Chlamydia (Woychik) - 5/2/16

Question 1

“The Pirates of Chlam Island”

General Characteristics:

Answer 1

• Obligate intracellular bacteria (can’t create its own ATP)
• Poor gram staining
• Lack of muramic acid (component of PG that make up cell wall) - important in treatment options
• Inclusion bodies visible under microscope in infected cells

Life Cycle:

• Elementary stage - bacteria sits outside cell (infectious form)
• Reticular body - bacteria multiplies via binary fission (active form) [clam splits into 2 w/ 2 pearls]
• Release of newly replicated bacteria outside cell (back in elementary form –> cycle repeats)

Question 2

C. trachomatis

Clinical manifestations:

Complications:

Answer 2

Ocular trachoma - leading cause of blindness in the world –> chronic conjunctivitis –> progresses into scarring and blindness

Inclusion conjunctivitis - acute infection of conjunctiva

• In adults, >50% have concurrent genital tract infections
• In infants, usually acquired during passage through infected birth canal

Infant pneumonia

• 10-20% infants born to mothers with genital tract infections develop pneumonia
• staccato cough
• can be seen in babies that are born to mothers with gonorrhea as well (gonorrhea present earlier - within 2-4 days, chlamydia is about 1-2 weeks later)

Genital tract infections

• Most common cause of bacterial STI in US
• Symptoms can vary or remain asymptomatic: watery discharge (vs. gonorrhea that has white discharge)
• If you don’t have symptoms, can progress to PID –> ectopic pregnancies and infertility

Lymphogranuloma venereum (LGV)

• Infection of lymphatics specifically the inguinal nodes
• STD more common in tropical climates

Complications:

• PID –> infertility
• Reactive arthritis (Reiter’s Syndrome) - maladaptive autoimmune response (body tries to fight bacteria but antibodies cross-react and attack the joints) - knee

Triad of symptoms: Can’t see, can’t pee, can’t climb a tree

Question 3

Lab testing?

Answer 3

PCR-based tests (NAAT) from vaginal swab (women) or urine (men)

Can test for cervical cancer and chlamydia with single ThinPrep endocervical specimen

Question 4

Chlamydia pneumoniae

General info:

Transmission:

Clinical characteristics:

Treatment:

Answer 4

• Of 3 species of chlamydia, most common cause of human infection
• Most common among children ages 5-14 and elderly
• Direct transmission through respiratory secretions
• Atypical PNA (walking PNA) similar to mycoplasma and Legionella
• Mostly associated with mild URT but can also cause pneumonia or bronchitis

Treatment: Doxycycline first line, macrocodes second line

Question 5

Chlamydia psittaci

General info:

Tranmission:

Clinical characteristics:

Treatment:

Answer 5

• Also transmits PNA
• Category B level bioterrorism agent because it can be aerosolized
• Occurs in wide range of avian species but may infect other animals
• Usually latent in birds, activated with stress from recent captivity or transport
• Human-to-human transmission rare
• Transmitted by birds - often parrots

Clinical:

• Produces spectrum of clinical manifestations ranging from severe pneumonia to mild and undetectable infection–hard to diagnose
• Most common symptoms = fever, headache, sore throat; cough not present initially and usually only late in disease

Treatment:
- Macrolides (azithromycin)
(topical macrocodes aren’t effective for conjunctivitis in newborns - have to give them an oral form)
- Tetracyclines(doxycycline)

Co infection of chlamydia and gonorrhea so treat both (ceftriaxone to cover gonorrhea)