Inflammatory bowel disease in sub-Saharan Africa: epidemiology, risk factors, and challenges in diagnosis.

Over the past century, the incidence of inflammatory bowel disease (IBD) in high-income countries has shown a sharp rise that then plateaued, and a similar trend has been observed in newly industrialised countries. IBD has long been considered uncommon in sub-Saharan Africa, possibly reflecting low exposure to environmental risk factors described in high-income populations. Alternatively, individuals living in sub-Saharan Africa might have a different genetic disposition. However, some cases of IBD might remain undetected in sub-Saharan Africa because of a lack of awareness, deficiencies in diagnostic and clinical capacity, and a substantial rate of misdiagnosis due to the high burden of infectious diseases. There are few published data describing the natural history of IBD in sub-Saharan Africa, and the true burden of the disease remains largely unknown, although there is some evidence that the incidence of IBD is rising in this region. This Series paper summarises the present understanding of IBD and challenges facing clinicians when diagnosing this disease in sub-Saharan Africa.

Challenges in the management of inflammatory bowel disease in sub-Saharan Africa.

Inflammatory bowel disease (IBD) is generally considered a disease of high-income countries and is regarded as rare in sub-Saharan Africa. However, this assumption is almost certainly an underestimate, and the high burden of communicable diseases makes IBD in sub-Saharan Africa difficult to detect. Furthermore, some gastrointestinal infections can closely mimic IBD, contributing to delays in diagnosis and complicating therapeutic decision making. Constraints in endoscopic capacity alongside a scarcity of qualified diagnostic pathologists add to the difficulties. Implementing evidence-based guidelines recommended by international societies is challenging, mostly due to high costs and unavailability of medication. However, cost-effective approaches can still be implemented to manage IBD in sub-Saharan Africa as the predominant disease phenotype is mild-to-moderate ulcerative colitis, which often responds to treatment with basic medication. In this Series paper, we summarise the current management of IBD in sub-Saharan Africa and propose how it can be tailored to suit the epidemiological and socioeconomic specificities of the region. We also discuss measures required to address existing challenges, such as educating health-care workers about the diagnosis and management of IBD or improving endoscopic capacity.

Whole Genome Sequencing Reveals Virulence Potentials of Helicobacter pylori Strain KE21 Isolated from a Kenyan Patient with Gastric Signet Ring Cell Carcinoma.

Helicobacter pylori (H.pylori) infection is etiologically associated with severe diseases including gastric cancer; but its pathogenicity is deeply shaped by the exceptional genomic diversification and geographic variation of the species. The clinical relevance of strains colonizing Africa is still debated. This study aimed to explore genomic features and virulence potentials of H. pylori KE21, a typical African strain isolated from a native Kenyan patient diagnosed with a gastric cancer. A high-quality circular genome assembly of 1,648,327 bp (1590 genes) obtained as a hybrid of Illumina Miseq short reads and Oxford Nanopore MinION long reads, clustered within hpAfrica1 population. This genome revealed a virulome and a mobilome encoding more than hundred features potentiating a successful colonization, persistent infection, and enhanced disease pathogenesis. Furthermore, through an experimental infection of gastric epithelial cell lines, strain KE21 showed the ability to promote interleukin-8 production and to induce cellular alterations resulting from the injection of a functional CagA oncogene protein into the cells. This study shows that strain KE21 is potentially virulent and can trigger oncogenic pathways in gastric epithelial cells. Expended genomic and clinical explorations are required to evaluate the epidemiological importance of H. pylori infection and its putative complications in the study population.

Helicobacter pylori eradication: A randomised comparative trial of 7-day versus 14-day triple therapy.

Background. Helicobacter pylori is associated with several upper gastrointestinal conditions including chronic gastritis, peptic ulcer disease, and gastric malignancy. Proton pump inhibitor-based triple therapies are considered the standard regimens for H. pylori eradication, but the optimal duration of therapy is controversial. To prevent infection and complications, local studies should be undertaken to evaluate H. pylori eradication rates in a country. Objectives. We compared 7-day and 14-day regimens to determine the optimum duration of triple therapy for H. pylori eradication. Methods. We undertook a prospective randomised comparative trial of 7-day and 14-day triple therapy regimen for H. pylori eradication at the Aga Khan University Hospital, Nairobi; 120 patients with dyspepsia and H. pylori infection were randomised to receive esomeprazole, amoxicillin and clarithromycin for either 7 days (EAC 7) or 14 days (EAC 14). Compliance and side-effects were assessed 2 weeks after the start of therapy and H. pylori eradication was assessed by stool antigen tests 4 weeks after treatment. Results. Both the intention-to-treat (ITT; N=120) and per protocol (PP; N=97) analyses showed no significant differences between the eradication rates of EAC 7 (ITT 76.7%; PP 92%) and EAC 14 (ITT 73.3%; PP 93.6%) (ITT p=0.67; PP p=0.76). Poor compliance was reported in one patient in the EAC 14 group. The incidence of adverse events was comparable in the two groups. Conclusion. One-week and 2-week triple treatments for H. pylori eradication are similar in terms of efficacy, safety and patient compliance.

Helicobacter pylori: prevalence and antibiotic susceptibility among Kenyans.

BACKGROUND: Helicobacter pylori infection in Kenya is staggeringly high. Evidence links infection of the gastric mucosa by H. pylori with subsequent development of gastric pathologies. AIM: We investigated the prevalence of H. pylori in dyspeptic patients, its relationship with gastric pathologies, and associated antibiotic susceptibility profiles, and compared two media to find the appropriate medium that enhances growth and expedites culture and isolation. METHODS: Rapid urease and histological tests were used to screen for H. pylori. Culture was performed to test sensitivity and evaluate media. Selective and nutritional supplements were added to culture media (Colombia blood agar and brain-heart infusion agar) for growth enhancement. E-test strips for metronidazole, amoxicillin and clarithromycin were used for susceptibility testing. RESULTS: The prevalence of H. pylori infection in children was 73.3%, and 54.8% in adults. All the H. pylori investigated in this study were largely sensitive to clarithromycin (100%, minimum inhibiting concentration (MIC) <2 microg/ml), amoxicillin (100%, MIC <2 microg/ml) and metronidazole (95.4%, MIC <8 microg/ml). There was, however, occasional resistance to metronidazole (4.6%, MIC >8 microg/ml). Both Colombia blood and brain-heart infusion agar, with the supplements, effectively supported H. pylori growth. Growth was achieved in an average of 36 hours for primary isolations and 24 hours for subcultures. CONCLUSION: The media described here reduce the time required to culture and isolate bacteria and perform susceptibility testing. Despite the high prevalence of H. pylori infection, the associated pathology is low and does not parallel H. pylori prevalence in the population.