Surveillance tools and methods including field surveillance and - - PowerPoint PPT Presentation

Felix Njeumi, FAO Susanne Münstermann, OIE

Surveillance tools and methods including field surveillance and national, regional and international Networks

Members of the PPR working group

Introduction

• Surveillance is a key element of the GCES and more specifically its strategic

approach, based on 4 different stages of the global strategy.

• Surveillance systems are one of the 5 technical elements characterising each

stage of the GCES

Diagnostic systems Surveillance systems Prevention and control Legal framework Stakeholders

• Surveillance is key to understand the PPR epidemiology in a county and to

monitor progress in the control and eradication efforts

• Surveillance systems become more complex along the progression along the 4

stages

Prevalence and distribution of the disease/infection Early warning/detection Information planning and research Identify priority areas for control/prevention Assessment of health situation Demonstrate the absence of clinical disease

Objectives of the surveillance

Epi network

• National focal point, regional network in each region

coordinated by the global network

• Networks are essential forum for the discussion and

analysis of disease status data and the exchange of information,

• Link with reference laboratories for confirmatory

diagnosis, vaccines QC and sustained surveillance programmes,

• Stakeholders & their roles
• Trainings, workshops, Reporting and IT systems in place

Along the stages of the GCES, the use of different surveillance methods vary.

Methodology - general

No Stage title Stage objective Surveillance method Active Passive 1 Assessment Epi situation: absence

• r presence of PPRV

+++ + 2 Control Implementation of targeted control strategy ++ ++ 3 Eradication Nation-wide control & eradication program ++ +++ 4 Post- eradication Evidence that no PPRV is circulating + ++++ PVE

Active surveillance Stage s Passive surveillance Stage s Serology 1,4 Clinical / syndromic 1,2,3 Abattoir (specific surveys) 1,2 Abattoir (reported cases) 2,4 Wildlife (as sentinels) 2,3 Wildlife (reported cases) 2,3,4 Markets (specific surveys) 1,2,3 Markets (reported cases) 2,3,4 Border VS post inspection surveys 3,4 Border VS post inspection reports 3,4 Participatory disease search 1,2,3 Questionnaire surveys 1,2 Reporting systems from veterinary/ para-vet networks 1,2,3,4

Sero-surveillance

• Target population
• all susceptible small ruminants in a particular location at risk of PPR.
• Study population
• the population included in the surveillance programme
• Can be stratified by AGE and HUSBANDRY SYSTEM
• Case definition
• presence of PPR virus or specific antibodies against PPR virus

antigens is demonstrated in susceptible species (Art. 14.7.1 TAHC)

• Epi unit
• All small ruminants have the same chance of being infected with PPR
• virus. (could be the flock/herd or village)

Methodology - specific

• Surveillance method (a guide, to be adapted to

local situation)

• Assumption: in case of incursion of PPR virus:
• 5% of epi units infected and 30% of individual animals

within each epi unit infected

• two-stage sampling:
• first stage: the epi unit
• second stage: individual animals within the selected epi

units.

Methodology – specific cont.

• Sample size at epi unit level Sample size for animals

5% prevalence at epi unit 30% prevalence at animal level level

Number of Epi Unit Sample size 0‐ 25 All 26‐30 26 31‐40 31 41‐50 35 51‐70 40 71‐100 45 101‐200 51 201‐1200 57 >1200 59 Number animals in epi unit Sample size 1 – 6 All 7‐10 6 11 – 25 7 26 – 55 8 >56 9

Implementation

• Training of field officers (Gov & CAHW) on a number
• f essential subjects
• Logistics
• Close collaboration with laboratories, short turn-

around time, good communication laboratory to field

• Budget
• Cooperation with national and regional Epi networks

for harmonised surveillance protocols

Conclusion

• Surveillance is key to the implementation and

ultimate success of the GCES

• Regional and international epi and laboratory

networks, as envisaged in the GCES are essential in supporting the implementation of a successful surveillance program at national level

• Differentiation of sero-surveillance from post-

vaccination evaluation

Thank you

PPR WORKING GROUP Felix.njeumi@fao.org; s.munstermann@oie.int