PMC:4596361 / 23390-31003 JSONTXT

{"target":"http://pubannotation.org/docs/sourcedb/PMC/sourceid/4596361","sourcedb":"PMC","sourceid":"4596361","source_url":"https://www.ncbi.nlm.nih.gov/pmc/4596361","text":"Discussion\nThe substantial time span of this diagnostic record affords an interesting insight into the profile of upper gastrointestinal disease in Zambia over the last 4 decades, with evidence of important trends. Retrospective analysis of data like these is inevitably fraught with difficulties of interpretation, notably the inevitable turnover of staff which when combined with inter-observer variation generates changes in diagnostic patterns. However, the length of service of a few doctors who contributed the most to the record provides some consistency in diagnostic language, which may ameliorate some of these uncertainties. Furthermore, doctor 8 (Fig. 1) also taught endoscopy to doctors 9, 11, 12, 13, 14 and 15, which reinforces a consistency in the diagnostic nosology and helps to reduce inter-observer variation. There are differential trends for peptic ulceration (GU increasing and DU decreasing, and increasing diagnosis of oesophageal but not gastric cancer) so these changes are not merely a consequence of greater use of the endoscopy unit.\nThe burden imposed by HIV on the population of Zambia over the period of this analysis has been heavy, and this is reflected in the dramatic changes in oesophageal candidiasis and Kaposi’s sarcoma. The first description of the new ‘epidemic’ form of KS in this same hospital was published in 1984 [24] and it is clear from Fig. 2 that gastrointestinal KS and oesophageal candidiasis were both rare before then, even though HIV must have been circulating. The steep rise in these diagnoses in the 1980s and 1990s reflects the rising HIV seroprevalence over those years. It is satisfying to note the substantial fall in both diagnoses since the widespread use of ART. These findings are consistent with findings in Zimbabwe and Uganda where a reduction in KS cases (not gastrointestinal) has been reported during the ART era [25, 26]. We have also shown that oesophageal candidiasis, once the most common finding in patients with HIV infection, has been declining with more widespread use of ART. This was observed in the USA also [27]. In addition to reduced incidence of candidiasis we have also seen a reduction in severity which is hard to measure; in the 1990s candidiasis was sometimes so severe as to block the air/water channel of the endoscope, but this is very rare now. Cases are still seen, however, and anecdotally we find that most of these occur in patients who have not had a diagnosis of HIV.\nThe burden of cancer is increasing in Sub-Saharan Africa with the burden expected to double within the next 20 years [28] leading to an estimated 1 million cancer deaths per year by 2030 [29]. The temporal trends in endoscopic diagnosis of upper GI malignancy we report here are of particular concern. Both oesophageal cancer and gastric cancer appear to have risen in adults under 60 years of age. In contrast, in patients of 60 years of age or more the frequency of diagnosis of gastric cancer appears to have declined by 15 % per decade, and the frequency of diagnosis of oesophageal cancer in patients over 60 has remained unchanged. These differential trends suggest that the changes are not merely due to improved endoscopic equipment or changes in personnel, but we cannot rule out the possibility that these temporal trends may be influenced by changes in awareness and referral pattern. As this was a retrospective review, we could not confirm the histological diagnosis in these cancer cases. However, GI cancers in Africa often present with advanced, unmistakeable lesions, and the high proportion of cancer in young adults is consistent with our findings in recent studies in which the diagnosis was confirmed histologically [30–32]. In the UK, less than 5 % of upper GI cancers are under 50 years of age [33], but a report from Tanzania 29 % of gastric cancer cases were under 50 years of age [34], and this is true of oesophageal cancer in Ghana [35] and Kenya [36]. Our findings may therefore be representative of Africa more widely.\nAn important contributor to the temporal trends is referral pattern. When the endoscopy service first began, in 1977, health care in Zambia was free at the point of care and was fully supported by the government. After 1991 when most of the state’s assets were being privatised and the economy could no longer support free health care for all, cost sharing user fees were introduced in government hospitals including UTH. A state insurance scheme was later introduced but suffered from the drawback that, as it was not compulsory, contributions were often only made when the potential contributor was feeling ill and wanted care, so it was in effect a form of user fee. Currently, medical care remains free for children and elderly patients and for those with communicable diseases such as HIV infection or Tuberculosis. Diagnostic services attract fees, and the fee for endoscopy is now ZMW 150 (USD 22 approximately), which represents a considerable barrier to investigation as 60.5 % of the population in Zambia are living in poverty and can barely afford it. User fees have thus been applied to endoscopy for almost all of the last 24 years. While these changes have been going on, referral patterns have almost certainly changed, but in a way that is difficult to quantify. Awareness of the endoscopy service around the country has certainly changed over the last four decades, and this may help explain the rising diagnostic rate of oesophageal varices. Our analysis may suffer from a selection bias as only those who could afford user fees and transport costs would have been able to attend the endoscopy unit. The cohort selection could also have been affected by referral awareness by the referring doctors and easy of geographical accessibility to the service. In order to reduce these biases, we have in our analyses considered proportions of diagnoses made as opposed to absolute numbers.\nThe proportion of patients who were referred for abdominal pain who had a normal endoscopy was high at 48 %. This figure is consistent with reports from other countries and is consistent with our clinical impression that functional dyspepsia is just as common in Africa as elsewhere. Oesophageal varices were found to be the most common cause of haematemesis, and most of these are attributed to Schistosoma mansoni infection [30, 37]. Other African investigators within the region have also reported oesophageal varices as the leading cause of haematemesis, in contrast to the dominance of peptic ulceration in industrialised countries [30, 38, 39], but this may vary across the continent. Duodenal ulcer (DU) is assumed to be due to H. pylori infection, which is common [18], but this is not routinely confirmed as confirmation is costly and probably unnecessary in the light of the high seroprevalence. The seasonality of DU, with lower incidence in the hot season, is consistent with data from other countries [40] but remains unexplained.\nThese data from one endoscopy unit provide a useful insight into profiles of upper gastrointestinal disease in Zambia, and they differ substantially from current trends in industrialised countries. There is a serious shortage of data on the epidemiology of gastrointestinal disease in Africa [41], but we can predict that further changes will occur, and these may be rapid in the increasing number of people surviving long term with HIV infection [42]. These endoscopy records go some way to identifying issues which require urgent investigation, prominent among which is the disturbing incidence of oesophageal and gastric cancer in young adults.","divisions":[{"label":"title","span":{"begin":0,"end":10}},{"label":"p","span":{"begin":11,"end":1063}},{"label":"p","span":{"begin":1064,"end":2471}},{"label":"p","span":{"begin":2472,"end":4020}},{"label":"p","span":{"begin":4021,"end":5921}},{"label":"p","span":{"begin":5922,"end":6965}}],"tracks":[{"project":"2_test","denotations":[{"id":"26444265-6145025-9921197","span":{"begin":1362,"end":1364},"obj":"6145025"},{"id":"26444265-23364833-9921198","span":{"begin":1888,"end":1890},"obj":"23364833"},{"id":"26444265-24615279-9921199","span":{"begin":1892,"end":1894},"obj":"24615279"},{"id":"26444265-10685750-9921200","span":{"begin":2094,"end":2096},"obj":"10685750"},{"id":"26444265-21796634-9921201","span":{"begin":2660,"end":2662},"obj":"21796634"},{"id":"26444265-23547703-9921202","span":{"begin":3710,"end":3712},"obj":"23547703"},{"id":"26444265-19473205-9921203","span":{"begin":3948,"end":3950},"obj":"19473205"},{"id":"26444265-23515280-9921204","span":{"begin":6564,"end":6566},"obj":"23515280"},{"id":"26444265-11283050-9921205","span":{"begin":6695,"end":6697},"obj":"11283050"},{"id":"26444265-24029198-9921206","span":{"begin":6937,"end":6939},"obj":"24029198"},{"id":"26444265-22136952-9921207","span":{"begin":7259,"end":7261},"obj":"22136952"},{"id":"26444265-25117963-9921208","span":{"begin":7414,"end":7416},"obj":"25117963"}],"attributes":[{"subj":"26444265-6145025-9921197","pred":"source","obj":"2_test"},{"subj":"26444265-23364833-9921198","pred":"source","obj":"2_test"},{"subj":"26444265-24615279-9921199","pred":"source","obj":"2_test"},{"subj":"26444265-10685750-9921200","pred":"source","obj":"2_test"},{"subj":"26444265-21796634-9921201","pred":"source","obj":"2_test"},{"subj":"26444265-23547703-9921202","pred":"source","obj":"2_test"},{"subj":"26444265-19473205-9921203","pred":"source","obj":"2_test"},{"subj":"26444265-23515280-9921204","pred":"source","obj":"2_test"},{"subj":"26444265-11283050-9921205","pred":"source","obj":"2_test"},{"subj":"26444265-24029198-9921206","pred":"source","obj":"2_test"},{"subj":"26444265-22136952-9921207","pred":"source","obj":"2_test"},{"subj":"26444265-25117963-9921208","pred":"source","obj":"2_test"}]}],"config":{"attribute types":[{"pred":"source","value type":"selection","values":[{"id":"2_test","color":"#93ec97","default":true}]}]}}