Morbidity and Mortality Due to Schistosoma mansoni Related Periportal Fibrosis: Could Early Diagnosis of Varices Improve the Outcome Following Available Treatment Modalities in Sub Saharan Africa? A Scoping Review

Abstract

Schistosomiasis affects about 240 million people worldwide and Schistosoma mansoni alone affects over 54 million people leaving 400 million at-risk especially in Sub Saharan Africa (SSA). About 20 million people are currently suffering from complications of chronic S. mansoni infection and up to 42% of those infected have been found with periportal fibrosis (PPF). About 0.2 million deaths are attributed to chronic S. mansoni every year, which is mainly due to varices. Death occurs in up to 29% of those who present late with bleeding varices even with the best available in-hospital care. The diagnosis of varices before incident bleeding could potentially improve the outcome of this subgroup of patients is SSA. However, there is no prior review which has ever evaluated this issue detailing the magnitude and outcome of varices following available treatment modalities among patients with Schistosoma PPF in SSA. This review summarizes the available literature on this matter and exposes potential practical gaps that could be bridged to maximize the long-term outcome of patients with S. mansoni related PPF in SSA. A total of 22 studies were included in this review. The average prevalence of varices was 82.1% (SD: 29.6; range: 11.1%–100%) among patients with PPF. Late diagnosis of varices was frequent with average bleeding and mortality of 71.2% (SD: 36.5; range: 4.3%–100.0%) and 13.6% (SD: 9.9; range: 3.5%–29%), respectively. Predictors were reported in seven (31.8%) studies including platelet count to splenic diameter ratio (PSDR) for prediction large varices in one study. Active S. mansoni infection was very prevalent, (mean: 69.9%; SD: 24.4; range: 29.2–100.0%). Praziquantel could reverse PPF and use of non-selective B-blockers reduced both rebleeding and mortality. Use of sclerotherapy for secondary prevention of variceal bleeding was associated with high rebleeding and mortality rates. Conclusions: This review shows that varices due to schistosomal PPF are a big problem in SSA. However, patients are often diagnosed late with fatal bleeding varices. No study had reported a clinical tool that could be useful in early diagnosis of patients with varices and no study reported on primary and effective secondary prevention of bleeding and its outcome. Regular screening for S. mansoni and the provision of Praziquantel (PZQ) is suggested in this review. More studies are required to bridge these practical gaps in Sub Saharan Africa.

Schistosomiasis, Upper Gastrointestinal Bleeding, and Health Related Quality of Life Measurements in Rural Africa

“…What is known is that acute UGIB is the main reason for hospitalization and death among patients with schistosomiasis due to S.mansoni [3,4,28,29]. It therefore stands to reason that preventing acute UGIB could probably decrease health loss in this population [8]. In the same way, addressing ascites in this population could also decrease health…”

“…Early diagnosis and appropriate preventive therapy are therefore recommended for those who experience variceal UGIB due to schistosomiasis. This has been shown to mitigate disease progression, prevent new acute episodes of UGIB, and decrease hospital admissions [7][8][9]. However, the impact of these interventions remains elusive due to the paucity of baseline or follow-up data on measures of health-related quality of life (HRQOL) from this patient population.…”

Diagnosis and clinical management of hepatosplenic schistosomiasis: A scoping review of the literature

“…With the repeated embolization of eggs over time, especially in case of high-burden infection, this process involves increasingly larger portal trunks, progressing to presinusoidal portal hypertension and formation of portosystemic collateral veins [ 6 , 7 ]. Hepatosplenic schistosomiasis (HSS) encompasses a characteristic type of portal fibrosis, also called Symmer’s clay pipe fibrosis or periportal fibrosis (PPF), and its resulting complications ( Fig 1 ), such as portal hypertension, splenomegaly, hypertensive gastropathy, portosystemic collaterals, esophageal varices, and upper gastrointestinal bleeding (UGB), which is the most dangerous complication of this condition [ 8 , 9 ]. It has been estimated that 0.2 million deaths occur every year in sub-Saharan Africa due to this complication [ 9 ].…”

Five-Year Follow-Up on the Prevalence and Intensity of Infections of Schistosoma mansoni in a Hard-to-Reach District of Madagascar

“…9 Studies have demonstrated that through treatment with praziquantel, some downstream conditions of intestinal schistosomiasis, including liver fibrosis, can be reversed, alongside decline in the fecal EPG. [10][11][12] In areas with high endemicity, characterized by a > 50% prevalence of schistosomiasis among school-aged children (SAC), the WHO advises preventive chemotherapy by annual mass drug administration (MDA) with praziquantel to the entire community. 13 The aim is for more than 75% of SAC at risk of schistosomiasis to receive regular MDA with PZQ.…”