Diagnostic methods for the detection of Helicobacter pylori in Nigeria

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Smith, S I
Omonigbehin, E A
Goodluck, H A
Abdulkareem, F B
Onyekwere, C A
Agomo, C
Ndububa, D A
Fowora, M A
Otegbayo, J A
Contreras, M
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Tropical Gastroenterology
Helicobacter pylori is a curved, highly motile, gram-negative rod that colonizes the mucosa of the human stomach of more than half of the world’s population.1,2 Infection is mainly acquired in childhood and stays asymptomatic for decades in approximately 80% of cases.2 There are several diagnostic tests for the detection of H. pylori and are grouped into two categories: (I) invasive tests that require endoscopy such as culture, rapid urease test (RUT), histology, direct gram-stain of biopsies, and PCR; (II) non-invasive or minimally invasive tests such as serology, urea breath test (UBT), and H. pylori stool antigen tests (HpSA).3 Although culture is the gold standard, it is very much dependent on some infrastructure conditions and power supply. Therefore, the culturing of H. pylori can be unreliable especially for an environment like Nigeria where power outages are quite regular and lasting for days. This is also in addition to the problem of overgrowth or contamination with other microorganisms. Due to this situation, cultivation of H. pylori is not routinely applied for the detection of H. pylori in Nigeria. However, culture is necessary in treating cases with failure of primary attempt at H.pylori eradication. The study aimed at evaluating various methods for the diagnosis of H. pylori in developing countries where facilities for culture of H.pylori may not be easily available at all centres. Methods 167 patients with dyspepsia undergoing upper gastrointestinal endoscopy were included after informed consent. Patients on NSAIDs, PPIs, and antibiotics were excluded. A total of 835 stomach biopsy samples (three antrum and two corpus) were obtained from these patients during endoscopy. The study was carried out between January 2008 and December 2008. The biopsies were subjected to H. pylori culture, CLO test kit (Delta West pty, Australia), H. pylori stool antigen test (HpSA, Meridien UK) using stool samples or rectal swabs, serology test (Human, Germany), histology (Giemsa stain), and direct gram stain of smear from biopsy. Three biopsies from the antrum were used :- one each for CLO test, culture/ PCR, and histology. While the other two corpus biopsies were used only for histology and culture/PCR. All tests with kits were carried out according to their manufacturer’s instructions. The specimens were obtained from two centres in Nigeria: Lagos State University Teaching Hospital (LASUTH, Ikeja) and Obafemi Awolowo University Teaching Hospital Complex (OAUTHC), Ile Ife. Ethical approval was obtained from the NIMR-IRB before the study commenced.
Tropical Gastroenterology 2010;31(2):113–115