Genetic Variations In Schistosoma Haematobium And Disease Severity In The Greater Accra Region

ABSTRACT

Background: Schistosomes are parasitic worms that dwell in the blood vessels and belong to the genus Schistosoma. Schistosoma haematobium, one of the species of Schistosoma cause urogenital schistosomiasis (urinary schistosomiasis). The knowledge of urogenital schistosomiasis has improved over the years; however, there are still endemic areas with reported cases in Africa including Ghana. The disease may present as mild or severe with accompanying morbidity and mortality. Genetic variation in S. haematobium may play an important role in developing pathology which may lead to difference in severity in clinical symptoms.

Aim: The aim of this study was to determine a possible link between genetic variations in S. haematobium, and disease severity in the Greater Accra Region.

Methodology: Three hundred and sixty-seven (367) urine samples were collected from school children in Zenu and Weija communities. Presence of S. haematobium eggs was determined microscopically from the urine deposit after centrifugation. Disease severity was determined using urine cytology method, while genetic variation was determined by amplifying a part of the Second Internal Transcribed Spacer (ITS 2) gene and Nicotinamide Adenine Dinucleotide Dehydrogenase Subunit 1 (NAD 1) gene.

Results: Sixty-six (66) of the urine samples were positive with S. haematobium ova, out of which 16 were graded as severe by cytology. All 33 samples selected for genetic variation determination amplified for the ITS 2, however, 8 amplified for the NAD 1 gene while 25 did not amplify. There was no association between genetic variation in the NAD 1 gene and disease severity of S. haematobium.