7. Sexually Transmitted Infections

These flashcards cover key concepts and facts related to epidemiology and various STIs based on the provided lecture notes.

Which age group accounts for almost half of new STI cases in the US?

Individuals aged 15–24.

Which region of the US has the highest rates of STDs?

The South (7 out of the top 10 states are in the South).

What is the most common reported bacterial infection in the US?

Chlamydia trachomatis.

What is the most common STI worldwide?

Human Papillomavirus (HPV).

Differentiate between HSV-1 and HSV-2 based on typical location.

HSV-1 typically causes herpes labialis (oral/cold sores), while HSV-2 typically causes genital herpes.

Which HSV type typically has more severe initial outbreak symptoms?

HSV-2.

What is the classic description of an HSV lesion?

Clustered vesicles on an erythematous base.

What is the 'prodrome' associated with recurrent HSV infection?

A sensation of pain, burning, tingling, or pruritus at the site 6–36 hours before the lesion appears.

What is the diagnostic test of choice for active HSV lesions?

PCR or cell culture (best if done during the first 3 days).

What is the 'Gold Standard' treatment window for starting antivirals in a primary HSV outbreak?

Within 72 hours of symptom onset.

Can a patient transmit HSV even when they do not have an active outbreak?

Yes, due to asymptomatic viral shedding.

Which HPV types are responsible for 90% of anogenital warts?

HPV types 6 and 11.

Which HPV types are high-risk for cervical cancer?

HPV types 16 and 18.

How are Condyloma Acuminata (genital warts) described clinically?

Flesh-colored, discrete papillary growths that may be pedunculated or arise from a single stalk.

At what age is the HPV vaccine (Gardasil 9) recommended?

Routinely at 11–12 years old (catch-up available for ages 13–26).

What is a common first-line surgical treatment for genital warts?

Cryotherapy.

What is the causative organism of Gonorrhea?

Neisseria gonorrhoeae (a Gram-negative intracellular diplococcus).

What is a classic symptom of Gonococcal Urethritis in men?

Mucopurulent urethral discharge.

What is the triad of Disseminated Gonococcal Infection?

Tenosynovitis, dermatitis, and polyarthralgias.

What is the current recommended treatment for Gonorrhea?

High-dose Ceftriaxone (500mg IM single dose; 1g if patient >150kg).

Why is Doxycycline often added to the Gonorrhea treatment regimen?

To treat potential coinfection with Chlamydia trachomatis unless it has been ruled out.

What is a major complication of untreated Chlamydia in women?

Pelvic Inflammatory Disease (PID), which can lead to infertility and ectopic pregnancy.

What is Fitz-Hugh-Curtis syndrome?

Perihepatitis (inflammation of the liver capsule) associated with PID, presenting with RUQ pain.

What is the Reactive Arthritis Triad (RAT) associated with Chlamydia?

Reactive arthritis, conjunctivitis/uveitis, and cervicitis/urethritis.

What is the diagnostic test of choice for Chlamydia?

Nucleic Acid Amplification Testing (NAAT).

What is the preferred treatment for Chlamydia?

Doxycycline 100 mg BID x 7 days.

What organism causes Trichomoniasis?

Trichomonas vaginalis (a protozoan with flagella).

What is the characteristic appearance of the cervix in Trichomoniasis?

'Strawberry cervix' (punctate hemorrhages).

Describe the discharge associated with Bacterial Vaginosis (BV).

Thin, grayish-white, homogeneous discharge with a 'fishy' odor.

What are 'Clue Cells'?

Vaginal epithelial cells with borders obscured by bacteria; they are the most reliable predictor of BV.

What is the Amsel Criteria for diagnosing BV?

Need 3 of 4: 1. Homogeneous, thin, gray-white discharge; 2. Vaginal pH > 4.5; 3. Positive 'Whiff test' (fishy odor with KOH); 4. Presence of Clue Cells.

What is the treatment for Bacterial Vaginosis?

Metronidazole (Flagyl) 500 mg BID x 7 days.

Which organism causes LGV?

Chlamydia trachomatis types L1, L2, and L3.

Describe the 'Groove Sign' in LGV.

Enlargement of inguinal and femoral lymph nodes separated by the inguinal ligament.

What is the treatment for LGV?

Doxycycline 100mg BID for 21 days.

What organism causes Syphilis?

Treponema pallidum (a spirochete).

Describe the lesion of Primary Syphilis.

A chancre: a painless, indurated ulcer with raised borders.

What are the key features of Secondary Syphilis?

A rash involving the palms and soles, generalized lymphadenopathy, condylomata lata, and 'moth-eaten' alopecia.

What is the Argyll-Robertson pupil?

A pupil that accommodates but does not react to light (seen in Neurosyphilis/Tertiary Syphilis).

What physical signs are associated with Late Congenital Syphilis?

Hutchinson's teeth, Mulberry molars, Saber shins, and Saddle nose.

Which serologic tests are 'Nontreponemal'?

RPR and VDRL.

Which serologic tests are 'Treponemal'?

FTA-ABS, TP-PA (these remain positive for life).

What is the drug of choice for all stages of Syphilis?

Penicillin G Benzathine (IM).

What organism causes Chancroid?

Haemophilus ducreyi.

How does a Chancroid ulcer differ from a Syphilis chancre?

Chancroid is painful with a purulent, dirty base ('soft chancre'), whereas Syphilis is painless with a clean base ('hard chancre').

What is the treatment for Chancroid?

Azithromycin 1g PO single dose OR Ceftriaxone 250mg IM single dose.

What is the most common bacterial STI in the US?

Chlamydia.

What is the typical age of onset for Trichomoniasis?

Often affects sexually active women around age 16–35.

Which testing method is preferred for Chlamydia diagnosis?

Nucleic Acid Amplification Testing (NAAT).

What is the recommended follow-up for Gonorrhea treatment?

Test-of-cure in certain populations.

What type of organism is Neisseria gonorrhoeae?

A Gram-negative intracellular diplococcus.

What symptom is classically associated with Disseminated Gonococcal Infection?

Polyarthralgias.

How long after treatment for Gonorrhea should a follow-up be considered?

3 months.

What is a common co-infection with Gonorrhea?

Chlamydia trachomatis.

What type of discharge is associated with Chlamydia in men?

Mucopurulent.

How does Chlamydia commonly present in women?

Often asymptomatic.

What is the effect of untreated Chlamydia on pregnancy?

Increases risk of ectopic pregnancy.

What is the common age for HPV vaccine initiation?

11-12 years.

What does the HPV vaccination help prevent?

Cervical cancer and anogenital warts.

What are the HPV types included in Gardasil 9 for warts?

HPV types 6 and 11.

What is the medical term for painful intercourse due to an STI?

Dyspareunia.

What symptom might indicate Trichomoniasis?

Foul-smelling yellow-green vaginal discharge.

What is the typical duration for Chlamydia antibiotic treatment?

7 days.

What age group has the highest incidence of STIs?

15–24 years old.

What STI is often tested with a 'Whiff Test'?

Bacterial Vaginosis.

What is the most common cause of cervicitis?

Chlamydia trachomatis.

What are common symptoms of Gonorrhea in women?

Often asymptomatic but may include increased vaginal discharge.

What is one potential serious complication of untreated Latent Syphilis?

Tertiary Syphilis.

What are typical findings in Tertiary Syphilis?

Gummas, cardiovascular complications, and neurosyphilis.

What defines Primary Syphilis?

The presence of a painless chancre.

Which population is particularly at risk for Syphilis?

Men who have sex with men (MSM).

WHat is one method of testing for latent Syphilis?

Serology for treponemal markers.

What is the protocol for treating Chlamydia in pregnancy?

Azithromycin 1g PO.

What do you call the secondary stage rash of syphilis?

Maculopapular rash.

What is a common cause of bacterial vaginosis?

Imbalance in normal vaginal flora.

How long is the course of treatment for bacterial vaginosis with Metronidazole?

7 days.

In which demographic is Trichomoniasis most prevalent?

Women in their reproductive years.

What type of organism is Trichomonas vaginalis?

Protozoan.

What type of lymphadenopathy is associated with LGV?

Inguinal lymphadenopathy.

What are key characteristics of Chancroid lesions?

Painful ulcers with irregular edges.

What is a classic sign of Neurosyphilis?

Argyll-Robertson pupil.

What type of test remains positive for life in Treponemal testing?

FTA-ABS.

What is typically seen on physical exam during primary syphilis?

Painless ulcer (chancre).

What is the role of serological testing in Syphilis management?

Screening and diagnosis.

Which age group is encouraged to receive the HPV vaccine?

Children aged 11-12.

How are condylomata acuminata typically treated?

Cryotherapy or surgical removal.

What criteria help diagnose bacterial vaginosis?

Amsel Criteria.

What does PID stand for?

Pelvic Inflammatory Disease.

What type of testing is recommended for diagnosing Gonorrhea?

Nucleic Acid Amplification Testing (NAAT).

What two STIs does Doxycycline treat as part of Gonorrhea regimen?

Gonorrhea and Chlamydia.

What is considered a treatment failure for Gonorrhea?

Persistent symptoms after therapy.

Describe how a syphilis chancre differs from a chancroid ulcer.

Syphilis chancre is painless, while chancroid is painful.

Which demographic tends to have higher rates of Chlamydia?

Women under 25.

How does one characterize the discharge associated with Trichomoniasis?

Frothy and yellow-green.

What are effective treatments for Gonorrhea?

Ceftriaxone and Azithromycin.

What serology tests are used for syphilis screening?

RPR and VDRL.

What treatment is specifically recommended for pregnant women with Syphilis?

Penicillin G.

What is a common complication of untreated Chlamydia in men?

Epididymitis.

Which test is used to confirm active HSV infection?

PCR (Polymerase Chain Reaction) or culture.

What symptom typically signals the onset of herpes lesions?

Prodromal pain or burning.