INFECTION OF SEXUALLY TRANSMITTED INFECTION

• The incidence of sexually transmitted diseases has increased tremendously through the years. The age incidence has also increased not only in the adult population but more so among adolescents.
• Sexually transmitted infections (STI) are mostly caused by mixed infections and not just single organisms.

  
• Ways STIs can be acquired

  • Unprotected sex (vaginal, oral, or anal)
  • Skin to skin contact with the genital area
  • Blood transfusion
  • Perinatal transmission through transplacental transfer or during childbirth as the infant passes through the infected birth canal
• STIs are worldwide in distribution and can affect all age groups but sexually active individuals are the most vulnerable.
• Most common sexually transmitted infections

  • Neisseria gonorrhea
  • Haemophilus ducreyi
  • Treponema pallidum
  • Chlamydia trachomatis
  • HIV
  • Herpes simplex virus
  • Human papillomavirus
  • Hepatitis viruses
  • Zika virus
  • Candida albicans
  • Trichomonas vaginalis
  • Phthirus pubis

  
• Individuals at risk of sexually transmitted infections

  • Those who engage in unprotected sex
  • Those with multiple sexual partners
  • Rape victims
  • IV drug users who share needles
• Prevention and Control of Sexually Transmitted Infections

  • Practicing safe sex especially among travelers
  • Correct use of condoms can lessen the chances of contracting STIs
  • Avoiding sharing of needles and razors as well as getting tattoos, body piercings, or acupuncture treatments also lessen the risk of STI
  • Screening of blood donors is also being implemented to prevent the contraction of STIs
  • Available vaccines for the Human Papillomavirus (HPV) and Hepatitis B virus

  
• Components of the World Health Organization's Global strategy for the prevention and control of sexually transmitted infections

  • Technical - methods on the use of protective barriers, promotion of sexual behavior, accessibility to effective care system, and improved monitoring and evaluation of control strategies
  • Advocacy - addresses the need for an effective STI advocacy campaign to raise awareness and mobilize resources at the national and international level

  
• Education of the public on sexually transmitted infections, identification of infected individuals, contact tracing, and prompt treatment of infected individuals are important in preventing the spread of such infections.

  
• Clinical Manifestations of STIs

  • Skin Lesions
  • Discharge

  
• Skin Lesions


  • Ulcerative Lesions - Chancre, Chancroid, Genital herpes
  • Granulomatous reactions - typical of granuloma inguinale
  • Rashes - commonly seen in secondary syphilis, gonorrhea, and candidiasis
  • Warty lesions - characteristic of condylomata acuminata and molluscum contagiosum

  
• Vaginal Discharge


  • Trichomonas vaginalis - thin, foamy, foul smelling
  • Neisseria gonorrhea - greenish, purulent
  • Candida albicans - thick, cheesy exudates (milk curd like appearance)
• In males, any urethral discharge other than ejaculation is abnormal.
• Syphilis


  Caused by Treponema pallidum, a spirochete with fine regular coils with tapered ends. It is a strict human pathogen and is sensitive to oxygen. The organism cannot be grown in cell free culture medium.
• Modes of Transmission of Syphilis

  • Through direct sexual contact
  • Congenitally
  • Through blood transfusion
• Stages of Adult Syphilis

  • Primary syphilis
  • Secondary syphilis
  • Latent syphilis
  • Tertiary (late) syphilis
• Stages of Congenital Syphilis

  • Early congenital syphilis
  • Late congenital syphilis
• Laboratory Diagnosis of Syphilis

  • Dark field microscopy
  • Non specific treponemal test - VDRL and RPR
  • Specific treponemal test - Fluorescent Treponemal Antibody Absorption (FTA ABS)

  
• Treatment and Prevention of Syphilis

  The drug of choice is penicillin. Alternative drugs in cases of penicillin resistance or allergy are tetracycline or doxycycline. There is no vaccine for syphilis. It can be controlled through practice of safe sex and regular testing.
• Gonorrhea


  • Caused by Neisseria gonorrhoeae, gram negative diplococci. It has pili which are used for attachment to host cell, motility, transfer of genetic materials and plays an important role in the pathogenesis.
  • Females are asymptomatic carriers of the infection. The risk after single exposure is higher in females (50%) than in males (20%).

  
• Clinical Findings of Gonorrhea

  • Gonorrhea infection in males
  • Gonorrhea infection in females
  • Disseminated infections

  
• Laboratory Diagnosis of Gonorrhea

  Gram negative intracellular diplococci may be seen using microscopy. Culture using modified Thayer Martin medium as selective medium allows the growth of Neisseria only.

  
• Treatment and Prevention of Gonorrhea


  For uncomplicated gonorrhea, ceftriaxone, ciprofloxacin, cefixime, or ofloxacin are recommended. For mixed infection with Chlamydia, any of the aforementioned drugs must be combined with doxycycline or azithromycin. Prevention of ophthalmia neonatorum is through the use of 1% silver nitrate or 0.5% erythromycin or tetracycline eye ointment.

  
• Lymphogranuloma Venereum (LGV)


  Caused by Chlamydia trachomatis, obligate intracellular bacteria that do not have cell walls. Serovars D to K are associated with non gonococcal urethritis, cervicitis, and PID while serovars L1, L2, and L3 are associated with lymphogranuloma venereum.

  
• Clinical Findings of Lymphogranuloma Venereum

  • Urogenital tract infections
  • Lymphogranuloma venereum

  
• Laboratory Diagnosis of Lymphogranuloma Venereum


  The organism can be visualized using Giemsa stained specimen obtained from scrapings from the lesion. Culture is the most specific diagnostic method.

  
• Treatment and Prevention of Lymphogranuloma Venereum

  Treatment of the infection involves giving of azithromycin, doxycycline, or erythromycin.

  
• Chancroid


  The etiologic agent is Haemophilus ducreyi, a gram negative coccobacillus. Haemophilus means "blood loving" and must be grown in culture medium containing blood. It only requires hemin (X factor) for growth which is derived from the blood in the culture medium.
• Clinical Findings of Chancroid

  • Chancroid presents with a soft, painful papule with an erythematous base that develops into an ulcer with ragged edges associated with inguinal lymphadenopathy.

  
• Laboratory Diagnosis of Chancroid

  Definitive diagnosis is made through culture on at least two kinds of enriched media containing vancomycin.

  
• Treatment and Prevention of Chancroid

  Antibiotics for treatment include cephalosporins, azithromycin, erythromycin, or ciprofloxacin.
• Genital Herpes


  Caused by Herpes Simplex Virus (HSV), a DNA virus under the family of Human Herpesviridae. There are two types of HSV, type 1 and type 2. The virus is capable of latency in the neurons hence the occurrence of recurrent infections.

  
• Modes of Transmission of Genital Herpes

  The main mode of transmission is through oral sex.
• Haemophilus


  Means "blood loving" and must be grown in culture medium containing blood
• Hemin (X factor)


  Derived from the blood in the culture medium, required for Haemophilus growth
• Genital herpes


  Caused by Herpes Simplex Virus (HSV), a DNA virus under the family of Human Herpesviridae

  
• HSV types


  Type 1 and type 2
• Majority of genital herpes cases are caused by HSV type 2

  
• Condylomata acuminata


  Caused by the Human papillomavirus (HPV) (serotypes 6 and 11), a DNA virus under the family of Papillomaviruses that is transmitted through sexual contact

  
• HPV serotypes


  Serotypes 6 and 11 are most commonly associated with condylomata acuminata, while serotypes 16 and 18 are associated with cervical and penile cancer