STI's and STD's Flashcards
What are STD’s?
Infections or parasitic diseases transmitted primarily through sexual contact
• Chlamydia, gonococcal infections, nongonococcal urethritis, pelvic inflammatory disease, acute epididymitis, syphilis, HIV/AIDs, trichomoniasis, chancroid, herpes simplex and venereal warts
What is Syphilis?
- Local and systemic manifestations caused by treponema pallidum
- Transferred by minor abrasions during sexual intercourse and becomes a systemic disease after infection
- Can be transferred to a foetus (from the 9th week) with transmission risk decreasing with each subsequent pregnancy
What is the pathophysiology of syphilis?
- Primary - “chancre” are hard, red, protruding and painless sores
- Secondary - 2 weeks after the chancre heals and the disease becomes systemic. Bacteria spreads to all major organ systems and serology and medical history confirm syphilis, but the individual has no clinical manifestations
- Tertiary - develops 5-40 years following the initial infection. Skin, bone and soft tissue lesions become hypersensitive and Aneurysms, CV lesions, heart failure, neurosyphilis can develop
What are the diagnosis and tx of syphilis?
Diagnosis:
• Early diagnosis is through microscopic examination of a specimen (lymph, chancre, lesion)
• Serologic testing
○ Nontreponemal antigen test (non-specific) can show the presence of regain in serum (positive in >50% primary)
○ Treponemal antibody test (specific) demonstrates the antibody response to T. pallidum
• Latent stage may be difficult to diagnose microscopically - CSF examination may be needed
Treatment: Treatment for all stages of syphilis is benzathine penicillin with a frequency and duration dependent on presentation. It is prescribed for 1 and 3 weekly injections for 14 or 28 days
What is congenital syphilis? What are the diagnosis and tx?
- Early signs manifest in the first two years of life
- Evident through premature labour and growth retardation, hepatosplenomegaly, bone marrow depression (causing blood dyscrasias), bone and skin lesions, retinal inflammation and glaucoma
- Signs of the late stage occurs near puberty including CV lesions and neurosyphilis
Diagnosis: Microscopic identification of T. pallidum in a specimen (nasal discharge or skin lesions)
Treatment: Maternal treatment may prevent congenital syphilis in infants with penicillin. A negative serology test is expected at six months
What are genital herpes?
- Caused by herpes simplex virus (HSV): Type 1 (HSV-1) or and Type 2 (HSV-2)
- Transmitted via intimate contact: secretion from a lesion or mucosal surface
- 70-90% of adults have circulating antibodies to HSV-1, indicating previous infection
- Of concern is intrauterine transmission = can cause premature delivery and is the greatest risk for infants if the mother has a primary infection near the time of delivery
What is the pathophysiology of genital herpes?
- Exposure to HSV includes viral replication in the epidermis and dermis = cell destruction, transudation and vesicle formation
- Virus spreads to sensory nerves to the intra-axonal transport to the dorsal root
- Reactivation of HSV is not fully understood but may include physical, hormonal and immunologic stimuli
- Viral genome is transported back to the dermis
What are the clinical manifestations, diagnosis and tx of genital herpes?
Clinical Manifestations:
• First episode: primary genital infection with local signs of small multiple vesicular lesions (1-2 mm) which may heal or form large ulcers
• Systemic signs: fever, enlarged lymph nodes and pharyngitis
• The first-episode of non-primary HSV has few lesions. Recurrent infections are more common with HSV-2
Diagnosis:
• Papanicolaou (Pap) test - demonstrates giant cells with multiple nuclei
• Definitive diagnosis through serologic tests
Treatment:
• No cure and treatment involves symptom relief of primary and periodic outbreaks
• Anti-virals like acyclovir, famciclovir and valaciclovir can be used. Adverse effects include headache, nausea and vomiting
What is the Human papillomavirus?
- > 120 different types of HPV identified
- Classified into high-risk and low-risk cervical cancer (benign lesions)
- High-risk types: 16 and 18 lead to >50% cases of cervical dysplasia, and 18 leads to adenocarcinoma of the cervix
- Low-risk types (6 and 11) causes genital warts and can co-exist with high-risk types but is not malignant
- Persistent infection with high-risk serotypes leads to cervical cancer
what is the pathophysiology, clinical manifestations, diagnosis, and tx of HPV?
Pathophysiology: transmission through sexual contact and infection of the basal cells of the epithelium The entry into the cell is poorly understood. This causes warty growths which usually occurs over 2-3 months
Clinical Manifestations:
• Genital warts: soft, skin-coloured growth; not painful but can cause pain during intercourse and bleeding
• In infants, they may present with laryngeal wart
Diagnosis:
• Diagnosis of genital warts and clinical signs
• Best diagnosed with a serologic test and biopsy of lesions
Treatment of External Genital Warts:
• Podophyllotoxin (natural product derived from a plant) which inhibits mitosis
• Cryotherapy and surgery of cervical lesions
What is Neisseria Gonorrhoeae?
- Gonorrhoeae is a Gram-negative diplococcus which is transmitted almost exclusively by sexual contact
- Symptoms in men are a burning sensation with urination and pus draining from the penis; severe infection may result in sterility in men
- In women, it is often asymptomatic or mild cervicitis
What is pelvic inflammation Disease (PID)?
- Includes endometritis, pelvic peritonitis, tubo-ovarian abscess, and inflammation of the fallopian tubes which can be caused by gonorrhoea or C. trachomatis
- Treatment includes broad coverage, and combination therapy is required, for example, doxycycline may be used with or without metronidazole
