Applying the principles of epidemiology and health management for curbing Vaccine Preventable Disease (VPD) outbreak

1. Measles Outbreak-
Epidemiological analysis
1

2. BTL
SNI
SVP
CDW
BLG
SAG
CTP
RSN
KRG
MDL
STN
DHR
VDS
KND
PAN
SJP
HSB
DMH
SOP
SEH
RJG
UJN
SDL
JBP
DWS
SGL
GUN
RWATKM
DDR
MDS
KTN
AKN
NSP
BRW
IDR
BHD
SDH
RTM
GLR
MRN
ANP
NMC
UMR
JBA
ALR HAR
BHP
BPL
DTA
• Blocks – 06
• Population – 11,53,168
• Area in Sq. Km. – 10,536
Sidhi- District information
2

3. Timeline Measles Outbreaks
2
9
3
0 0 0
99
374
180
2 2 1
0
50
100
150
200
250
300
350
400
0
1
2
3
4
5
6
7
8
9
10
2010 2011 2012 2013 2014 2015
MOB Cases
3

4. Timeline Measles Outbreaks
2
9
3
0 0 0
99
374
180
2 2 1
0
50
100
150
200
250
300
350
400
0
1
2
3
4
5
6
7
8
9
10
2010 2011 2012 2013 2014 2015
MOB Cases
Measles Catch-upRound
Coverage:95%
4

5. District-SIDHI
KUSMI
SIHAWAL
RAMPUR NAIKIN
SEMARIYA
SIDHI
MAJHOLI
Rewa
Rewa (MP)
Singrauli (MP)
Sargija (CG)
Satna
Shahdol
06 Dec to
10 Dec 10
15 Aug to
14 Nov 10
14 Jan to
31 Jan 11
07 Jul to
18 Jul 11
05 Dec 10
to 22 Feb 11
12 Jan to
26 Feb 11
15 Sep to
01 Dec 11
09 Mar to
24 Mar 11
28 Sep to
16 Dec 11
27 Oct to
28 Nov 11
88/0
10/0
19/0
25 Feb to
10 Mar 11
5/0
5/0
42/0
14/0
117/2
70/0
78/0
MOB -2010MOB -2010
MOB-2011MOB-2011
MOB-2012MOB-2012
122/0
9/0
17/0
02 Jan to
10 Mar 12
08 Jan to
12 April
12
08 Apr to
18 Apr 12
35/0
5

6. District-SIDHI
KUSMI
SIHAWAL
RAMPUR NAIKIN
SEMARIYA
SIDHI
MAJHOLI
Rewa
Mirzapur (UP)
Sonbhadra (UP)
Sargija (CG)
Satna
Shahdol
15 Sep to
01 Dec 11117/2
MOB -2010MOB -2010
MOB-2011MOB-2011
MOB-2012MOB-2012
6

7. Block information:
• Name: Sihawal
• Population – 267,842
• Area in Sq. Km.- 1589 sq
km
• Village information:
• Population ~ 2600
• Total Households- 523
KUSMI
SIHAWAL
RAMPUR NAIKIN
SEMARIYA
SIDHI
MAJHOLI
Rewa
Singraoli
Sarguja (CG)
Satna
7

8. 8

9. Demographic Analysis
Gender Age distribution
9

10. Vaccination status- Gender- Age
10

11. Epi- Curve
Notification of
Outbreak
Deaths
11

12. Index case
• Vaccinated, female, 60 mth old
• Travel history to Nana’s place- day 30 to day
10 before onset
• 2 more cases (8 yr- vaccinated, 6 mth- unvaccinated) in
the same household on day 2 and day 3 of
development of rash in Index case
• Two cases (Index case and 8 yr old case)- participated
in school before rash
• No clinical measles cases found at Nana’s
place 12

13. CFR
• Total Deaths= 2 (11 & 72 mth old)
• CFR= (2/ 117)* 100
= 1.71%
• Age-Specific CFR:
– For </= 12 mth: 4.76%
– For > 60 mth: 1.96%
13

14. Positive Predictive Value
• 5 Blood specimens collected for IgM- Antibody
• All the 5 specimens +ve for Measles IgM
• PPV of clinical case definition= 100%
14

15. Attack Rate
• Population of the village: 2600
• Birth rate of district (Sidhi rural): 26.7*
*AHS 2012- 13
• Birth cohort: 70 births/ yr
• Total Population <5 yr: 350
• Don’t have primary data to derive attack rate
i.e. denominator
15

16. Age-specific Attack rate
Age Population in
age group
Cases in Age group Age-specific attack rate
</ = 12 mth 70 21 30% i.e. 30000/ 1L
13- 24 mth 70 14 20% i.e. 20000/ 1L
25- 60 mth 210 31 14.761% i.e. 14761/ 1L
61- 180 mth 586 51 8.703% i.e. 8703/ 1L
16

17. Age-specific Attack rate
Age Population in
age group
Cases in Age
group
Age-specific
attack rate
Vaccination
Coverage in age-
group
</ = 12 mth 70 21 30% i.e.
30000/ 1L
?
13- 24 mth 70 14 20% i.e.
20000/ 1L
?
25- 60 mth 210 31 14.761% i.e.
14761/ 1L
?
61- 180 mth 630 51 8.095% i.e.
8095/ 1L
?
17

18. Attack Rate and Vaccine Efficacy
• Measles vaccine coverage (Sidhi rural):
77.5%*
*AHS 2012-13
• Total vaccinated children U- 5 yr**: 271
• Total unvaccinated children U- 5 yr: 79Clinical Measles
symptoms
Measles
asymptomatic
Total
Unvaccinated**
(**unknown=
unvaccinated)
28 51 79
Vaccinated 38 233 271
Total 66 284 350

19. Vaccine Efficacy in U- 5
Attack rate unvaccinated- Attack rate vaccinated
--------------------------------------------------------------------------------------------------
Attack rate unvaccinated
= 70.3%
19

20. Odds Ratio of developing clinical
measles in U-5 UnVacc vs Vacc
(a/b)/ (c/d)= (28/ 51)/ (38/ 233)
= 0.549/ 0.163
= 3.37
20

21. Correlation- age and vaccination
Vaccinated Unvaccinated Total
</ = 60 mth 38
(58%)
28
(42%)
66
> 60 mth 15
(29%)
36
(71%)
51
Chi- square test
Value p- value
Pearson Chi-square 9.209 0.002
Continuity correction 8.108 0.004
21

22. Odd’s Ratio 95% CI
</ =60 mth old & vaccinated 1.958 (1.220- 3.141)
Vaccinated Unvaccinated Total
</ = 60 mth 38
(58%)
28
(42%)
66
> 60 mth 15
(29%)
36
(71%)
51
Correlation- age and vaccination
22

23. Correlation- gender and vaccination
Chi- square test
Value p- value
Pearson Chi-square 2.637 0.104
Continuity correction 2.068 0.150
23
Vaccinated Unvaccinated Total
Male 21
(38%)
35
(62%)
56
Female 32
(53%)
29
(47%)
61

24. Correlation- gender and vaccination
Odd’s Ratio 95% CI
female& vaccinated 1.399 (0.925- 2.116)
24
Vaccinated Unvaccinated Total
Male 21
(38%)
35
(62%)
56
Female 32
(53%)
29
(47%)
61

25. Age vs Gender
25

26. Correlation- age and gender
</= 60 mth > 60 mth Total
Male 29
(52%)
27
(48%)
56
Female 37
(60%)
24
(40%)
61
Chi- square test
Value p- value
Pearson Chi-square 0.934 0.334
Continuity correction 0.608 0.435
26

27. Summary
• Delayed outbreak notification lead to spread
of disease and preventable deaths
• Vaccine efficacy ??
• Statistically significant correlation between
age and vaccination status
• No significant correlation between vaccination
status- gender, and age- gender
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28. Recommendations (based on findings)
Summary Recommendations
Delayed outbreak notification Outbreaks must get notified in their early
stages to prevent large epidemics and deaths
- Vaccine efficacy ??
- Statistically significant correlation
between age and vaccination
Reasons for high attack rate in < 60 mth old
must be investigated
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29. Recommendations (future actions)
• Keeping a watch on contacts and reporting of
cases as soon as they develop the rash
• Report and treat complications
29

30. Key actionable insights
Recommendation Actionable insight
Early notification of outbreaks Capacity building of the health staff to identify
measles cases early and report the same
High attack rate in <60 mth old -Vaccination coverage in <60 mth old
- Regularity of vaccination sessions
-Vaccination practices
Watch on contacts - Physician responsible for affected area to
visit the same on every 4th
day till “Zero” case
reporting for 2 consecutive weeks
Reporting of complications -Training of health staff to identify Vit A
deficiency, Pneumonia etc
Treatment of complications - Training of health staff to administer Vit A,
antibiotics for pneumonia, supply of ORS- Zn
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