept on regimen of Triple therapy for 2 weeks then follow up after 8 weeks those still tested positive declared as eradication failure and referred on second line regime as per protocol suggested HDDT or Bismuth quadruple therapy. Close follow up are done for eradication of helicobacter pylori infection.

Study participant enrolment flow Chart

Socio-Demographic and Clinical Characteristics of Study Participants

The total number of patients using low dose of aspirin attended from both tertiary hospitals were 1321 in which 981 were excluded due to antibiotic use. 341 patients met inclusion criteria in which 181 patients were excluded due to sampling technique. Therefore, total number of participants enrolled in this study were 159, with median age of study participants was 59 years (IQR 20–75 years) majority were aged 60 years and above 75(49.7%) followed by 40–59 years (48.31.8%). Female gender was the most encountered among these patients accounting 87(57.7%), regarding education level majority accounting 56(37.1%) had secondary education followed by college level (Table.1).

Majority of study participants had elevated blood pressure, about 48(31.8%) were using alcohol, total of 34 (22.5%) were smoking whereby 19(55.9%) were smoking less than 20 packs per year and 15(44.1%) were smoking more than 20 packs per year. Significant number of these patients had anemia with Hemoglobin less than 11.5g/dl, they were about 31(20.5%) (Table 4.1).

Regarding medical history of patients using low dose aspirin, majority were under this medication for more than 12 months followed by 7–12 months accounting 60(39.7) and 50(33.1%) respectively. The most common medical condition which was the reason of using low dose aspirin were ischemic heart disease 50(33.3%), myocardial infarction 32(21.2%) and stroke 24(15.9%) (Table 4.2).

Table 1

Socio-demographics and clinical characteristics of patients using low dose aspirin (N = 151)
Variables	Frequency (n)	Percentage (%)
Age		59.0 ± 20 Median (IQR)
Age group (years)
< 40	28	18.5
40–59	48	31.8
≥ 60	75	49.7
Sex
Male	64	42.4
Female	87	57.6
Education level
Non formal	11	7.3
Primary	33	21.9
Secondary	56	37.1
College	51	33.8
Body mass index(kg/m²)
Normal (18.5–25)	45	29.8
Over weight (25-29.9)	89	58.9
Obese (≥ 30)	17	11.3
Blood pressure (mm hg)
Normal	34	22.5
Elevated	51	33.8
Stage one	46	30.5
Stage two	20	13.2
Alcohol use
Yes	48	31.8
No	103	68.2
Smoking
Yes	34	22.5
No	117	77.5
Source of water
Boiled water	110	72.8
Un boiled water	41	27.2
Hemoglobin level (g/dl)
<11.5	31	20.5
≥11.5	120	79.5
Duration of LDA 75mg
3–6 months	41	27.1
7–12 months	50	33.1
>12 months	60	39.8
Therapy used
lansoprazole 20mg + Clarithromycin 500 + Tinidazole 500mg BID 14/7	58	38.4
Rabeprazole 20mg + amoxicillin 1000mg 12hrly for 14/7	55	35.7
Negative Stool for antigen	39	25.9
Indication of LDA
Ischemic heart disease	87	57.6
Stroke	37	24.5
Peripheral arterial disease	27	17.9

Prevalence of H. Pylori Infection among Low Dose Aspirin Users Attending Clinics at Public Hospitals in Dodoma

The prevalence of helicobacter pylori among patients using low dose aspirin was noted to be unacceptably very high reaching 74.8% (Fig. 4.1). Helicobacter pylori was diagnosed by using stool antigen test.

Helicobacter Pylori Eradication Rate among Low Dose Aspirin Users Attending Clinics at Public Hospitals in Dodoma

Total of 81(71.7%) patients using low dose aspirin were tested negative at eight weeks. The eradication rate of H. pylori among patients using low dose Aspirin was as high as 71.7% where ass eradication failure was reaching up to 28.3% (Fig. 4.2).

Factors Associated with Eradication Failure of H. Pylori Infection among Low Dose Aspirin Users Attending Clinics at Public Hospitals in Dodoma

In chi square test several factors were found to be associated with eradication failure of helicobacter pylori. Such factors are Age (p value = 0.037), use of alcohol (p value = 0.006), smoking (p value < 0.001) and self-reported adverse effect of medication (p value < 0.001) (Table 4.3). All variables showing significant association with p value less than 0.05 were taken into univariate regression along with those with p value less than 0.025.

Table 3: Univariate and multivariate regression of factors associated with helicobacter pylori eradication failure

Variables	H. pylori eradication		Univariate regression		Multivariable regression
Variables	Success (%)	Failure (%)	COR (95% CI)	P value	AOR (95% CI)	P value
Age (years)
<40	11(50.0)	11(50.0)	3.0(1.07-8.42)	0.037	0.20(0.04-1.03)	0.054
40- 59	28(80.0)	7(20.0)	0.8(0.27-2.09)	0.582	0.24(0.05-1.18)	0.079
≥60	42(75.0)	14(25.0)	Ref
Sex
Male	31(66.0)	16(34.0)	Ref
Female	50(75.8)	16(24.2)	1.6(0.71-3.68)	0.256
Body mass index (BMI)
Normal (18.5-25)	28(77.8)	8(22.2)	Ref
Overweight (25-29.9)	46(74.2)	16(25.8)	1.22(0.46-3.21)	0.691	0.55(0.62-1.86)	0.332
Obese (>30)	7(46.7)	8(53.3)	4.0(1.11-14.43)	0.034	5.44(0.85-34.79)	0.074
Alcohol use
Yes	21(55.3)	17(44.7)	3.24(1.38-7.61)	0.007	3.70(1.07-12,80)	0.039
No	60(80.0)	15(20.0)	Ref
Smoking
Yes	8(33.3)	16(66.7)	9.13(3.34-24.97)	<0.001	8.16(1.31-50.94)	0.025
No	73(82.0)	16(18.0)	Ref
Non adherence to treatment
Yes	10(41.7)	14(58.3)	5.5(2.11-14.46)	0.001	5.6(1.60-19.31)	0.007
No	71(79.8)	18(20.2)	Ref

In univariate binary regression, several variables were statistically significantly associated with h. pylori eradication failure. Such variables include age below 40 years [p value = 0.037, COR = 3.0, 95% CI (1.07–8.42)], obesity [p value = 0.034, COR = 4.0, 95% CI (1.11–14.43)], use of alcohol [p value = 0.007, COR = 3.24, 95% CI (1.38–7.61)]. Other variables were non adherence of medication due to self-reported adverse effect [p value = 0.001, COR = 5.5, 95% CI (2.11–14.46)], smoking [p value < 0.001, COR = 9.13, 95% CI (3.34–24.97)] (Table 4.4). All variables with p value less than 0.05 in univariate were then taken into multivariate regression to establish adjusted odds ratio.

In multivariate regression, it was found that patients with non- adherence to medication were about six-fold at risk of eradication failure compared to their counterpart [p value 0.007, AOR = 5.6, 95% CI (1.6-19.31)]. Also, patients with history of using alcohol were approximately four times at high risk of eradication failure compared to those who do not use alcohol. Furthermore, smoking was significant factor for eradication failure in such a way that patients who are smoking were eight-fold at risk of eradication failure compared to those who do not smoke at all [p value = 0.025, AOR = 8.16, 95% CI (1.31–50.94) (Table 4.4).

Table 4: Univariate and multivariate regression of factors associated with helicobacter pylori eradication failure

Variables	H. pylori eradication		Univariate regression		Multivariable regression
Variables	Success (%)	Failure (%)	COR (95% CI)	P value	AOR (95% CI)	P value
Age (years)
<40	11(50.0)	11(50.0)	3.0(1.07-8.42)	0.037	0.20(0.04-1.03)	0.054
40- 59	28(80.0)	7(20.0)	0.8(0.27-2.09)	0.582	0.24(0.05-1.18)	0.079
≥60	42(75.0)	14(25.0)	Ref
Sex
Male	31(66.0)	16(34.0)	Ref
Female	50(75.8)	16(24.2)	1.6(0.71-3.68)	0.256
Body mass index (BMI)
Normal (18.5-25)	28(77.8)	8(22.2)	Ref
Overweight (25-29.9)	46(74.2)	16(25.8)	1.22(0.46-3.21)	0.691	0.55(0.62-1.86)	0.332
Obese (>30)	7(46.7)	8(53.3)	4.0(1.11-14.43)	0.034	5.44(0.85-34.79)	0.074
Alcohol use
Yes	21(55.3)	17(44.7)	3.24(1.38-7.61)	0.007	3.70(1.07-12,80)	0.039
No	60(80.0)	15(20.0)	Ref
Smoking
Yes	8(33.3)	16(66.7)	9.13(3.34-24.97)	<0.001	8.16(1.31-50.94)	0.025
No	73(82.0)	16(18.0)	Ref
Non adherence to treatment
Yes	10(41.7)	14(58.3)	5.5(2.11-14.46)	0.001	5.6(1.60-19.31)	0.007
No	71(79.8)	18(20.2)	Ref

The prevalence of helicobacter pylori among patients using low dose aspirin in this study was noted to be very high accounting for 74.8%. The prevalence of H. pylori infection among patients using low dose aspirin is reported to be high in different geographical locations, however many studies reported the prevalence to be very high in developing countries (16, 17, 32). Several other studies have reported that "H. pylori infection is frequently found in LDA users. A systematic review and meta-analysis which involved new studies from different regions including Europe, Japan and Asia reported the increased H. pylori complication among the LDA users (33).

H. pylori prevalence is reported to be 50% of the global population, varying from 20–40% in developed nations and more than 80% in certain developing countries which is very similar to this study. However, the study done in UK was contrary to other studies in same developed countries and was similar to our study with very high prevalence reaching up to 89.8% among LDA users and 68.7% among non-users. (23). However, this systematic review was different from a reported randomized trial which included studies done in United Kingdom (UK), Wales and Northern Ireland where the prevalence 17% (34). However, in this study serological test was used to establish the prevalence which was different from other study which used SAT. The study findings in this region shows that the low prevalence and eradication rate was observed to be higher than in places with high prevalence. Among low dose aspirin users. Furthermore the study reported that in the pilot study the prevalence found to be 23% with eradication success of 91.3%.eradication success was confirmed by using breath test (34).

Some cohort studies conducted in Korea have reported the composite prevalence of H. pylori among patients using Low dose aspirin presenting with Upper Gastrointestinal Bleeding (UGIB) to be 64.2%. The research revealed that among the individuals examined, 57.9% in the study group and 51.8% in the control group were identified as having H. pylori infection. The diagnostic test used was Urease test which is different from our study (31, 35, 36).

The prevalence of H. pylori among LDA users can be explained based on various facts. Such facts include the direct mucosal damage caused by aspirin which expose the gastric mucosal leading to invasion of H pylori. Low-dose aspirin inhibit cyclooxygenase (COX) enzymes which reduce the protective prostaglandins hence increasing the vulnerability to H. pylori invasion. Some studies reported the synergism oh H. pylori and LDA in such a way that H. pylori tend to induces chronic inflammation in the gastric mucosa and adheres to damaged area which exacerbating the mucosal damage caused by Aspirin (10, 36–38).

Helicobacter Pylori Eradication Rate among Low Dose Aspirin Users

In this study eradication of H. pylori was assessed by using the stool antigen test (SAT) at eighth week post treatment commencement. This non-invasive diagnostic test is well reliable because it has high sensitivity ranging from 90–95% and specificity ranging from 95–98%, meaning that the test has a high accuracy in correctly identifying those with and without the infection respectively (39, 40). In this study the eradication success of H. pylori was 71.7% among patients using low dose aspirin at eight weeks. The eradication failure of H. pylori was reaching up to 28.3%. According to Khadim et al. (2024) and other scholars the effectiveness of H. pylori eradication is classified as excellent if the success rate is 95% or higher, good if it is 90% or higher, borderline acceptable if it falls between 85% and 89%, and unacceptable if it is below 85% (27). The eradication rate observed in this study was under the category of unacceptable eradication success which accounted for 71.7%.

Similar to this study, several studies have reported H. pylori eradication success rates below 90% which is recommended by WHO. A systematic analysis of 22 studies in Africa have revealed a pooled eradication rate of 79%. This systematic analysis reported significant variability, with higher success rate in Ethiopia (90%), Nigeria (87%), South Africa (86%), Egypt (82%), and Morocco (82%). However, lower rates were reported most in East Africa zone including in Tanzania (69%) and Kenya (68%), while the lowest being in Ivory Coast (22.3%) (22). This lower rate were also observed in Chile where eradication rate was reported to be 38% (41). The challenge of eradicating H. Pylori is higher even in some developed countries including Spain where it was reported to be 71.1% which is lower than the recommended by WHO (42).

The observed lower eradication rates of H. pylori infection may be explained by several factors varying from antibiotic resistance where H. pylori strains can be resistant to key medication like clarithromycin and metronidazole and amoxicillin. Some studies have reported the resistance reaching up to 90% to metronidazole which is used in many of the eradication therapy in Africa including Tanzania (16, 17, 32, 43). Also, inadequate treatment regimens which is explained by suboptimal dosages and treatment duration (44) poor patient adherence to medication, and poor healthcare system are significant challenges mainly in developing countries (45–47).

Eradication success of H. pylori is very low and vary with region being higher in sub-Saharan Africa including the east Africa zone. This variability may be suggestive of resistivity of bacteria due to several factors including over the counter drugs which exposes patients to antibiotic resistance. Regarding that the sensitivity test for H. pylori is costly and hard to be managed by each hospital, the regional test may be useful in establishing the effective regimen so as to raise the eradication rate of H. pylori among patients.

Predictors of Eradication failure of H. pylori

This study has found significant predictors of H. pylori eradication failure include the use of alcohol, smoking, and self-reported adverse effect of medication. Similar findings were reported from other studies including that of China which showed that excessive alcohol consumption and smoking were independent predictors of H. pylori eradication failure (29, 30, 48), however another study done in China have reported association between alcohol and smoking with eradication failure in > 7 days regimen but no significant association when vonoprazan (VPZ)-based therapy regimen was given (49). The difference in regimen may be the great influence on eradication failure as studies have shown H. pylori have developed resistance to most of used antibiotics. However, there may also be some effect of alcohol on non VPZ based regime.

Alcohol consumption can negatively impact the eradication of H. pylori by several mechanisms. Alcohol may cause direct irritation and inflammation of the gastric mucosa which hinder the healing process and reduce the effectiveness of antibiotic therapy (48).Furthermore, alcohol tend to interfere with the metabolism and absorption of the medications used to eradicate H. pylori hence reducing their concentration in the stomach which lead to eradication failure (21, 29, 30, 50).

Smoking is a significant factor for eradication failure, this may be because smoking cause detrimental effects on gastric health and H. pylori eradication. Smoking reduces gastric blood flow, which can impair the delivery of antibiotics to the stomach lining (18, 29). Also, smoking stimulates gastric acid secretion which create more acidic environment that can inactivate certain antibiotics (21, 28, 49).

Furthermore, this study has found that patients who experienced adverse effects after using medication were about six-fold at risk of eradication failure compared to those with no adverse effects. This increased risk can be attributed by several facts however poor adherence to the medication regimen may be significant reason for eradication failure among these patients. This finding is supported by several other studies which reported that inconsistent intake of medication can reduce the efficacy of the treatment, allowing H. pylori bacteria to survive and continue infecting the gastric mucosa (41, 47, 51, 52)

Limitation of the study

This study could not go further to assess the bacterial factors that influence the eradication failure because it faced limited resources. The study couldn’t establish the resistance of H pylori to first line medications because of limited resources.

The prevalence of H. pylori among adult patients using low dose aspirin is very high and the eradication success is very low compared to the recommendation of WHO.

Non adherence of medications, alcohol consumption, and smoking were independent predictors of H. pylori eradication failure among patients using low dose aspirin.

Acknowledgement

The authors would like to thank all of the healthcare providers and patients who participated in this study from both Dodoma regional referral hospital and Benjamin Mkapa hospital outpatient clinic in Dodoma Tanzania. I also Thank Dr Emmanuel Sindato and Dr Baraka Alphonce for their guidance and support

Authors’ contributions

L.J. conceptualized and designed the study also organized and coordinated the research efforts. E.S. and B.A provided guidance during proposal writing, data analysis and final report writing. collected the data from medical outpatient clinic. E.S and B.A were the major contributors in writing the manuscript. All authors reviewed the manuscript. The final manuscript was read and approved by all authors.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors

Availability of data and materials

Data available on request from the corresponding author.

Ethics approval and consent to participate

This study was approved by the the University of Dodoma Directorate of Research and Publication (reference number MA.) and was performed in accordance with the principles of the Declaration of Helsinki. All patients provided a written informed consent. In the case of illiterate patients, the consent was read to them in the presence of a literate relative and they provided a fingerprint on the consent form to indicate their informed consent to participate. To those who could not consent due to the severity of their illness, consent was obtained from next of kin who was taking care of the patient.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.

Author details

¹Department of Internal Medicine, School of medicine and dentistry, the University of Dodoma, Tanzania, ²Department of Internal Medicine, Dodoma regional referral hospital Tanzania. ³Department of Internal Medicine, Benjamin Mkapa Hospital Tanzania

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No competing interests reported.

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Prevalence and eradication rate of helicobacter pylori infection among the patient using the low dose of aspirin attending outpatient clinic at tertiary hospitals in Dodoma, Tanzania. A prospective longitudinal observational study

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Abstract

Introduction:

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Background

Methodology

Study design

Study settings

Study duration

Study population

Inclusion criteria

Exclusion Criteria

sampling technique

Sample size estimation

Data collection tools, methods and Procedure

Data collection tools and methods

Study procedure

Laboratory procedure and data collection

Definition of variables

Validity and reliability

Study validity

Reliability

Data analysis

Ethical consideration

Results

Study participant enrolment flow Chart

Socio-Demographic and Clinical Characteristics of Study Participants

Discussion

Helicobacter Pylori Eradication Rate among Low Dose Aspirin Users

Predictors of Eradication failure of H. pylori

Limitation of the study

Conclusion

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