3 ms·

> I would be interested to know the sensitivity of the test they are using. Bet that isn't discussed anywhere.

avs733 4y ago
So you can't really have sensitivity and specificity in the classic sense because you are not able to gold standard classify the infection of an individual. However, here is some research on the mater... >The location and timing of poliomyelitis cases showed spatial and temporal variability. The sensitivity of AFP surveillance to detect serotype 1 poliovirus infection in a district and its neighbours per month was on average 30.0% (95% CI 24.8–35.8) and increased with the incidence of poliomyelitis cases. The average population sensitivity of a single environmental sample was 59.4% (95% CI 55.4–63.0), with significant variation in site-specific estimates (median varied from 33.3–79.2%). The combined population sensitivity of environmental and AFP surveillance in a given month was on average 98.1% (95% CI 97.2–98.7), assuming four samples per month for each site. https://link.springer.com/article/10.1186/s12879-018-3070-4 https://link.springer.com/article/10.1186/s12879-018-3070-4 >Four quarterly visits were made to 78 ES sites in 21 states of Nigeria, and ES site characteristic data were matched to 1345 samples with an average enterovirus prevalence among sites of 68% (range, 9%–100%). A larger estimated catchment population, high total dissolved solids, and higher pH were associated with enterovirus detection. A random forests model predicted “good” sites (enterovirus prevalence >70%) from measured site characteristics with out-of-sample sensitivity and specificity of 75%. https://academic.oup.com/jid/article/225/8/1377/5818305?login=true https://academic.oup.com/jid/article/225/8/1377/5818305?logi... Other discussion of environmental surveillance for polio: https://journals.asm.org/doi/full/10.1128/AEM.07972-11 https://journals.asm.org/doi/full/10.1128/AEM.07972-11 https://link.springer.com/article/10.1007/s12560-017-9314-4 https://link.springer.com/article/10.1007/s12560-017-9314-4

So you can't really have sensitivity and specificity in the classic sense because you are not able to gold standard classify the infection of an individual. However, here is some research on the mater... >The location and timing of poliomyelitis cases showed spatial and temporal variability. The sensitivity of AFP surveillance to detect serotype 1 poliovirus infection in a district and its neighbours per month was on average 30.0% (95% CI 24.8–35.8) and increased with the incidence of poliomyelitis cases. The average population sensitivity of a single environmental sample was 59.4% (95% CI 55.4–63.0), with significant variation in site-specific estimates (median varied from 33.3–79.2%). The combined population sensitivity of environmental and AFP surveillance in a given month was on average 98.1% (95% CI 97.2–98.7), assuming four samples per month for each site. https://link.springer.com/article/10.1186/s12879-018-3070-4 https://link.springer.com/article/10.1186/s12879-018-3070-4 >Four quarterly visits were made to 78 ES sites in 21 states of Nigeria, and ES site characteristic data were matched to 1345 samples with an average enterovirus prevalence among sites of 68% (range, 9%–100%). A larger estimated catchment population, high total dissolved solids, and higher pH were associated with enterovirus detection. A random forests model predicted “good” sites (enterovirus prevalence >70%) from measured site characteristics with out-of-sample sensitivity and specificity of 75%. https://academic.oup.com/jid/article/225/8/1377/5818305?login=true https://academic.oup.com/jid/article/225/8/1377/5818305?logi... Other discussion of environmental surveillance for polio: https://journals.asm.org/doi/full/10.1128/AEM.07972-11 https://journals.asm.org/doi/full/10.1128/AEM.07972-11 https://link.springer.com/article/10.1007/s12560-017-9314-4 https://link.springer.com/article/10.1007/s12560-017-9314-4