Harmful microbes and healthy habits
Harmful microbes can enter the body when we breathe, when we eat contaminated food or drink contaminated water, or through the skin. Dysentery is caused by a protozoan, Entamoeba histolytica, which lives in the large intestine. It spreads through contaminated food. Signs include repeated diarrhoea with blood, stomach pain and weight loss. It is treated with medicines against protozoa. Typhoid fever is caused by the bacterium Salmonella Typhi and spreads through contaminated food and water. Signs include high fever, headache, tiredness and stomach and muscle pain, and it is treated with antibiotics. A doctor decides about any treatment: we never treat ourselves. Healthy habits protect us: wash fruit and vegetables, cover food, wash hands before eating and after using the toilet, and brush teeth after meals. Drink water regularly, and ask a doctor how much is right for you. If you feel ill, tell an adult.
| Dysentery | Typhoid fever | |
|---|---|---|
| caused by | a protozoan | a bacterium |
| spread by | contaminated food | contaminated food and water |
| treated by | medicines against protozoa | antibiotics |
Food-safety poster. Make a poster for your class with four habits that keep food and hands clean: washing fruit and vegetables, covering food, washing hands before eating and after the toilet, and brushing teeth after meals. Add the handwashing steps in order. Remember: if you feel ill, tell an adult. Only a doctor gives treatment.