Our prospective cohort study documents the strikingly high prevalence of variceal bleeding (70%) among 124 consecutive adult inpatients presenting with haematemesis to a regional hospital in western Tanzania. Moreover, we found that nearly 60% of patients presenting with haematemesis due to variceal bleeding and 30% presenting with haematemesis due to other causes had evidence of active schistosomiasis. These results are important for public health in sub-Saharan Africa because they document high rates of a preventable disease. Scaling up efforts to control schistosomiasis could lead to significant reductions in morbidity and mortality among the ~54 million people living in sub-Saharan Africa who have S. mansoni infection and are at risk for periportal fibrosis, oesophageal varices, and death .
To our knowledge, this is the first prospective study to determine endoscopic diagnoses, presenting features, and outcomes among adults with UGIB in East Africa. Two recent retrospective studies done in Tanzania have documented comparably high rates of oesophageal varices among patients with UGIB (41%-52%) [8, 9]. Our study, conducted in a region in which the prevalence of schistosomiasis is one of the highest in the world, additionally describes numerous factors that were highly associated with oesophageal varices in patients presenting with haematemesis. Associated characteristics included demographics, clinical findings at the time of admission, and documented active infections (hepatitis B and schistosomiasis). Taken together, these data suggest that patients who live near the lakeside and/or fished and present with signs of portal hypertension and liver dysfunction are highly likely to have variceal bleeding.
Identification and appropriate management of patients who have oesophageal varices is urgent because each episode of variceal haemorrhage carries 18-30% risk of death within six weeks with increasing mortality in the ensuing months and years [23–25]. These mortality estimates are from wealthier settings in which cirrhosis, which is associated with higher mortality, is more common but additional management options such as sclerotherapy and portosystemic shunting are available. We believe that mortality in resource-limited settings, particularly when patients often present with more advanced disease or live remotely from advanced medical care, may be higher. Moreover, endoscopy is a scarce resource in Tanzania, and when combined with transportation expenses, it easily costs over a month’s wages for an average rural patient. Therefore, identification of patients most likely to benefit from endoscopy (e.g., those with oesophageal varices that can be banded or sclerosed) is additionally important from a healthcare cost and resource utilisation perspective.
We determined clinical prediction rules with high sensitivity, specificity, PPV, and NPV that can be used in smaller hospitals where ultrasounds but not endoscopy are available, and in even smaller clinics using history and physical examination alone. When ultrasound is available, the single finding of portal vein diameter ≥ 13 mm has over 90% sensitivity, specificity and PPV for oesophageal varices. When ultrasound is not available, the presence of splenomegaly alone maintains a sensitivity and PPV > 90%, allowing focused use of the scarce resource of endoscopy for patients in whom intervention is possible. These clinical rules therefore represent a powerful tool that can be used to suggest which patients with haematemesis are highly likely to have oesophageal varices. These patients should be referred for urgent endoscopy and counselled that endoscopy may be life-saving.
Our data demonstrates active schistosome infection in nearly half of adults presenting with haematemesis. Similar rates of schistosomiasis in community-based studies of adults in this region have also been documented [12–14]. These results contrast with the common teaching in sub-Saharan Africa that schistosomiasis is predominantly an infection of children and that adults presenting with UGIB due to schistosomiasis have past but not present infection. The prevalence of schistosomiasis in endemic regions peaks between age ten and 20, and adults can develop partial immunity but many still remain infected [26, 27]. For this reason, we advocate universal testing and treatment for schistosomiasis and/or empiric anti-schistosome treatment as an integral component of managing patients who present with UGIB in schistosome-endemic settings, particularly given the evidence that schistosomal liver pathology will continue to worsen in the setting of ongoing schistosome infection but may regress following anti-schistosome treatment [28, 29].
In addition, our findings suggest that current schistosomiasis control efforts in Tanzania and many other countries in sub-Saharan Africa are inadequate. Many nations with limited healthcare funds focus schistosomiasis treatment efforts on schoolchildren despite the World Health Organization’s recommendations that both children and adults living in highly-endemic areas should be treated annually for schistosomiasis . The average lifespan of the S. mansoni worm is 3–5 years, while the time from infection to development of liver fibrosis typically takes 5–15 years . Therefore, the finding of active schistosomiasis in these adults presenting with end-stage liver fibrosis suggests that they have been subject to ongoing exposure and re-infection for many years. In the absence of the ability to eliminate schistosomiasis altogether through behavioural change, clean water provision, and improved sanitation, the next-best remedy is to decrease worm burden and morbidity through routine treatment for both children and adults.
Our study has several limitations. First, we were not able to perform liver biopsies in this resource-limited setting in order to corroborate our diagnoses histopathologically. The ability to do so would have been most useful to determine the predominant disease in the 11 patients who had both active schistosome infection and Hepatitis B antigen positivity. Second, we limited our study population to patients with haematemesis in the past 14 days in order to ensure that only patients with true upper gastrointestinal bleeding were enrolled. It is possible that this led to the exclusion of patients with less acute or lower-volume upper gastrointestinal bleeding.