Transmission of diseases

• Many of these are respiratory diseases (diseases that affect the airways of the lungs).
• The organsisms are carried in tiny droplets through the air when an infected person coughs or sneezes. 
• They are inhaled by other people.

Examples of diseases

Common cold, influenze, tuberculosis, pneumonia

• The microorganism transmitted in this way often infect regions of the gut.
• When a person drinks unclean water containing organisms.
• They colonise a sutiable area of the gut and reproduce.
• They are passed out with faeces and find their way back into the water

Examples of disease

Chlorea, typhoid fever, polio

• Most food poisoning is bacterial
• Though some viruses are transmitted in this way
• The organisms initially infect a region of the gut

Examples of disease

typoid fever, polio, salmoneliosis, listeriosis, botulism

• Many skin infections are contracted this way
• Spread by direct contact with an infected person 
• Or contact with a surface carrying the organism

Examples of diseases

athlete's foot, ringworm

• Organsims infecting the sex organs can be passed from one sexual partner to another during intercourse.
• Some (such as fungus thrush, which causes candidiasis) are transimitted by direct contact.
• Others (such as AIDS virus) are trasmitted in semen or vaginal secretions.
• Some (such as syphilis) can be transmitted in saliva.

Examples of diseases

Chlamydia, syphilis, AIDS, gonorrhoea

• Many sexually tramsmitted disease can also be transmitted in this way.
• Drug users sharing an infected needle can transmit AIDS.

Examples of dieseases

AIDS, hepatitus B

• Many diseases are tramitted by insect bites. 
• Mosquitoes spread malaria and tsets flies spread sleeping sickness. 
• In both cases, the disease-causing organism is transmitted when the insect bites humans in order to **** blood.
• Also, flies can carry microorganism from faeces onto food.

Examples of disease 

Malaria, sleeping sickness, typoid fever, salmonellosis