Australia Trachoma Surveillance Report 2011

Technical terms and definitions

Page last updated: 09 April 2013


These definitions are based on the 2006 CDNA Guidelines for the public health management of trachoma in Australia.

Active trachoma:

The presence of chronic inflammation of the conjunctiva caused by infection with Chlamydia trachomatis; includes World Health Organization grades trachomatous inflammation follicular (TF) and trachomatous inflammation intense (TI).

At-risk communities:

Communities classified by jurisdictions as being at higher risk of trachoma (generally based on prevalence above 5% in age group 5-9).

Clean face:

Absence of dirt, dust and crusting on cheeks and forehead.

Community screening coverage:

The number of communities screened for trachoma as a proportion of communities designated by jurisdictions to be at risk of trachoma.


Includes all members of the household or households in which a person with active trachoma regularly sleeps. However where the community prevalence was greater than 10% this term includes all members of the community, not only household members.

Endemic trachoma:

Prevalence of active trachoma of 5% or more in children aged 1-9 years or a prevalence of trichiasis of at least 0.1% in the adult population. Hyperendemic trachoma: Prevalence of active trachoma of 20% or more in children aged 1-9 years.

Prevalence of active trachoma:

Proportion of people found in a screening program to have active trachoma.

Screening coverage:

The proportion of people in a population examined for trachoma or trichiasis through a screening program.

Trachomatous inflammation follicular (TF):

Presence of five or more follicles in the upper tarsal conjunctiva, each at least 0.5 mm in diameter, as observed through a loupe.

Trachomatous inflammation intense (TI):

Pronounced inflammatory thickening of the tarsal conjunctiva that obscures more than half of the normal deep tarsal vessels.

Trachomatous trichiasis (TT):

Evidence of the recent removal of in-turned eyelashes or at least one eyelash rubbing on the eyeball.

Treatment coverage:

The proportion of people requiring treatment for trachoma under guidelines who actually received treatment.