From: From river blindness control to elimination: bridge over troubled water
Monitoring tools | Advantages | Disadvantages |
---|---|---|
Skin snip surveys during the treatment implementation phase | Detection of skin microfilariae is the gold-standard diagnostic of active infection. PCR can be used on skin snips | Need ethical approval*; painful; require sterilisation of punches between individuals being sampled; decreasing acceptance by communities |
Ivermectin coverage surveys | Relatively easy and affordable; can provide information about treatment uptake | May lead to overestimation of coverage and/or provide incomplete information about treatment adherence |
Ov16 rapid diagnostic test (RDT) surveys in children aged up to 10Â years | Relatively affordable, immediate answer on site | Need ethical approval*, sensitivity and specificity of RDTs not yet well established |
Ov16 ELISA surveys in children aged up to 10Â years | Sensitivity of up to 80% and specificity of up to 97% [72] | Need ethical approval*; more expensive than RDTs; samples need to be sent to a lab, often located abroad. Variability in diagnostic performance according to lab and presence of other filarial infections [92] |
PCR pool screening of simuliid vectors | No ethical approval needed?*; many flies can be sampled; in principle, separate analysis of flies’ heads and bodies can provide information on infectivity to and from human populations | Lack of trained entomologists and labs, as samples often shipped to reference labs for PCR analysis; increasing number of flies needed as infection levels decrease; sampling protocols need to be refined |