The magnitude of antibiotic resistance to Helicobacter pylori in Africa and identified mutations which confer resistance to antibiotics: systematic review and meta-analysis

BACKGROUND

Worldwide Helicobacter pylori (H.pylori) treatment is of great challenge due to increased antibiotic resistance. The burden of H. pylori antibiotic resistance in Africa is high with unclear information regarding the real magnitude. This systematic review and meta-analysis was conducted to investigate the magnitude of H.pylori antibiotic resistance in Africa to gain insight of the extent of the problem among H.pylori naïve treatment patients.

METHOD

The search was performed in the academic databases, Embase, PubMed, Web of Science and Africa Wide Information. ProQuest Dissertation and Theses, Scopus, Ethos, Africa Index Medicus (WHO), BioMed Central Proceedings, BASE, British Library, Open grey, Library of Congress and the New York Academy of Grey Literature Report were additionally searched for grey literature. Published articles from Africa on H.pylori antibiotic resistance between 1986 and June 2017 were systematically reviewed to estimate the H. pylori extent of resistance to macrolides, quinolones, amoxicillin, tetracycline and metronidazole.

RESULTS

In 26 articles a total of 2085 isolates were tested for metronidazole, 1530 for amoxicillin, 1277 for tetracycline, 1752 for clarithromycin and 823 for quinolones.The overall pooled proportion of H.pylori resistance to quinolones, clarithromycin, tetracycline, metronidazole and amoxicillin were: (17.4%, 95%CI 12.8 - 21.9), (29.2%, 95%CI:26.7-31.8), (48.7%, 95%CI: 44.5-52.9), (75.8%, 95% CI: 74.1-.77.4) and (72.6%, 95% CI: 68.6-76.6), respectively. The commonest mutation detected were A2143G (49/97) for clarithromycin, RdxA (41/56) for metronidazole and D87I (16/40) for quinolones.

CONCLUSION

Prevalence of metronidazole, clarithromycin, and amoxicillin resistance is high in developing world including Africa. This could impair the first line triple therapy of the H.pylori infection. There is a need of conducting surveillance of H.pylori susceptibility pattern in Africa for dual and triple resistance which can be used for the empirical treatment.

Gastric outlet obstruction at Bugando Medical Centre in Northwestern Tanzania: a prospective review of 184 cases

BACKGROUND

Gastric outlet obstruction poses diagnostic and therapeutic challenges to general surgeons practicing in resource-limited countries. There is a paucity of published data on this subject in our setting. This study was undertaken to highlight the etiological spectrum and treatment outcome of gastric outlet obstruction in our setting and to identify prognostic factors for morbidity and mortality.

METHODS

This was a descriptive prospective study which was conducted at Bugando Medical Centre between March 2009 and February 2013. All patients with a clinical diagnosis of gastric outlet obstruction were, after informed consent for the study, consecutively enrolled into the study. Statistical data analysis was done using SPSS computer software version 17.0.

RESULTS

A total of 184 patients were studied. More than two-third of patients were males. Patients with malignant gastric outlet obstruction were older than those of benign type. This difference was statistically significant (p < 0.001). Gastric cancer was the commonest malignant cause of gastric outlet obstruction where as peptic ulcer disease was the commonest benign cause. In children, the commonest cause of gastric outlet obstruction was congenital pyloric stenosis (13.0%). Non-bilious vomiting (100%) and weight loss (93.5%) were the most frequent symptoms. Eighteen (9.8%) patients were HIV positive with the median CD 4+ count of 282 cells/μl. A total of 168 (91.3%) patients underwent surgery. Of these, gastro-jejunostomy (61.9%) was the most common surgical procedure performed. The complication rate was 32.1 % mainly surgical site infections (38.2%). The median hospital stay and mortality rate were 14 days and 18.5% respectively. The presence of postoperative complication was the main predictor of hospital stay (p = 0.002), whereas the age > 60 years, co-existing medical illness, malignant cause, HIV positivity, low CD 4 count (<200 cells/μl), high ASA class and presence of surgical site infection significantly predicted mortality ( p< 0.001). The follow up of patients was generally poor as more than 60% of patients were lost to follow up.

CONCLUSION

Gastric outlet obstruction in our setting is more prevalent in males and the cause is mostly malignant. The majority of patients present late with poor general condition. Early recognition of the diagnosis, aggressive resuscitation and early institution of surgical management is of paramount importance if morbidity and mortality associated with gastric outlet obstruction are to be avoided.

Hepatocellular carcinoma: clinicopathological profile and challenges of management in a resource-limited setting

BACKGROUND

Hepatocellular carcinoma is one of the most common cancers worldwide and its incidence is reported to be increasing in resource-limited countries. There is a paucity of published data regarding hepatocellular carcinoma in Tanzania, and the study area in particular. This study describes the clinicopathological profile of hepatocellular carcinoma in our local setting and highlights the challenging problems in the management of this disease.

METHODS

This was a retrospective study of histopathologically confirmed cases of hepatocellular carcinoma seen at Bugando Medical Center between March 2009 and February 2013.

RESULTS

A total of 142 patients (M: F = 2.2: 1) were studied representing 4.6% of all malignancies. The median age of patients was 45 years. Hepatitis B virus infection (66.2%) and heavy alcohol consumption (60.6%) were the most frequently identified risk factors for hepatocellular carcinoma. The majority of patients (88.0%) presented late with advanced stages. HBsAg was positive in 66.2% of the patients and Hepatitis C Virus antibody in 16.9%. Thirteen (9.2%) patients tested positive for HIV infection. Most patients (52.8%) had both right and left lobe involvement. The trabecular pattern (47.9%) was the most frequent histopathological type. None of patients had curative therapy because of the advanced nature of the disease. Coagulopathy (45.7%) was the most common complications. The overall mortality rate was 46.5% and it was significantly associated with comorbidity, HIV positivity, CD4+ count <200 cells/μl, high histological grade, advanced stage of the tumor, presence of distant metastases at the time of diagnosis, and associated complications (P < 0.001). The overall median duration of hospital stay was 14 days. The majority of patients (71.1%) were lost to follow-up at the end of the follow-up period.

CONCLUSIONS

Hepatocellular carcinoma patients in this region are relatively young at diagnosis and the majority of them present late with an advanced stage and high rate of distant metastasis. Lack of awareness of the disease, poor accessibility to healthcare facilities, and lack of screening programs in this region may contribute to advanced disease at the time of diagnosis. There is a need for early detection, adequate treatment, and proper follow-up to improve treatment outcome.

A fibreoptic endoscopic study of upper gastrointestinal bleeding at Bugando Medical Centre in northwestern Tanzania: a retrospective review of 240 cases

BACKGROUND

Upper gastrointestinal (GI) bleeding is recognized as a common and potentially life-threatening abdominal emergency that needs a prompt assessment and aggressive emergency treatment. A retrospective study was undertaken at Bugando Medical Centre in northwestern Tanzania between March 2010 and September 2011 to describe our own experiences with fibreoptic upper GI endoscopy in the management of patients with upper gastrointestinal bleeding in our setting and compare our results with those from other centers in the world.

FINDINGS

A total of 240 patients representing 18.7% of all patients (i.e. 1292) who had fibreoptic upper GI endoscopy during the study period were studied. Males outnumbered female by a ratio of 2.1:1. Their median age was 37 years and most of patients (60.0%) were aged 40 years and below. The vast majority of the patients (80.4%) presented with haematemesis alone followed by malaena alone in 9.2% of cases. The use of non-steroidal anti-inflammatory drugs, alcohol and smoking prior to the onset of bleeding was recorded in 7.9%, 51.7% and 38.3% of cases respectively. Previous history of peptic ulcer disease was reported in 22(9.2%) patients. Nine (3.8%) patients were HIV positive. The source of bleeding was accurately identified in 97.7% of patients. Diagnostic accuracy was greater within the first 24 h of the bleeding onset, and in the presence of haematemesis. Oesophageal varices were the most frequent cause of upper GI bleeding (51.3%) followed by peptic ulcers in 25.0% of cases. The majority of patients (60.8%) were treated conservatively. Endoscopic and surgical treatments were performed in 30.8% and 5.8% of cases respectively. 140 (58.3%) patients received blood transfusion. The median length of hospitalization was 8 days and it was significantly longer in patients who underwent surgical treatment and those with higher Rockall scores (P < 0.001). Rebleeding was reported in 3.3% of the patients. The overall mortality rate of 11.7% was significantly higher in patients with variceal bleeding, shock, hepatic decompensation, HIV infection, comorbidities, malignancy, age > 60 years and in patients with higher Rockall scores and those who underwent surgery (P < 0.001).

CONCLUSION

Oesophageal varices are the commonest cause of upper gastrointestinal bleeding in our environment and it is associated with high morbidity and mortality. The diagnostic accuracy of fibreoptic endoscopy was related to the time interval between the onset of bleeding and endoscopy. Therefore, it is recommended that early endoscopy should be performed within 24 h of the onset of bleeding.

Predictors of triple therapy treatment failure among H. pylori infected patients attending at a tertiary hospital in Northwest Tanzania: a prospective study

BACKGROUND

Helicobacter pylori (H.pylori) infection is a common medical problem in resource limited areas. The treatment outcome after triple therapy has not been well studied in developing countries and preliminary data suggests a high rate of treatment failure. This study investigated the triple therapy treatment failure rate and associated factors among dyspeptic patients receiving H. pylori first line therapy at a tertiary hospital, Tanzania.

METHODS

A prospective study in the Gastroenterology unit of the Bugando Medical Centre (BMC) was conducted between October 2015 and May 2017. All dyspeptic patients with stool antigen tests positive for H.pylori were given first line therapy, and stool antigen testing was repeated within 7 days and 5 weeks after completion of the treatment. Biopsies were taken before initiation of therapy and analysed for clarithromycin and quinolone resistance mutations using polymerise chain reaction (PCR) and sequencing. Adherence and other social-demographic characteristics were documented.

RESULTS

A total of 210 patients were enrolled; the median age was 35 years (interquartile range, 27-48). First line treatment failure as defined by positive stool antigen 5 weeks post treatment was observed in 65/210 (31%) of patients. Independent predictors of first line treatment failure were presence of clarithromycin resistance mutations (OR: 23.12, 95% CI (9.38-56.98), P < 0.001) and poor adherence (OR: 7.39, 95% CI (3.25-16.77), P < 0.001). The sensitivity and specificity of stool antigen testing within 7 days after completion therapy in detecting treatment failure was 100 and 93.2%, respectively.

CONCLUSION

Nearly one-third of patients with clarithromycin resistance mutations and poor adherence develop first line treatment failure. Routine stool antigen testing within seven days after completion of therapy can be considered in order to initiate second line treatment early to prevent associated morbidities.

Helicobacter pylori Mutations Conferring Resistance to Fluoroquinolones and Clarithromycin among Dyspeptic Patients Attending a Tertiary Hospital, Tanzania

Objectives. Helicobacter pylori (H. pylori) isolates resistant to clarithromycin and quinolones are increasing worldwide. Data regarding the magnitude of H. pylori resistance are limited in developing countries. Here, we report the prevalence of mutations conferring resistance to clarithromycin and fluoroquinolones among dyspeptic patients attending a tertiary hospital, Tanzania. Methods. Between August 2014 and August 2016, patients undergoing upper gastrointestinal endoscopy at the Bugando Medical Centre were enrolled. Biopsies were taken for polymerase chain reaction (PCR) and sequencing to detect mutations conferring resistance to clarithromycin and fluoroquinolones. Results. A total of 208 nonrepetitive biopsies were examined of which 188 (90.4%) tested positive for H. pylori specific 23S rRNA PCR. Clarithromycin resistance mutations were detected in 54/188 (28.7%) of patients tested. The most frequently detected mutation was A2143G (30) followed by A2142G (20). Out of 131 nonrepetitive biopsies tested for fluoroquinolones resistance mutations, 77/131 (58.8%) were positive, with N87I (20) mutation being the most frequently detected mutation followed by A92T mutation which was detected in 16 samples. Conclusion. A significant proportion of dyspeptic patients attending tertiary hospital in Tanzania are infected with H. pylori strains harbouring clarithromycin or fluoroquinolones resistance mutations. Detection of more than 50% of strains with fluoroquinolones resistance mutations makes the H. pylori second line treatment questionable in our setting. There is a need of surveillance of H. pylori resistance patterns in Tanzania to provide data that can guide empirical treatment to reduce associated morbidity of H. pylori infections. The correlation between A92T fluoroquinolone mutation and phenotypic resistance requires further investigations.

Strongyloides stercoralis infection presenting as an unusual cause of massive upper gastrointestinal bleeding in an immunosuppressed patient: a case report

Strongyloidiasis caused by Strongyloides stercoralis is a rare but well documented cause of massive upper gastrointestinal (GI) bleeding especially in endemic areas. However, oesophagogastroduodenoscopic findings and extractions of S. stercoralis, in the adult worm form, from the duodenum is even rarer. We report a case of a 27-year-old Tanzanian woman with HIV who presented with massive upper GI bleeding. She had S. stercoralis, in the adult worm form, traversing the stomach and duodenum and extracted by oesophagogastroduodenoscopy (OGD). She was treated successfully with Ivermectine and antiretroviral therapy for HIV was initiated. Strongyloidiasis should be included in the differential diagnosis of mass upper GI bleeding in immunosuppressive patients living in, or originating from, endemic areas. We believe this to be the first case to be reported from our environment.

Sero-prevalence and associated factors of Helicobacter pylori infection among adult patients with dyspepsia attending the gastroenterology unit in a tertiary hospital in Mwanza, Tanzania

BACKGROUND

Prevalence of H.pylori infection varies greatly between populations in different countries. This study was conducted to determine the magnitude of H.pylori among adult patients with dyspepsia attending the gastroenterology unit at Bugando medical centre.

METHODS

A cross sectional study involving 202 dyspeptic patients was conducted between June and July 2014. A Standardized data collection tool was used to collect socio-demographic characteristics. H.pylori antibodies were detected using rapid immunochromatographic tests according to manufacturer's instructions.

RESULTS

The median age of study population was 42 (IQR: 33-54). Females 105 (51.9%) formed majority of the population studied. Of 202 participants; 119 (58.9%) were from rural areas. Seroprevalence of H.pylori infection was found to be 79/202 (39.1%, 95% CI: 32.3-45.7). As the age increased the risk of having H.pylori infection also increased (OR: 1.02 95% CI: 1-1.04, P=0.02). On multivariate logistic regression analysis untreated drinking water was found to predict H.pylori seropositivity (OR: 2.33, CI: 1.09-4.96, p=0.028).

CONCLUSION

The seroprevalence of H.pylori among dyspeptic patients is high in this setting. Therefore the community in Mwanza should be educated on the use of safe drinking water in order to minimize H. pylori infections.

Forty Years of Helicobacter pylori: The African Perspective

BACKGROUND

Helicobacter pylori colonises 50% of the world population and is a causative agent of gastritis, peptic ulcer disease, mucosa associate lymphoid tissue lymphoma and gastric cancer.

SUMMARY

In Africa, the prevalence rate has been found to be the highest in comparison to other parts of the world. Despite its high prevalence there are low rates of gastric cancer recorded in Africa. This African perspective gives an insight into the history of H. pylori in Africa and also examines the issue of the so-called "African Enigma," it's diagnosis and treatment and where we are now.

KEY MESSAGES

Our vision is to have an African community that is free from H. pylori infections and complications. To this end, the African Helicobacter and Microbiota Study Group was initiated in 2021 and launched on the June 27, 2022 in Lagos, Nigeria (https://ahmsg-africa.org/). The African perspective includes the need for more detailed information on actual community and hospital prevalence, resistance data, and standardizing processes and algorithms to enable comparative diagnosis and therapy of H. pylori infections using a multi-pronged approach with international support.