What is the most reported STD in the US?
Chlamydia (C. Trachomatis)
Annual new infections of STDS:
50 million
Reason for number of new cases of bacterial STDs outnumbering existing cases:
They are treatable
Young people (15-24) represent what % of all new reported STIs?
50%
What patient group have the highest rate of STIs?
MSM
What patient group typically have lowest rate of STIs:
WSW
What is the most common species of Chlamydia:
Chlamydia Trachomatis
Chlamydia is a bacteria, but what makes it different from most bacteria?
They replicate ONLY within cells (intracellular pathogen). They LACK peptidoglycan.
C. Trachomatis is a common cause of:
Genital infection and conjunctivitis
Chlamydia characteristics:
Obligate intracellular pathogen (cannot make own ATP). Have a gram - like envelope but NO peptidoglycan. EB + RBs.
Two distinct stages of Chlamydia’s life cycle:
Elementary: infectious. Reticulate: replicative (will divide)
Elementary bodies characteristics versus Replicative Bodies:
Elementary= small with rigid cell wall and adapted for extracellular survival. Reticulate: adapted for intracellular growth.
Life Cycle of Chlamydia:
Elementary bodies infect > EBs become reticulate bodies > INCLUSION formed of RBs> elementary bodies formed and released for more infection. All within 72 hours.
What is the host of C. Trachomatis:
Humans are ONLY known host.
The two biovars of C. Trachomatis:
Trachoma and LGV
**After biovars, how is C. Trachomatis differentiated:
By SEROVARS, based on major outer membrane protein (MOMP) (each leads to a different immune response)
Tropism of C. Trachomatis:
Tropism for NON-CILIATED, columnary, cuboidal or transitional epithelial cells
Disease by C. Trachomatis is due to:
Destruction of epithelia and the pro inflammatory cytokine response.
Without treatment, C. Trachomatis can lead to what in women:
Fibrosis (fertility implicated)
Diseases caused by C. Trachomatis (5):
Trachoma. Inclusion conjunctivitis. STI/Urogenital infections. Lymphogranuloma venereum (LGV). Infant pneumonia
Serovars of C. Trachomatis that cause Trachoma:
A, B, Ba, C
Serovars of C. Trachomatis that cause disease of the urogenital tract:
D-K
**Serovars of C. Trachomatis that cause LGV:
L1-L3
Why are LGV serovars more invasive than other serovars
Because they replicate in phagocytes
Cause of Chronic Conjunctivitis:
C. Trachomatis. Destruction of conjunctiva and folding.
What is the leading cause of preventable blindness?
Chronic Chlamydia Conjunctivitis
Acute conjunctivitis in sexually active adults commonly caused by:
C. Trachomatis
Presentation of Neonatal Conjunctivitis:
5-12 days following birth > eyelid swelling and discharge.
Cause of Neonatal Conjunctivitis:
Neonate exposed at birth to C. Trachomatis
**C. Trachomatis UG Infection in Men- Symptoms:
Urethritis with dysuria. Thin urethral MUCOPURULENT discharge.
**C. Trachomatis infection in men may progress to:
Reiter Syndrome: Triad: urethritis, conjunctivitis, polyarthritis
*C. Trachomatis UG Infection in Women mainly:
80% are asymptomatic and they serve as reservoir for infection
C. Trachomatis UG Infection in Women- Symptoms:
Mucopurulent Discharge. May also lead to pelvic inflammatory disease
Most common age range for infection by C. Trachomatis:
20-24 (15-24 overall)
What type of C. Trachomatis infection is highly prevalent in Africa, Asia and S. America or associated with travel?
Lymphogranuloma Venereum (LGV)
**Presentation of Lymphogranuloma Venereum:
PAINLESS lesion/papule at site of infection with inguinal lymphadenopathy. Proctitis is a common result of lymphatic spread.
**Diagnosis of C. Trachomatis:
Must have EPITHELIAL CELLS > iodine identifies glycogen inclusions in RETICULATE bodies
**Test of Choice for C. Trachomatis Diagnosis:
Nucleic acid amplification from URINE or DISCHARGE (Also used for gonorrhoeae)
**Treatment of C. Trachomatis Infection:
Doxycycline or Macrolides