Aquaculture and human health Flashcards
What are the consequences of increased organic load/eutrophication due to feeding/fertilisation in water?
- Multiplication of vectors
- Survival of pathogens
Water acts as the breeding site for which terrestrial vectors?
- Mosquitoes: Malaria and others
- Tetse flies: Trypanosomiasis or “Sleeping sickness.”
- Rats: Leptospira spp.
Name some diseases in people caused by terrestrial vectors
- Filariasis or “Elephantiasis”
- Onchocerciasis or “River blindness”
- Malaria
Name 2 diseases in people caused by aquatic vectors
- Cercarial dermatitis or “Swimmers itch” (water snails are the intermediate hosts)
- Schistosomiasis or “Belharzia”
Describe Schistosomiasis or “Belharzia”
- Chronic debilitating disease
- Migration of pathogen to the liver
- Fever, diarrhoea, cough, hepatomegaly
- Decreasing snail populations for control
Describe cholera
Vibrio cholerae
- Faecal contamination of food and water in areas of poor sanitation
- Diarrhoea, dehydration, death
Where do most hazards from eating aquatic products come from?
Most result from contamination of food with toxin producing or food poisoning organisms:
usually associated with poor handling or storage
Name some infectious contaminants of aquatic products
- Hepatitis A – shellfish: Poor sanitary conditions where sewage has polluted waters where shellfish grow
- Cholera: shellfish
- Vibrio parahaemolyticus: undercooked shellfish
Name some biological contaminants of aquatic products
- Clostridium botulinum: botulism
- Shellfish poisoning Amnesic, diarrhoeic, paralytic
- Scromboid toxin
- Puffer fish – fugu - tetrodontotoxin
Name some non-infectious contaminants of aquatic products
Pollutants: - Heavy metals - Herbicides - Pesticides Chemotherapeutants
Name the parasite of fish and humans
Diphylobothrium latum - broad tapeworm of man
Describe the features and life cycle of Diphylobothrium latum
- Adult lives in the gut of a mammal e.g. man
- Adult can be over 3m
- Can live for years
- Can cause chronic debilitation and pernicious anaemia in man
How is Diphylobothrium latum controlled?
- Don’t eat Raw, pickled, poorly cooked fish
* Frozen/hot smoked/cooked/brined - OK
Describe mycobacteriosis in fish
- Chronic condition, fresh water and marine species
- Multiple internal granulomas and low persistent mortalities
- Difficult to culture
How does mycobacteriosis from fish affect humans?
o People working with infected fish or water
- Entry through open wounds
- Treatment in humans can be problematic and require protracted chemotherapy
- Surgery may result in the spread of the infection down lymphatics
- Known as “aquarist nodule” or “swimming pool granuloma”
- Non-healing wounds
