「Sexually-transmitted infections」の版間の差分

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**health education
 
**health education
 
**contact tracing
 
**contact tracing
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<math>R_0 = B \times C \times D</math>
 +
*<math>B</math>: transmission coefficient ←condoms, education
 +
*<math>C</math>: mean rate of partner change ←
 +
*<math>D</math>: mean duration of infectiousness ←

2021年4月16日 (金) 12:05時点における版

Definition

  • infections that are commonly transmitted by sexual activity
    • vaginal sex
    • anal sex
    • oral sex

Pathogen and disease

syphilis

  • Treponema pallidum
    • one of 3 major spirochaetes - leptospirosis and borrelia
  • 6 mil. new cases/2018
  • higher in female sex worker and MSM
  • diagnosis
    • non-treponemal - positive during active stage; sensitive, not specific
      • VDRL
      • RPR
    • treponemal - positive for lifelong; specific, not sensitive
      • TPHA
      • TPPA
      • FTA
non-treponemal positive non-treponemal negative
treponemal positive active syphilis past syphilis
treponemal negative other active disease nothing
  • difficulty of microscopy - endemic treponematoses
    • T. pallidum - Syphilis
    • T. ssp pertenue - Yaws
    • T. pallidum spp. endemicum - Bejel
    • T. carateum - Pinta
  • morphologically identical and serologically indistinguishable


  • maternal syphilis
    • congenital syphilis
      • neonatal presentation - poor prognosis
      • postnatal presentation - fair prognosis
  • importance of syphilis screening during pregnancy

genital herpes

  • Herpes simplex

chancroid

  • Haemophilus ducreyi
  • Azithromycin

lymphogranuloma venerum (LGV)

  • Chlamydia trachomatis L1,2,3
    • different serovars from genital chlamydiasis
  • rare; increasing among MSM in Europe and US

donovanosis (granuloma inguinale)

  • Krebsiella granulomatis
  • India, Papua New Guinea, Brazil, Caribbean
  • microscopy shows Donovan bodies similar to lieschmania

Chlamydia trachomatis serovars A, B, Ba, C

  • cervicitis and urethritis in females
  • urethritis in males
  • neonatal conjunctivitis
  • classical ocular trachoma
  • worldwide resistance against azithromycin

gonorrhea

  • Neisseria gonorrhoea
  • microscopic investigation tends to be false-negative in female gonorrhea

ophthalmia neonatorum

  • etiology
    • gonorrhea
    • chlamydia
    • herpes simplex
    • and more

human papilloma virus

Epidemiology

  • Syphilis in pregnancy > 350,000/year adverse birth outcome
  • Cervical cancer due to HPV
  • Infertility due to gonorrhea and chlamydia
  • HIV, needless to say


  • considerations
    • no significant non-human reservoirs
    • role of sexually active groups
    • highlye dependent upon human behavior


[math]\displaystyle{ R_0 = B \times C \times D }[/math]

  • [math]\displaystyle{ B }[/math]: transmission coefficient
  • [math]\displaystyle{ C }[/math]: mean rate of partner change
  • [math]\displaystyle{ D }[/math]: mean duration of infectiousness
  • mode of propagation
    • core groups ⇄ bridging population ⇄ general population
    • size of each group differs among different countries

Presentations

genital ulcer

  • herpes simplex
  • syphilis
  • chancroid
  • donovanosis
  • LGV
  • undetermined

urethral discharge

  • vaginal discharge
  • inguinal swelling
  • scrotal swelling
  • lower abdominal pain
  • neonatal conjunctivitis
  • warts/carcinoma
  • hepatitis
  • fever

Diagnosis

Treatment

  • WHO has published Tx guidelines for each of STIs
  • syndromic management algorithms, e.g. by MSF, are more effective in high STI burden situation without advanced diagnostics
    • disadvantages of over treatment
      • e.g. using penicillin, azithromycin and aciclovir for genital ulcer (against each of syiphilis, chancroid and HSV)
    • disadvantages for women
      • problems with partner notification; stigmatization
      • only symptomatic STIs treated

Control

  • Primary prevention
    • risk reduction
    • condom distribution
    • health education
    • vaccine
  • Secondary prevention
    • promote early healthcare seeking behavior
      • facility based
      • online self test; send self-sampling test kit
    • health education
    • contact tracing


[math]\displaystyle{ R_0 = B \times C \times D }[/math]

  • [math]\displaystyle{ B }[/math]: transmission coefficient ←condoms, education
  • [math]\displaystyle{ C }[/math]: mean rate of partner change ←
  • [math]\displaystyle{ D }[/math]: mean duration of infectiousness ←