Modes of transmission of diarrhoeal diseases
All three types of diarrhoeal diseases discussed so far are transmitted directly or indirectly by faeco-oral routes.
Briefly distinguish between direct and indirect modes of faeco-oral transmission of infectious agents.
Direct transmission occurs through contact between hands contaminated with faeces and the person's mouth; indirect modes of transmission are through ingestion of contaminated food or water, contact with infected soil, utensils, etc., and transmission by flies that have crawled on faeces (figure below).
The main modes of transmission for cholera, shigellosis and viral diarrhoeal diseases are summarised in the table and figure below.
Main modes of transmission for bacterial and viral diarrhoeal diseases.
|Diarrhoeal disease||Main modes of transmission|
|Cholera||Contaminated water or food (summarised in the figure below)|
|Shigellosis (bacillary dysentery)||Person-to-person contact, e.g. while caring for a sick person, or via contaminated water or food|
|Viral diarrhoeal diseases||Contaminated water or food, particularly when feeding infants with milk or other nutritious fluids in a contaminated bottle|