Study of Diagnostic Tests for Helico B Acter Pylori Infection

Abstract

Helicobacter pylori is the causative agent of most cases of gastritis and peptic ulcer. The diagnosis of H. pylori is an essential element in the management of many common gastrointestinal pathologies. AIMS1. Comparison of invasive and non-invasive tests to choose the appropriate test for the diagnosis of H. pylori infection. 2. Validation of the comparison of the different diagnostic tests. METHODBlood and antral biopsy specimens from 100 acid peptic disease patients and blood samples from 10 control subjects were collected. Biopsies were used for Rapid Urease Test (RUT), culture and Gram's stain by conventional method. Serology using Euroimmun Anti Helicobacter pylori IgG ELISA was done. The efficacy of these tests was determined by calculating the sensitivity, specificity, positive predictive value, negative predictive value and accuracy using culture as gold standard. RESULTSOf the 100 cases 14% were culture positive, 18% Gram stain positive, 36% Rapid urease test positive and 42% were positive for Serology IgG antibodies for H. pylori. Maximum percentage of positivity was in peptic ulcer cases (52.9%) followed by Gastritis cases (23.6%) and Dyspepsia cases (14.2%). Among the 100 cases of study group, 42(42%) were positive by serological test IgG ELISA for H. pylori, whereas 3(30%) were positive out of 10 in control group. RUT, IgG Serology showed 100% sensitivity and negative predictive value and Gram stain showed highest specificity (90.1%). CONCLUSIONRUT+Gram's stain+IgG Serology showed highest Sensitivity, Specificity, Positive predictive value, Negative predictive value and Accuracy. IgG Serology indicates a marker for infection. It can be used as a primary diagnostic procedure.

Isolation, biochemical characterization and comparative study of diagnostic methods for Helicobacter pylori infection from dyspepsia patients

“…In the current investigation, 18 samples showed positive results for H. pylori culture. The ndings were close to Pilli and Kirani (2015) who showed a 14% positive culture. The antibiotic susceptibility testing is not normally done for initial disease diagnosis, however, it is recommended after the failure of second-line therapy (Thung et al, 2016).…”

“…The result indicated that urease test showed 44.79% positivity as compared to others which are due to recent or active bleeding and subjects taking drugs (antibiotics or antisecretory compounds) (Suerbaum and Michetti, 2002). This study also correlates with Pilli and Kirani (2015) and Mohsun et al (2011) who reported 36 and 35.6% positivity for the urease test. Gram staining is another rapid screening technique for the judgment of causative agents.…”

“…The results showed that all isolated were transparent with a spiral shape and positive to oxidase test. On the other hand, maximum positivity was observed in the urease test + serology (40) followed by the urease test + gram stain and culture (18) and urease test + gram staining + serology (16) among different combinations of tests (Table 2).…”

“…Moreover, the microaerophilic conditions required by the organism and common use of anti-secretory, antibiotics, or bismuth drugs as well as protozoan are the other major factors for decreased outcome. Other factors like age, ethinic group, area, social status, smoking habits, gender, loss of feasibility during transportation, time from collection to culture, insu cient mincing and patchy distribution of the causative agent in gastric mucosa may result in low sensitivity for detection and isolation (Pilli and Kirani, 2015). Mainly, the contagion was associated with variable gastrointestinal illness such as chronic gastritis, intestinal metaplasia and ulceration disease.…”

Helicobacter Pylori Infection among Patients Attending the Gastroenterology Department in Tertiary Care Hospital, Kathmandu, Nepal

“…The prevalence of H. pylori infection as 16% was reported by Ansari et al by stool antigen test [ 16 ]. Another report by Pilli and Kirani showed that 14% of patients were culture positive, 18% were Gram stain positive, 36% were rapid urease test positive, and 42% were serology IgG antibody positive for H. pylori [ 17 ]. The direct Gram-stained smear is an invasive, highly specific, rapid screening test, and in a resource-limited laboratory, a need for additional testing of positive specimens may be avoided.…”