Epidemiology of Schistosoma Hematobium Flashcards
What is epidemiology?
the study of the distribution and determinants of health-related states or events (including disease), and the application of this study to the control of diseases and other health problems
What is schistosomiasis?
An acute and chronic, parasitic disease caused by blood flukes/trematode worms of the genus Schistosoma.
Infections causing illness in humans are with?
- Schistosoma mansoni,
- S. haematobium,
- S. japonicum,
- S. guineensis
- S. mekongi and S. intercalatum
- less commonly can cause disease.
Which species causes intestinal schistosomiasis?
S. mansoni
Which species causes urogenital schistosomiasis?
S. haematobium
Describe the signs and symptoms in the early phase of infection of schistosomiasis?
- Rash or itchy skin within days after infection
- Fever, chills, cough, and muscle aches can begin within 1-2 months of infection.
- Most people have no symptoms at this stage
Describe the signs and symptoms in the late phase of infection of schistosomiasis?
Symptoms are caused by body’s reaction to the eggs produced by worms
- Eggs from adult worms travel to the intestine, liver or bladder, causing inflammation or scarring
- Damage to the liver, intestine, lungs, and bladder.
- Rarely, eggs are found in the brain or spinal cord and can cause seizures, paralysis, or spinal cord inflammation.
- Female genital schistosomiasis
Children who are repeatedly infected by schistosomiasis can develop?
- anemia
- malnutrition
- learning difficulties
Describe the signs and symptoms of S. haemotobium?
include urogenital symptoms & signs:
- Cystitis
- Ureteritis with hematuria,
- Bladder cancer
- Glomerulonephritis and
- Central nervous system lesions e.g. transverse myelitis with flaccid paraplegia
How do you diagnose SH?
Use samples of urine
1. Color – blood urine
2. Examined for the presence of eggs
– using the filtration technique for SH
Describe the global burden and distribution of SH?
- Schistosomiasis transmission reported in 78 countries
- Only 51 countries with moderate-to-high transmission require large scale treatment in communities
- Affects 240 million people worldwide
- At least 206 million people were infected or required treatment in 2018
- At least 91.4% of those requiring treatment for schistosomiasis live in Africa
- WHO estimates the annual death rate at 200 000 globally
Describe the geographical distribution of S. mansoni?
parts of South America (Brazil and Venezuela) and the Caribbean, Africa, and the Middle East
Describe the global geographical distribution of S. haemotobium?
Africa and the Middle East and Corsica (France)
Describe the global geographical distribution of S. japonicum?
Far East
China, Indonesia, the Philippines
Describe the global geographical distribution of S. mekongi?
Southeast Asia and Several districts of Cambodia and the Lao People’s Democratic Republic