This document discusses Chlamydia, an obligate intracellular parasite bacteria. It has two morphological forms, the elementary body and reticulate body, which undergo a developmental cycle within host cells. Three species are highlighted: C. trachomatis which infects humans, C. psittaci which infects birds, and C. pneumoniae. C. trachomatis is further discussed, as it can cause trachoma, a leading cause of preventable blindness. Trachoma is characterized by recurrent conjunctivitis and scarring. The SAFE strategy of surgery, antibiotics, facial cleanliness and environmental improvement is used to treat and prevent trachoma. C. trachomatis can also cause

1. CHLAMYDIA
DR. HARI BIKRAM ADHIKARI
HIMALAYA EYE HOSPITAL

2. INTRODUCTION  The bacteria in the taxonomic family
Chlamydiaceae
 Small (0.3–1 lm) obligate cell parasites
 Gram-negative cell wall
 Bacteria but similar to viruses

3. OBLIGATE PARASITES
 Obligate intracellular parasites of mammals and birds
 not transmitted by arthropods.
 incorrectly called the PLT viruses or Bedsonia or basophilic viruses,
 Multiply in the cytoplasm of the host cell.

4. SIMILAR TO VIRAL
INFECTIONS
 The methods used to study Chlamydia
are those of the virologist rather than the
bacteriologist.
 The clinical features, pathogenesis,
pathology and epidemiology of
chlamydial infections are similar to those
of viral infections.

5. ENERGY PARASITES  The cells can synthesize DNA, RNA and
protein.
 No flavoproteins or cytochromes.
 lack of ATP-generating ability
 need to obtain ATP from the host cell.

6. MORPHOLOGY AND DEVELOPMENTAL CYCLE.
Two morphologically and functionally
distinct forms are known:
 Elementary body
 Reticulate Body

7. CHLAMYDIAL MORPHOLOGIES
Elementary body
 metabolically inactive infectious forms
 0.25 - 0.3 um diameter
 electron-dense nucleoid
 Released from ruptured infected cells. Human to human & bird to human.
 EBs are resistant to many harsh environmental factors

8. CHLAMYDIAL MORPHOLOGIES
Reticulate Body
 metabolically active, noninfectious forms
 Intracytoplasmic form 0.5 - 1.0 um
 Replication and growth. ( Inclusion body )
 without a dense center.

9. 1.Elementary
body (EB)
attaches to
surface of cell.
2. Elementary
body enters by
endocytosis.
3. Elementary
body enters
endosome.
4. Elementary
bodies
reorganize into
reticulate bodies
(RB).

10. 5. Reticulate
bodies (RB)
replicate.
6. Reticulate
bodies (RB)
reorganize into
Elementary
bodies (EB)
7. Both RB and
EB reside in
inclusion
granule.
8. Reverse
endocytosis

11. THREE SPECIES:
C.
trachomatis
C. psittaci
C.
pneumoniae

12. CHLAMYDIA
TRACHOMATIS
infects only humans
Trachoma
Conjunctivitis
Proctitis
Urethritis
Salpingitis
Lymphogranuloma venereum

13. TRACHOMA
 Follicular keratoconjunctivitis
 One of the leading cause of preventable blindness
 Chronic, inflammatory granulomatous process of eye surface,
leading to corneal ulceration, scarring, pannus formation, and
blindness

14. PREDISPOSING
FACTORS:
climate - hot , dry
shortage of water
standards of hygiene low
Transmitted by flies, dirty towels, fingers, cosmetic eye pencils.
Initial infection in childhood mostly by 10-15 years of age.

15. FLIES ALSO PLAY A MAJOR ROLE IN THE
SPREAD OF THE DISEASE.
http://bjo.bmj.com/content/88/6/750.full

16. CLINICAL FEATURES
Early Active
stage
Late cicatrical
stage

18. CLINICAL FEATURES
Early Acive stage
 usually seen in childhood,
 Characterised by recurrent episodes of chronic, follicular
conjunctivitis.
 Follicles are subepithelial collections of lymphoid cells and appear
as small, yellow-white elevations on the conjunctiva of the everted
upper lid.
 Papillary hypertrophy (engorgement of small vessels with
surrounding oedema) also occurs and can obscure the deep tarsal
vessels if severe enough.

19. CLINICAL FEATURES
Early Acive stage
 Vascular infiltration of the upper cornea (pannus) may also develop in active disease, but this rarely
affects vision.
 Conjunctival follicles at the upper margin of the cornea leave shallow depressions after they resolve
known as ‘Herbert’s pits
Herberts
pit

20. CLINICAL FEATURES
Late Cicatrical stage
 conjunctival scarring
 Contraction of this scar tissue causes
 entropion
 Trichiasis
 Corneal opacity

21. WHO CLASSIFICATION
FISTO
1. TF: Trachomatous inflammation-follicular.
 The presence of five or more follicles (each >0.5 mm in diameter) in the upper tarsal
conjunctiva
2. TI : Trachomatous inflammation intense.
 This stage is diagnosed when pronounced inflammatory thickening of the upper tarsal
conjunctiva obscures more than half of the normal deep tarsal vessels
3. TS:Trachomatous scarring
 The presence of scarring in the tarsal conjunctiva
4. TT: Trachomatous trichiasis
 At least one lash rubs on the eyeball
5. CO: Corneal opacity
 Easily visible corneal opacity over the pupil

22. WHO CLASSIFICATION
a. Normal b. TF c. TI
d. TS e. TT f. CO

23. THE SAFE STRATEGY WAS
DEVELOPED BY WHO AS AN
APPROACH TO TREATMENT
AND PREVENTION OF
TRACHOMA.

24. SURGERY
http://www.cbmuk.org.uk/our-work/campaign/nicodems-story-NTDs-trachoma

25. ANTIBIOTICS
www.sightsavers.org/images/content/1785

26. FACIAL CLEANLINESS
http://fieldnotes.unicefusa.org/2011/06/effort_to_eliminate_trachoma.html

27. ENVIRONMENTAL IMPROVEMENT
http://fiaintl.org/fiaintl/myweb.php?hls=10021&id=7

28. OTHER DISEASES BY CHLAMYDIA TRACHOMITIS
Inclusion conjunctivitis.
• This is an acute,
purulent papillary
conjunctivitisthat may
affect neonates,
children, and adults
Genital infections
Lymphogranuloma
venereum.
• This venereal disease
(syn. Lymphogranuloma
inguinale, lymphopathia
venerea