Methods of microbial transmission
(how you can catch or spread these diseases)
Direct contact does not involve a carrier
- vertical transmission (mother to foetus)
e.g. HIV, passed from mother to child via the blood from the placenta
other examples: hepatitis B and hepatitis C
- horizontal transmission (from one person to another)
- droplet infection from coughs and sneezes e.g. flu, cold, TB
- direct contact, or via bodily fluids e.g. hepatitis (in blood), STIs (sexually transmitted infections: syphilis, gonorrhoea, HIV), SARS
Indirect contact involves a carrier mechanism
- vehicle-borne diseases are spread by means of inanimate (non living) objects
e.g.
food poisoning such as that caused by Salmonella - in food!,
typhoid spread by (flood?) water,
athlete’s foot and verrucas spread by wet conditions in shower rooms etc
- vector-borne diseases are spread by means of living organisms
e.g.
malaria is spread by the bite of a mosquito (specifically of the genus Anopheles)
sleeping sickness is spread by the bite of a tsetse fly
rabies, spread by dog
(or bat
) bites
This knowledge can be put to good use in preventing or controlling the spread of these diseases.