Genetic diversity of Schistosoma haematobium parasite IS NOT associated with severity of disease in an endemic area in Sudan

Abstract

BackgroundOver 650 million people globally are at risk of schistosomiasis infection, while more than 200 million people are infected of which the higher disease rates occur in children. Eighty three students between 6-20 years (mean 12.45 ± 3.2) from Quran School for boys in Radwan village, Gezira state were recruited to investigate for the relationship between the genetic diversity of Schistosoma haematobium strains and the severity of the disease.MethodSchistosoma haematobium infection was detected by filtration of urine. Ultrasonography was done on each study subject, while PCR technique was used for genotyping via random amplified polymorphic DNA (RAPD) with A01, A02, A12, Y20 and A13 primers. A01 primer gave three different genotypes (A01-1, A01-2 and A01-3).ResultsAbout 54.2% (45/83) were S. haematobium egg positive by urine filtration. On assessment of the upper and lower urinary tract by ultrasound technique, 61.4% (51/83) were positiveand73.3% (60/83) samples were PCR positive. No significant difference was found when comparing the three different genotypes with severity of the disease.ConclusionThis study concludes that no association was found between the different genotypes of S.haemtobium and the severity of the disease. Examination of more samples from different areas to identify any possible differences between the parasites genes and disease severity was recommended.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2334-14-469) contains supplementary material, which is available to authorized users.

Significance of Echogenic Snow Sign as an Ultrasonography Finding for Diagnosis of Urogenital Schistosomiasis

“…Another study performed in Gezira State in Sudan also detected more schistosomiasis-related morbidity by US than UM after filtration. 9 The prevalence of S. haematobium in the White Nile State was reported to be 21.4% by UM in 1996, 12 28.5% in 2009, and 13.5% in 2011, 13 but it was 14.0% in our study. The subjects were screened and medicated with praziquantel by a control program supported by the KOICA.…”

“…A recent study also mentioned the sign as an abnormality related to UGS. 9 Usually, the urinary bladder is examined by US under full state and congestive change of the ureter and the kidney is evaluated after voiding. We confined the US examination only to the bladder and distal ureter under the full bladder state.…”

“…8 Other studies performed in other states of Sudan reported the prevalence as 1.7% in River Nile, 23.7% in southern Kordofan, 73% in Upper Nile, and 54.2% and 71% in Gezira among the schoolchildren. 9,[13][14][15][16] The studies performed surveys on the UGS prevalence by investigating schoolchildren in the age group of 10-19 years. Our study confirmed that the prevalence and the age group with the highest disease burden were 20.8% in 0-9 years, 16.3% in 10-14 years, and 14.1% in 15-19 years.…”

Genetic diversity among natural populations of Schistosoma haematobium might contribute to inconsistent virulence and diverse clinical outcomes

“…Genetic variability may alter some of the virulence-related parasitic features like fecundity and immunogenicity. Emergence of parasitic strains that are more immunogenic or fecund than others might shape the clinical outcome of such infection [ 25 26 ].…”

“…A few studies have investigated the relation between morbidity caused by S. haematobium infection and genetic diversity of the parasite, with conflicting results [ 25 26 ]. The aim of the current study was to explore genetic diversity within natural populations of S. haematobium selected from different geographic areas across Africa, using parasite isolates of Schistosoma eggs sampled directly from their natural human hosts, thereby avoiding the biological biases encountered on using laboratory-passed adult worms.…”