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PubMed2005

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.

Animals↗
PubMed1983

Tunga penetrans in south Florida.

We have described a 25-year-old man with infestation of the feet by the burrowing flea Tunga penetrans, acquired in Brazil. We have also presented the microscopic characteristics of the flea and the histologic differential diagnosis.

Adult↗
PubMed2004

The animal reservoir of Tunga penetrans in severely affected communities of north-east Brazil.

Tungiasis is a zoonotic ectoparasitosis caused by the sand flea Tunga penetrans L. (Siphonaptera: Tungidae). This disease is hyperendemic in poor communities of north-east Brazil, causing considerable morbidity in affected human populations, but the animal reservoirs have not been investigated previously in Brazil. To assess the prevalence and intensity of T. penetrans infection in domestic and peri-domestic animals, as well as in the human population, we surveyed two typical communities of north-east Brazil: an urban slum and a traditional fishing village. In the slum we examined 849 humans, 121 cats, 82 dogs, 2 pigs, 2 rabbits, 1 monkey and 56 rodents, comprising 34 rats (Rattus rattus L.) and 22 mice (Mus domesticus L). In the fishing village we examined 505 humans, 68 dogs, 37 cats, 7 donkeys, 4 cattle, 3 pigs and 1 monkey. Tungiasis was common among dogs and cats of both communities, with respective prevalence rates of 67.1% (95% CI: 55.8-77.1) and 30.9% (95% CI: 20.2-43.3) in dogs, 49.6% (95% CI: 40.4-58.8) and 32.4% (95% CI: 18.0-49.8) in cats. Slum rats were 41.2% (95% CI: 24.6-59.3) infested, but the other animals were not. Human prevalence rates were 54.4% (95% CI: 51.0-57.8) in the slum and 52.1% (95% CI: 47.6-56.5) in the fishing village. High prevalence rates (range 31-67%) of tungiasis in humans, pets and rats (but apparently not other animals) indicate the need for an eco-epidemiological approach to control of this anthropo-zoonotic problem.

Animals↗
PubMed1995

Cutaneous infection with Tunga penetrans.

A 23-year-old man presented with a small black lesion at the distal margin of the right great toenail. He had returned from the Ivory Coast 1 month previously, having spent 6 weeks there. Histopathological examination of material extruded from the lesion showed a variety of arthropod internal organs, allowing a definitive diagnosis of infection with the ectoparasitic flea Tunga penetrans. Curettage of the lesion revealed a gravid adult female flea.

Adult↗
PubMed2007

Tunga penetrans: a stowaway from around the world.

Tungiasis is a cutaneous ectoparasitic infestation by the female sand flea Tunga penetrans. It is predominantly a health problem in sub-Saharan Africa, the Caribbean, Latin America and South America. However, increasing numbers of returning travellers, immigrants, and adopted children are also affected in non-tropical countries. It is a cause of substantial morbidity, with prevalence rates as high as 76% in certain endemic areas. To date, the early extraction of the flea is still the first line therapy.

Animals↗
PubMed2002

Typical histologic features of Tunga penetrans in skin biopsies.

CONTEXT: Tunga penetrans is a flea that burrows into human skin, causing the disease tungiasis. Although the parasite is not endemic in the United States, patients may present with this disease upon returning from tropical locales. Histologic sections contain a variety of flea parts that may present a diagnostic dilemma for pathologists unfamiliar with this disease. OBJECTIVE: To determine the typical histologic features of T penetrans in biopsies from patients with tungiasis. METHODS: We reviewed biopsy specimens from 7 patients with tungiasis and sought 8 distinct structures: the exoskeleton, hypodermal layer, respiratory tract (tracheae), digestive tract, striated muscle, head, posterior end, and developing eggs. RESULTS: The exoskeleton, hypodermal layer, tracheae, digestive tract, and developing eggs were present in all biopsy specimens reviewed. Striated muscle, the posterior end, and head, however, were present in 57%, 43%, and 0% of the biopsies, respectively. In addition, we noted a unique, pale-staining layer in the exoskeleton at the posterior end of the organism that, to the best of our knowledge, has not previously been described and that may be of diagnostic value. CONCLUSIONS: Despite the absence of 3 key morphologic features in many (posterior end and striated muscle) or all (head) of our biopsies, the exoskeleton with a hypodermal layer, tracheae, and developing eggs were uniformly present, and together these features are sufficient for a diagnosis of tungiasis.

Adult↗
PubMedDate not supplied

[Record of Dasypus novemcinctus (Mammalia: Xenarthra) parasited by Tunga terasma (Siphonaptera: Tungidae) in Alegre, State of Espírito Santo, Brazil].

During a survey of Mycobacterium leprae in wild armadillos in the State of Espírito Santo, thirty-four armadillos were captured in the municipality of Alegre (20 degrees 45'S, 41 degrees 29'W, 150m). The armadillos, Dasypus novemcinctus were examined by clinical and macroscopic examination. In four armadillos (11.7%), were found nodes in the abdomen. The nodules were identified as Tunga terasma. This is the first report of T. terasma in D. novemcinctus armadillos in the State of Espírito Santo, Brazil.

Animals↗
PubMed1989

[Observations of the sand flea (Tunga penetrans) in humans and dogs in French Guiana].

The occurrence of sand fleas (Tunga penetrans) in a reservation in the north of French Guyana is described. The parasite is found on dogs, Europeans and children of the local Indian tribes. Infections in man are supported by a big population of stray dogs as well as by the local cottage construction. Due to the simultaneous efficiency against the larvae of Dermatobia hominis lvermectin is only of limited suitability for the treatment of tungiasis in dogs. In man single parasites can be removed with a splinter forceps. In dogs footbathing with 0.2% Neguvon has shown to be effective. On long term a reduction of the stray dog population is recommended.

Animals↗
PubMed1994

Distribution patterns of Tunga penetrans within a community in Trinidad, West Indies.

This paper describes patterns of infection with Tunga penetrans within the town of Icacos, Trinidad, West Indies, assessed by the number of persons infected and the extent of the chigoe flea burden by physical examination. The overall prevalence of infection was 31.4% (102 infected persons) of the 325 persons examined (41% of males and 23% of females). Both measures showed a significant difference among the different age groups with peak chigoe burden found in the 5-9, 10-14 and > 55 age-groups, with 9, 5.6 and 12 fleas per infected person, respectively. The aggregated distribution of chigoe flea burden showed a few persons with many fleas and many persons with none (68%). In contrast, in chigoe flea burden there were no significant sex differences but age-associated differences (G = 17.9; d.f. 7; P < 0.01). It is recommended that all cases of tungiasis should be treated and the source of infection effectively managed or eradicated.

Adolescent↗
PubMed1976

Ultrastructural comparison of the midgut epithelia of fleas with different feeding behavior patterns (Xenopsylla cheopis, Echidnophaga gallinacea, Tunga penetrans, Siphonaptera, Pulicidae).

This morphological study describes the ultrastructure of the midgut of three flea species, including temporary parasitic fleas (both sexes of Xenopsylla cheopis, males and immature females of Echidnophaga gallinacea and Tunga penetrans) and stationary parasitic fleas (mature females of E. gallinacea and T. penetrans). (1) Three cell types (a,b,c) constitute the midgut epithelium, each appearing in a characteristic and constant frequency along the whole midgut, a) The functional digestive cells form the main part of the epithelium as one layer of cylindric cells. Nuclear volume and nucleus/cytoplasm ratio have been estimated (with morphometric methods) to be the same in both sexes of E. gallinacea and T. penetrans. b) Some single regenerative cells or nests, containing 5-10 cells per section plane, lay at the base of the epithelium (2-3 cells or nests per cross section of a midgut). c) Secretory cells are characterized by their opaque cytoplasm which contains electron-dense vesicles. They have few microvilli and no basal labyrinth and are placed between digestive cells only as single cells (1-2 per cross section of a midgut). (2) After the first bloodmeal some ultrastructural changes occur in the midgut of all fleas. These changes are interpreted as a structural reflection of metabolic processes such as secretion of digestive enzymes, resorption, storage and transport of digested nutrients, and synthesis of digestive enzymes. (3) More conspicious changes occur in the midgut of the stationary parasitic and maturing females of E. gallinacea and T. penetrans. The nuclear volumes of the digestive cells reach the two-fold and eight-fold value, respectively. The nucleus/cytoplasm ratio decreases by half. The corresponding cytoplasmic growth of each cell is reflected in an enlargement of the whole midgut. The digestive cells form long apical cell extensions. The nucleus, basal labyrinth, rer, and golgi complex all change their morphology, and this can be interpreted as the result of a higher level of metabolic activity than during the first bloodmeal. (4) The midgut of the oviparous female of T. penetrans undergoes a process of compensatory hypertrophy which consists in the cellular hypertrophy of each digestive cell and in an extensive proliferation of the regenerative cells. A unique structure, called 'nuclear halo' appears within the process of cellular hypertrophy. This structure consists of a layer of 70-100 A thick filaments along the periphery of the nucleus. The nuclear halo contains few ribosomes and is screened from the cytoplasm by an rer cisterna. The filaments may contain RNA molecules which are on their way to the cytoplasm. It has been demonstrated that the structure of the midgut epithelium is influenced by the nutritive and parasitic behavior of the flea. The stationary and oviparous E. gallinacea and T. penetrans reveal an extensive and irreversible change of their midgut epithelium.

Animals↗
PubMed2003

Investigations on the biology, epidemiology, pathology and control of Tunga penetrans in Brazil. II. Prevalence, parasite load and topographic distribution of lesions in the population of a traditional fishing village.

Tungiasis is hyperendemic in many poor communities in Brazil and is associated with considerable morbidity. In order to understand the factors that determine the distribution of this ectoparasitosis in a rural community, an epidemiological study was carried out in a traditional fishing village in Ceará State, north-eastern Brazil. Based on active case detection and voluntary participation, 91% of the population (belonging to 95% of all families) was examined. Embedded fleas were looked for over all parts of the body, counted, and the lesions were staged. The overall prevalence of infestation was 51.3% (95% CI: 47.0-55.5). More males than females were infested (54.8% vs 48.3%); however, this difference was not statistically significant. Age-specific prevalence rates followed an S-shaped curve with peaks in children aged 5-9 years and people elder than 60 years. The parasite burden was high (range 1-145 lesions; arithmetic mean: 8.9) and particularly elevated in males, children <15 years and the elderly. The distribution of the parasite burden was uneven within the population with the majority of the lesions in a few individuals: the 23 subjects (8% of all infested) with severe infestation (>30 lesions) accounted for 1,366 of the 2,493 lesions (54.8%) documented. The study shows that tungiasis is a highly prevalent ectoparasitosis in this deprived community with a peculiar distribution of prevalence and parasite burden.

Adolescent↗
PubMed2005

Molecular characterization of Tunga trimamillata and T. penetrans (Insecta, Siphonaptera, Tungidae): taxonomy and genetic variability.

A new species of the genus Tungo, 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.

Amino Acid Sequence↗