Pooled Prevalence Calculator – Demonstration analyses
Variable pool size and perfect test
This method estimates prevalence and confidence limits for variable pool sizes and assumed 100% test sensitivity and specificity. This method should be used if you can be confident that the sensitivity and specificity of the test are both close to 100%, and if pool sizes vary.
For this analysis, it was assumed that samples from 210 individual fruit bats were aggregated into 40 pools of 5 samples each with 10 samples tested individually, that 20 pools and 2 individual samples produced a positive test result and that the test sensitivity and specificity were both 100%. Input values and results for this analysis are summarised in the table below.
Variable
pool size 


Input values: 


Confidence
level: 
0.95 

Pool size 
Number of
pools tested 
Number of
pools positive 
5 
40 
20 
1 
10 
2 



Results: 


Est.
Prevalence 
0.1339 

2.5
percentile 
0.0871 

97.5
percentile 
0.1930 