Assuntos
Ectoparasitoses/prevenção & controle , Doenças Endêmicas/prevenção & controle , Repelentes de Insetos/uso terapêutico , Ácido Pantotênico/uso terapêutico , Óleos de Plantas/uso terapêutico , Sifonápteros , Adulto , Idoso , Animais , Brasil/epidemiologia , Criança , Pré-Escolar , Combinação de Medicamentos , Ectoparasitoses/epidemiologia , Doenças do Pé/tratamento farmacológico , Doenças do Pé/parasitologia , Humanos , Masculino , Ácido Pantotênico/análogos & derivados , Resultado do TratamentoRESUMO
The jigger Tunga penetrans (Linnaeus, 1758: type-species of the family Tungidae) is the smallest known species of flea (Siphonaptera), causing serious ectoparasitosis of humans and domestic animals. The adult female Tunga lodges in the epidermis of the mammalian host, grows by neosomy, becomes gravid and expels eggs. Relatively little is known about the free-living male Tunga adults. Among impoverished communities of Fortaleza in north-east Brazil, we observed T. penetrans males as well as females penetrating the skin of human hosts. After penetrating the epidermis for a few hours, evidently for capillary feeding from the dermis, males withdrew their mouthparts and crawled away, whereas the females remained completely embedded, hypertrophying to become gravid, eventually dying in situ after oviposition. Caged rats were placed on the sandy soil and examined periodically for Tunga infestation. On five rats we obtained 140 females embedded and we detected 75 males biting, with rat erythrocytes observed in the proventriculus and midgut of all five males dissected and examined microscopically. This confirms that T. penetrans males are hamatophagous ectoparasites of mammals.
Assuntos
Comportamento Alimentar/fisiologia , Sifonápteros/fisiologia , Animais , Ectoparasitoses/parasitologia , Feminino , Humanos , Masculino , Ratos , Ratos WistarRESUMO
Ten monosyllabic, 10 trochaic, and 10 spondaic words were presented monaurally to 10 severely (70-95 dB HTL) and 10 profoundly (larger than 95 dB HTL) hearing-impaired children at sensation levels (SL) ranging from near detection to near discomfort. Two methods were used to evaluate word perception as a function of stimulus intensity: the percentage of words recognized correctly and the percentage of words categorized correctly as to stress pattern. Both word-recognition and categorization scores reached maxima at 24-36 dB SL for the severe group, supporting previous result. For the profoundly deaf group, word-recognition scores were low regardless of SL, but their perception of the stress patterns of words improved as a function of increasing intensity, reaching maxima at 12-30 dB SL. The procedure and results described in this paper may be used by audiologists to help select optimal hearing aid volume settings for young hearing-impaired children.