Morbidity Assessment and Diagnosis of Schistosomiasis Haematobium in Female Reproductive Organs by the Detection of Schistosome Circulating Antigens

Abstract

Schistosomiasis haematobium is an important public health problem in Africa and the Middle East and the infection causes considerable morbidity in a high proportion of cases (Warren et al., 1979). The frequency of genital schistosomiasis was encountered in areas where infection with Schistosoma haematobium prevails. It also occurs with S. mansoni, S. mattheei and more rarely S. intercalatum (Smith and Christie, 1986). Schistosomiasis haematobium related morbidity in females’ reproductive organs in the Midwestern Sudan was investigated. In total, 118 females at the childbearing age (15-50 years old) were enrolled in the study after being informed consent. The application of immunoassay techniques to detect schistosome antigens in genital secretions was evaluated. Females at the childbearing age having gynecological complaints were submitted to selection criteria for a case control study. The study investigated cases infected with S. haematobium and negative controls from Rahad area-Midwestern Sudan that is endemic for schistosomiasis haematobium. A group of negative controls from a non-endemic area (Khartoum area-central Sudan) were also included. Sample collection as well as parasitological, clinical, ultrasonography and gynecological examination were conducted in the hospital following the selection of cases and controls. Treatment was given to patients as directed by the physician. Monoclonal antibody based enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of schistosome circulating cathodic antigen (CCA), circulating anodic antigen (CAA) as well as soluble egg antigen (SEA) in urine, serum and vaginal wash samples. Thirty-four (28.8%) were cases from Rahad area and 84 (71.2%) were controls, of whom 45 (38.1%) were from Rahad area and 39 (33.1%) were from Khartoum area, representing an approximate 1:2 cases to controls ratio. Significant differences in morbidity patterns were found between cases and controls. Antigen levels varied between study groups and significant differences in vaginal wash CCA, serum CAA as well as urine SEA levels were found between cases and controls; and coincided with pathological findings reported by ultrasonography and gynecological investigations. Significant correlations of morbidity with antigen levels were also found. The use of circulating antigens determination in cervico-vaginal secretions, especially CCA, has the potential to be used as a diagnostic method for FGS. The measurement of SEA in vaginal wash sample can also be used as a confirmatory test