25 - Tungiasis and bed bugs

Summary

Tungiasis

In recent years, increased ecotourism and international travel to tropical countries has produced a growing incidence of infestations formerly limited to certain regions.

Tungiasis is a common ectoparasitic infestation that occurs mainly in the tropics, particularly where poverty and poor standards of basic hygiene exist. Despite recent progress in the treatment and prevention of tungiasis, diagnosis can present a challenge to those unfamiliar with the disorder, especially when happening in nonendemic countries.

Tungiasis is caused by the penetration of the female sand flea, Tunga penetrans, a hematophagous ectoparasite, into the epidermis of the host. The infestation is usually self-limited and presents few complications. It is known by several popular designations, including – chigoe flea, jigger flea, pico, nigua (Mexico, Caribbean islands, Peru), pique (Argentina), bicho dos pès, pulga da areia (Brazil), moukardan (Sudan), puce chique, ogri eye (South America).

Epidemiology

Tunga penetrans is one of the few parasites that has spread from the western to the eastern hemisphere. Sand flea disease is common in resource-poor communities in South America and sub-Saharan Africa, with a prevalence of up to 60% in the general population. The parasite originally lived only on the American Continent and came to Angola with the sand carried by travelers from Brazil. Within a few decades, it spread from Angola to sub-Saharan Africa, East-Africa, and Madagascar. At present, tungiasis is endemic in many countries in Latin America (from Mexico to Northern Argentina), in the Caribbean islands, and in sub-Saharan Africa. Recent studies in Nigeria, Cameroon, and Brazil reported a similar high prevalence of tungiasis, from 45% to 51%; the higher rates occur in some communities of Brazil, Nigeria, and Trinidad and Tobago. The infestation happens mostly in underdeveloped communities in the rural hinterland, in secluded fishing villages along the coast, and in the slums of urban centers. The seasonal variation of tungiasis in endemic communities shows a highest incidence that corresponds to the peak of the dry season in the tropics.