2. Introduction
Sentinel Surveillance for COVID-19 helps in complementing the outbreak
surveillance and investigations.
Sentinel surveillance is an efficient way to collect high-quality data in a timely
manner systematically and routinely from representatives of the population
under surveillance.
Sentinel surveillance for COVID-19 is a cost effect way to meet some of the
following objectives: -
monitor the geographic spread
intensity of transmission
severity trends of community transmission of COVID-19 over time
6. 6th ROUND SENTINEL
Surveillance 29 Sept-1st
Oct
Positivity Rate : 3.0 to above
4 DISTRICTS
• Darjeeling (3.7)
• Kalimpong (3.8)
• Bisnupur HD (4.2)
• Hooghly(4.3)
Comparison between 5th , 6th and 7th Round of Sentinel Surveillance (3)
7th ROUND SENTINEL
Surveillance 27th – 29th
OCT
Positivity Rate : 3.0 to above
1 DISTRICT
• Hooghly(4.72)
5th ROUND SENTINEL
SURVEILLANCE 14-16
SEPT Positivity Rate : 3.0 to
above
5 DISTRICTS
• Dakhin Dinajpur (3.0)
• N24 Pgs (3.0)
• Bishnupur HD (3.1)
• Basirhat HD (3.1)
• Purba Midnapur (4.2)
7. MORBIDITY PROFILE OF THE PARTICIPANTS ≥ 45 YEARS OF AGE
130
78
148
26
28
6
1
0
20
40
60
80
100
120
140
160
HYPERTENSION
DIABETES
CHRONIC LUNG DISEASE
OBESITY
CHRONIC RENAL DISEASE
HEART DISEASE
MALIGNANCY
8. 6th and 7th Round Sentinel Surveillance
Calculation of Vaccine Efficacy
Vaccinated – Getting one dose of Covaxin or Covishield 28 days before
Among 18 years group and above (6th Round)
Vaccination
Status
mentioned
Non
Vaccinated
Vaccinated
No Covid-19 5372 2264
Covid-19 99 10
Total 5471 2274
Incidence among non vaccinated = 1.81
Incidence among Vaccinated = 0.4
Vaccine Efficacy = (1.81-0.4) / 1.81 = 0.78
i.e. 78 %
Vaccination
Status
mentioned
Non
Vaccinated
Vaccinated
No Covid-19 6443 2232
Covid-19 90 8
Total 6533 2240
Among 18 years group and above (7th Round)
Incidence among non vaccinated = 1.38
Incidence among Vaccinated = 0.36
Vaccine Efficacy = (1.38-0.36) / 1.38 = 0.74
i.e. 74 %
9. Vaccination
Status
mentioned
Non
Vaccinated
Vaccinated
No Covid-19 6744 892
Covid-19 106 3
Total 6850 895
5th and 6th Round Sentinel Surveillance
Calculation of Vaccine Efficacy
Vaccinated – Getting two doses of Covaxin or Covishield 28 days before
Incidence among non vaccinated = 1.55
Incidence among Vaccinated = 0.3
Vaccine Efficacy = (1.55-0.3) / 1.55 = 0.81
i.e. 81 %
Vaccination
Status
mentioned
Non
Vaccinated
Vaccinated
No Covid-19 7747 928
Covid-19 96 2
Total 7843 930
Incidence among non vaccinated = 1.22
Incidence among Vaccinated = 0.2
Vaccine Efficacy = (1.22-0.2) / 1.22 = 0.84
i.e. 84 %
6th Round 7th Round
10. CONCLUSION
• Sentinel Surveillance conducted in all the districts and in each round
samples are collected as per target
• Positivity rates are varied by districts and over period of time.
• Vaccine efficacy is high indicating the effectiveness of the vaccination
program which will be number one priority in all eligible age group
• Sentinel Surveillance to continue
• The eighth round for the Sentinel surveillance for planning strategies for
control of COVID19 human infection in West Bengal to begin from
• 15th November 2021 to 17th November 2021 - Completion of sample collection
• 18th November 2021 to 19th November2021 - All reports from Lab with excel sheet must be
mailed to the Nodal person, at State level at the email ids mentioned:
covid 19.1ab.spsrc@gmail.com
lizaprasu@gmail.com