STIs

Question 1

Chlamydia (general)

Answer 1

Cause: bacteria - 'Chlamydia trachomatis' 
Transmission: vaginal or anal sex
Symptoms: mostly asymptomatic
Diagnosis: swabs
Treatment: antibiotics

Question 2

Non-specific urethritis (males)

Answer 2

• Around 50% of cases are caused by chlamydia bacteria
• symptoms include inflammation of urethra, pain whilst urinating and yellow discharge
• can be caused by other micro-organisms
• if left untreated, bacteria can cause inflammation of the epididymis; epididymitis
• can cause infertility, though very rare

Question 3

Chlamydia (females)

Answer 3

• can cause infertility, eye infection and arthritis
• some show symptoms of pelvic inflammatory disease (inflammation of uterus and fallopian tubes)
• implantation of an embryo outside the uterus can also occur (ectopic pregnancy)
• if pregnant mother is infected, chlamydia can be transmitted to the baby during birth
• the baby with suffer from conjunctivitis, nasal and throat infections and pneumonia

Question 4

Genital Herpes

Answer 4

Cause: virus - ‘Herpes simplex’
Transmission: skin-to-skin contact
Symptoms: HSV1 causes cold sores on lips but can affect genitals, HSV2 causes blisters on genitals.
Herpes doesn’t leave the body once infected.
Treatment: anti-pain medication, antiviral drugs
Childbirth can cause infection

Question 5

Genital Warts (HPV)

Answer 5

Cause: virus - ‘Human papillomavirus’
Transmission: anal, oral, vaginal sex
Symptoms: wart growths on and in genitals
Childbirth can cause infection.
Non-wart producing strains can cause cervical cancer.

Question 6

Trichomoniasis

Answer 6

Cause: protozoan - ‘Trichomonas vaginalis’
Transmission: vaginal sex
Symptoms: inflammation of mucous membranes in urethra (males) and vagina (females)
Treatment: antibiotics

Question 7

Public Lice

Answer 7

Cause: parasite - ‘Phthirus pubis’
Transmission: skin-to-skin contact
Symptoms: intense itching of the genital area (caused by allergic reaction) and sometimes on other hairy areas.
Treatment: topical lotions

Question 8

Scabies

Answer 8

Cause: parasite - ‘Sarcoptes scabei’
Transmission: skin-to-skin contact
Symptoms: intense itching of the genital area, wrists and finger webs (caused by allergic reaction)
Treatment: topical lotions

Question 9

Gonorrhoea (general)

Answer 9

Cause: bacteria - ‘Neisseria gonorrhoeae’
Transmission: anal, vaginal or oral sex
Diagnosis: smears (females)
Treatment: antibiotics (though some strains are growing resistance)

Question 10

Gonorrhoea (males)

Answer 10

• after incubation period, urethral inflammation, yellow discharge and pain during urination occurs
• if left untreated, urethra will close, and infection can spread to the testes, causing sterility, to the joints, causing arthritis and to the heart and eyes

Question 11

Gonorrhoea (females)

Answer 11

• most women are asymptomatic
• the bacteria infect the cervix and urethra
• yellow discharge occurs
• if left untreated, infection spreads to the fallopian tubes, causing infertility
• childbirth can cause infection

Question 12

Syphilis (general)

Answer 12

Cause: bacteria - ‘Treponema pallidum’ (thin & spiral-shaped)
Transmission: vaginal, anal or oral sex
Treatment: antibiotics, though in later stages surgery becomes necessary
Childbirth can cause infection

Question 13

Primary stage (Syphilis)

Answer 13

• bacteria enter any small skin breaks
• incubation period of 2-4 weeks (bacteria multiply)
• first symptom = chancres: small sores on genital areas but can occur on lips, fingers and eyelids
• chancres heal autonomously in 3-8 weeks

Question 14

Secondary stage (Syphilis)

Answer 14

• a few weeks after primary stage
• symptoms can include skin rash, sores, ulcers, fevers, eye and bone disorders
• skin rash lasts several weeks
• this stage is the most infectious and lasts around 2 years
• symptoms autonomously disappear

Question 15

Latent stage (Syphilis)

Answer 15

• after symptoms of primary and secondary stages disappear
• this stage involves no symptoms
• can last for years or even the rest of the person’s life
• transmission is not possible in this stage

Question 16

Tertiary stage (Syphilis)

Answer 16

• last stage; only a minority experiences it
• occurs from 5-40 years after infection
• can be devastating: heart disease, insanity, blindness, weakening of blood vessels, physical incapacity

Question 17

Human Immunodeficiency Virus (HIV)

Answer 17

• weakens the immune system, and almost always results in Acquired Immune Deficiency Syndrome (AIDS)
• HIV = retrovirus, therefore RNA core
• it infects T-lymphocytes and uses them to convert its RNA into DNA
• the DNA then multiplies millionfold
• around a month after infection, flu-like symptoms may occur, though the immune system deals with this
• during a period of apparent fitness, the virus continues to destroy T-lymphocytes, until their numbers are too low to resist other diseases
• the person now has AIDS

Question 18

Spread of HIV

Answer 18

• transmitted through blood, seminal fluids, vaginal and cervical fluids and breast milk
• transmission is involved with direct contact with mucous membranes or the blood stream, therefore saliva, urine, faeces, tears, sweat and vomit will not cause infection
• transmission is caused by unprotected sex, pregnancy, childbirth or breastfeeding, blood transfusions, unsterilised equipment

Question 19

Diagnosis of HIV

Answer 19

• body responds to HIV with antibodies, therefore they can be detected in blood tests
• viral load-measuring tests can detect the amount and activity of HIV in the blood

Question 20

Treatment of HIV

Answer 20

• there is no cure or vaccine to prevent infection
• antiviral drugs are available to inhibit viral replication
• post-exposure prophylaxis within 3 days of infection can be given; this treatment prevents viral replication