Chlamydia

Question 1

How to classify?

Answer 1

Obligate intracellular pathogens with almost no peptidoglycan (muramic acid in cell wall) -> cannot stain with gram stain

Question 2

Treatment

Answer 2

Doxycycline, macrolides, quinolones

Question 3

Where can they be cultured on?

Answer 3

Grow in vacuoles in host cells and can be seen after staining (inclusion bodies)
Cannot be cultured on agar/media

Question 4

What are the 3 species? How are they spread?

Answer 4

C.trachomatis - human to human
Ch.pneumoniae - human to human respiratory infection
Ch. psittaci - animal source usually bird respiratory infection

Question 5

What are the 3 variants and diseases of C.trachomatis?

Answer 5

1. Trachoma (A-C) - eye disease
2. Lymphogranuloma venereum (L1-L3) - STI
3. Chlamydia (D-K) - common STI (also cause eye disease)

Question 6

How is C.trachomatis trachoma spread?

Answer 6

Fingers, flies (important means of transmission), fomites

Question 7

What does C.trachomatis trachoma cause?

Answer 7

Recurrent eye infection leads to scarring of eyelids (eyelashes turn in -> corneal damage and clouding) and eventual blindness

Question 8

What is C.trachomatis Lymphogranuloma venereum?

Answer 8

Genitalium ulcer disease - sexually transmitted infection

Question 9

What does C.trachomatis Lymphogranuloma venereum cause?

Answer 9

• Papule/vesicle/ulcer on genitals
• Lymph nodes enlarge and suppurate (Elephantiasis of genitals when lymph cannot drain properly)
• Proctitis (females and male homsosexuals)

Question 10

Where and who does C.trachomatis Lymphogranuloma venereum occur in?

Answer 10

Mostly tropics and subtropics
Resurgence in developed countries in men who have sex with men

Question 11

What does C.trachomatis Chlamydia cause in males?

Answer 11

1. Urethritis (NGU/PGU, epididymitis)
2. Proctitis in MSM
3. Reiter’s syndrome (reactive arthritis, conjunctivitis/uveitis, urethritis)

Question 12

What do males with C.trachomatis Chlamydia feel?

Answer 12

Painful so they seek help and get treated

Question 13

What is C.trachomatis Chlamydia?

Answer 13

Very common STI

Question 14

What does C.trachomatis Chlamydia cause in females?

Answer 14

• Cervicitis (endocervical canal)
• Most are asymptomatic but lead to ascending infections (acute salpingitis, pelvic infectious disease), urethritis, proctitis, reactive arthritis

Question 15

What does CDC recommend for females who might potentially have C.trachomatis Chlamydia?

Answer 15

Annual screening for sexually active women <25y/o and older women with risk factors - new partner(s), partner with a partner or STI

Question 16

What do females with C.trachomatis Chlamydia feel?

Answer 16

Silent so don’t get treated

Question 17

How does C.trachomatis Chlamydia cause eye infections in adults?

Answer 17

Autoinfection via fingers (adult inclusion conjunctivitis)

Question 18

What does C.trachomatis Chlamydia cause in neonates? What do they need?

Answer 18

Ophthalmia neonatorum
Need systemic treatment and mum needs STI referral

Question 19

How to diagnose C.trachomatis?

Answer 19

Molecular methods are the best as it is sensitive, specific, automated (nucleic acid tests, urine/swabs from genitals/eyes/ulcers)
-Immunoassays replaced by NAT
-Serology not very useful
-Cell culture not sensitive and labour intensive

Question 20

Which body part does C.pneumoniae infect and in who?

Answer 20

Upper and lower respiratory tract
Pneumonia, bronchitis, sinusitis in older children and adults

Atypical pneumonia in young adults

Question 21

What is the route of transmission of C.pneumoniae?

Answer 21

Person to person

Question 22

How is C.psittaci acquired?

Answer 22

Birds
Does not spread from person to person

Question 23

What does C.psittaci cause?

Answer 23

Atypical pneumonia