Std

STD

Gonorrhea (GC)

• Neisseria gonorrhoeae is a Gram-negative intracellular diplococcus.

• Humans are the only host and the organism is spread by intimate physical contact.

Clinical features

• Incubation period is 2–14 days.• most symptoms occurr between days 2 and 5.

In men:• anterior urethritis-dysuria and urethral

discharge.• Ascending infections-epididymitis,prostatits.• MSM-proctitis,discharge,itch.

In women:• primary site- endocervical canal.• vaginal discharge, pelvic pain, dysuria and

intermenstrual bleeding.

Complications:• Bartholin’s abscesses• perihepatitis (Fitzhugh–Curtis syndrome)-rare.• GC is one of the most common causes of

female infertility.

• Disseminated GC leads to arthritis (usually monoarticular or pauciarticular)

• Characteristic papular or pustular rash with an erythematous base in association with fever and malaise.

• More common in women.

Diagnosis

• By culture of infected areas.Sensitivity 95%.

• Nucleic acid amplification tests (NAATs) using urine specimens are non-invasive and highly sensitive.May give false positive.

• Microscopy of Gram-stained secretions.

• Microscopy should not be used for pharyngeal specimens.

Treatment

• Single-dose ceftriaxone i.m. (250 mg) treats uncomplicated anogenital infection

• Single-dose oral amoxicillin 3 g with probenecid 1 g, ciprofloxacin (500 mg) may be used in areas with low prevalence of antibiotic resistance.

Chlamydia Trachomatis (CT)

• Regularly found in association with other pathogens.

• Often asymptomatic.• In men: anterior urethritis,proctitis,epididymitis.• In women: vaginal discharge, postcoital or

intermenstrual bleeding and lower abdominal pain.

• Reactive arthritis has been related to infection with C. trachomatis.

Diagnosis

• NAAT investigation of choice. 90–95% sensitivity.

• Culture is the “gold standard”,100% specific, but expensive.

• In men: First void urine tested/urethral swabs.

• In women: Endocervical swabs.

Treatment

• Doxycyline 100mg po bd x 1 week OR• Azithromycin 1g po stat.

• Tetracyclines are contraindicated in pregnancy.

• Routine test of cure is not necessary after treatment with doxycycline or azithromycin.

• NAATs may remain positive for up to 5 weeks after treatment-picks up nonviable organism.

Syphilis

• Acquired or congenital

• Early and late stages

• Caused by Treponema pallidum (TP).

• Primary- between 10-90 days.

• Secondary-between 4-10 weeks.

• Individuals with either primary or secondary disease are highly infectious.

Congenital syphilis

• Apparent between 2nd to 6th weeks after birth.

• Early signs being nasal discharge, skin and mucous membrane lesions, and failure to thrive.

Investigations

Treponemal specific (highly specific)

• EIA

• TPHA

• FTA abs

• Does not differentiate between syphilis and other treponemal disease.ie: yaws.

• Test remains positive for life.

Treponemal non-specific:• VDRL • RPR• Positive within 3-4 weeks of primary

infection.• Used to monitor treatment efficacy and are

helpful in assessing disease activity.• Become negative by 6 months after

treatment in early syphilis.

Clinical use

• EIA screening test of choice. Detects IgM and IgG ab.

• A positive test is then confirmed with the TPHA/TPPA and VDRL/RPR tests

• All serological investigations may be negative in early primary syphilis.

• EIA IgM and the FTA-abs being the earliest tests to be positive.

Treatment

• Early syphilis-procaine benzylpenicillin.

• Late stage-course extended for a further week.

• If penicillin sensitive, treat with doxycyline or erythromycin for 2-4 weeks.

• If non-compliant-give single dose of benzathine penicillin G 2.4 g IM.

• Azithromycin is not recommended.

The Jarisch–Herxheimerreaction.

• Due to release of TNF-α, IL-6 and IL-8.• Occurs about 8 hours after first injection and

usually consists of mild fever, malaise and headache lasting several hours.

• Prednisone given for 24 hours prior to therapy may ameliorate the reaction-little evidence.

• Penicillin should not be withheld because of the Jarisch–Herxheimer reaction.