I: | Salmonella typhi is a pathogenic bacterium which causes typhoid fever in human beings. |
II: | These pathogens generally enter the small intestine through food and water contaminated with them |
III: | The pathogen remains confined to the small intestine. |
IV: | Intestinal perforation and death may occur in severe cases. |
V: | Typhoid fever could be confirmed by Widal test. |
1. | Streptococcus pneumoniae and Staphylococcus aureus |
2. | Haemophilus influenzae and Streptococcus pneumoniae |
3. | Pneumocystis carinii and Mycoplasma hominis |
4. | Streptococcus pyogenes and Bacillus anthracis |
1. | Rhino viruses cause the common cold. |
2. | Rhino viruses infect the nose and respiratory passage and frequently involve the lungs. |
3. | The common cold is characterised by nasal congestion and discharge, sore throat, hoarseness, cough, headache and tiredness. |
4. | It spreads though droplets and through contaminated objects. |
I: | Sporozoites are the infectious form for humans. |
II: | The parasites initially multiply within the red blood cells and then attack the liver cells. |
III: | The rupture of RBCs is associated with release of a toxic substance, haemozoin, which is responsible for the chill and high fever recurring every three to four days. |
IV: | Fertilization occurs in human RBCs |
1. | Droplet |
2. | Direct contact |
3. | Contaminated water, vegetables, fruits, etc. |
4. | Mosquito Vector |