Table 3 Proposed Target Product Profile (TPP) for an IR-ML based system for entomological surveillance of malaria
Characteristics | Entomological surveillance | ||
|---|---|---|---|
Essential characteristics | Desired characteristics | ||
Scope | Intended use | Mosquito identification; mosquito age-grading, detection of Plasmodium-infected mosquitoes and blood meal identity | One-stop platform for most desired entomological indicators; species IDs, age grading, blood meal identifications, infection detection and assessment of insecticide resistance status i.e. ability to predict resistance phenotype as per standard bioassays |
Implementation level | Can be used in research laboratories and training centres | Used for research and routine surveillance services in laboratory and field settings | |
Types of spectrometers and durability | Bench-top units that require minimum electricity, and can operate 5 years or more with minimal maintenance | Off –the-shelf portable units with long-life battery; can be solar-powered; can operate for up to 10 years with minimal maintenance | |
Technical performance | Plasmodium sporozoites: Sensitivity of > 90% with reference to ELISA | Plasmodium sporozoites: Sensitivity of > 90% with reference to PCR | |
Plasmodium sporozoites: Specificity of > 90% with reference to ELISA, Microscopy or PCR | Plasmodium sporozoites: Specificity of > 90% with reference to PCR | ||
Resolution of predictions | Mosquitoes age: can classify young (e.g. 1–6 days) vs old (e.g. > 10 days) mosquitoes, with > 90% accuracy Species identification: Can distinguish between members of a species complex (e.g. An. gambiae vs. An. arabiensis) with > 90% accuracy Mosquito blood meals: Can distinguish between human blood meal from any other vertebrate blood meals, with > 90% accuracy | Mosquitoes age: Can classify mosquito ages chronologically at 2-day resolution (e.g. 1, 3, 5 days etc.) with > 90% accuracy Species: Can identify all major malaria vectors (An. gambiae, An. arabiensis, An. coluzzii and An. funestus) with > 90% accuracy Blood meal: Can identify most vertebrate blood meals (i.e. human, cattle, goat, chicken, dog etc.) even if the meals are mixed, and with > 90% accuracy | |
Lower limit of parasite detection | Plasmodium sporozoites: has performance equivalent to ELISA or PCR | Plasmodium sporozoites: has performance equivalent to PCR | |
Temperature and humidity stability | Functions and can be stored in ambient temperature; withstands frequent temperature rises to 35 °C for a long periods under diverse humidity | Functions and can be stored in ambient temperature; withstands frequent temperature rises to 45 °C for a long periods under diverse humidity | |
Operational aspects | Equipment & maintenance costs | Less than $ 30,000 per spectrometer; lasts > 5 years; costs < $100/yr to maintain | Less than $ 2000 per portable spectrometer; lasts > 5 yrs; Costs < $50/Yr to maintain |
Sample handling costs | Costs < $0.1 per test | Costs < $0.01per test | |
Test duration |  < 5 min |  < 1 min | |
Sample preservation and storage | Requires freezing, desiccants, RNAlater Uses must be less than 30Â days old | Can use any preservation method Samples can be older than 6Â months as long as preserved fresh | |
Operational aspects | Human resources: Skills & training | Requires minimal training on sample handling, scanning & data/results interpretation | No more than 30Â min training needed to use, conduct the tests and read results |
Type of sample | Can analyse dried mosquito body parts | Can analyse either fresh or dried mosquito body parts | |
Reagents | No reagents needed except for cleaning the instruments or sample collection | No reagents needed except for cleaning the instruments or sample collection | |