MP Board · Class 12 · Biology · Reproductive HealthWhat are Sexually Transmitted Infections (STIs)? Name any four major STIs and explain their causative agents and common symptoms.

Introduction to Sexually Transmitted Infections (STIs)\nInfections or diseases that are transmitted through sexual intercourse are collectively called Sexually Transmitted Infections (STIs) or Venereal Diseases (VD) or Reproductive Tract Infections (RTIs).

Characteristics and Transmission

• Transmission primarily occurs through sexual contact with an infected partner, sharing of infected needles, surgical instruments, transfusion of blood, or from infected mother to fetus.
• Early symptoms are minor, including itching, fluid discharge, slight pain, and swellings in the genital region. Infected females often remain asymptomatic in early stages and hence may go undetected.
• Untreated STIs can lead to complications like pelvic inflammatory disease (PID), abortions, stillbirths, ectopic pregnancies, infertility, and even cancer of the reproductive tract.

Major STIs, Causative Agents, and Symptoms

1. Gonorrhoea:

   • Causative Agent: Neisseria gonorrhoeae (Bacterium)
   • Symptoms: Inflammation of mucous membrane of urogenital tract, painful urination, and pus discharge from urethra in males.

2. Syphilis:

   • Causative Agent: Treponema pallidum (Bacterium)
   • Symptoms: Development of painless ulcers (chancres) on genitals, skin rashes, fever, and damage to internal organs in later stages.

3. Genital Herpes:

   • Causative Agent: Herpes simplex virus (Virus - HSV-2)
   • Symptoms: Painful fluid-filled blisters and sores on the external genitalia, buttocks, and thighs, accompanied by burning sensation.

4. Chlamydiasis:

   • Causative Agent: Chlamydia trachomatis (Bacterium)
   • Symptoms: Discharge from penis or vagina, burning sensation during urination, and lower abdominal pain in women.