Morphometric analysis of schistosome eggs recovered from human urines in communities along the shoreline of Oyan River Dam in Ogun State, Nigeria

Abstract

There are growing concerns that communities characterized with surface water, where both humans and livestock interact for agricultural, domestic, cultural and recreational purposes, are likely to support hybridization between schistosome species infecting humans and livestock. This study therefore investigated the morphometrics of schistosome eggs recovered from human urine samples in four schistosomiasis endemic communities (Imala-Odo, Abule-Titun, Apojula and Ibaro-Oyan) along the banks of Oyan River Dam in Ogun State, Nigeria. Recovered eggs were counted, photographed, and measured with IC Measure™ for total length, maximum width and a ratio of egg shape. A total of 1984 Schistosoma eggs were analysed. Two major egg morphotypes were identified: the first represented 67.8% of the eggs, with the typical round to oval shape and mean length and width of 166 μm, 66.8 μm, respectively; the second represented 32.2% of the eggs and are more elongated, with a mean length of 198 μm, and width of 71.3 μm. Our results revealed significant variations in sizes of the schistosome eggs recovered (length: t = −35.374, degrees of freedom (df) = 1982, P = 0.000; weight: t = −10.431, df = 1982, P = 0.000), with the atypical shaped eggs appearing more elongated than expected. These eggs might represent individuals with some degree of contribution from Schistosoma bovis or possibly other Schistosoma species known to be present in Nigeria. Hence, this observation calls for further molecular studies to establish the genetic information about the miracidia from both atypical and typical eggs. It is also important to establish the presence of bona fide S. bovis infection in cattle and vector snails in the presumptive areas of hybridization.

Livestock Reservoir Hosts: An Obscured Threat to Control of Human Schistosomiasis in Nigeria

“…Information on the epidemiology of hybrid schistosomes in humans in Nigeria is sparse. However, there are emerging reports on morphological [104] and genetic [105] characterization of hybrid Schistosoma eggs obtained from human urine. Little is known about the spatial extent and overlapping distribution of livestock schistosomes, S. bovis and S. currasoni, in Nigeria [106].…”