The objective of this study was to show which species of flies are responsible for human myiasis in the Brazilian state of Goiás and to determine the frequency of cases. Patients at the Clinical Hospital of the Federal University of Goiás (UFG) were examined, and any fly larvae found in their wounds were collected for taxonomic identification. First instar larvae were observed using light microscopy; second and third instars were examined using stereoscopy. The following screwworm flies were observed, in decreasing order of prevalence: Cochliomyia hominivorax, Sarcodexia lambens, Dermatobia hominis, Chrysomya albiceps, Chrysomya megacephala, Lucilia cuprina, and Eristalis tenax. Myiasis was most frequent in the legs in adults, male patients, elderly people, and people of reproductive age. It was lowest in children, females, and patients with neurologic or psychiatric disorders. Frequency was high in patients living in low socioeconomic conditions with poor personal hygiene. Education and sanitation measures are needed to counteract this situation.
In order to monitor the susceptibility of Boophilus microplus to acaricides and improve control measures, the effects of cypermethrin, deltamethrin and permethrin on larvae obtained in the city of Goiânia in the Brazilian state of Goiás were studied. Although these pyrethroids are already sold as acaricides, their cost-benefit efficiency has been questioned. Fasting 14-21 day-old larvae were immersed in solutions of the acaricides under test, maintained at 27±1° C, and relative humidity over 80%, and observed under the stereoscope within an apparatus originally designed for studying the non-parasitic phase of the tick life cycle. The observed toxicological effects were: excitability, repetitive motion, decreased motor ability, detachment, paralysis, knock-down and cuticular proliferation of liquids and gases. The materials used in the manufacture of this apparatus consisted of disposable Petri dishes, "organza" cloth and paraffin, none of which are toxic to tick larvae. Mean death rates after 24h were 76.3%, 87.5%, 77.6%, 91.2%, 86.2% and 100% for 25 and 50ppm deltamethrin, 150 and 300ppm cypermethrin and 1250 and 2500ppm permethrin, respectively. The ticks were resistant to commercial concentrations of deltamethrin and cypermethrin. Only 2500ppm permethrin produced the mortality recommended by the Brazilian Ministry of Agriculture.
Lutzomyia (Nyssomyia) intermedia (Lutz & Neiva 1912) and Lutzomyia (Nyssomyia) whitmani (Antunes & Coutinho 1939) (Diptera: Psychodidae) are vectors of American cutaneous leishmaniasis in several endemic regions of Brazil. We analyzed the external morphological aspects of the immature stages of these two vectors by using scanning electron microscopy. In general, the larval stages of the two species are morphologically similar, although some differences were noted. Detailed examination of the eggs of both species revealed similar exchorionic ornamentations of unconnected parallel ridges. The larval head capsules are well defined, heavily sclerotized, and bear prominent chewing mouthparts. The abdominal segments are easily recognized by the presence of prolegs on their ventral surfaces. The morphology of the anal lobe on the terminal abdominal segment differs between the two species. We found the following three types of sensillae inserted on the antennae: (1) clavate basiconic; (2) small, blunt coeloconic; and (3) multipourous clavate coleoconic. In addition; five subtypes of trichoid sensillae were found on the larval body: (1) long, (2) short, (3) curved long, (4) brush-like, and (5) weakly brush-like. The caudal filaments located on the last abdominal segment were recognized as long trichoid sensillae. We observed pores on the surface of the clavate coelonic sensillae and on the caudal filaments that presumably function as chemoreceptors. The larvae of the two species show similarities in the lobular-form antennae of L1 larvae, which changes to digitiform in second instar (L2), L3, and L4. This study demonstrated that the external surface of the eggs and larvae of Lu. intermedia and Lu. whitmani are morphologically similar, but they can be distinguished by details in the microanatomy observed by scanning electron microscopy.
Investigaram-se os efeitos toxicológicos in vitro de três piretróides em diferentes concentrações, formulados para uso pecuário, domiciliar e em cães, sobre larvas de R. sanguineus, objetivando monitorar sua suscetibilidade e fomentar seu controle. Utilizaram-se 1.604 larvas em jejum, com 15 a 21 dias, obtidas por infestação artificial em cão, imersas nas soluções testadas, contidas em dispositivos constituídos por placa de Petri descartável, papel filtro e parafina, mantidas em incubadoras do tipo BOD e observadas ao estereoscópio por 24h. Observaram-se excitabilidade, movimentação repetitiva, diminuição da locomoção, desprendimento, paralisia, "knock-down" e proliferação cuticular de gases e líquidos. A mortalidade na 24ª hora foi de 86,9%, 100,0%, 80,3%, 86,0%, 68,2% e 78,0%, respectivamente, para permetrina 1250ppm e 2500ppm, cipermetrina 150ppm e 300ppm, e deltametrina 25ppm e 50ppm. Não houve mortalidade no grupo controle.
The objective of the present work was to register the first proven cases of human pseudomyiasis due to Eristalis tenax in Goiás State, Brazil, underscoring their clinical manifestations and direct relationship with hygiene. The taxonomic identification of the instars was done according to the descriptions and keys presented by James (1947), Hartley (1961) and Guimarães & Papavero (1999 James (1947), Hartley (1961) e Guimarães & Papavero (1999 Gastrointestinal myiasis caused by the cosmopolitan drone fly Eristalis tenax (Diptera: Syrphidae) is classified as pseudomyiasis, given the biology of the fly and that it occurs in an accidental manner. Its presence, in the surface of the digestive tract is responsible for the pathologic physiology, in general of lesser gravity than that caused by the obligatory or facultative parasites 6 . RESUMO O presente trabalho visa registrar os primeiros casos evidenciados de pseudomiíases humanos por Eristalis tenax no estado de Goiás, Brasil, destacando suas manifestações clínicas e suas relações diretas com os hábitos higiênicos. A identificação taxonômica das larvas foi realizada com base nas descrições e chaves apresentadas porThe genus Eristalis (Linnaeus) was designated commonly as Tubifera (Meigen), and some researchers have also denominated it Eristalomyia. The simple observation of the family rat-tailed maggot (long respiratory siphon) characteristic in larvae instars has incited some researchers to the diagnosis of E. tenax. Though, this is not a pathognomonic characteristic, or exclusive to this species or its genus. Thus, many incorrect records and inaccurate descriptions result from this extrapolation 3 .The larvas of E. tenax are extremely resistant to adverse conditions of pressure, heat and salinity 5 . They live in water polluted by feces, sewage, liquid excrements and organic materials in decomposition, including carcasses. Occasionally they can be found in relatively clean water 3 , however, the occurrence of E. tenax larvae in stagnated waters indicates a high degree of pollution 1 .Gastrointestinal pseudomyiasis presents unspecific symptoms and its clinical aspects vary in agreement with the 186
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