CAPITULO 4: EVALUACIÓN DELDESEMPEÑO PROFESIONAL DE
4.4. Perfil de los Directivos
pylori in the stool. The sensitivity was found to be about 94% and specificity 100%112. It is however not as sensitive as UBT and monoclonal stool antigen assay113. It may be used in mapping the distribution of H. pylori genotypes
within families and therefore in determining the routes of transmission and risk factors.105
4) URINE TEST: It is now possible to detect antibodies to H. pylori in the urine. One such test developed is known as URINELISA. It is based on ELISA technique. A study by Miwa et al. reported a sensitivity and specificity of 86.3% and 91.5%, respectively114. In that study, result obtained was compared with those of UBT and some other H. pylori serological kits and it reflected a diagnostic accuracy of 88.6%.
5) SALIVA TEST: Antibodies to H. pylori can also be detected in the saliva.
Results obtained from such tests are encouraging115. Examples include Helisal salivary kit and OraSure salivary device. PCR can also be used on saliva and oral plaque116.
6) STOOL ANTIGEN TEST (SAT): This is a novel H. pylori test, which is fast becoming popular. It is based on the detection of H. pylori antigens in the stool. With the normal shedding of gastric epithelium, the H. pylori adhering to it appear in the stool of the infected person. Detection of these antigens in the stool is therefore a direct test of active infection. Thus, SAT has an advantage over serology.
SAT is simple and relatively cheap. It can be carried out in most routine laboratories. Many studies have shown it to have sensitivity and specificity
>90%10, 18, 19, 117. The test is adequately sensitive in both adult and paediatric
SAT is an enzyme immunoassay test. The two forms available are polyclonal and monoclonal assay techniques. The polyclonal immunoassay is the older technique by which earlier researches were done. An example of this is the Premier Platinum HpSA. A faster and portable version of this is the ImmunoCard STAT HpSA, which can be used by the physician, and the result is obtained in less than half an hour. In a particular study, it was found to have a sensitivity of 92.6%120.
The monoclonal immunoassay is a newer test, which detects the H. pylori antigen through the use of monoclonal antibodies. An example of this is the Femtolab H. pylori cnx. Monoclonal assay is more specific than the polyclonal assay121 and many studies have shown it to be of higher sensitivity, and hence, a better method of diagnosing H. pylori infection. One study found the sensitivity and specificity to be 97.8% and 99% respectively122.
The diagnostic accuracy of SAT is impaired by proton pump inhibitors (PPI) and gastroduodenal bleeding. SAT is therefore not advisable if the patient has been on PPI within the two weeks preceding the test. It gives a high number of false positive results in patients with peptic ulcer bleeding, probably because of blood constituents cross-reacting in the enzyme immunoassay123.
Monoclonal assay may be considered as an alternative to UBT in the initial diagnosis of patients with dyspepsia who do not require immediate endoscopy124.
The sensitivity and specificity patterns of the various diagnostic tests for H. pylori are shown in Table 3.
Table 3: Sensitivity and specificity of various diagnostic tests for H. pylori Test Sensitivity (%) Specificity (%)
Rapid urease test 90 95
Culture 98 100
Histology 95 100
Polymerase chain reaction 93 96
Serology 91 97
Urea breath test 96 97
Stool polymerase chain reaction 94 100
Urine test 86 91
Saliva test 81 73
Stool antigen test 92 94
TREATMENT OF H. PYLORI
Considering the wealth of evidence implicating H. pylori in the development of chronic gastritis, peptic ulcer and gastric malignancies, all presenting with undesirable symptoms of dyspepsia, it is safer for the H. pylori-positive dyspeptic patient to undergo H. pylori eradication therapy115. The ‘test and treat’ approach in which a symptomatic patient is screened, and if positive, is treated for H. pylori is practical and cost effective but further investigations are advisable when the patient
iii. has alarm symptoms125-128.
Alarm symptoms7 include anorexia, weight loss, odynophagia, dysphagia, vomiting anaemia, jaundice and gastroduodenal bleed. Under such circumstances, endoscopy may prove invaluable and sinister pathologies can be diagnosed early. When there are no alarm symptoms the ‘test and treat’ approach (multidrug therapy) is employed in H.
pylori eradication127, 129.
Drugs can be given in combinations of 2 (dual), 3 (triple) and 4 (quadruple). Each regimen consists of at least one antibiotic. Antibiotics used include amoxicillin, tetracycline, metronidazole, clarithromycin, bismuth and furazolidone.
Adjunctive agents include histamine2 receptor antagonist (H2RA), proton pump inhibitors, ranitidine bismuth citrate (RBC).
Dual therapy: One antibiotic + one adjunctive agent.
Triple therapy: two antibiotics + one adjunctive agent.
Quadruple therapy: two antibiotics + two adjunctive agents
Two lines of therapy were suggested at the Maastricht 2-2000, consensus report130: First-line therapy
PPI (RBC) + Clarithromycin 500mg b.d. + Amoxicillin 1000mg b.d. or metronidazole 500mg b.d. for a minimum of 7 days.
In case of failure, second-line therapy is used.
Second-line therapy
PPI b.d. + bismuth subsalicylate/subcitrate 120mg q.d.s. + metronidazole 500mg t.d.s. + tetracycline 500mg q.d.s. for a minimum of 7 days.
If bismuth is not available, PPI-based triple therapies should be used.
CHAPTER THREE
SUBJECTS, MATERIALS AND METHODS
STUDY SITE: The study was carried out in the Outpatient Clinics of the University College Hospital, Ibadan.
STUDY POPULATION
This is a case-control study and consecutive subjects presenting with dyspepsia were recruited from the general and medical out-patient departments of the University College Hospital, Ibadan (between October 2004 and April 2005). The controls were drawn from the hospital staff, medical students and relatives of patients.
SAMPLE SIZE: The sample size was calculated using the formula below:
n = Z2PQ d2 where n – sample size
Z - 1.96 (at 95% confidence level) P - Estimated prevalence
Q - 1 – p
d- Desired precision limit = 5%
Since the prevalence of H. pylori among South Western Nigerians with dyspepsia is between 88 and 94.5%, the sample size therefore ranged between 80-162, using the above formula. However, in view of the non-availability of the stool antigen test kits on the
SELECTION OF PATIENTS
Only those who satisfied the inclusion and exclusion criteria among consecutive subjects presenting with dyspepsia were involved in the study.
INCLUSION AND EXCLUSION CRITERIA FOR SUBJECTS INCLUSION CRITERIA
1. Subjects with symptoms of dyspepsia.
2. Symptoms must have persisted for a minimum of 3 months or recurrent in nature over the same period.
3. Subjects who gave informed consent to participate in the study.
EXCLUSION CRITERIA
1. Subjects with symptoms of dyspepsia of less than 3 months duration.
2. Subjects who had had anti H. pylori eradication treatment.
3. Subjects who had taken Proton Pump inhibitors or other anti-secretory drugs within the 4 weeks preceding the test.
4. Subjects who had had antibiotic therapy in the 4 weeks preceding the test.
5. Subjects who had taken Bismuth Compounds in the 4 weeks preceding test.
6. Subjects with clinical features of gastro-oesophageal reflux disease (GORD).
INCLUSION AND EXCLUSION CRITERIA FOR CONTROLS INCLUSION CRITERIA
- Individuals that were age and sex matched with subjects recruited into the study.
- Apparently healthy individuals.
- Individuals who gave informed consent EXCLUSION CRITERIA
- Individuals with previous history of chronic or recurrent symptoms of dyspepsia.
- Individuals in whom a clinical or laboratory diagnosis of peptic ulcer disease had been made in the past.
ETHICAL APPROVAL: Ethical approval for the study was sought and obtained from the Joint University of Ibadan/ University College Hospital Institutional Review Committee (Appendix I).
DATA COLLECTION
After an informed consent was obtained, a preformed questionnaire (appendix XI) was administered by me to each participant to obtain biodata and other relevant history.
CLINICAL EVALUATION
Physical (general and abdominal) examination was performed on all participants by me.
SAMPLE COLLECTION AND ANALYSIS Serum
1. 5 milliliters of whole venous blood was obtained from each subject and control by venepuncture.
2. This was transported to the laboratory in a plain serum bottle where it was centrifuged, the serum obtained was kept in another plain bottle and was stored in a freezer at -200C until analysis.
Stool
2. The samples were presented for storage shortly after collection.
3. All samples were immediately stored in a freezer at -200C until analysis.
The stool samples were analysed for H. pylori antigen using Premier Platinum HpSATM, enzyme immunoassay kit (see test procedure in appendix II). The sera were analysed for H. pylori IgG antibody using PremierTM H. pylori, an enzyme immunoassay kit (see procedure in appendix III). Both kits were manufactured by Meridian Bioscience, Inc.
(Cincinnati, Ohio). The spectrophotometer used was stat fax 2100, Awareness technology Inc .The absorbance results and other procedures are shown in appendices IV to X.
These tests were personally carried out by me under the supervision of an experienced laboratory scientist at the Department of Virology, University College Hospital, Ibadan.
DATA ANALYSIS
The data collected were analysed using SPSS version 10.0 (SPSS Inc. Chicago Illinois). Means were expressed as means ±SD. Categorical variables were compared with Chi-square while means were compared with ‘t’ test. Significant P value was taken to be <0.05.
CHAPTER FOUR RESULTS
Forty six subjects (20 males, 26 females) and 46 controls (20males, 26 females) participated in the study. The mean age of subjects was 40.87±13.31 years while that of controls was 40.83±13.20 years. There was no statistical significance in the mean ages of the two groups (Table 4). The minimum age in both subjects and controls was 18 years and the maximum was 70 years.
Table 4: Demographic characteristics of subjects and controls
Variable Subjects
n=46
Control n=46
χ2 P-value
Sex Male 20(43.5%) 20(43.5%)
Female 26(56.5%) 26(56.5%) 0.00 1.000
Age (years) <30 10(21.7%) 10(21.7%)
30-39 13(28.3%) 14(30.4%)
40-49 13(28.3%) 12(26.1%)
≥ 50 10(21.7%) 10(21.7%)
Mean Age(SD) 40.87(13.31) 40.83(13.20) t=0.016 0.987 Occupation Students 5(10.9%) 6(13.0%)
Traders 15(32.6%) 13(28.3%)
Civil servants 18(39.1%) 26(56.5%)
Artisans 8(17.4%) 1(2.2%) 7.18 0.127
Table 5. Borehole was the commonest source of water supply in subjects while pipeborne water was the commonest source of water supply in controls 17(37.0%) vs. 19(41.3%).
Abdominal pain was more in subjects, while 26(56.55%) of subjects had burning abdominal pain. None of the controls smoked cigarette or took local concoction.
Other factors associated with clinical features in subjects and controls are shown in Table 6. Majority of subjects had their pain related to meals 40(87.0%) which was significant statistically. None of the controls had associated symptoms. Alcohol and non steroidal anti-inflammatory drugs were significantly taken in subjects as compared to controls.
Table 5: Clinical features in subjects and controls
Variable Subjects
n=46
Controls n=46
Total n=92
Χ2 P-value
Source of water Well 15(32.6%) 16(34.8%) 31(33.7%) Pipeborne 14(30.4%) 19(41.3%) 33(35.9%) Borehole 17(37.0%) 9(19.6%) 26(28.3%)
Stream 0 2(4.3%) 2(2.2%) 5.251 0.154
Past abdominal pain / discomfort
Yes 45(97.8%) 6(13.0%) 51(55.4%)
No 1(2.2%) 40(87.0%) 41(44.6%) 66.92 <0.0001 Recent upper abd
pain/discomfort
Yes 42(91.3%) 0 42(45.7%)
No 4(8.7%) 46(100.0%) 50(54.3%) 77.28 <0.0001 Duration of symptoms
(SD)
6.08(7.12) 0 <0.0001
Description of pain Peppery 11(23.9%) 0 11(12.0%)
Burning 26(56.5%) 0 26(28.3%)
Dull pain 4(8.7%) 0 4(4.3%)
Stabbing 4(8.7%) 0 4(4.3%)
None 1(2.2%) 46(100.0%) 47(51.5%) 32.34 <0.0001
Herbal medicine Yes 17(37.0%) 0 17(18.5%)
No 29(63.0%) 46(100.0%) 75(81.5%) 20.85 <0.0001
Smoking Yes 2(4.3%) 0 2(2.2%)
No 44(95.7%) 46(100.0%) 90(97.8%) 2.04 0.247
Table 6: Other factors associated with clinical features in subjects and controls
Variable Subjects n=46 Controls n=46 χ2 P-value
Yes No Yes No
Relation to meals 40(87.0%) 6(13.0%) 0 46(100.0%) 70.77 <0.0001
Provoked/worsened by hunger 38(82.6%) 8(17.4%) 0 46(100.0%) 64.74 <0.0001
Relieved by meals 29(63.0%) 17(37.0%) 0 46(100.0%) 42.35 <0.0001
Provoked/worsened by meals 10(21.7%) 36(78.3%) 0 46(100.0%) 11.22 0.001
Associated symptoms 35(76.1%) 11(23.9%) 0 46(100.0%) 56.49 <0.0001
Belching 18(39.1%) 28(60.9%) 0 46(100.0%) 22.38 <0.0001
Bloating 21(45.7%) 25(54.3%) 0 46(100.0%) 27.21 <0.0001
Flatulence 23(50.0%) 23(50.0%) 0 46(100.0%) 30.67 <0.0001
Diarrrhoea 5(10.9%) 41(89.1%) 0 46(100.0%) 5.29 0.028
Alcohol ingestion 7(15.2%) 39(84.8%) 1(2.2%) 45(97.8%) 4.929 0.029
NSAID intake 12(26.1%) 34(73.9%) 1(2.2%) 45(97.8%) 10.84 0.001
The frequency of aggravating factors in subjects is as shown in Table 7. Many of the subjects had no known aggravating factor 19(41.3%), while hunger was the most common aggravating factor 23 (50.1%). Others are as listed below.
Table 7: Frequency of aggravating factors in subjects Aggravating factors Number (%)
Alcohol 1(2.2)
Anxiety 1(2.2)
Fried food 1(2.2)
Gaseous drinks, NSAIDs 1(2.2)
Hunger 23 (50.1)
None 19(41.3)
The relieving factor and type of treatment among subjects are shown in Table 8. The subjects were relieved with antacids 34(75.6%), followed by meals 28(60.9%).
Majority were not relieved by vomiting or analgesic intake. Antacids 43(93.5%) was the commonest form of treatment with Proton pump inhibitor being the least.
Table 8: Relieving factors and types of treatment among subjects Subjects
n=46
Variable Yes No
Relieving factor
Meals 28(60.9%) 18(39.1%)
Avoidance of meals 3(6.5%) 43(93.5%)
Vomiting 2(4.3%) 44(95.7%)
Analgesic 6(13.0%) 40(95.7%)
Antacids 34(75.6%) 12(26.1%)
Types of treatment
Dietary 21(45.7%) 25(54.3%)
Analgesic 20(43.5%) 26(56.5%)
Antacid 43(93.5%) 3(6.5%)
H2 antagonist 11(23.9%) 35(76.1%)
Proton pump inhibitor 2(4.3%) 44(95.7%)
Herbal medicine 8(17.4%) 38(82.6%)
The physical examination findings in subjects are shown in Table 9. Abdominal tenderness was present in 24(52.2%) of subjects and the most common localization is epigastric region.
Table 9: Clinical findings among subjects
Variable Subjects n=46
Yes No
Abdominal tenderness 24(52.2%) 22(47.8%)
Site of tenderness
Epigastric 17(37.0%) 0
Epigastric, left hypochondrium 2(4.3%) 0 Epigastric, right hypochondrium 2(4.3%) 0
Epigastric, umbilical 2(4.3%) 0
Abdominal mass 2(4.3%) 44(95.7%)
Hepatomegaly 3(6.5%) 43(93.5%)
Splenomegaly 0 46(100.0%)
The serology and stool antigen test results in both groups are depicted in Table 10.
The controls had more positive serology results compared to subjects 42(91.3%) vs.
31(67.4%) and this was statistically significant (p=0.01). Stool antigen test for H.
pylori (HpSA) was more positive in controls than in subjects 36(78.3%) vs.
31(67.4%) and 1(2.2%) equivocal result in both groups. This, however, was not significant statistically (p=0.48).
Table 10: Serology and stool antigen test in subjects and controls Variable Subjects Controls Total
n=92
χ2 P-value n=46 n=46
H. pylori IgG 8.03 0.005 Positive 31(67.4%) 42(91.3%) 73(79.3%)
Negative 15(32.6%) 4(8.7%) 19(20.7%)
Stool antigen test for H. pylori(HpSA) 1.46 0.482
Positive 31(67.4%) 36(78.3%) 67(72.8%)
Negative 14(30.4%) 9(19.6%) 23(25%)
Equivocal 1(2.2%) 1(2.2%) 2(2.2%)
The comparison of stool antigen test and serology in subjects and controls are shown in Table 11. The subjects had 24(77.4%) both positive for HpSA and H. pylori IgG with P-value of 0.07. While 35(83.3%) of the controls positive for HpSA and H.
pylori IgG, which was significant. The prevalences obtained using both methods are depicted in Figure 2
Table 11: Comparison of stool antigen test and serology in subjects and controls
Group H. pylori IgG Total χ2
P-value Positive Negative
Subjects HpSA Positive 24(77.4%) 7(46.7%) 31(67.4%) 5.41 0.067 Negative 7(22.6%) 7(46.7%) 14(30.4%)
Equivocal 1(6.7%) 1(2.2%)
Controls HpSA Positive 35(83.3%) 1(25.0%) 36(78.3%) 8.56 0.014 Negative 6(14.3%) 3(75.0%) 9(19.6%)
Equivocal 1(2.4%) 1(2.2%)
0 10 20 30 40 50 60 70 80 90 100
%
Patients Controls
Hp IgG HpSA
Figure 2: Prevalence of H. pylori using H. pylori IgG (Hp IgG) and stool antigen test (HpSA)
The demographic characteristics and stool antigen result among subjects and controls are shown in Table 12. Subjects in the age range of >50yrs years were more positive to HpSA 8(80%), and so were controls in the age range 30-39 years 13(92.9%). The male gender had more positive HpSA in subjects 15(75%) but the HpSA is more positive among the female controls 22(84.6%). These differences observed in age and sex were however not statistically significant.
Table 12: Demographic characteristics and stool antigen among subjects and controls
GROUP X2 P
SUBJECTS CONTROL AGE
GROUP
< 30 Positive Negative Total
6 60.0%
4 40.0%
10 100.0%
8 80.0%
2 20.0%
10 100.0%
0.952 0.628
30-39 Positive Negative Total
9 69.2%
4 30.8%
13 100.0%
13 92.9%
1 7.1%
14 100.0%
2.494 0.165
40-49 Positive Negative Equivocal Total
8 61.5%
4 30.8%
1 7.7%
13 100%
10 83.3%
1 8.3%
1 8.3%
12 100.0%
1.985 0.371
>50 Positive Negative Total
8 80.0%
2 20.0%
10 100.0%
5 50.0%
5 50.0%
10 100.0%
1.978 0.350
SEX MALE Positive
Negative Equivocal Total
15 75.0%
5 25.0%
- - 20 100.0%
14 70.0%
5 25.0%
1 5.0%
20 100.0%
1.034 0.596
FEMALE Positive 16
61.5%
22 84.6%
The demographic characteristics and serology among subjects with dyspepsia are depicted in Table 13. Controls in the age range <30 years were more positive to H. pylori IgG 10(100%).
However in the subjects, it was more positive in those above 30 yrs. The male sex was more positive to H. pylori IgG in subjects 16(80.0%), while female sex was more positive in controls 24(92.3%). However, stratified analyses did not reveal age and sex as confounding variables in the relationship between dyspepsia and H. pylori serology.
Table 13: Demographic characteristics and serology among subjects with dyspepsia
GROUP X2 P
SUBJECTS CONTROL AGE
GROUP
< 30 Positive Negative Total
6 60.0%
4 40.0%
10 100.0%
10 100.0%
- - 10 100.0%
5.000 0.087
30-39 Positive Negative Total
9 69.2%
4 30.8%
13 100.0%
13 92.9%
1 7.1%
14 100.0%
2.494 0.165
40-49 Positive Negative Total
9 69.2%
4 30.8%
13 100.0%
11 91.7%
1 8.3%
12 100.0%
1.963 0.322
>50 Positive Negative Total
7 70.0%
3 30.0%
10 100.0%
8 80.0%
2 20.0%
10 100.0%
0.267 1.000
SEX MALE Positive
Negative Total
16 80.0%
4 20.0%
20 100.0%
18 90.0%
2 10.0%
20 100.0%
0.784 0.661
FEMALE Positive Negative Total
15 57.7%
11 42.3%
26 100.0%
24 92.3%
2 7.7%
26 100.0%
8.308 0.009
Mantel-Haeszel χ2: Age groups = 6.35, p-value = 0.01 Sex = 6.59, p-value = 0.01
The types of treatment, abdominal tenderness in subjects and stool antigen result are shown in Table 14. The subjects that received antacid treatment had 29(93.5%) who were positive to HpSA, while subjects with abdominal tenderness had 17(54.8%) who were positive to HpSA.
Table 14: Types of treatment, abdominal tenderness in subjects and stool antigen result
Variable HpSA Total
Positive Negative Equivocal
Antacid treatment Yes 29(93.5%) 13(92.9%) 1(100%) 43(93.5%)
No 2(6.5%) 1(7.1%) 3(6.5%)
H2 Antagonist Yes 10(32.3%) 1(7.1%) 11(23.9%)
No 21(67.7%) 13(92.9%) 1(100%) 35(76.1%) Proton pump
inhibitor
Yes 1(3.2%) 1(7.1%) 2(4.3%)
No 30(96.8%) 13(92.9%) 1(100%) 44(95.7%)
Herbal medicine Yes 6(19.4%) 2(14.3%) 8(17.4%)
No 25(80.6%) 12(85.7%) 1(100%) 38(82.6%) Abdominal
tenderness
Yes 17(54.8%) 6(42.9%) 1(100%) 24(52.2%)
No 14(45.2%) 8(57.1%) 22(47.8%)
The types of treatment, abdominal tenderness in subjects and serology result are depicted in Table 15. The subjects that received antacid treatment had 29(93.5%) who were positive to. H. pylori IgG, while subjects with abdominal tenderness had 16(51.65) who were positive to H. pylori IgG.
Table 15: Types of treatment, abdominal tenderness in subjects and serology results
Variable H. pylori IgG Total
Positive Negative
Antacid treatment Yes 29(93.5%) 14(93.3%) 43(93.5%)
No 2(6.5%) 1(6.7%) 3(6.5%)
H2 Antagonist Yes 10(32.3%) 1(6.7%) 11(23.9%)
No 21(67.7%) 14(93.3%) 35(76.1%)
Proton pump inhibitor
Yes 2(6.5%) 2(4.3%)
No 29(93.5%) 15(100%) 44(95.7%)
Herbal medicine Yes 6(19.4%) 2(13.3%) 8(17.4%)
No 25(80.6%) 13(86.7%) 38(82.6%)
Abdominal tenderness
Yes 16(51.65) 8(53.3%) 24(52.2%)
No 15(48.4%) 7(46.7%) 22(47.8%)
CHAPTER FIVE DISCUSSION
Dyspepsia is a complex syndrome which most physicians encounter frequently in clinical practice. The understanding of dyspepsia varies to some extent among clinicians, as evident in its various definitions, but it is generally conceived as emanating from the upper gastrointestinal system. The association of H. pylori with dyspepsia has, however, caused a dramatic change in the management of dyspepsia.
In this study the mean age of subjects was 40.83 years and there is no age preponderance, although it consisted slightly of more females (56.5% vs. 43.5%
males). This is in contrast to the pattern observed by Jones3 et al. in the British population. He observed more complaints of dyspepsia in the older age group and suggested that the older subjects are probably more concerned about their health or are afraid of more serious underlying diseases. He concluded that this may be of advantage in that severe diseases can be picked early and management instituted promptly.
The slight preponderance of females could reflect a greater consciousness in the issue of their health or their ready presentation in the hospital could be due to emotional/psychosomatic disorders which tend to be commoner among that gender.
In contrast to this study, Ihezue25 et al. in the North-Central part of Nigeria, found that most of the dyspeptics (60%) were males and symptoms were commoner in those below the age of 40 years.
The significant history of ingestion of herbal medicine (for reasons other than to relieve dyspeptic symptoms) in patients as compared to controls could be contributory to the cause of their dyspeptic symptoms. Often times the full
Alcohol is a known cause of dyspepsia, more so the local form of alcohol commonly used has very high ethanol content.
Ingestion of alcohol (other than in herbal medicine) is also higher in the subject group, which is similar to that observed in North-Eastern Nigeria2. The history of NSAID intake among subjects is significant. NSAIDs are known to cause upper gastrointestinal lesions. In a study done by Atoba131 et al. ingestion of NSAIDs resulted in the development of gastric and duodenal lesions. Moayyedi132 et al. also suggested that NSAIDS may be responsible for about 4% of cases of dyspepsia.
The relationship of meals to the development/exacerbation of dyspeptic symptoms cannot be downplayed since majority of the patients experienced symptoms in relation to meals. The proportion that had their abdominal pain worsened by meal (21%) is comparable to that obtained in the study by Ihezue25 et al.
(29%). This further corroborates the need for dietary management in dyspepsia.
A 67.4% prevalence of H. pylori was obtained among the dyspeptic population in this study using both serology and stool antigen test. Most studies assessing stool antigen test in the diagnosis of H. pylori infection were directed at determining the sensitivity and specificity of the test, hence, actual values were not stated but rather their positives and negatives were interpreted with respect to a pre-determined gold standard. However, a study carried out in Turkey133 on 445 subjects aged between 2-78 years showed a prevalence of 36.6%. Age stratification showed that the prevalence of H. pylori in those aged 16-78 years in that same study was 42.4%. The study population in this study is far smaller than in the Turkish study, and with a larger population the faecoprevalence obtained here might vary. It is also important to note that even though a similar kit was used in the Turkish study, a higher cut-off value was used in determining the positive cases in that study. In
essence, if a lower cut-off value had been used, the prevalence would most likely have been higher in spite of the possibility of Turkey and Nigeria actually varying in H.
pylori prevalence rates.
There is a dearth of case control studies in the assessment of the faecoprevalence of H. pylori as researchers focus on the symptomatic population.
This is not surprising since various studies carried out both in adult and juvenile populations depicted good sensitivity and specificity119, 134 and generally, the prevalence of H. pylori (evaluated by various diagnostic methods) has often been reported as being higher in the dyspeptic group than in the asymptomatic controls12. The faecoprevalence among dyspeptics in this study is comparable to the values obtained through other diagnostic tests. Using CLO-urease test and histology, Ndububa84 et al. got a prevalence of 73% among dyspeptics.
The fact that there has not been much experience with stool antigen test in contrast to serology in this environment prompted this case control study. It is surprising to note that the faecoprevalence of H. pylori is higher among controls in this environment, though not statistically significant (78.3% in controls, 67.4% in subjects). This result was corroborated by a similarly higher seroprevalence among the same healthy control population, and this is statistically significant (91.3% in control, 67.4% in subjects). The sero- and faeco-prevalences in the dyspeptic subjects are similar whereas the seroprevalence in the control is higher than the faecoprevalence. This is not totally unexpected when one considers that an individual may possess antibody to H. pylori subsequent to previous exposure, even though he may not be currently infected with the organism.
seroprevalence among dyspeptics in this study (67.4%vs. 94.5% in Otegbayo’s study) is, however, an interesting finding. As part of the exclusion criteria, subjects who had undergone H. pylori eradication therapy were excluded from the test and so this may not be responsible for the lower value, but then antibiotic abuse is generally common since they can be purchased without prescription. Also worth considering is the fact that subjects with functional dyspepsia constitute the larger percentage of dyspeptic cases and such patients are known to have more emotional/psychosomatic complaints and consequently more frequent hospital visits. More exposure to antibiotics over time could therefore be responsible for a lower prevalence among them.
In a random serological survey conducted by Holcombe135 et al. in the Northern part of Nigeria, 228 out of 268 (85%) subjects were seropositive for H.
pylori, yet only 58 (25.4%) of them had symptoms of dyspepsia. As observed in such earlier studies conducted in this part of the world, in addition to the high prevalence of H. pylori among controls, the cause of dyspepsia here may be of an origin other than H. pylori, and if at all H. pylori plays a significant role then it cannot be singularly so.
There are likely to be other important co-morbid factors which ought to be keenly studied.
Taking a close look at the sero- and faeco-prevalences in dyspeptics, the concordance is obvious. On the strength of this, it can be deduced that either of stool antigen test and IgG serology can give a fair representation of the true prevalence of H. pylori in dyspeptics. In the control group, however, the significant disparity in the sero- and faeco-prevalences may not allow for interchangeability of the two tests.
Based on the principle behind the stool antigen test, it can be concluded that the actual prevalence of H. pylori in controls is 78.3%.