Rate of incidence therefore is greatly increased in poor communities and populations because of the lack of adequate housing. This occurs in significantly higher proportions during the peak of the dry season in local communities. Reservoirs and transmission
T. penetrans has been documented to use various warm-blooded animals as reservoir hosts, including humans, pigs, dogs, cats, rats, sheep, cattle, donkeys, monkeys, birds, and elephants. These hosts directly propagate the disease by being the origin of the next generation of fleas. Once the female flea expels 100–200 eggs, the cycle of transmission begins again. Lifecycle
T. penetrans eggs, on average, are 604 μm long, The larva will hatch from the egg within one to six days, assuming the environmental conditions (e.g., moisture, humidity, etc.) are favorable. After hatching, the flea will progress through two instar phases. This is unique in that most fleas go through three, instead. Over the course of that development, the flea will first decrease in size from its just-hatched size of 1,500 μm to 1,150 μm (first instar) before growing to 2,900 μm (second instar).About 6 to 8 days after hatching, the larva pupates and builds a cocoon around itself. Because it lives mostly on and below the surface of the sand, sand is used to stabilize the cocoon and help to promote its development. An environmental disturbance such as rain or a lack of sand have been shown to decrease incidence, most likely due to decreasing the environmental factors (i.e., sand) on which the flea depends for overall growth.
Controlled, in-home spraying of DDT is effective as it gives the home immunity against arthropods while not contaminating the local water supplies and doing as much ecological damage as was once the case when DDT was first introduced.While other species gradually gained resistance to DDT and other insecticides that were used, T. penetrans did not; as a result, the incidence of tungiasis in Mexico is very low when compared to the rest of Latin America, especially Brazil, where rates in poor areas have been known to be as high or higher than 50%. There was a 40-year period with no tungiasis cases in Mexico. It was not until August 1989 that three Mexican patients presented with the disease. Though there were other cases of tungiasis reported thereafter, all were acquired in Africa. Treatment
As the disease is self-limiting, at least when exposure to the parasite is limited, management is mostly confined to treatment. Due to the secondary infection that can cause serious medical issues, the recommended course of action upon diagnosis is a surgical extraction of the fleas followed by the application of a topical antibiotic. Care should be taken to avoid tearing the flea during the extraction procedures as severe inflammation will result. The same will occur if part of the flea is left behind. Sterile equipment should always be used, as contaminated instruments could act as mechanical vectors for pathogens to enter the body.There is no drug that has proven to be effective against embedded fleas.