So I went to an interesting talk on the role of water and sanitation on incidence of Trachoma, and for the first time in recent memory, somebody besides me used the word “fomites”. So I naturally wanted to blog all about it.
Trachoma is an infectious eye disease caused by Chlamydia trachomitis. [Side note: inour lab safety training, the safety coordinator tells a story about how she got Chlamydia in her eye when she was working in the lab] A typical infection, which lasts for 5-12 days, causes conjunctivitis-like symptoms, with eye inflamation leading to irritation and discharge. If you visited the poorest of regions in Africa, Asia, the Middle East, and/or Latin America, and ended up with Trachoma, it’d be no big thing. Your doctor would hand you antibiotics like he always does and you’d keep on walking. But the locals who are continually re-infected with Trachoma end up with permanent blindness. The constant inflamation from repeat infections leads to entropian, a painful form of blindess, which (according to Wikipedia) is the leading cause of infectious blindness.
Gross.
So trachoma is spread through contact with eye, nose, and throat secretions. Either by direct contact, indirect contact via fomites, or indirect contact via vectors (like flies and cattle). People who like the F-diagram say it is spread through feces, flies, fomites, and fingers.
The fomites in question are thought to be items like towels, but the speaker mentioned that the cloths women use to wrap and hold their babies [is kitenge the right word? When i Googled it, i just got a bunch of photos of the whitest people wrapping random African-looking cloths around themselves and their sun-deprived babies, so there's probably a better word out there] rubs right against the baby’s eyes, allowing discharge from one infection to continually cause reinfection.
So secretions appear to be the main form of transmission, but the speaker’s premise for the talk was that sanitation would reduce incidence of Trachoma because it would remove feces from areas where individuals and flies had access. In general, promoting sanitation is always a great thing, but I’m not completely sold on its usefulness in combating an infectious disease spread through secretions.
And, perhaps, neither are the individuals at WHO working on its elimination who apparently rely heavily on the use of antibiotics to treat individuals, instead of trying to interrupt the transmission pathway.
