Bibliographic information
Recommendation
In communities approaching the interruption of transmission (defined as having no autochthonous human cases reported for 5 consecutive years), WHO suggests a verification framework that consists of: 1. Testing for Schistosoma infection in humans with a diagnostic that has high sensitivity and specificity. This may require the use of a two-step diagnostic process starting with a high sensitivity test confirmed with a second, high specificity test. 2. Testing for Schistosoma infection in snails with a diagnostic that has high sensitivity and specificity. This may require the use of a two-step diagnostic process starting with a high sensitivity test confirmed with a second, high specificity test. 3. Testing for Schistosoma infection in non-human mammalian hosts, as applicable, with a diagnostic that has high sensitivity and specificity. This may require the use of a two-step diagnostic process starting with a high sensitivity test confirmed with a second, high specificity test.
Recommended in favor
Conditional
Certainty of evidence
Low
Notes and Remarks
Implementation considerations The eventual predictive performance of the sampling of humans, snails and non-human mammalian hosts to identify settings that have eliminated transmission will depend upon the sampling strategy, with decisions on sample size, geographical zone and timespan for sampling. Future work could consider a two-step verification of Schistosoma infection status in humans with a first highly sensitive test (for example, serology) and a second confirmatory highly specific test (for example, miracidia hatching test). Sampling and diagnostic tools in snail populations and in non-human mammalian hosts should be considered when interruption of transmission is the public health goal and is suspected based on recent epidemiological surveys in human populations.