Tungiasis (sand flea disease) is a neglected tropical disease, prevalent in
resource-poor communities in South America and sub-Saharan Africa. It is
caused by an inflammatory response against penetrated female sand fleas (Tunga
penetrans) embedded in the skin of the host. Although associated with
debilitating acute and chronic morbidity, there is no proven effective drug
treatment. By consequence patients attempt to remove embedded sand fleas with
non-sterile sharp instruments, such as safety pins, a procedure that
represents a health threat by itself. In this proof-of-principle study we
compared the topical application of a mixture of two dimeticones of low
viscosity (NYDA) to the topical application of a 0.05% solution of KMnO4 in 47
school children in an endemic area in rural Kenya. The efficacy of the
treatment was assessed during a follow up period of seven days using viability
signs of the embedded parasites, alterations in the natural development of
lesion morphology and the degree of local inflammation as outcome measures.
Seven days after treatment, in the dimeticone group 78% (95% CI 67–86%) of the
parasites had lost all signs of viability as compared to 39% (95% CI 28–52%)
in the KMnO4 group (p<0.001). In the dimeticone group 90% (95% CI 80–95%) of
the penetrated sand fleas showed an abnormal development already after 5 days,
compared to 53% (95% CI 40–66%; p<0.001) in the KMnO4 group. Seven days after
treatment, signs of local skin inflammation had significantly decreased in the
dimeticone group (p<0.001). This study identified the topical application of
dimeticones of low viscosity (NYDA) as an effective means to kill embedded
sand fleas. In view of the efficacy and safety of the topical treatment with
dimeticone, the mechanical extraction of embedded sand fleas using hazardous
instruments is no longer warranted