A PROJECT WORK
ON
“SEXUALLY TRANSMITTED DISEASES”
SUBMITTED TO
THE BIOLOGY DEPARTMENT
ST. PAUL SENIOR SECONDARY SCHOOL, NAGPUR
SUBMITTED BY--
ADITI SINHA
12TH STANDARD, YEAR 2019-20
ST. PAUL SENIOR SECONDARY SCHOOL, NAGPUR
UNDER THE GUIDANCE OF
Mrs. VAISHALI BAND
PROFESSOR, BIOLOGY DEPARTMENT
CONTENTS
Certificate
Acknowledgement
STD
Caused by Bacteria
Caused by Viruses
Caused by Chlamydia
Caused by Protozoa
Caused by Nematode
Caused by Arthropods
Caused by Yeast
CERTIFICATE
This is to certify that Aditi Sinha student of class XII has successfully
completed the research project on the topic “SEXUALLY
TRANSMITTED DISEASE” under the guidance of Mrs. Vaishali Band.
Signature (Teacher) Signature (Examiner)
ACKNOWLEDGEMENT
I feel proud to present my investigatory project in biology on the
“Sexually Transmitted Diseases”. This project would not have been
feasible without the proper rigorous guidance of biology teacher Mrs.
Vaishali Band who guided me throughout this project in every possible
way. I would like to thank my Principal Mrs. Dewagana Punde and
school for providing me with facilities required to do my project. An
investigatory project involves various studies, which have to obtain
the observations and conclude the reports on a meaningful note.
Rigorous hard work has put in this project to ensure that it proves to
be the best.
SEXUALLY TRANSMITTED DISEASES
Definition:
Diseases or infections which are transmitted through sexual intercourse with
infected persons are collectively called Sexually Transmitted Diseases (STDs)
or venereal diseases (VD) or reproductive tract infections (RTI).
Causing agents (Pathogens):
STDs are usually caused by:
1. Bacteria
2. Viruses
3. Chlamydia
4. Protozoa
5. Nematodes
6. Ectoparasites
7. Fungi
Mode of transmission:
STDs are transmitted by:
1. Sexual intercourse with infected persons
2. Sharing of injection needles, surgical instruments etc.
3. Transfusion of blood from an infected mother to the foetus.
Cure for STD:
Except HIV infection, hepatitis B and genital herpes all other STDs are completely
curable if detected early and treated properly.
Common symptoms:
Early symptoms of most of these diseases are itching, fluid discharge, swelling,
slight pain etc.
Consequences of Delayed Treatment:
If proper and timely treatment is not given STD may lead to complication such a
pelvic inflammatory diseases (PID), abortion, still birth, infertility or even cancer
of reproductive tract.
1. STDs caused by Bacteria
a) Syphilis. Pathogen:
Symptoms:
1) In the first stage there is indurated infections and painless ulcer or
chancre on the genitals and swelling of local lymph glands. Chancre is the
initial lesion of syphilis commonly a more or less distinct ulcer or sore with
hard base.
2) In the second stage, chancre is healed and there are skin lesion, rashes
hair loss, swollen joints and flu like illness occasionally.
3) In the tertiary stage chronic ulcers appear on palate, nose and lower leg.
There can be paralysis, brain damage, blindness, heart trouble and aortic
impairment.
4) In the latent syphilis, there is no evidence of the disease.
Diagnosis: The disease is diagnosed by clinical symptoms, microscopic
examination and antibody detection, VDRL (Venereal Disease Research
Laboratory), ELISA test.
Transmission: It is through sexual contact and from mother to children.
Incubation Period: 10-90 days
Treatment: It is curable through appropriate antibiotics.
b) Gonorrhoea. Pathogen:
Symptom: The bacterium lives in genital tube, produces pus-containing
discharge, pain around genitalia and burning sensation during urination. It may
lead to arthritis and eye infection in children of gonorrhoea afflicted mothers.
Diagnosis: It is carried out by clinical symptoms, Gram staining of discharge and
culture.
Transmission: It is spread through sexual contact.
Treatment: Effective antibiotics are ceftriaxone, erythromycin, ciprofloxacin
and trimethoprim - sulphamethoxazole.
2. STDs caused by Viruses.
a) AIDS. Pathogen
Symptoms: The symptoms of AIDS include fever, lethargy, pharyngitis,
weight loss, nausea, headache, raches. Because HIV attacks helper T
lymphocytes, the patient gets immune deficiency and he/she is unable to
protect himself/herself against infections.
Diagnosis: AIDS can be diagnosed by ELISA test and western blotting test.
Western Blotting test is used for confirmation of ELISA positive cases.
Transmission: Virus of AIDS in transmitted via blood and semen.
Incubation Period: 6 moths to 10 years.
Treatment: Although there is no cure of AIDs. Yet use of certain drugs can
prolong the life of certain patient.
b) Hepatitis B. Pathogen
Symptoms: Its symptoms include fatigue, jaundice, persistent low-grade
fever, rash and abdominal pain. It can cause cirrhosis and possibly liver
cancer.
Diagnosis: Hepatitis B can be diagnosed by Australian Antigen Test which is
now also called Hepatitis B surfage antigen (HBSAg). It also diagnosed by
ELISA.
Transmission: Mode of transmission may be blood transfusion, sexual
contact, saliva, tears, intravenous drug abuse, tattooing, ear and nose
piercing, sharing of razors.
Incubation Period: 30 to 80 days.
Treatment: It is incurable STD.
c) Hepatitis C: It is also STD caused by HCV. It is also diagnosed by ELISA.
d) Genital Herpes:
Symptoms: There are vesiculopustular lesions followed by clusters of painful
erythematous ulcers over external genitalia and peri-anal regions. Symptoms
are more severe in females. There is fever, headache, pain, itching, vaginal
and urethral discharge, with tender inguinal lymphadenopathy. Urethral and
cervix infections also occur.
Diagnosis: Detection is carried out by clinical symptoms, antigen detection,
PCR and nucleic acid hybridisation.
Transmission: The disease is primarily transmitted sexually through genital
secretions but also contact with viroid and genitalia.
Treatment: It is also incurable STD.
e) Genital Warts. Pathogen. Human papilloma virus (HPV)
Symptoms: Warts develop over the skin and mucosal surface of external
genitalia and perianal area. In women infection may inter vagina and cervix.
Diagnosis: Diagnosis is made through clinical symptoms, antibody detection,
culture and DNA hybridisation.
Transmission: It spreads through sexual intercourse with carrier of viruses of
this disease.
Treatment: Treatment requires special skill especially in case of internal
warts. Cryosurgery is used to removal of warts.
3) STDs caused by Chlamydia
Chlamydiosis. Pathogen
Symptoms: Chlamydia trachomatis is a human pathogen that causes
trachoma, sexually transmitted and perinatal infection. Chlamydia is obligate
intracellular pathogen.
Diagnosis: Detection techniques are clinical. Gram-staining of discharge,
antigen detection and nucleic acid hybridisation.
Transmission: It spread by sexual contact with the infected mating partner.
Incubation Period: About one week.
Treatment: Antibiotics like tetracycline, erythromycin and rifampicin are
effective but penicillin is not effective in chlamydiosis.
4) STDs Caused by Protozoa.
i) Trichomoniasis. Pathogen.
Symptoms: The parasite infects both males and females. In females it causes
vaginitis with foul smelling, yellow vaginal discharge and burning sensation.
In males it causes urethritis, epididymitis and prostatitis resulting in pain and
burning sensation.
Transmission: Through sexual intercourse.
Diagnosis: Diagnosis is made by clinical symptoms, microscopic examination,
culture.
Treatment: Standard treatment is metronidazole but partners be treated
simultaneously.
ii) Amoebiasis. Pathogen.
Symptoms: The patient passes blood along with the facces and feels pain in
the abdomen.
Transmission: Its infection is normally via contaminated food but sometimes,
it is transmitted through sexual contact.
Treatment: Ant amoebic tablets are given to the patient.
5) STDs caused by Nematode
Enterobiasis Pathogen
Symptoms: The parasite causes intense itching of the anus, inflammation
of mucous membrane of colon and appendix, nausea, abdominal pain and
diarrhoea.
Transmission: The patient scratches the affected area. The eggs easily
get under the finger nails from where they may get into the mouth. The
infection is also through sexual contact.
Treatment: Anthelminthic tablets are recommended.
6) STDs caused by Arthropods
i) Scabies. Pathogen.
Symptoms: Intense itching and patches on the skin.
Transmission: Mite spreads the parasite.
ii) Pediculosis. Pathogen.
Symptoms: Painful itching and red patches on the skin of pubic hair.
Transmission: The female lice lay eggs near the base pubic region are
found.
Treatment: Medicated shampoos are recommended.
7) STD caused by Yeast (Fungus)
Candidiasis. Pathogen
Symptoms: This yeast is normally found in the mouth, colon and vagina.
Women with yeast infection experience painful inflammation of the
vagina often with a thick, cheesy discharge. Man may develop a painful
inflammation of the urethra through sexual contact with an infected
woman.
Transmission: The parasite spreads through sexual contact.
Treatment: It involves the use of antibiotics.
