Codebook for "Trachoma prevalence and age-specific prevalence of anti-Pgp3 antibodies from Lower River Region and Upper River Region, The Gambia" blood_card_number: a unique identifying number for each individual, linked to a clinical sample normalised_od: The Pgp3-specific ELISA value, read at 450nm, of the sample od_3sd: coded 0/1 for sample considered negative/positive when threshold was set using a finite mixture model at 3 standard deviations of the negative population od_4sd: coded 0/1 for sample considered negative/positive when threshold was set using a finite mixture model at 4 standard deviations of the negative population gender: coded M for males, F for females ethnicity: string variable, describing ethnicity of study participant age_in_years: numeric variable giving age of participant when data was collected, Feb-March 2014 right_eye_tf: clinical examination of the right eye for trachomatous inflammation- follicular (TF): yes/no right_eye_ti: clinical examination of the right eye for trachomatous inflammation- intense (TI): yes/no right_eye_ts: clinical examination of the right eye for trachomatous scarring (TS): yes/no right_eye_tt: clinical examination of the right eye for trachomatous trichiasis (TT): yes/no right_eye_co: clinical examination of the right eye for corneal opacity (CO): yes/no left_eye_tf: clinical examination of the left eye for trachomatous inflammation- follicular: yes/no left_eye_ti: clinical examination of the left eye for trachomatous inflammation- intense: yes/no left_eye_ts: clinical examination of the left eye for trachomatous scarring: yes/no left_eye_tt: clinical examination of the left eye for trachomatous trichiasis: yes/no left_eye_co: clinical examination of the left eye for corneal opacity: yes/no any_tf: coded 0/1 for the presence of any TF, in either or both eyes any_ti: coded 0/1 for the presence of any TI, in either or both eyes any_ts: coded 0/1 for the presence of any TS, in either or both eyes any_tt: coded 0/1 for the presence of any TT, in either or both eyes any_co: coded 0/1 for the presence of any CO, in either or both eyes region: coded 1 for Lower River Region, coded 2 for Upper River Region age_recode: used to re-code ages as follows: 0 = 1-9 years old, 1 = 10-19, 2 = 20-29, 3 = 30-39, 4 = 40 and older