Our parents and elders always talk to us regarding hygiene. They always insist that we wash our hands, legs and face once we reach home. We have often heard of a lot of infections transmitted by contact, food, water and air. 

You must have heard of a disease called AIDS! 

What is the mode of transmission of AIDS? 

Food? Water? Air? Soil?

No!

Besides these mode of transmission, there are certain infections which are transmitted by sexual intercourse. These infections are referred to as sexually transmitted diseases.

AIDS is a sexually transmitted disease i.e. a disease which is transmitted by unprotected sex. It is one of the deadliest and incurable diseases. The intention is not to scare you but to make you understand what are sexually transmitted diseases? How are they transmitted, cured and prevented?

Let’s understand more about STDs. 

Table of Contents

• What are Sexually Transmitted Diseases?
• Gonorrhoea
• Syphilis
• Genital Herpes
• Genital Warts
• Hepatitis B
• AIDS
• Chlamydiasis
• Trichomoniasis
• Complications of Sexually Transmitted Diseases
• General Precautions to Avoid Sexually Transmitted Diseases
• Practice Problems of Sexually Transmitted Diseases
• FAQs Sexually Transmitted Diseases

What are Sexually Transmitted Diseases?

Diseases which are transmitted through sexual intercourse or body fluid interaction are called sexually transmitted diseases. Examples include gonorrhoea, syphilis, genital herpes, genital warts, hepatitis B, AIDS, chlamydiasis, trichomoniasis etc.

Gonorrhoea

Causative Organism

Gonorrhoea is caused by a bacteria named Neisseria gonorrhoeae.

Symptoms

Humans infected with gonorrhoea experience burning sensation during urination, penile or vaginal discharge, swelling in testicles in males and bleeding between periods in females. Kids born to gonorrhoea infected mothers may develop arthritis and eye infections. 

Transmission

Transmission can occur generally through vaginal, anal or oral sex. An infected mother can transmit it to the newborn. 

Detection 

Diagnosis is possible with clinical symptoms. Gram staining of discharge and culture can be done for identification of the disease.

Treatment

Gonorrhoea can be treated by antibiotics which are medicines with the ability to kill bacteria and prevent them from growing, multiplying or causing disease.

Syphilis

Causative Organism

Syphilis is caused by Treponema pallidum. It is a spirochaete, a type of bacteria. 

Symptoms

Syphilis causes infectious painless genital sores in the initial stages. It causes swelling in the lymph nodes, sore throat, hair loss, swollen joints, body rashes and flu-like symptoms in the second stage of infection. In the third stage it causes brain damage, paralysis, blindness etc. 

Detection

It can be diagnosed by clinical symptoms. Identification of the disease is possible with microscopic examination of the discharges and antibody detection. 

Transmission

Syphilis is transmitted by vaginal, oral or anal sex. It can also be transmitted by direct contact with sores.

Treatment

Syphilis is caused by a bacteria and hence, can be treated by antibiotics which are medicines with the ability to kill bacteria and prevent them from growing, multiplying or causing disease.

Genital Herpes

Causative Organism

Genital herpes is caused by a virus named Herpes simplex virus type 2 (HSV-2).

Symptoms

Genital herpes causes infectious sores in the mouth, penis, anus and vagina. It may also cause high fever, itchiness, swelling of lymph nodes and body pain. Symptoms are severe in females. Newborns may get infected from infected mothers. Urethra and cervix also get affected. 

Transmission

Genital herpes can be transmitted by unprotected sex and by direct contact with sores.

Detection

Diagnosis is possible by clinical symptoms. Identification of the disease can be done by antigen detection, PCR etc. 

Treatment

Immune system of the body has the ability to fight against genital herpes on its own. Besides that, antiviral drugs prevent the worsening of disease and petroleum jelly is effective in pain relief. Acyclovir, famciclovir and valacyclovir are the common drugs used. 

Genital Warts

Causative Organism

This sexually transmitted disease is caused by a virus named Human papillomavirus (HPV).

Symptoms

Painful warts on the genitals and itching are the common symptoms of genital warts. In females infections can spread to vagina and cervix. 

Transmission

Genital warts are transmitted by unprotected sex (vaginal, oral or anal) and by direct contact with warts.

Detection

Diagnosis is done through clinical symptoms. Identification of the disease causing agent can be done through antibody detection, DNA hybridization etc. 

Treatment

Various methods are available for the treatment of genital warts as follows:

Cryotherapy

This method is used to remove the warts. In this method, warts are frozen using liquid nitrogen by the doctor.

Surgery 

This method involves physical removal of the warts.

Injection 

Infected person is injected with some antiviral drugs for treating the warts in this method.

Disinfectant Gel 

Disinfectant gels are applied on the warts which helps in curing the warts. Examples include polyhexamethylene biguanide

Hepatitis B

Causative Organism

Hepatitis B is a sexually transmitted disease caused by Hepatitis B virus.

Symptoms

Individuals infected with hepatitis B experience fever, jaundice, vomiting, weakness, headache and abdominal pain. It may lead to cirrhosis and cancer of the liver. 

Transmission

This viral disease can be transmitted by organ transplant, from expecting mother to the baby, through infected needle and blood transfusion. Intravenous drug abusers are at a high risk of contracting the Hepatitis B virus because these viruses transmit through body fluids such as blood. Intravenous drug administration is often done with the help of unsterilized reusable syringes. These unsterilized reusable syringes, if infected with the blood of Hepatitis B infected individuals, can transfer the virus to a healthy individual who uses it without sterilising it. 

Detection

Disease can be identified through PCR, DNA hybridization etc. 

Treatment

Hepatitis can be an acute (short term) disease or a chronic (long term) disease. Acute hepatitis can be cured by taking plenty of rest and increasing intake of fluid diet while chronic disease can be cured by antiviral drugs. Vaccines are produced through recombinant DNA technology. 

AIDS (Acquired Immune Deficiency Syndrome)

Causative Organism

It is a viral disease caused by Human Immunodeficiency Virus (HIV). It is considered as one of the deadliest of all sexually transmitted infections as it is an incurable disease.

Symptoms

Fever, body pain, body rashes, weakness, chills, itchiness and sore throat are some of the common symptoms observed in individuals infected with AIDS.

Stages of HIV Infection

Infection by HIV occurs in the following stages, it includes acute infection, latent infection, ARC (AIDS related complex) and AIDS. Within the first 3-6 weeks of infection, clinical symptoms like fever, fatigue, enlarged lymph nodes, rashes, etc. can be seen in the infected patients. This phase is the acute infection phase. 

The infection progresses in due course of time through various stages. This includes gradual reduction in the numbers of helper T lymphocytes, occurrence of minor opportunistic pathogenic infections, etc. This stage may continue for years, with alternating periods of wellness and sickness in the patient. Some people have even gone undetected for 10 years or more. This is the asymptomatic phase or the latent phase. 

Then there is a huge reduction in the number of T lymphocytes leading to a marked decrease in immunity of the patient. It is at this stage of infection when the patient actually shows symptoms of AIDS. The patient also suffers from fatigue, unexplained fever, persistent diarrhoea, and marked weight loss. This stage is called ARC (AIDS Related Complex). Full blown AIDS refers to the stage where there is complete breakdown of the immune response machinery of the body. 

Transmission

This viral disease can be transmitted by organ transplant, from expecting mother to the baby, infected needle, sexual contact with the infected person, by transfusion of blood or blood products.

Detection

It can be detected using the ELISA test. Western blot is the confirmatory test. 

Treatment

There is no cure for this viral disease discovered till date. Antiretroviral drugs are used to increase the lifespan of the infected individual. Commonly used drugs include zidovudine, AZT, didanosine etc. 

Chlamydiasis

Causative Organism

It is a bacterial infection caused by Chlamydia trachomatis.

Symptoms

Common symptoms include urethritis, epididymitis, rectal pain, occasional bleeding, testicular pain, vaginal discharge and fever. 

Transmission

Transmission of Chalmydia can occur by unprotected vaginal, oral or anal sex.

Detection

Microscopic examination, culturing, nucleic acid hybridization and gram staining are the common techniques used for detection of the disease-causing agent. 

Treatment

Since it is a bacterial disease, it can be treated by using antibiotics.

Trichomoniasis

Causative Organism

Trichomoniasis is caused by a protozoa, Trichomonas vaginalis.

Symptoms

Individuals infected with this disease experience burning sensation during urination, genital irritation and yellow vaginal discharge with foul smell. It causes epididymitis, urethritis and prostatitis in males.

Transmission

Transmission of trichomoniasis can occur by unprotected vaginal, oral or anal sex.

Detection

Diagnosis is done through the clinical symptoms. Microscopic examination, culture and immunofluorescent antibody staining are used for the identification of the disease-causing agent. 

Treatment

Various drugs have been tested as successful in curing trichomoniasis. Both partners need to be treated simultaneously for the disease. Common drugs used include metronidazole. 

Complications of Sexually Transmitted Diseases

Sexually transmitted infections can have various detrimental effects, if not treated properly. The common complications are listed below:

• It cause inflammation of the pelvic region which constitutes organs like vagina, fallopian tube etc. 
• It increase the chances of abortion (failed pregnancy) in females. It has been observed that chances of abortion increase by three folds in AIDS affected females. 
• It can also cause stillbirths or newborns with birth defects. 
• It causes ectopic pregnancy (development of embryo outside the uterus), 
• It can cause infertility (loss of ability to reproduce). 
• It can cause cancer also.

General Precautions to Avoid Sexually Transmitted Diseases

Sexually transmitted diseases are very common in individuals who are sexually active. Various preventive measures have proved to be successful in reducing the chances of contracting these infections. They are enlisted below:

• Protected sex is one of the method used to prevent sexually transmitted infections. 
• Use of condoms during sexual intercourse is advised in order to reduce the risk of infections.
• One should get themselves tested regularly for sexually transmitted infections since these infections might be asymptomatic. 
• One can always talk about STIs with their partner and get themselves tested regularly.
• It is advised to involve sexually with a fewer partners in order to reduce the risk of STIs.
• Use of fresh needles in injections and fresh blades while shaving are some other measures to reduce the risk of STIs.

Practice Problems of Sexually Transmitted Diseases

Ques:- Given below are the sexually transmitted disease along with their respective causative organism. Find the correct match.

1. A. AIDS - Bacteria
2. B. Chlamydia - Virus
3. C. Hepatitis B - Virus
4. D. Trichomoniasis - Bacteria

Solution: Hepatitis B is a viral sexually transmitted disease caused by Hepatitis B virus. Hence the correct option is c.

Ques:- Ankita was experiencing a burning sensation during urination, vaginal discharge and bleeding between periods. She was diagnosed with sexually transmitted disease. Ankita is suffering from which of the following disease?

• A. Gonorrhoea
• B. AIDS
• C. Syphilis
• D. None of the above

Solution: Burning sensation during urination, vaginal discharge and bleeding between periods are the symptoms of gonorrhoea, a sexually transmitted disease. Gonorrhoea is caused by a bacteria named Neisseria gonorrhoeae. Hence the correct option is a.

Ques:- Which of the following is a myth regarding AIDS?

• A. It can be contracted by physical contact
• B. It can be contracted by blood transfusion
• C. It is uncurable sexually transmitted disease
• D. None of the above

Solution: AIDS, acronym for, Acquired Immune Deficiency Syndrome, is a sexually transmitted disease caused by a virus named Human Immunodeficieny Virus (HIV). This viral disease can be transmitted by organ transplant, from expecting mother to the baby, infected needle and blood transfusion. It cannot be contracted by physical contact like hugging, touching or kissing.

Hence, the correct option is a.

Ques:- Find the odd one out among the following.

• A. Trichomoniasis
• B. Gonorrhoea
• C. Chlamydiasis
• D. Syphilis

Solution: Among the given options, gonorrhea (Neisseria gonorrhoeae), chlamydia (Chlamydia trachomatis) and syphilis (Treponema pallidum) are the sexually transmitted disease caused by bacteria while trichomoniasis is the sexually transmitted disease caused by protozoa, Trichomonas vaginalis. Hence, the correct option is a.

FAQs of Sexually Transmitted Diseases

Ques:- Mention name of five sexually transmitted diseases along with their causative organisms.

Answer: Diseases which are transmitted through sexual intercourse or body fluid interaction are called sexually transmitted diseases. Examples are enlisted below: 

• Gonorrhoea - It is caused by a bacteria named Neisseria gonorrhoeae.
• Syphilis - It is caused by a bacteria named Treponema pallidum.
• Genital herpes - It is caused by a virus named Herpes simplex virus type 2 (HSV-2).
• Genital warts - This sexually transmitted disease is caused by a virus named Human papillomavirus (HPV).
• Hepatitis B - It is a viral sexually transmitted disease caused by Hepatitis B virus.

Ques:- What are the general precautions one must take to avoid sexually transmitted diseases?

Answer: Sexually transmitted diseases are very common in individuals who are sexually active. Various preventive measures to reduce the chances of contracting these infections are as follows:

• Use of condoms while sexual intercourse.
• Individuals who are sexually active are advised to get themselves regularly tested for sexually transmitted diseases.
• One should involve with fewer partners sexually.

Ques:- If left untreated, how can sexually transmitted disease affect reproductive health of an individual?

Answer: Sexually transmitted infections can have various detrimental effects, if not treated. The common complications are enlisted below:

• It can cause inflammation of the pelvic region which constitutes organs like vagina, fallopian tube etc. 
• It can increase the chances of abortion (failed pregnancy) in females. 
• It has been observed that chances of abortion increase by three folds in AIDS affected females. 
• These infections can also cause stillbirths or newborns with birth defects. 
• It can cause ectopic pregnancy (development of embryo outside the uterus)
• It can lead to infertility (loss of ability to reproduce).
• It can cause cancer also.

Ques:- What is the cause, mode of transmission, symptoms and treatment of syphilis?

Answer: Syphilis is caused by a bacteria named Treponema pallidum. Syphilis is transmitted by oral, vaginal or anal sex. It can also be transmitted by direct contact with sores. Syphilis causes infectious painless genital sores. It also causes swelling in the lymph nodes, sore throat, hair loss and body rashes.

Syphilis is caused by a bacteria and hence, can be treated by antibiotics which are medicines with the ability to kill bacteria and prevent them from growing, multiplying or causing disease.

Other Related Topic Of Biology

• Infertility