Fig 1.
Examples of representative soil sampling areas from different households.
Loose sand floors in coastal Kenya (A); compacted clay floors in eastern Uganda (B); and outdoor sitting location (Kenya), animal tethering place (Uganda) and an outdoor kitchen (Kenya) as examples of outdoor sampling locations (C).
Fig 2.
Berlese-Tullgren funnel apparatus for extraction of Tunga penetrans off-host stages from soil samples.
Schematic diagram showing components of individual funnel made from 2 L PET soda bottle, mesh screen and light bulb (A). Wooden frame with twelve units of Berlese-Tullgren funnels (B). High-throughput set up of 60 Berlese-Tullgren Funnels assembled in 5 units in the laboratory (C). Experimental set-up for the calibration of optimum conditions using 15, 25 and 40 W bulbs and 4 versus 8 hours of extraction (D).
Fig 3.
Tunga penetrans (sand flea) adult (A) and larva (B); Echidnophaga gallinacea (stick tight (hen) flea) adult (C) and larva (D); Ctenocephalides felis (cat flea) adult (E) and larva (F); Pupa cocoons of Tunga penetrans (small on left) and Ctenophalides felis (G); Polypod insect larva [24] which can be distinguished from the flea larvae by the 3 pairs of legs and 5 pairs of prolegs (Order Lepidoptera) (H). Photos of adult fleas captured using Macropod Pro macrophotography system (Macroscopic Solutions.com), photos of larvae captured using Axiocam ERc 5s Rev, 2.0 mounted on the Zeiss Stemi 508 stereo microscope (Carl Zeiss Suzhou Co., Ltd.) and photos of pupa cocoons captured using a DinoCapture 2.0 (Dunwell Tech., Inc. Dino-Lite US).
Table 1.
Morphological features of the larvae of Tunga penetrans, Echidnophaga gallinacea, and Ctenocephalides felis.
Fig 4.
Model estimated mean proportions (including 95% confidence intervals) of larvae extracted (total versus alive) from spiked soil samples in relation to bulb wattage and extraction time. Mean soil temperature is shown on secondary axis.
Table 2.
Outputs from generalised models exploring the association between the proportion of Tunga larvae recovered and bulb wattage and extraction time in experiments.
Table 3.
Bivariate analyses results investigating the prevalence and abundance of Tunga off-host stages in relation to sample location.