3. Sexually transmitted diseases Flashcards
What are the main issues that concern STIs as a whole?
Many clinical presentations and many are asymptomatic Different risks in different populations Some are incurable There is always more than one patient - vertical transmission or partner notification Confidentiality High rates of re-infection Might be a life long infection Stigma and psychological morbidity Becoming increasingly difficult to treat
What factors lead to an increased risk of STIs?
Age Sexual partner Sexual practice Lack of condom usage Ethnicity Area of resistance
What is the most common STI in England and how has this differed?
Chlamydia but the rates have stabilised due to a national Chlamydia screening programme
In what group of people is the STI rate the highest?
Heterosexuals under the age of 25
Also in men who have sex with other men
Is Gonorrhoea more common in men or women?
Men
Is syphilis more common in men or women?
Men
What is the pathogen responsible for chlamydia infection?
Chlamydia trachomatis - intracellular pathogen
What are the clinical presentations of chlamydia?
Asymptomatic infections are common
Some strains cause eye infections which can lead to blindness
Men - pain when passing urine, discharge from the penis, infection of prostate gland
Women - can cause pelvic inflammatory disease, pain when passing urine, vaginal discharge
Reactive arthritis - patients may present with joint symptoms or a rash
What is the impact of chlamydia on fertility and on a neonate?
Chlamydia can be carried for a long time without you realising as it is often asymptomatic
Associated with a very high risk of infertility in both men and women
If infected as a neonate from the mother - baby can develop conjunctivitis and pneumonia
How might chlamydia present in homosexual men?
Serovars L1-3 are the most common in men who have sex with men
Rectal bleeding
Change in bowel habit
Swollen lymph nodes around the inguinal/genital region
How is chlamydia treated?
With tetracyclines: azithromycin, doxycycline
What is the pathogen responsible for genital warts
Human papilloma virus
Second most common STI
What are the clinical presentations of genital warts?
90% of people with this infection are asymptomatic
The warts can otherwise present in multiple sites but mainly the genitals
What are the risks associated with a HPV infection?
Some of these strains are associated with carcinoma - 16, 18, 31, 33
There is an increasing incidence in ano-genital and oro-pharyngeal carcinoma i.e. increasing cancers associated with HPV
What is the treatment for genital warts?
Topical podoophyllotoxon, imiquimod
Cryrotherapy - can freeze the warts off
There is currently a vaccination in place - hoping that this will result in a decreasing incidence over time
What is the pathogen responsible for gonorrhoea?
Neisseria gonorrhoea
How does gonorrhoea present in patients?
Males - urethritis, proctitis (inflammation of rectum and anus), sore throat, epididymitis, prostatitis
Females - cervicitis, PID, pain and discharge from the ureter, discharge during sex
Can also lead to infertility
How does gonorrhoea present in neonates?
Conjunctivitis: eye infection, sticky eyes - this can lead to blindness if untreated
What is the treatment for gonorrhoea?
What is the problem with this?
Current management is drug Ceftriaxone
BUT there is increasing resistance to this so must make sure that the patient is fully treated before discharging them
What are the pathogens responsible for herpes infection?
Herpes simplex virus 1 and 2
HSV-1 oral and HSV-2 genital but now understood that they both contribute to both
What are the different stages of a Herpes infection?
Primary infection
Stage of latency - the DNA virus sits and does nothing in the trigeminal or sacral nerve ganglia
Can then have a reactivation of the virus
What are the clinical presentations of Herpes?
The primary infection is very asymptomatic - may present with painful ulcers and blisters
No symptoms during the latent stage
When reactivated, may either present with symptoms or may be asymptomatic
May feel unwell - have a fever or a headache
HSV 1 - commonly known as a cold sore
HSV 2 - commonly known a a genital wart
What it the treatment for herpes?
Herpes is not curable - it will stay forever within (like chicken pox) and can reactivate
Management includes aciclovir, famciclovir, valaciclovir
What is the pathogen responsible for syphilis?
Treponema Pallidum
What are the different types and stages of syphilis?
Primary
Secondary - occurs 4 to 10 weeks after primary infection
Latent
Tertiary - occurs 3 to 15 years after primary infection
Congenital
How is syphilis diagnosed?
Via serology
What are the clinical presentations of primary syphilis?
Primary chancre - single, usually painless ulcer in the mouth, anus, vulva, vagina, penis - heals up after a few weeks and goes away on its own
Highly infectious at this stage
What are the clinical presentations of secondary syphilis?
Rash - affects the palms of the hand and the soles of the feet (no other infection causes this! big clue that this is syphilis!)
Fever
Condyloma lata (flesh-like warts
Describe the current epidemiology of HIV and why it is changing?
Decreasing incidence
Increasing prevalence
Have gotten better at preventing the disease but ageing population with sufferers of the disease
How does HIV cause disease in the cells of the body?
HIV infects CD4+ cells (T-helper), macrophages and dendritic cells and there is increased viral replication
This acute primary infection leads to a massive loss of CD4+ cells
Chronic HIV infection is associated with on-going loss of CD4+ cells, a decline in immune function and progressive immunosuppression
Why can HIV show as a false negative in serology?
The HIV antibody can take up to 3 months to become positive
What are the clinical presentations of a primary HIV1 infection/
Headache Pharyngitis Oral/genital ulceration Nausea Rash Fever and fatigue Weight loss/night sweats
What is the aim of the antiretroviral therapy in HIV?
Suppression of the HIV replication
CD4+ count recovery
Immune reconstitution
Long term reduced risk of morbidity and mortality
How is HIV currently treated?
HAART - highly active antiretroviral therapy
There are 6 classes of antiretroviral drugs
Must always treat with a combination of antiretroviral drugs - combine at least 3 drugs from at least 2 classes
The treatment is lifelong
What are the adverse effects associated with HAART?
Short term - nausea, vomiting, headache, sleep disturbance
Long term - renal dysfunction, peripheral neuropathy, lactic acidosis
May have adverse drug interactions
How is HIV managed in pregnancy?
Must carry out early screening for HIV
Antiretroviral therapy must be administered for the mother - this should be immediate and continued if the CD4 count is low
Elective c-section (vaginal delivery is possible if there is an undetected HIV load)
Antiretroviral therapy for the infant
No breastfeeding
