Certain bacterial diseases of human beings are as follows:

1. Tuberculosis: It is caused by the bacterium Mycobacterium tuberculosis, which infects all parts of the body by secreting a toxin called tuberculin. Symptoms of this disease include sickness, loss of appetite and weight, fever and night sweats. It can be prevented by immunisation with BCG (Bacillus Calmette-Guerin), which gives immunity for 3‒5 years.

2. Cholera: It is caused by the bacterium Vibrio cholerae, which is transmitted by flies, contaminated food and water when there is poor sanitation. Symptoms of cholera include watery diarrhoea, vomiting, loss of weight and muscular cramps.

It can be prevented by improving personal hygiene and sanitation conditions in the community. Tetracycline is an antibiotic that kills the bacteria.

3. Typhoid: It is caused by Salmonella typhi, which affects the human intestine. It spreads via contaminated food and water through houseflies. Symptoms of typhoid are headache and high fever that maximise during afternoons in the first and second weeks. It can be prevented by TAB vaccination, which provides immunity for three years.

4. Diarrhoea: It is caused by various bacteria that spread via contaminated food, water, hands, clothes, utensils, etc. It is marked by frequent discharge of fluid faeces, vomiting and loss of appetite. In some cases, dehydration occurs due to rapid loss of water from the body.

It can be prevented by increasing personal and community hygiene.

Certain antibiotics are given for curing diarrhoea.

5. Peptic ulcers: It is caused by the bacterium Helicobacter pylori, which causes painful bleeding within the stomach and the duodenum. It can be cured by the antibiotic amoxicillin.