Sand flea (Tunga spp.) infections in humans and domestic animals: state of the art.

Tungiasis is a parasitic disease of humans and animals caused by fleas (Siphonaptera) belonging to the genus Tunga. Two species, Tunga penetrans (L.) and Tunga trimamillata, out of 10 described to date, are known to affect man or domestic animals; the other eight are exclusive to a few species of wild mammals. Tunga penetrans and T. trimamillata originated from Latin America, although the first species is also found in sub-Saharan Africa (between 20 degrees N and 25 degrees S). Hundreds of millions of people are at risk of infection in more than 70 nations, mostly in developing countries. The second species has been reported only in Ecuador and Peru. Males and non-fertilized females of Tunga are haematophagous ectoparasites; pregnant females penetrate the skin where, following dilatation of the abdomen, they increase enormously in size (neosomy) and cause inflammatory and ulcerative processes of varying severity. The importance of Tunga infection in humans concerns its frequent localization in the foot, which sometimes causes very serious difficulty in walking, thereby reducing the subject's ability to work and necessitating medical and surgical intervention. Tungiasis in domestic animals can be responsible for economic losses resulting from flea-induced lesions and secondary infections. Because tungiasis represents a serious problem for tropical public health and because of the recent description of a new species (Tunga trimamillata), it seems appropriate to review current knowledge of the morphology, molecular taxonomy, epidemiology, pathology, treatment and control of sand fleas of the genus Tunga.

Anatomy of Tunga trimamillata Pampiglione et al., 2002 (Insecta, Siphonaptera, Tungidae) and developmental phases of the gravid female.

This paper deals with some internal anatomical features observed in histological sections and freshly dissected mounts of Tunga trimamillata, a Siphonaptera recently discovered in Andean regions of Ecuador from several mammals, including man. It was possible to study in males and also non-gravid and gravid females, the location and anatomy of several organs not previously described for this species: the testes, epididymis, ganglia, Malpighian tubules, eyes, rectal ampulla with one of its pads and structures which could be interpreted as midgut diverticula, whose presence has not been recorded in the Siphonaptera. The process of neosomy in the female during pregnancy is illustrated by photographs of the consecutive developmental phases, taken at the stereomicroscope. Furthermore, some details of the exoskeleton, spermatheca during different phases of pregnancy of the gravid female and the presence of a foreign body (parasite?) within the haemocoel have been displayed in specimens cleared with Hoyer's medium.

Additional description of a new species of Tunga (Siphonaptera) from Ecuador.

A new species of chigoe flea belonging to the genus Tunga Jarocki, 1838 (Siphonaptera, Pulicidae, Tunginae), Tunga trimamillata, was recently described by Pampiglione et al. (2002). A better description and more details of the epidemiology of the flea are now presented. It is a species found in goats, pigs and cattle in Santa Isabel in Andean Ecuador. This new species differs from its most similar congener, Tunga penetrans (L., 1758), by several features, the most important of which are a) the presence on the anterior extremity of the gravid female of three rounded humps surrounding the head and thorax (which, however, are not visible if viewed in profile), b) slightly larger dimensions and c) the length of the first segment of the maxillary palpi which is longer than each of the other three.

[On a new species of sand flea from Ecuador and tungiasis, a problem of Public Health in many developing countries]. / Su di una nuova specie di pulce penetrante dell'Ecuador esulla tungiasi, problema di Sanità Pubblica in molti paesi in via di sviluppo.

The authors recently described a new species of sand flea (genus Tunga) occurred in goat, sheep, cow, pig and man, in the Andean village of S.ta Isabel (Ecuador) and named Tunga trimamillata. Its most important morphological characteristics are: slightly larger dimensions than T. penetrans, both in male and female; presence on the anterior extremity of gravid female of three rounded humps surrounding head and thorax; length of the first segment of maxillary palpi which is longer than each of the other three. The importance of this parasite is due to the fact that it can cause the same damages as T. penetrans both in humans and domestic animals, with conseguent walking difficulties and local or generalized infections. For breeders, economic losses can be remarkable. Tungiasis is a serious problem of Public Health in many countries of Latin America and Subsaharian Africa, and it can be considered in these localities as an indicator of underdevelopment and poor hygiene conditions.