Not all microorganisms are harmful to humans. Some microorganisms, like plankton and intestinal flora, are beneficial and important for things like decomposition and food production. However, some pathogenic microorganisms can cause illnesses when transmitted from person to person through various means like air, food/water, skin contact, or sexual contact, with examples being malaria, pneumonia, and tuberculosis.

1. Are all microorganisms harmful?
Beneficial microorganisms Harmful microorganisms
pathogenic
microorganisms
plankton
illnesses
food
intestinal flora
decomposer
microorganisms
antibiotics spoilage

2. Illnesses caused by microorganisms
Transmission Female Anopheles mosquito
in air
in food or
water
Infection
skin
sexual Malaria
transmission
headache
vomiting
Plasmodium Mortality of some
fever infectious diseases
BACK CLOSE

3. Illnesses caused by microorganisms
Transmission Number of deaths per
100,000 inhabitants
in air 250
Pneumonia
in food or
Tuberculosis
water 200
Diarrhea
150
skin
100
sexual
transmission
50
1900 1910 1920 1930 1940 1950 1960 1970 1980

4. Protection against infectious disease
Prevention Wash your hands
before eating.
Eat fresh food.
Resources
Antibiotics Vaccines
vaccination
penicillin
Edward Jenner
Alexander Fleming discovered vaccination.
discovered penicillin.