Sexually Transmitted Diseases Problem Set

Problem 1: Symptoms of Sexually Transmitted Diseases

Help to answer the question

One can be infected with a sexually transmitted disease without experiencing any symptoms.

A. True
B. False


The control of sexually transmitted disease is complicated by the fact that people may be infected and contagious without experiencing any symptoms of the disease. A recent study on herpes conducted by the Centers for Disease Control and Prevention revealed that only 9% of the infected participants in the study knew they had the virus. For many STDs, the lack of symptoms is more frequent among women than among men. For example, gonorrhea is asymptomatic in 85% of the women, but only in 5% of the men. Likewise, chlamydia is asymptomatic in 65% of women as opposed to 25% in men.
STDs are also more readily transmitted from male to female than vice versa for two reasons:
  1. During sexual intercourse, females receive 3-4 ml of seminal fluid from the male ejaculate, whereas males get only a small amount of vaginal fluid from the females.
  2. Females receive the fluid internally in the vagina, which is an ideal environment for organisms to thrive. Males are exposed to female secretions primarily on the exterior surface of the penis, which is readily cleaned.

Thus, male to female transmission of STDs is much more frequent than female to male. Condoms, when properly used, prevent fluid transfer during intercourse, and significantly lower the risk of STD transmission.

The Biology Project
University of Arizona
Wednesday, September 30, 1998
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