Lecture 8: Trachoma and Teamwork Flashcards
(38 cards)
What is trachoma?
an infectious eye disease caused by chlamydia trachomatis
It is the leading infectious cause of ____ worldwide
blindness
What is unique about trachoma?
No animal reservoir, only found in humans
Which 3 countries recently eliminated trachoma in 2017?
Mexico, Oman, Morocco
Where is trachoma most highly prevalent and in what population?
5 countries in Sub Saharan Africa
Children with ocular infection <10y/o are primary reservoir
What kinds of diseases is chlamydia trachomatis associated with?
ocular (trachoma)
genitourinary (pelvic inflammatory diseases)
respiratory (pneumonia)
What are 4 characteristics of diseases caused by chlamydia trachomatis?
- infections that are long lasting w/out tx
- repeated infections (body does not retain immunologic memory of chlamydia)
- infections that are asymptomatic or minimal sx.
- infections that produce inflammation and scarring without tx (blindness in trachoma occurs over time- can often be minimally symptomatic until that point, scarring of fallopian tubes can result in ectopic pregnancy)
What kind of bacteria is chlamydia trachomatis?
obligate intracellular bacterium
What are the target cells of chlamydia trachomatis?
epithelial cells of endocervix and upper genital tract in women
conjunctiva, urethra, rectum in men and women
Does natural infection with chlamydia trachomatis protect against reinfection?
No
How is trachoma infection spread?
- direct contact with eye secretions
- spread via fomites (inanimate objects)
- eye seeking flies
What occurs for trachoma to be considered “active trachoma”?
ocular infection with chlamydia occurs
conjunctivital inflammation and follicle formation
transmission can lead to repeat infections
What is cicatricial disease and how does it occur?
Long term effects of chronic trachoma/reinfection:
- chronic inflammation and recurring infections leads to eyelid scarring and ingrown eyelashes
- longer exposure occurs leads to corneal opacification (scar tissue over the eye) and blindness
2 main clinical manifestations of trachoma?
active trachoma (inflammation) and cicatricial disease (scarring)
What criteria do flies need to be considered a vector of trachoma?
- be present in area
- come into contact with disease
- spread disease
- transfer disease to new hosts
Which fly species causes trachoma?
-M. SORBENS was the main species of flies that transmit trachoma from person to person
M domestica and C albiceps were also caught in fish bait traps but not enough were found on kids eyes
What does the trachoma graph show?
Over time recurring trachoma leads to blindness
infection as children leads to scarring + blindness as adults
Active trachoma symptoms?
majority asymptomatic
white inflammatory patches w/discharge
follicle
Cicatricial disease symptoms?
eyelid scarring
inward rolling of eyelid (entropion)
ingrown eyelashes (trichiasis)
blindness
Main risk factors for trachoma?
poverty, crowding, poor sanitation
Is trachoma diagnosed clinically or microscopically?
Clinically
using WHO clinical manifestation chart and pictures to make it easier to diagnose
What is GET2020?
Team founded in response to stop blinding trachoma
- Alliance between WHO and various NGOs
- Goal: to prevent BLINDNESS from trachoma
- Uses SAFE strategy
What is the SAFE strategy?
• Active Form
- Surgery (for trichiasis)
- Antibiotics
- Facial cleanliness
- Environmental improvements
AFE are used more widely for active trachoma*
S is done for more severe
How effective is surgery as tx and who is trained to do it?
- important that other providers are taught to do surgery because trachaisis can reoccur and can be pretty common
- improves visual acuity but doesn’t necessarily prevent blindness
- RNS are taught to do it
- epilation used when surgery not an option
