57 Trachoma
- Responsible for 3% of global blindness
2 million people world wide blindness with it.
The commonest infectious cause.
Organism: Chlamydia trachomatis
57.1 Clinical Progression
Active trachoma, inside of eyelid is thickened, inflammed, white spots (lymphoid follicles). (TF/TI)
This progresses to trachomatous scarring. (TS)
This scarring contracts and pulls the eyelid and eyelashes in, causing “trachomatois trichiasis” (TT)
This will result in a corneal opacity. (CO)
You usually see TF/TI in school age children.
57.2 Control
Organised by the Global Trachoma Mapping Project. 2.6 million people examined over 29 countries.
Most seen in Ethiopia (40% of Global Burden) and South Sudan.
SSA has majority of global burden
3.2 milllion people have trichiasis.
Initial aim was GET (Global Elimination Trachoma) 2020, the aim to eliminate it as a public health problem by 2020
So far: Nepal, Ghana, Iran have eliminated as a public health problem.
57.3 Bug: Chlamydia trachomatis
This is a different set of serovars than the ones that cause urogenital infection. Urogenital can sometimes affect eyes but not in the same way as opthalmic/endemic trachoma
57.4 Transmission
- Fingers: mucky kids poking each other in the eyes
- Fomites: towels
- Flies
Made worse by limited water/crowded conditions = worse for fingers and fomites
Made worse by no latrines/unclean environment = more flies
57.5 Infection and Disease
You get inoculated with bug, the eye swab will be PCR positive shortly after. You shortly after will get an epithelial infection, triggering inflammation, causing the “active disease”. So the infection may have resolved, but the inflammation, the disease, is persisting!
57.6 Strategy for Dealing With Trachoma: SAFE
- S Surgery
- A Antibiotics
- F Facial Cleansing
- E Environmental Improvements
57.6.1 Surgery
Over the last 20 years theres been a massive scale up in trachoma operations to clear the back log of surgeries required.
There are multiple barriers, how to find the cases, how to get patients to take it up getting well trained surgeons, practical resources needed, quality improvement.
1/5 have recurrent trichiases in one year after operation. 2/3 within 3 years.
It depends on how severe the trichiasis, how the wound healed (plus infection), what the surgeon did.
Practically, you can do a BLTR bilamellar tarsal rotation. Or you can do a PLTR, p = posterior, cutting just behind, but not actually cutting the eyelid skin. It only takes 15 minutes!
Which is better for avoiding recurrent trichiasis, PLTR! About half the rates.
It tends to be nurses trained to do eyelid surgery rather than opthalmology. Not necessarily ophthalmic nurses. Theres been a lot of effort to improve training in this, using a surgical.
You can these operations safely in a not full theatre environment, village based surgery. This will have a bigger uptake of surgery.
57.6.2 Antibiotics
By treating communities with antibiotics, you’ll reduce the duration of infection and inflammation. This is a population approach, not an individual. If you just treat some they’ll be reinfected by the others!
Topical tetracyclines remain treatment of choice for young children (<6 months)
But oral azithromycin is used for everyone else. Single dose, way more well tolerated, but pricier. However Pfizer are donating the meds for it.
Who needs treated? Only treating active disease patients would only catch 1/4 of those who were PCR positive.
WHO recommends that if the TF prevalence is > 10%, you should give MDA to everyone in the district. If les than 10% you should go from community to community. (And give MDA to communities >10%, and F+E to greater than 5%)
57.6.3 Face Washing and Environmental Improvements
Helps reduce transmission.
Trachoma is a community level disease, it needs community level interactions.