Table 2.

Comparison of mosquito screening for xenomonitoring and transmission monitoring of lymphatic filariasis^*

	Xenomonitoring	Transmission monitoring
Mosquito samples	Any human-biting (anthropophilic) mosquitoes, no detailed species identification required	Only vector competent species (cytospecies), proper identification required
Sampling method	Human bait or indoor resting. Identification of anthropophilic species required when light or gravid traps are used.	Human bait or indoor resting. Identification of vector species (cytospecies) required when light or gravid traps are used.
Collection of large numbers of samples	Easy	Easy, if the vector is the predominant mosquito species
Screening method	Dissection of individual mosquitoes (cumbersome), pool screening for filarial DNA by conventional or real-time PCR (more sensitive)	Dissection of individual mosquitoes (cumbersome), mass dissection, pool screening for L3-specific filarial mRNA (experimental, not yet validated, requires special techniques)
Identification of vectors	Requires microscopy (detection of L3), high DNA detection rates in a mosquito may indicate vector competence, but confirmation required	Yes, by microscopy or detection of L3-specific mRNA (identification of 100% L3-specific transcripts difficult)
Indicator of prevalence in humans	Yes, indirectly	Yes, indirectly
Indicator for transmission	No. Probably, if DNA is detected in vector species	Yes, directly

^*PCR = polymerase chain reaction; L3 = third-stage larvae.