An ultrasound-based referential of body height-adjusted normal liver organometry in school children from Bokito in rural Cameroon

Severin Donald Kamdem,René Ghislain Essomba,Alim Oumarou,Michel Kengne,Bienvenu Etogo Ondigui,Mamadou Hamza,Erve Martial Kuemkon,Francis Konhawa,Frank Brombacher,Leonel Meyo Kamguia,Marie Claire Okomo Assoumou,Justin Komguep Nono,Frungwa Nche,Gladys K Tchanana

doi:10.1038/s41598-020-59613-z

Abstract

The grading system for ultrasonographic assessment of Schistosoma mansoni morbidity is crucial for evaluation of control programs. This requires prior definition of normal liver organometric ranges in the population from the endemic area. A cross-sectional study was conducted in a S. mansoni endemic area in rural Cameroon. 1002 Participants were screened and 234 of them, free from all common liver-affecting diseases in the area (schistosomiasis, malaria, hepatitis B and C) and with no ultrasonographic signs of liver disease were selected and their liver parameters measured by ultrasonography. All statistics were considered significant for p-values < 0.05. Normal dimensions of livers lobe sizes, portal vein wall thickness and portal vein diameters are reported. The liver organometric data are presented for the entire study population as a whole and separately for males and females as prediction plots, with observed values and fitted regression line with 95% confidence. Reference ranges for liver parameters (size, portal vein thickness and diameter) adjusted for body height established in the current study are novel for Cameroon. The prediction plots generated should improve the accuracy of the assessment of liver morbidity by ultrasonography in the region.

Highlights

Hepatic schistosomiasis caused by the blood fluke Schistosoma mansoni remains one of the most widespread infections worldwide, and in Africa in particular[1]
This latter focused on the thickness and the location of periportal thickening based on the impression of an “experienced ultrasound observer”[14]. It appeared vital for the implementation of this unifying grading approach, a need of standardized organometry[2,11] which is widely recognized[8,15] and recommended by the World health Organisation to regional programs for their surveillance efforts. Such referentials are being defined by measurements of liver lobe size and portal vein wall thickness and diameter adjusted to body height in healthy members in some endemic regions from western Europe, Asia, South America, West African and South African regions[16,17,18,19,20], no referential is available until date for any country of the Central African Region where hepatic schistosomiasis-driven liver morbidity heavily distributes[4,5]
The Maquisard cohort is a cohort of 1002 school-age children in five schools within a radius of 5 kilometers of a schistosomiasis-infested river in the locality of Bokito in rural Cameroon established in 2018, with the aim of identifying host regulators of liver fibrosis in hepatic schistosomiasis-diseased children

Summary

Introduction

Hepatic schistosomiasis caused by the blood fluke Schistosoma mansoni remains one of the most widespread infections worldwide, and in Africa in particular[1]. The protocol was defined to ensure rapid generation of results comparable from one endemic site to another so as to enable an overall picture on a world-wide scale to help reliably assess the anti-morbidity success of national control programs and drive a better informed global schistosomiasis control program[3] For this purpose, an ultrasound-based grading approach for hepatic pathology was defined. It appeared vital for the implementation of this unifying grading approach, a need of standardized organometry[2,11] which is widely recognized[8,15] and recommended by the World health Organisation to regional programs for their surveillance efforts Such referentials are being defined by measurements of liver lobe size and portal vein wall thickness and diameter adjusted to body height in healthy members in some endemic regions from western Europe, Asia, South America, West African and South African regions[16,17,18,19,20], no referential is available until date for any country of the Central African Region where hepatic schistosomiasis-driven liver morbidity heavily distributes[4,5]. The aim of this study was to apply ultrasound liver organometry to healthy schoolchildren from five different villages of a S. mansoni endemic area in rural Cameroon, and to establish a referential for the area for liver parameters

Objectives

Results

Conclusion