Which of the following statements about sexually transmitted infections (STIs) is true?

• A. All STIs are curable with antibiotics.
• B. Vaccines are available for all types of STIs.
• C. STIs can be caused by bacteria, viruses, or parasites.
• D. STIs only affect the reproductive system.

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the nature of sexually transmitted infections (STIs). STIs are infections that are primarily spread through sexual contact and can be caused by different types of pathogens including bacteria, viruses, and parasites.
2. Step 2: Evaluate the statement 'All STIs are curable with antibiotics.' Recall that antibiotics are effective against bacterial infections but not viral infections, so this statement is false because some STIs are viral and cannot be cured with antibiotics.
3. Step 3: Consider the statement 'Vaccines are available for all types of STIs.' Recognize that vaccines exist for some STIs, such as HPV and Hepatitis B, but not for all STIs, so this statement is false.
4. Step 4: Analyze the statement 'STIs only affect the reproductive system.' Understand that while STIs primarily affect the reproductive organs, they can also impact other parts of the body, such as causing systemic symptoms or affecting the newborn during childbirth, so this statement is false.
5. Step 5: Conclude that the true statement is 'STIs can be caused by bacteria, viruses, or parasites,' as this accurately reflects the diverse types of pathogens responsible for STIs.