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.
S u m m a ry :Of the ten currently known species of sand fleas, only two, Tunga penetrans and Tunga trimamillata, are known to be parasites of man, besides other warm blooded animals, most of which are peridomestic. The hosts of the other eight are limited to a few genera of wild mammals. T. trimamillata was only recently identified and differentiated from T. penetrans by features of the gravid female phase. In the present paper the different morphological characters of both for non-gravid females and males of the two species are described. In the non-gravid-females the distinguishing characters are: a) differences in the length of the first two segments of the maxillary palps (the first is the longest in T. trimamillata, whereas the second is the longest in T. penetrans), this feature is associated with another character i.e . the presence of short, thick spines in addition to the bristles on the surface of the segments only in T. trimamillata; b) the presence, only in T. trimamillata, of a row of spines on the antero-medial surface of the tibia of the 3rd pair of legs; c) the last abdominal spiracle protrudes in T. trimamillata but not in T. penetrans; d) the hood of the hilla in spermatheca is surrounded by a papilla only in T. penetrans. The following morphological characters differentiate males of T. trimamillata and T. penetrans; a] T. trimamillata has a row of spines on the antero-medial surface of the tibia of the 3rd pair of legs; b) the diameter of the abdominal spiracles of T. trimamillata is smaller than that of T. penetrans and the edges of the spiracles are more regular; c) the claspers and aedeagus of T. trimamillata are shorter than those of T. penetrans; d) the profile of the aedeagal apodeme differs between the two species.KEY WORDS : differential diagnosis, Tunga penetrans, Tunga trimamillata, taxonomy, tungiasis.R ésu m é : D ia g n o se d if f ér e n t iel l e en t r e T u n g a p e n e t r a n s (L ., 1 7 5 8
Summary:A new species of chigoe flea belonging to the genus Tunga Jarocki, 1 838 (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.
Electron microscopy of the cells of the follicle duct of Triops cancriformis shows that the follicular ducts are lined by a single-layered epithelium which also produces the eggshell material. The cytoplasm is rich in rough endoplasmic reticulum that synthesizes the eggshell material which subsequently aggregates into preformed vacuoles. Newly formed spheres of eggshell material are then excreted into the lumen. At the end of vitellogenesis the oocytes descend toward the longitudinal oviduct and pass through the eggshell material which fills the follicle ducts. The production of the eggshell and its chemical composition in some Phyllopoda are compared. The paper discusses the relationship between the eggshell construction and the reproductive biology of the population.
Summary :A new species of the genus Tunga, T. trimamillata has recently been described on the basis of several morphological traits. To explore the taxonomic status of this flea with respect to T. penetrans, we undertook a molecular analysis of cytochrome oxydase II and 16S rDNA mitochondrial genes and of the internal transcribed spacer 2 nuclear marker on samples of both species. Maximum Parsimony evaluations of the three data set indicate a differentiation compatible with a specific rank between the two fleas with very high levels of divergence. Both mitochondrial and nuclear data are in line with a recent bottleneck in the Malagasy population of T. penetrans, possibly due to the recent colonisation of Africa via human transportation. Further, significantly lower mitochondrial variability in the Ecuadorian populations of T. penetrans with respect to the T. trimamillata ones is also evidenced. Résumé
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