Comprehensive Classification of Sexually Transmitted Diseases (STDs)

Last Updated on 02/13/2026 by Helal Medical

Classification of Sexually Transmitted Diseases (STDs) can be based on causative agents including bacterial, viral, parasitic infections, and others. STDs are infections, primarily transmitted through sexual contact, and can cause a wide range of symptoms and health complications. Here is a comprehensive classification of STDs based on their causative agents:

1- Bacterial Infections:

Among others in the long list of STDs, bacterial STDs are often the most common. Bacteria cause several sexually transmitted diseases. They are usually easy to diagnose. Treatment and prevention are straightforward if diagnosed early. So, they belong to the curable infections.

Sexually Transmitted Diseases caused by bacteria are cured by antibiotics. However, if not treated, they can cause serious implications, such as urethritis, ectopic pregnancy, and infertility. Most common bacterial STDs includes:

• Chlamydia:
  Caused by the bacterium Chlamydia trachomatis. It is one of the most common STDs. It can affect the reproductive organs. In women, it can lead to pelvic inflammatory disease (PID). In both men and women, it can cause urethritis.
• Gonorrhea:
  Caused by the bacterium Neisseria gonorrhoeae. It can affect the genitals, rectum, and throat. If left untreated, it can cause serious complications such as infertility and pelvic inflammatory disease.
• Syphilis:
  Caused by the bacterium Treponema pallidum. It progresses through different stages and can affect various organs. Syphilis can cause ulcers, rash, neurological complications, and other systemic manifestations if not treated.

2- Viral Infections:

These infections are caused by viruses. They are incurable but can be managed and controlled by medications. Transmission can occur through sexual contact. It can also occur through non-sexual contact. Additionally, they can be passed from mother to baby during pregnancy. They may also be transmitted during breast feeding, blood transfusion, and sharing needles with an infected person.

They usually persist life long and cannot be cured. Examples include Herpes, HIV infections, Hepatitis B, and HPV. Medications can only help in alleviating the symptoms and keeping the virus inactive. The exceptions to this are some cases of HPV, and hepatitis that respond well to treatment or cure naturally for unknown reasons The following are common example of viral STDs:

• Human Papillomavirus (HPV) Infection:
  Caused by the human papillomavirus. Certain types of HPV can cause genital warts, while high-risk types can lead to cervical, anal, and other cancers.
• Herpes:
  Caused by the herpes simplex virus (HSV). It can cause painful sores or blisters on the genitals, mouth, or rectum. Herpes is a chronic infection that can recur periodically.
• Human Immunodeficiency Virus (HIV):
  HIV attacks the immune system, making individuals more susceptible to other infections and diseases. It is transmitted through sexual contact, blood, or from mother to child during childbirth or breastfeeding. If left untreated, HIV can progress to AIDS (Acquired Immunodeficiency Syndrome).
• Viral Hepatitis:
  Caused by Hepatitis B virus and Hepatitis C virus.
  

3- Parasitic Infections:

These are caused by parasites. They can be transmitted during sexual activity. Contact with an infected person is another way of transmission. The infection can also pass from an infected mother to an infant during childbirth. Additionally, sharing personal objects can transmit them. Common examples includes:

• Trichomoniasis: Caused by the parasite Trichomonas vaginalis. It primarily affects the urogenital tract, causing symptoms like itching, discharge, and discomfort during urination.
• Pubic Lice (Crabs): Caused by tiny insects called Phthirus pubis. They infest the pubic area and can cause itching and irritation.
• Intestinal parasitic infections
• Scabies
• Vaginitis

4- Fungal Infections:

• Candidiasis by the yeast Candida. It can affect the genital area, leading to symptoms such as itching, burning, and abnormal discharge.

5- Protozoan STDs:

• Protozoan STDs are infections caused by protozoan parasites. They include Trichomoniasis which is caused by Trichomonas vaginalis.

Curable and Incurable STDs

1. Curable

• Curable diseases:
  These infections can be cured when the patient receives the proper medications. Some can be cured naturally without any medications. But, if you have been infected, you don’t need to take the risk. You have to opt for testing and medications.
• Example of curable ones:
  Syphilis, chancroid, gonorrhea, chlamydia, and trichomoniasis infections are the most common in the curable group. All are bacterial, except for trichomoniasis, which is a protozoan infection.

2. Incurable

• Incurable:
  These infections, till currently, cannot be cured. These diseases can be controlled and managed. They can achieve a latent (non-active) status when the patient receives the proper medications. They can be managed but virus remains in the body. Research and studies are carried intensively to find a cure.
• Example of incurable diseases:
  They are mostly viral. The most dangerous is human immunodeficiency virus (HIV). It can cause AIDS. Other incurables include human papilloma virus (HPV), hepatitis B and genital herpes. In this presentation, genital herpes will be referred to as herpes only.

SUMMARY:

Classification of Sexually Transmitted Diseases can be based on the causative agents. They may have overlapping symptoms. Some STDs can be asymptomatic. This makes regular testing important, especially for individuals who are sexually active. Early diagnosis is crucial. Proper treatment plays a significant role. Adopting preventive measures, such as consistent condom use and safe sexual practices, effectively prevents the spread of STDs.

If you suspect you have an STD or have engaged in high-risk sexual behavior, it is advisable to seek medical attention. Get tested and receive a diagnosis. Then follow up with appropriate treatment. You can contact us here: Google page – Helalmedical, or Facebook page. We offer quick and convenient testing options.

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