Additional morbidity associated with schistosomiasis
Ectopic deposition of schistosoma eggs results in unexpected morbidities in other organs e.g. - central nervous system, genital organs, skin and eyes.
Central nervous system
Central nervous system involvement causes neuroschistomiasis, which is arguably the most severe clinical outcome associate with the infection.
- migration of adult worms to the brain or spinal cord and deposition of eggs leads to granuloma formation in these structures which in turn lead to neurological complications early in the course of infection
- S. japonicum - causes acute encephalitis of the cortex, subcortical white matter, basal ganglia, and internal capsule
- S. mansoni and S. haematobium - causes more commonly myelopathy of the lumbosacral region
Signs and symptoms of the disease are:
- encephalopathy with headache
- visual impairment
- delirium
- focal or generalised epilepsy (S. japonicum)
- motor deficit
- ataxia
- spinal symptoms - lumbar pain, lower limb radicular pain, muscle weakness, sensory loss, and bladder dysfunction
Diagnosis of neuroschistomiasis:
- although eggs in stool or positive serology does not provide direct evidence of schistosomal involvement of the CNS, together with neuroimaging (CT, MRI, myelography) and neurological symptoms should point towards a diagnosis of the condition
- definitive diagnosis can be achieved through biopsy or at necropsy (presence of schistosomal eggs and granulomas)
Management
- seek expert advice
- corticosteroid and anticonvulsant therapy within two months of infection
- praziquantel chemotherapy two months after known water contact
Reference:
- Gray DJ et al. Diagnosis and management of schistosomiasis. BMJ. 2011;342:d2651.