Unit 11
Communicable Diseases and
Sexually Transmitted Infections

Despite the great success of antibiotic treatments and immunizations, infectious disease remains a serious health problem. This unit examines various communicable diseases, the different biological agents that cause them, their modes of transmission, the body’s defence mechanisms against them, their treatment, and their prevention. This unit also looks at several of the most common sexually transmitted infections (STIs). STIs constitute an entire family of infectious diseases that continue to pose major medical challenges.

Objectives

After completing this unit, you should be able to

1. discuss the controllable and non-controllable risk factors for communicable diseases.
2. describe viruses, bacteria, fungi, protozoa, and parasitic worms, and discuss the infectious diseases that they cause.
3. explain how infectious diseases are transmitted.
4. describe how the body protects itself from infection, and discuss the purpose of immunization.
5. describe the key features of major infectious diseases such as colds, influenza, severe acute respiratory syndrome, meningitis, hepatitis, mononucleosis, tuberculosis, and West Nile virus.
6. describe the modes of transmission, symptoms, and treatments for the most common types of sexually transmitted infections, particularly chlamydia, HIV/AIDS, genital herpes, gonorrhea, and syphilis.
7. describe vaginal and urinary tract infections.