Sexually transmitted infection

STI. Epidemiology, Prevention and Treatment

Most common?
Human papilloma virus infection Syphilis Genital herpes Genital chlamydiosis HIV Gonorrhoea Hepatitis B Trichomoniasis

Most significant?

Human papilloma virus infection Syphilis Genital herpes Genital chlamydiosis HIV Gonorrhoea Hepatitis B Trichomoniasis

Significance

In relation to the health of the population of a country or territory in general ... ... or of particular populationsDetermined by a range of factors:PrevalenceSeverity of acute symptomatologyTransmissibility – preventability CurabilityLong term consequences or complications

General Information

20 million new infections cost $16 billion in medical costs (CDC, 2013)Most STI’s are caused by viral or bacterial Protozoal, Fungal, Ectoparasites infectionsBacterial = usually curableComplications caused by bacterial infection may be irreversibleViral = usually treatable, not curableSTI’s may be asymptomatic, esp. in women

General Information

Transmission: vaginal sex, anal sex, oral sex Other Breastfeeding: if have chlamydia or gonorrhea; syphilis and herpes = can transmit via sores; HIV = can transmit. Kissing: herpes, syphilis (outbreak), hepatitis B Injection drug users Mother to fetus: syphilis & HIV. Vaginal delivery: gonorrhea, chlamydia, hepatitis B, herpes

Causes for increased prevalence

Increased promiscuity and multiple sex partners Better understanding of modes of transmission Better screening tests Antibiotic resistance Increasing DNA virus infection

SOCIAL FACTORS

Prostitution Broken homes Sexual disharmony Easy money Emotional immaturity Urbanization & industrialization

SOCIAL FACTORS (contd)

Social disruption International travel Changing behavioural patterns Social stigma Alcoholism

Testing Information

Sexually Transmitted Infection
Test Used
Chlamydia
Swab of discharge, urine test, exam
Gonorrhea
Swab of discharge, urine test, exam
Herpes
Swab from cells, blood test
HIV
Blood test, swab from mouth
HPV
Physical exam for warts, pap exam for women tests for cervical abnormalities (no such test for men)
Syphilis
Blood test, sample from sore

Human Papilloma Virus

Non-enveloped DNA virus Replicates exclusively in epithelial cells Transmitted by skin to skin contact with micro abrasions Enters cell and modifies cell cycle to maximise further transmissibility Naturally cleared in months to years Median duration of infection 8 months, 9% persistent after 2 years Persistence related to: Infection with multiple types Infection with high risk types

HPV associated disease

>100 genetically related types Different types adapted for different skin areas Types 16 & 18 (and others) strongly associated with cervical carcinoma Types 6 & 11 (and others) associated with visible anogenital warts Some types also associated with anal, penile and oral cancers.

Genital warts: treatment

Lots of different approaches – nothing is perfect!Most treatment is cosmetic not curativeVery high recurrence ratesImiquimod cream (Aldara®) Induces local immune response5% cream applied 3x/week for up to 16 wksResponse is delayedLower recurrence rateContraindicated in pregnancyExpensive!

First line treatment:

Podophylotoxin Diathermy Cryotherapy Imiquimod Surgical excision Nothing Something else

HPV: Cervical cancer

Importance of screening programs Potential impact of HPV vaccines

HPV Vaccines

Vaccines for several HPV strains HPV Vaccine Safety Gardasil FDA approved for males & females, age 9-26 yrs 3 injections across 6 months Protects against four high-risk HPV types (6, 11, 16, 18) Cervarix FDA approved for females, aged 10-25 3 injections Protects against HPV types 16, 18



Genital herpes
Caused by two types of DNA viruses herpes simplex 1 & 2 (HSV 1 & 2 = HHV 1 & 2)Other herpesviruses that cause human diseases :HHV3 (Varicella zoster) Chickenpox/shinglesHHV4 (Ebstein-Barr virus) infectious mononucleosisHHV5 (Cytomegalovirus)HHV6 & 7 (Roseola infantum)HHV8 (Kaposi’s sarcoma)

Genital herpes

HSV spread by skin to skin or mucosa to mucosa contact with frictionPrimary infection at site of entry then lifelong infection of sensory dorsal ganglia supplying infected skin/mucosa‘Originally’ HSV1 – oral ‘cold sores’HSV2 – genital herpesNow primary HSV1 is common cause of genital herpes in developed countries

Genital herpes

1 – 26 days (usually 6 – 8 days) after first acquisition – primary infectionComplications of primary infection include urinary retention, aseptic meningitis and rarely transverse myelitisFirst clinical episode is not always primary infection

Clinical course of episode

Prodromal tingling  vesicles  ulcers  crusts  healingAll takes 5 – 7 days but active HSV infection is the first 48 hours – after that it is just healing Need to treat episode within first 48 hours or not worth it (except in people with HIV)

Genital herpes treatment

Setting
Drug
Duration
First episode
aciclovir 200mg 5x/dayvalaciclovir 500mg – 1g 2x/dayfamciclovir 250mg 3x/day 5 – 10 days Episodic therapy for recurrent disease (patient initiated)
aciclovir 200mg 5x/day valaciclovir 500mg 2x/day famciclovir 125mg 2x/day
5 days 3 days 5 days
Continuous suppressive therapy
aciclovir 400mg 2x/dayvalaciclovir 500mg – 1g dailyfamciclovir 250mg 2x/day All safe and effective for long term use – but expensive!


Genital herpes treatment
Setting
Drug
Duration
First episode
aciclovir 200mg 5x/dayvalaciclovir 500mg – 1g 2x/dayfamciclovir 250mg 3x/day 5 – 10 days Episodic therapy for recurrent disease (patient initiated)
aciclovir 200mg 5x/day valaciclovir 500mg 2x/day famciclovir 125mg 2x/day
5 days 3 days 5 days
Continuous suppressive therapy
aciclovir 400mg 2x/dayvalaciclovir 500mg – 1g dailyfamciclovir 250mg 2x/day All safe and effective for long term use – but expensive!

Genital herpes treatment

Setting
Drug
Duration
First episode
aciclovir 200mg 5x/dayvalaciclovir 500mg – 1g 2x/dayfamciclovir 250mg 3x/day 5 – 10 days Episodic therapy for recurrent disease (patient initiated)
aciclovir 200mg 5x/day valaciclovir 500mg 2x/day famciclovir 125mg 2x/day
5 days 3 days 5 days
Continuous suppressive therapy
aciclovir 400mg 2x/dayvalaciclovir 500mg – 1g dailyfamciclovir 250mg 2x/day All safe and effective for long term use – but expensive! Some evidence of survival benefit in people with HIV who have HSV if HSV treated Continuous suppressive therapy certainly worthwhile if symptomatic

Syphilis

Caused by a spirochaete (spiral bacterium): Treponema pallidum Transmitted by skin to skin or mucous membrane contact with abrasion Four classical stages: Primary Secondary Latent Tertiary Early syphilis is not always classical

Primary syphilis

9 – 90 days after exposure.Appearance of chancre at site of exposure.Usually single, painless, indurated, sharply defined edges.Can often be missed (if not penile!).Disappears in 3 to 6 weeks if not treated.

Secondary syphilis

6 weeks to 6 months after primary infection In ~1/3rd chancre will still be present Fever, malaise, headache, myalgia Rash in 80-90% Classically dark pink macules. Can affect palms and soles Transient or can last weeks

Secondary syphilis

Secondary syphilis
Mouth ulcers – multiple Can coalesce  ‘snail track’ ulcersRash on scalp can cause hair lossGenital lesions – condylomata lataRarely neurological complications:Aseptic meningitisCranial nerve palsiesMore common in people with HIVRarely glomerulonephritis, hepatitis

Latent syphilis

AsymptomaticNow divided into:Early latent:Six months to 2 years (1 year in USA)Still considered ‘infectious syphilis’Late latent:> 2 years (1 year in USA) and asymptomaticCondsidered ‘late syphilis’ Can still be transmitted from mother to child


Tertiary syphilis
Four to 30+ years from primary infectionApproximately 1/3rd of patients untreatedGummatous (‘benign’)CardiovascularNeurosyphilis

Diagnosis of syphilis

Dark ground illumination of fluid from chancre T. pallidum PCR from chancre fluid Serological testing: 1. Non-treponemal tests: VDRL (Venereal Disease Research Laboratories) RPR (Rapid Plasma Reagin) 2. Treponemal specific tests: T. Pallidum haemagglutination assay (TPHA) Flourescent treponenal Ab absorbtion (FTA-ABS) Treponemal IgG immunoassays

Syphilis serology

Non-specific tests (RPR or VDRL) are either reactive or non-reactive ... But can measure level of reactivity through dilution

Congenital syphilis

Occurs when woman with secondary or early latent becomes pregnant or woman has secondary syphilis during pregnancy40% stillborn40-70% of survivors infected (in utero), of whom 12% will die in infancyLiver, spleen and bony abnormalitiesHutchison’s triad: deafness, Hutchinson’s teeth, interstitial keratitis

Congenital syphilis

Syphilis New Therapies
Penicillin G (an injectable) remains the first line treatment Limited data support the use of Azithromycin (in a one-time oral dose) as an alternative regimen Azithromycin 2 gm orally in a single dose as treatment for early syphilis Azithromycin 1 gm orally in a single dose as prophylactic treatment for contacts to infectious syphilis Has not been well-studied in HIV + patients; larger trials ongoing Cefrtiaxone almost certainly effective, but best dose/duration has not been established

Chlamydia Infection

Most common reportable disease in the U.S. Estimated 3million cases annually Incidence is highest among sexually active adolescents and young adults Most infections are asymptomatic Leading cause of preventable infertility in women or vertical transmission during child birth leads to conjenctivitis in Newborn Men : urethritis with possible epiddidymitis Treatment : Doxycycline or Azithromycin

Chlamydia Infections in Women, Men, and Neonates

Genitals Cervicitis PID Urethritis Eye (Conjunctivitis) Throat (Pharyngitis) Rectum (Proctitis)
Eye (conjunctivitis) Lungs (pneumonia)
70-80% ASYMPTOMATIC
Genitals(Urethritis)(Epididymitis)Rectum(Proctitis)Throat (Pharyngitis) Eye(Conjunctivitis)Systemic(Reiter’s Syndrome) >50% ASYMPTOMATIC

Chlamydia: complications

Pelvic inflammatory disease (~40% of untreated women) Female Infertility Early spontaneous abortion Premature labour Neonatal eye disease Epididymitis Male infertility.

Chlamydia Screening Recommendations

All sexually active women under 26 yrs Initial screen Repeat annually Consider repeat with new or multiple sex partners Repeat 2-3 months after an infection All pregnant women under 26 yrs Men, and women 26 and older, consider with New or multiple sex partners, Inconsistent condom use

Urine-Based CT Tests

Highly accurate Non-invasive collection High patient acceptability Only test appropriate for screening asymptomatic males Screening in non-clinical settings Community settings Home testing

Chlamydia: KEY POINTS

Most common bacterial (curable) STD Most cases in women and men give no symptoms Leading cause of PID and infertility in women All sexually active women 25 y.o.a. and younger should be tested at least annually

Gonorrhea

Gonorrhea Infection
Caused by Neisseria gonorrhoeae Overall rates falling, but incidence in certain groups remains high Most common in the reproductive age group (menarche to menopause) Incubation period -2 to 10 days CT co-infection of GC cases remains at about 40% Resistance to medication is an spreading problem

About Gonorrhea

Incidence US: 321,849 cases reported to CDC in 2011 Bacterial infection Gonorrhea can be passed via vaginal, oral, anal intercourse, mother to child (vaginal delivery)

Gonorrhea Infections in Men, Women and Neonates

Men are usually symptomatic (urethra), women are commonly asymptomatic Men: urethral infection, epididymitis Usually gives pain with urination and heavy, thick penile discharge; few may be asymptomatic carriers Women: cervical infection, PID ~50% women asymptomatic, others have pain with urination, vaginal discharge or bleeding Other sites of infection: throat, rectum, eye Neonates: eye and skin infections

Microbiology

Etiologic agent: Neisseria gonorrhoeae Gram-negative intracellular diplococcus Infects mucus-secreting epithelial cells
Pathogenesis

Genital Infection in Men

Urethritis – Inflammation of urethraEpididymitis – Inflammation of the epididymis Clinical Manifestations

Male Urethritis

Symptoms Typically purulent or mucopurulent urethral discharge Often accompanied by dysuria Discharge may be clear or cloudy Asymptomatic in 10% of cases Incubation period: usually 1-14 days for symptomatic disease, but may be longer
Clinical Manifestations

Genital Infection in Women

Most infections are asymptomaticCervicitis – inflammation of the cervixUrethritis – inflammation of the urethra Clinical Manifestations

Cervicitis

Clinical findings: mucopurulent or purulent cervical discharge, easily induced cervical bleeding 50% of women with clinical cervicitis have no symptoms Non-specific symptoms: abnormal vaginal discharge, intermenstrual bleeding, dysuria, lower abdominal pain, or dyspareunia Incubation period unclear, but symptoms may occur within 10 days of infection
Clinical Manifestations

Urethritis

Symptoms: dysuria, however, most women are asymptomatic 40%-60% of women with cervical gonococcal infection may have urethral infection
Clinical Manifestations

Syndromes in Men and Women

Anorectal infection Pharyngeal infection Conjunctivitis Disseminated gonococcal infection (DGI)
Clinical Manifestations

Gonorrhea Infection in Children

Perinatal: infections of the conjunctiva, pharynx, respiratory tract Older children (>1 year): considered possible evidence of sexual abuse
Clinical Manifestations

Antimicrobial Susceptibility of N. gonorrhoeae

Fluoroquinolones are no longer recommended for therapy for gonorrhea acquired in Asia, the Pacific Islands (including Hawaii), and California. CDC no longer recommends fluoroquinolones as a first-line therapy for gonorrhea.
Management

Special Considerations: Pregnancy

Pregnant women should NOT be treated with quinolones or tetracyclines Treat with alternate cephalosporin If cephalosporin is not tolerated, treat with spectinomycin 2 g IM once
Management

GC Management

Ciprofloxacin , spectinomycin , cetriaxone Is used for treatment Transmissibility: Male to female: 50 - 90% Female to male: 20 - 80% Partners with contact during the 60 days preceding the diagnosis should be evaluated, tested and treated If no sex partners in previous 60 days, treat the most recent partner

Screening

PregnancyA test for N. gonorrhoeae should be performed at the first prenatal visit for women at risk or those living in an area in which the prevalence of N. gonorrhoeae is high.Repeat test during the 3rd trimester for those at continued risk.Other populations can be screened based on local disease prevalence and patient’s risk behaviors. Prevention

Gonorrhea Infection in Women:Complications

Untreated genital GC infection
Ectopic pregnancy
Infertility
Chronic pelvic pain
Acute PID Silent PID
9%
14-20%
18%
20-50%

GonorrheaScreening Recommendations

Targeted screening: consider in Populations with prevalence of 1-2% or more MSM High-risk women Young age New or multiple partners Pregnant women

Hepatitis B

DNA virus Body fluid transmission Transmissibility varies with viral load
HBeAg positivity = highly transmissible Transmitted from mother to child at time of delivery: 20% if HBeAg negative 90% if HBeAg positive


Hepatitis B
~10% prevalence in most Pacific Islands = ‘endemic’If acquired at birth 95% develop lifelong infectionIf acquired later 70-95% clear infection and develop immunityIf lifelong infection, 40% will die from cirrhosis or liver cancer

Trichomoniasis

Caused by protozoanTrichomonas vaginalisAt least 50% asymptomaticCauses vaginitis in women Causes urethritis in men (rarely)Yellowish ‘fishy’ discharge‘Strawberry cervix’

Trichomoniasis

Diagnosed on wet mount of vaginal discharge: see moving organisms must be done straight away2 – 3 x increase in risk of HIV acquisitionTreated with metronidazole or tinidazole Sorvillo F. Trichomonas vaginalis, HIV, and African-Americans. Emerging Infectious Diseases 7(6):927-32, 2001


Consequences of STIs: Female reproductive morbidity Pelvic inflammatory disease. Ectopic pregnancy. Infertility. Chronic pelvic pain. STI Related neoplasia: Cervical cancer, anal cancer, liver cancer 7. Adverse perinatal outcomes: congenital infection

Prevention

Communicate with all sex partners regarding STI. Refrain from sexual activity Condoms may help prevent transmission

Pubic Lice (Crabs)

Pubic lice are tiny insects that can crawl from the pubic hair of one person to the pubic hair of another person during sex. Use medication that kills the lice and their eggs. dry clean or use very hot water to wash all bedding, towels, or recently worn clothing to kill the lice. Pubic lice can be spread even when use a condom.

CONTROL

Initial Planning Intervention Strategies Support components Monitoring & Evaluation