Guidelines for Elimination of Blinding Trachoma
Recommendations from World Health Organization Global Scientific and Informal Meetings
Sheila West, PhD
Dana Center for Preventive Ophthalmology
Wilmer Eye Institute
Baltimore MD
Background
1997: WHO establishes the Global Alliance for the
Elimination of Blinding Trachoma by 2020 (GET2020)
1998: World Health Assembly signs resolution endorsing the
Alliance and encourages countries to eliminate trachoma
(WHA 51.11)
What is meant by Elimination?
Trachoma Signs
Ultimate Intervention Goals
Follicular Trachoma: TF
Intense Trachoma : TI
Prevalence of TF <5% in 1-9
year olds
Scarring Trachoma: TS
Trachomatous Trichiasis: TT
Corneal Opacity: CO
Prevalence of TT is <0.1% in
pop’n
Intervention: SAFE
“S” : Surgery targets TT-prevention of
immediate blindness
“AFE” : Antibiotic, Facial cleanliness,
environmental change:
Targets active trachoma, by reduction of
community pool of infection, and efforts to
reduce transmission, re-emergence
Prevention of blindness in long term
How do we operationalize UIGS
District
<5% TF
1-9 yo
100,00-250,000 people
Mapping/Baseline Survey
>10% TF
1-9 yo
5-9% TF
1-9 yo
No need for AFE
F and E for at least 3
years, targeted A
AFE for at least 3
years then impact
survey
Updates to Operationalization
District
IF: there is some evidence that trachoma is widespread and
highly endemic
THEN: a survey at super-district (regional) can be conducted
BUT: if survey results are TF<10%, then district level data will
be needed to plan a programme
Updates to Operationalization
District
100,00-250,000 people
Mapping/Baseline Survey
IF: If prevalence is ≥30%,
Impact surveys non informative
before 5 years of AFE
Aim for 100% coverage
Do not have interrupted treatment
>10% TF
1-9 yo
AFE for at least 3
years then impact
survey
How do we declare reaching UIG?
<5% TF
1-9 yo
No need for AFE
District
Impact/Outcome Survey
Proportion of villages at each prevalence when
mean=<5%
0.25
0.2
0.15
Proportion of villages
at each prevalence
when mean=<5%
% villages
0.1
0.05
0
0 1 2 3 4 5 6 7 8 9 10 11
Prevalence of Trachoma
How do we declare reaching UIG?
<5% TF
1-9 yo
District
Impact/Outcome Survey
5-9% TF 1-9 yo
Survey at SUB district level
>10% TF 1-9 yo
<5% TF
1-9 yo
5-9% TF 1-9 yo
F and E, no A
If all <5%, declare
UIG
AFE for at least 3 years
then impact survey
F and E for at least 3
years, targeted A
Surveys at Sub District Level
Sub district:
Stratification to make units more homogeneous for trachoma
-geographical information on hotspots
-absence of infrastructure suggesting higher rates
-sum of # of sub-units=district
Cannot be smaller than 3 villages
Survey precision is 4% +/- 2%
Surgery UIG: <1/1,000 TT pop’n
2005 WHO Working Group recommendation for elimination
“Satisfactory implementation of a program to reduce the
prevalence of trachomatous trichiasis through identification
and surgical management through the health system, with a
commitment to reach the Ultimate Intervention Goal of less
than 1 case of TT (refusals, recurrences, and incident cases) per
1,000 population”
Operationalize UIG for Surgery
At district level, <1/1,000 total population of TT cases unknown
to health system
“known”: operated, refusals, recurrent cases, listed but
not yet operated
“unknown”: in population and not recorded by health
system
Health system is able to identify and manage incident TT cases
Report recurrence rate as part of HIS with a target of recurrence
<10% at one year
Activities After UIGs are Met
Surveillance
Documents for Elimination
• Surveys to document elimination
1. Sub district surveys where TF <5%
2. Demonstrate sustained reduction of TF at least 3 years
after A stopped
• Evidence that district TT is <1/1,000 pop’n &health system is
able to detect, provide treatment and follow up TT cases
• Evidence of surveillance activities to detect and respond to
resurgent TF and incident TT
Timeline for Elimination
Surveys reveal
Sustained TF<5%
Surveys reveal TF<5%
A can be stopped
A activities stop
1 yr
2 yr
Implement surveillance activities
Create reporting network,
plan surveillance activities,
test in early success areas
Verify reports
Verify response if
new surge found
3 yr
Objectives of Surveillance System
1. Monitor the prevalence of TF to detect and
respond to potential resurgence
2. Ensure that routine eye care services are operating
incident and recurrent TT cases and monitoring
incidence to detect any unknown cases
Monitor the prevalence of TF to detect and
respond to potential resurgence
• Select 2 communities per district per year biased to the least
developed and suspected most endemic
Examine all school entrance-aged children where
attendance is >90% and there is no gender bias
Examine a minimum of 50 children in the community (5±2
years), but if feasible examine all
Monitor the prevalence of TF to detect and
respond to potential resurgence
• Respond to a finding of >5% TF in any community
-Examine all children aged 1-9 years and treat TF
-If >5% TF in all 1-9 year olds, assess AFE coverage and
treat community
-Examine school entrance aged children in all communities
in the surrounding sub-district
-If >5% TF in sub-district re-implement AFE for 3 years and
assess TF in other sub-districts to determine whether
district warrants AFE
Ensure that routine eye care services are operating
incident and recurrent TT cases and monitoring
incidence to detect any increase in blinding disease
• Ongoing collection and review of TT surgical output data and
recurrence rates
• Incorporate TT into National Health Information Management
System or similar national surveillance system
• In each community assessed for TF, examine adults aged 40
years and above for TT
– Classify cases as to known or unknown to health system
Conclusions
WHO guidelines evolve, in response to new data, concerns
Basic rules
-SAFE is recommended control strategy
-Map at district (special case: region)to document need
-Surgery: implement surgical program to meet needs by 2020, with
documentation of recurrence, plans
-Implement for 3-5 years and do impact survey at district level
-If impact survey suggest <10%TF, do impact survey at sub-district level
and follow guidelines
-Meet UIGs, start surveillance
Push for 2020!