Diseases that are transmitted through sexual contact are referred to as sexually transmitted diseases. For example, AIDS, gonorrhoea, syphilis, genital herpes and warts, chlamydiasis and hepatitis-B are commonly known STDs. Typhoid, tuberculosis and plague are not considered as STDs.
These are bacterial diseases that have different modes of transmission:
1. Typhoid - spreads through contaminated water and food
2. Tuberculosis - spreads through droplets released while coughing or sneezing
3. Plague - spreads through vectors like rats.