Trachoma
Non-genital Chlamydia trachomatis Eye Infection
Overview
- Caused by infection with a non-genital strain of Chlamydia trachomatis.
- Trachoma remains the leading infectious cause of preventable blindness worldwide.
- In Australia, it occurs almost exclusively in remote Aboriginal communities, particularly in the Northern Territory, South Australia, and Western Australia.
- Primarily affects young children.
- Highly contagious infection of the conjunctiva.
A community is classified as trachoma-endemic if:
- >5% of children aged 5–9 years have active trachoma (TF)
- >0.2% of adults, or >0.1% of the total population, have trichiasis (TT)
Transmission
- Spread via ocular and nasal secretions, particularly among children.
- Children may experience multiple reinfections per month.
Modes of transmission:
- Direct contact: eye-to-eye, fingers, during play or bed-sharing.
- Fomites: contaminated towels, bedding, clothing, face cloths.
- Respiratory droplets: coughing/sneezing.
- Vectors: eye-seeking flies.
Incubation and Infectious Period
- Incubation period: 5–10 days.
- Most clinical episodes are reinfections in children with ongoing active disease.
- Infectious period: 2–3 months.
- Shortens with age or repeated exposures.
Clinical Presentation and Disease Progression
- Active trachoma is frequently asymptomatic, particularly in its early stages. When symptomatic, children may present with red, irritated, or purulent eyes.
- With repeated infections, chronic inflammation leads to:
- Conjunctival scarring (trachomatous scarring)
- Eyelid contraction resulting in entropion (inward turning of the eyelid)
- Trachomatous trichiasis – inward-growing eyelashes that abrade the cornea
- This mechanical irritation causes corneal scarring and opacity, resulting in progressive visual impairment.
- Without surgical intervention to correct eyelid malposition, these changes may ultimately lead to blindness, typically 20–40 years after the initial infections.
- It is estimated that 150–200 reinfections are required to produce sight-threatening complications.
Differentials
- Conjunctivitis
- Infectious
- Viral
- Bacterial (e.g., staphylococcus and Chlamydia species)
- Noninfectious
- Allergic
- Dry eye
- Toxic or chemical reaction
- Contact lens use
- Occult conjunctival neoplasm
- Foreign body
- Factitious
- Idiopathic
- Infectious
- Keratitis
- Infectious
- Bacterial
- Viral
- Fungal
- Acanthamoeba
- Noninfectious
- Recurrent epithelial erosion
- Foreign body
- Infectious
- Uveitis
- Episcleritis/scleritis
- Acute glaucoma
- Eyelid abnormalities
- Entropion
- Lagophthalmos with globe exposure
- Trichiasis
- Molluscum contagiosum
- Orbital disorders
- Preseptal and orbital cellulitis
- Idiopathic orbital inflammation (pseudotumor)
Examination
- The ‘3Ts’ of trichiasis examination:
- Think to do it
- use a Thumb to lift the lid so the lashes lift away from the eye
- and use a Torch to provide enough light to see the dark lashes.
WHO simplified grading system for trachoma
 | Grade | Signs | |
| Infectious | TF | Trachomatous inflammation- Follicular | Presence of 5 or more follicles of >0.5mm in diameter on the upper tarsal conjunctiva |
| TI | Trachomatous inflammation – Intense | Presence of pronounced inflammatory thickening of the upper tarsal conjunctiva obscuring more than half of the normal deep tarsal vessels |
| Non-infectious | TS | Trachomatous conjunctival Scarring | Presence of easily visible scars on the upper tarsal conjunctiva |
| TT | Trachomatous Trichiasis | Presence of at least one in-grown eyelash touching the eyeball, or evidence of recent removal of in-turned lashes |
| CO | Corneal Opacity | Presence of corneal opacity blurring part of the pupil margin |
Diagnosis & Laboratory tests
- The diagnosis of active trachoma is based on clinical examination.
- Contacts of case need to be identified.
- to confirm trachoma infection are currently not recommended except perhaps to exclude other viral or bacterial infection
Screening
- ATSI children aged 5–9 years are screened in at-risk communities (via schools, child health records, etc.).
- Screening should include identification of cases and close contacts.
- Communities are classified as endemic if:
- 5% of children aged 5–9 have active trachoma
- 0.2% of adults or >0.1% of total population has trichiasis
Treatment
- General principles:
- All active cases and their contacts should be treated simultaneously.
- 100% of cases and ≥85% of contacts must receive treatment.
- Treatment is determined by community prevalence:
- Household-level treatment: for isolated cases.
- Mass drug administration: if trachoma is widespread.
- Medication:
- Single oral dose of azithromycin 20 mg/kg (max 1 g).
Azithromycin Treatment for Trachoma
- First-line treatment for both confirmed cases of active trachoma and their close contacts (≥3 kg) is:
- Azithromycin 20 mg/kg orally as a single dose (maximum 1000 mg).
- Contraindications:
- Known allergy to macrolides (e.g. azithromycin, erythromycin).
- Weight <3 kg.
- No other contraindications exist for single-dose azithromycin in this setting.
- In cases identified outside of scheduled community-wide screening, the index case and all household members should still receive treatment.
- Mass drug administration (MDA) using single-dose azithromycin is strongly supported by evidence as an effective strategy to reduce trachoma prevalence at the community level.
Screening and treatment schedule of contacts according to prevalence
| Trachoma prevalence in screened children aged 5-9 years | Treatment | Treatment frequency | Screening frequency |
| ≥20% | Single-dose azithromycin to people >3kg living in houses with children <15 years of age | 0, 6, 12, 18 & 24 months | Screen at 36 months after the initial screen (12 months after the 5th treatment)* |
| ≥5 to < 20% and there is no obvious clustering of cases | Single-dose azithromycin to people >3kg living in houses with children <15 years of age | 0, 12 & 24 months | Screen at 36 months after the initial screen (12 months after the 3rd treatment)* |
| ≥5 to < 20% and cases are obviously clustered within several households and health staff can easily identify all household contacts of cases | Single-dose azithromycin to people >3kg living in houses with an active trachoma case | Once at 0 months. Further treatment determined by prevalence at next screen | Screen at 1 year to determine prevalence |
| Age | Azithromycin Syrup | Azithromycin Tablets |
| Under 5 years | 1 bottle for every 2 children requiring treatment. | |
| 5-10 years | 1 bottle for every child requiring treatment. | |
| 10 – 12 years | 1.5 bottles for every child requiring treatment. | |
| Over 12 years | 1000mg = 2 x 500mg tablets for each person requiring treatment. |
✨ Non-Pharmacological Management of Trachoma
🧍♂️ Personal Hygiene
- Promote regular face and hand washing, especially in children.
- Aim to reduce ocular and nasal discharge that attracts flies and facilitates bacterial spread.
🌿 Environmental Improvements
- Improve access to clean water for hygiene.
- Ensure sanitation infrastructure (latrines, drainage).
- Promote waste management to reduce fly breeding grounds.
- Encourage reduction of household overcrowding to limit transmission.
🪰 Insect (Fly) Control
- Target Musca sorbens, the fly species that transmits Chlamydia trachomatis.
- Reduce breeding sites via proper waste disposal and latrine use.
- Install fly screens and promote insect control interventions.
📚 Education and Health Promotion
- Educate about trachoma transmission and prevention through:
- School-based programs.
- Community workshops.
- Visual aids and storytelling.
- Reinforce messages about face washing, fly control, and sanitation.
🔍 Community-Level Public Health Interventions
- Screening and surveys in endemic communities to detect early cases.
- Mass Drug Administration (MDA) with Azithromycin as part of control efforts.
- Contact tracing and treatment of family/close contacts.
- Integration with existing health programs (e.g. Strong Eyes Strong Communities).
✨ Culturally Safe Communication for ATSI Communities
Trust and Engagement
- Build rapport and engage in informal conversation (“have a yarn”) before clinical dialogue.
- Show respect for community norms, history, and lived experiences.
Language and Communication
- Use local Indigenous languages via Aboriginal Health Workers where possible.
- Ensure two-way communication that values patient input and understanding.
- Use visual aids, metaphor, and storytelling to explain medical concepts.
Community Involvement
- Partner with community leaders, Elders, and local organisations.
- Support community-designed initiatives for trachoma prevention.
- Acknowledge cultural protocols (e.g. gender roles, kinship obligations).
✨ WHO SAFE Strategy for Trachoma Control
| Component | Description |
|---|---|
| S – Surgery | For trichiasis, surgery prevents corneal scarring/blindness. |
| A – Antibiotics | Oral Azithromycin (single dose); Tetracycline eye ointment if contraindicated. |
| F – Facial Cleanliness | Promotion of face washing in children to reduce bacterial load. |
| E – Environmental Improvements | Access to water, sanitation, and reduced fly breeding areas. |
🔑 Note: Trachoma elimination requires integrated, community-wide efforts targeting all four SAFE components, especially in remote Aboriginal communities where it remains endemic.