Health, hygiene, sanitation and communicable diseases
Definitions and transmission
Health is physical, mental and social well-being. Communicable diseases spread by direct contact, droplets or airborne particles, water and food (faecal-oral route), vectors, and blood. Non-communicable diseases such as diabetes and hypertension do not spread.
Diseases with cause and route
- Tuberculosis: Mycobacterium tuberculosis, droplet route; BCG vaccine and DOTS treatment.
- Malaria: Plasmodium, bite of the female Anopheles mosquito, which bites at night.
- Dengue: virus, spread by Aedes aegypti, a day-biting mosquito breeding in standing water.
- Cholera and typhoid: contaminated water and food.
- Hepatitis A: faecal-oral; hepatitis B: blood and sexual contact.
- Rabies: dog bite, virus in saliva; wash the wound and get vaccination.
- Polio: virus, faecal-oral; prevented by oral and injectable polio vaccine.
Sanitation and hygiene
Safe drinking water by boiling or chlorination, soap handwashing before food and after using the toilet, covered food, safe disposal of faeces, mosquito nets, removal of stagnant water, no public spitting, and immunisation on schedule.
Worked example
After monsoon flooding, many villagers develop sudden watery rice-water stools and rapid dehydration. Sudden watery diarrhoea in many people after flooding is cholera, a water-borne disease; give ORS immediately, chlorinate or boil water and treat at a health centre.
Marks-losing traps
Malaria is spread by a mosquito bite, not by dirty water; Aedes bites in daytime; a person can carry TB without symptoms; ORS corrects dehydration but does not kill the organism.