Evaluation of a surveillance system

1. • Revise case definition to include IGRA test results
• Collect data on LTBI treatment
• Evaluate the surveillance system and its public health usefulness
Copyright © 2014 Theocharopoulos Georgios, e-mail: theocharopoulos1@yahoo.com
Georgios Theocharopoulos (1, 2), D. Antoine (2)
(1)European Programme for Intervention Epidemiology Training (EPIET), European Centre for
Disease Prevention and Control (ECDC), Stockholm, Sweden
(2) Santé Publique France, Paris, France
Questioning the usefulness of the latent tuberculosis
infection (LTBI) surveillance in children in France,
2010-2014
• Limitations :
o IGRA, test result not included in case definition
o not possible to estimate sensitivity of LTBI surveillance
o no data on LTBI treatment
• Reported LTBI cases in children increased in 2010-2014, possibly due to improved reporting or case investigation practices
• The ratio of LTBI/pulmonary TB was consistent with literature data for France and its increase in 2010-2014 might be attributed
to increase of reported LTBIs and decrease of reported pulmonary TB cases during that period.
• Reported LTBI cases were largely detected through active case finding, suggesting that only a fraction of LTBIs was detected through
surveillance
Data analysis:
• Description of LTBI cases by age, gender, place of birth
of case and parents, ways of detection
• Calculation of ratio: LTBI in children / pulmonary TB in
≥ 15 year olds (most likely to transmit TB)
Background: Children with latent tuberculosis (LTBI) infection have increased risk to progress to active TB
Methods: Surveillance data analysis
Objective:
To describe LTBI cases notified in 2010-2014
To identify areas of improvement in LTBI surveillance
Treatment of LTBI in children can prevent progression to active TB
2003: LTBI in children made notifiable in France
 To improve LTBI detection and early treatment
 To trigger investigations for active TB cases
Results: 87% of LTBI cases were detected through active case finding
Discussion/conclusions: The LTBI notification system alone may not be sufficient to detect all LTBI cases
Recommendations : Evaluate the LTBI surveillance system
Table 1. Number of latent tuberculosis infections in children <15 years,
by age group, France, 2010 -2014.
Figure 2. Number of latent tuberculosis infections in children reported
by country of birth, France, 2010-2014. (N = 3647)
Age group N %
<1 years 259 6,7
1-4 years 1144 29,7
5-9 years 1 137 29,5
10-14 years 1316 34,1
Total 3856 100
2351
504
288 213 109 99 83
0
1000
2000
3000
France Subsaharan
Africa
Europe (other
than EU)
Europe (EU) Asia Americas,
Oceania
North Africa
Numberofcases
Place of birth
824
539
148 103 80
0
300
600
900
Africa France Europe Americas, Oceania Asia
Numberofcases
Parents' place of birth
* Note:. If place of birth differed between parents, the region with the highest TB
incidence (WHO data) was retained.
Data source: surveillance data collected in France including
overseas districts* in 2010-2014
Case definition: positive skin test following injection of 5U
tuberculin, with no evidence of active TB in children <15 years old
*Note: Data from the region of Mayotte, (French department since 2011) has been excluded
• In 2010-2014, 3,856 cases of LTBI were notified in France,
634 in 2010 and 867 in 2014
• 36% of cases were children <5 years (Table 1)
• 51% of cases were male
Figure 3. Number of latent tuberculosis infections in children born in
France reported by parents’ origin. France, 2010-2014. (N = 1694) *
• Origin: 67% of children with LTBI were born abroad or at least one
parent was born abroad (Fig 2 & 3)
• Way of detection: 87% of LTBI cases detected through active case
finding (66% contact investigation, 21% systematic screening)
• LTBI/TB ratio: LTBI / pulmonary TB case ratio: 21/100 (17/100 in
2010 and 25/100 in 2014).