Participatory disease surveillance:
Cost effectiveness relative to passive surveillance
in Kajiado County, Kenya
1 1 2 1 1
Hannah, H. , Kimani, T. , Irungu, P. , Grace, D. and Randolph, T.
1 2
International Livestock Research Institute, Nairobi, Kenya; University of Nairobi, Kenya
August 2012
Objective Methods
1 District Veterinary Officers in Isinya & Kajiado Table 1. Surveillance indicators and costs associated with PS (1
Determine the cost effectiveness (CE) of participatory 3 district, 1 outbreak investigation, 3 months) and PE surveys (6
2 Central districts (total: 38 villages ) were
disease surveillance (PDS) compared with routine village visits, 3 in each of 2 districts, 6 days) from Kajiado Central
interviewed and monthly surveillance reports
passive surveillance (PS) for notifiable diseases (ND) and Isinya Districts, Kenya, July 2012
were reviewed to determine the number of ND
over a 12-month interval in a primarily pastoralist 4
outbreak events detected (cattle, sheep, goats & Passive PE
region of Kenya. Surveillance Surveys
poultry) and specimens collected by passive Surveillance indicators
Background: Effective surveillance for is essential for surveillance between July 2011 and June 2012. Number of ND outbreaks, June 2012
PS: 38 villages, 1 month 21 28
mitigating negative consequences of ND, especially in PE surveys in 6 primarily pastoralist villages (3 in PE: 6 village surveys
resource poor countries. Working with the Department each district), determined retrospectively the Number of ND outbreaks, July 2011-
number of ND outbreaks experienced in the same June 2012
of Veterinary Services (DVS), Kenya, we considered PS: 2 districts, 1 year
180 1,139
5
resource costs of participatory epidemiology (PE) interval. Linear extrapolation to 38 villages was PE: 2 districts, 1 year (extrapolated)
surveys compared with routine PS for outbreak used to estimate total ND outbreaks for both Specimens collected
districts for 12 months. Activity-specific costs for PS: 1 year 97 06
detection to determine CE and to generate evidence PE: 6 village surveys
for surveillance policies and disease control strategies. PS and PE were determined from Government of Costs (US$)
Kenya salary rates and local market prices. Personnel
PS: 4 staff 8 days/month 3,241.4 499.5
PE: 3 staff 1 day/village
Passive Suveillance Community mobilization
Findings 200
180 PE Surveys PS: elder fee 42.3 42.9
PE: elder fee
Surveillance: In 1 year, PS detected 180 ND 160
Outbreaks Detected
Transport
140 PS: 1 outbreak investigation/3 months 91.4 274.1
outbreaks from 38 villages in 2 districts, 120 PE: 2 contiguous villages/trip
including 21 in June 2012. PE surveys in 6 100 Sample collection & processing
80 PS: 10 samples/outbreak 178.6 1,091.3
villages recorded 180 ND outbreaks for the 60
7 PE: 10 samples/village
same interval, 28 of which were active . 40 Follow-up with lab
Extrapolating to 38 villages for the same 20 PS: phone calls/1outbreak 1.2 3.6
0 PE: phone calls/samples from 6 villages
interval, PE would have detected 1,139 Feedback to farmers
outbreaks (95%CI: 838, 2881), significantly PS: 1 call/1 outbreak 2.4 14.3
PE: 1 call to each of 6 villages
more than PS (p<0.001)(Figure 1). PS Pictures TOTAL
Month/Year PS: 38 villages, 1 month 2,371.5 1,925.7
recorded few mortalities. PE-derived disease
PE: 6 village surveys
specific morbidity and mortality estimates Figure 1. ND outbreaks from Isinya & Kajiado Districts detected prospectively by
passive surveillance (blue, 38 villages) and retrospectively by PE (red, extrapolated Cost effectiveness for June 2012
differed by more than 15% between villages, 112.9 68.8
to 38 villages) from July 2011-June 2012, including monthly mean and 95% CI8 (US$/Outbreak detected)
except for FMD. Cost per village (US$)
PS: 1 village for 1 month 62.4 321.0
Cost effectiveness: PS in 2 districts cost US$2,371.5/month. PE surveys in 6 villages cost US$1,925.6. Ignoring PE: 1 village visit
Cost/month per 38 villages (US$)
PE training costs, personnel costs accounted for 91.1% and 25.9% of the total cost of PS and PE respectively. PS: status quo, 2 districts 2,371.5 12,196.1
Less than 5% of PS personnel costs supported outbreak response; the rest were idling costs due to limited PE: 1 visit each for 38 villages
Cost/year per 38 villages (US$)
transport capacity and operational budgets. Based on outbreaks detected in June 2012, the cost PS: status quo, 2 districts 28,458.0 146,353.2
effectiveness ratio for PS was US$112.9 and US$68.8 for PE (Table 1). PE: 1 visit/village/month
Assumptions & Limitations
Conclusions Limitations: small sample size and many
PE surveys provided better information for informing response, were more cost effective and identified assumptions, some of which are listed here:
outbreaks missed by PS. Costing more than 5 times PS, PDS is not suitable in all contexts. Alternatives for 1. PS and PE both lead to immediate response
enhancing PS by improving outbreak detection efficiency and reducing idling costs through increased funding when outbreaks are reported.
for transport and operational expenses deserve consideration. 2. Limited response capacity reduces the
benefits of rapid detection.
Footnotes 3. DVS personnel have adequate training and are
1.CE is defined as the cost of detecting a single outbreak by using either PE or PS.
2.PDS defined as ongoing and systematic collection of surveillance data using participatory methods competent performing PE.
3.The term village refers to administrative boundaries for locations within districts. 4. Benefits accrue only if surveillance information
4.An outbreak event is defined as at least one incident case of disease, recorded by month in a given location.
Few outbreaks detected by PS and none detected by PE were lab confirmed.
is acted upon.
5.Linear extrapolation assumptions are not ideal: not all villages have equal experiences of ND outbreaks. Acknowledgements
6.PE was performed by consultants rather than by DVS staff with less priority accorded to specimen collection. The authors gratefully acknowledge the Director of Veterinary Services and District Veterinary Offices in Isinya and Kajiado
7.Of 28 outbreaks identified by PE, 6 were also reported by the District Veterinary Officer. Central (Leonard Njagi, Lydia Nzoki, Penina Mutua & Julius Migwi), PE practitioners (Samuel Letereuwa, Geoffrey Omondi,
8.Confidence interval of 95% is conservative, based on 6 villages, having been performed before scaling to 38. Paul Chacha & Waweru Kabaka), the participating communities and Jane Poole, statistician.
Heather Hannah
h.hannah@cgiar.org ● Box 30709 Nairobi Kenya ● +254 20 422 3000
Nairobi Kenya ● ilri.org
This project was funded by USAID
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License Jun 2012