Additional characterization of the adult worm Mammomonogamus laryngeus (Railliet, 1899) and the tissue lesions caused by the infection in buffaloes.

Mammomonogamus spp. are parasites with curious characteristics, such as the "Y" shape that results from male and female maintaining the permanent copulation position and the controversial presence or absence of spicules. These nematodes are hematophagous and cause damage to the upper respiratory tracts of cattle, sheep, goats, deer, wild yaks, and orangutans. Human infection is rare and most cases until now have been in the Caribbean Islands or in Brazil, and mainly in farmworkers but recently there have been reports affecting tourists. In the present work, the parasites were recovered from the laryngopharynx and larynx region of Bubalus bubalis on the island of Marajó, Pará, Brazil. Different microscopy methodologies were applied (bright field, fluorescence, and scanning electron microscopy) to explore the ultrastructural details of the anterior end, genital structures and the host tissue damage caused by the nematodes. The well-developed mouth is an important structure in the identification of these nematodes and used by the parasite to adhere to the host's tissue. Different methodologies in microscopy and molecular biology contributed to a detailed morphological description and showed the phenotypic position of Mammomonogamus laryngeus. Light and scanning electron microscopy (SEM) showed details of the papillae, amphids, festoons, ribs, and teeth. Fluorescence microscopy enabled a detailed characterization of different structures, such as the bursal rays and SEM enabled the visualization of the specialized features of the cuticle surface in the male and female. Histopathological analyses, cryofracture and environmental SEM experiments of the infected tissues were carried out in order to investigate the lesions resultant from the parasitism. In addition, the parasite couples were submitted to cryofracture and these results revealed details of the reproductive structures of both sexes, including the male spicule.

[Leeches of the upper aerodigestive tract]. / Sangsues des voies aérodigestives supérieures.

INTRODUCTION: The leech is an aquatic worm living in fresh water, especially in tropical areas. It may be found exceptionally in the upper aerodigestive tract (UADT) after consumption of spring water or water from natural wells, after swimming in still waters (lakes and dams). The author's objective was to study epidemiological, clinical, therapeutic, and evolutive aspects of this infestation. PATIENT AND METHODS: This prospective 2-year study was carried out from January 1, 2007 to December 31, 2008. We included all patients consulting at the emergency unit presenting with leeches in the UADT. RESULTS: Twenty patients living in rural settings were included: 16 children, mostly boys (sex ratio 3:1). All cases were recorded during the summer season, with 14 cases due to consumption of fresh water and six due to swimming in still waters. The delay between infestation and onset of symptoms ranged from 2 to 15 days. Leeches were found in the oropharynx (six cases), the nasopharynx (five cases), the hypopharynx (six cases), and the glottis (three cases). An anemia syndrome was noted in four patients. All parasites were removed. All patients were given local antiseptics and analgesics. Patients with anemia were given iron supplementation. The outcome was favorable for all patients. DISCUSSION: UADT leeches are not uncommon in Morocco. The infestation is usually observed in the summer. Symptoms vary according to UADT localization. The diagnosis should be made rapidly to prevent complications. Whatever the localization, removing the parasite is difficult. In laryngeal localizations induction general anesthesia is recommended, without intubation. Evolution after treatment is rapidly favorable, with complete disappearance of symptoms.

Disseminated cutaneous rhinosporidiomas in an immunocompetent male.

Rhinosporidiosis is a chronic recurrent infective granulomatous disease of man and animals. It is endemic in India and Sri Lanka. Rhinosporidiosis is a chronic disease commonly involving the nose and nasopharynx. Cutaneous lesions, although rare, can occur due to autoinoculation or due to hematogenous spread. However, disseminated cutaneous lesions presenting as tumor-like swellings are rare. We report here a 48-year-old immunocompetent patient who had disseminated painless cutaneous tumor-like swellings over both the upper limbs, abdomen, left buttock and calf since 10 months, gradually increasing in size. On inquiring, the patient gave history of excisions and electrocauterization of subglottic and nasal polyps. Histopathological examination of these lesions was suggestive of rhinosporidiosis. The general and systemic examinations of the patient did not reveal any abnormality.

Rare living hypopharyngeal foreign body.

BACKGROUND: This is a case report about a rare hypopharyngeal foreign body causing dysphagia, dyspnea, and hemoptysis as well as melena: an ingested leech. The patient was in this condition for more than 1 week. METHODS: The ingested leech, attached to the right piriform fossa partially obstructing the larynx, had to be removed under general anesthesia. RESULTS: After removal, no further symptoms occurred. The leech was identified as the species Theromyzon tessulatum. CONCLUSIONS: Human infestation of a leech in the upper aerodigestive tract is a very rare condition in urban areas. The current literature is reviewed and the diagnostic approach as well as therapeutic options are discussed.

[A case of human infection with Clinostomum sp].

The genus Clinostomum is a cause of parasitic laryngo-pharyngitis. We report the 15th case of Clinostomum sp. infection in Japan. A 29-year-old female visited our hospital because of throat discomfort and expectoration of a worm by sneezing on November 17, 1997. The pharyngitis was caused by the worm. The worm was morphologically identified as the adult of the genus Clinostomum.

[Presence of metacyclical promastigotes of Leishmania pifanoi in the hypopharynx of Lutzomyia youngi and their sugar consumption]. / Presencia de nectomonadas metacíclicas de L. pifanoi en la hipofaringe de Lutzomyia youngi y la ingestión de azúcares.

The presence of metacyclical promastigotes of Leishmania pifanoi in the hypopharyngeal duct of Lutzomyia youngi is reported. The insects were experimentally infected by engorgement on the tarsal lesions of hamsters. The metacyclics, whose morphology is illustrated, appeared in the hypopharynx 5 to 9 days after engorgement; they were more frequently found in the insects fed on unrefined commercial sugar. They role of amino derivates of glucose and galactose, as well as of amino acids in the development and migration of metacyclics, is investigated.

Presencia de nectomonadas metaciclicas de L. pifanoi en la hipofaringe de Lutzomyia youngi y la ingestion de azúcares / Metacyclical forms of L. pifanoi in the hypopharynx of Lutzomyia youngi and their sugar consuption

Se evidencia la presencia de promastigotos metacíclicos de Leishmania pifanoi en el conducto hipofaríngeo de Lutzomyia youngi infectados experimentalmente por ingurgitación sobre lesiones tarsales de hámsteres. La aparición de metacíclicos en la hipofaringe, cuya morfología se ilustra, ocurre entre los 5 y 9 días de desarrollo postprandial y es más frecuente en insectos alimentados com sacarose comercial no refinada. Se investiga el papel de derivados aminados de glucosa y galactosa y también de aminoácidos, en la promoción y migración de los metacíclicos

[Leishmaniasis and ENT]. / Leishmaniasis en O.R.L.

Three cases of the infrequent mucocutaneous Leishmaniasis, with nasal involvement in two of them and affection of the hypophrarynx and larynx in the other one are presented. We remark, in the case with laryngeal disease, that it was the onset of an AIDS in a patient unknown to be HIV+. Leishmaniasis of the larynx has not been described before as the onset of an AIDS. Symptomatology, evolution and treatment of this disease are revised, pointing out the increasing association, in our country, between leishmaniasis and AIDS, and considering the possibility of including the leishmania infection as an AIDS criteria in HIV+ patients, and to rule out an IVH infection in a patient with an atypical leishmaniasis either for the site involved or the evolutive course of the disease.

A comparison of susceptibility of two allopatric populations of Glossina pallidipes for stocks of Trypanosoma congolense.

A colony of Glossina pallidipes Austen which originated from Nguruman, Rift Valley Province, Kenya, was significantly more susceptible to infection (19.3%) with a stock of Trypanosoma congolense Broden isolated from G. pallidipes in Nguruman than a colony of the same species which originated from Shimba Hills, Coast Province, Kenya (5.6%). Male G.pallidipes from Nguruman were significantly more susceptible than females to this T.congolense stock whilst the susceptibility of both sexes of G.pallidipes from Shimba Hills did not differ significantly. All six goats on which six infected G.pallidipes fed singly (three tsetse per colony) became infected. Similarly, the G.pallidipes colony of Nguruman origin was significantly more susceptible to infection (16.4%) with a stock of T.congolense isolated from G.pallidipes in Shimba Hills than the colony of Shimba Hills origin (4.9%). The susceptibility of the sexes of G.pallidipes from both the colonies to this stock of T.congolense did not differ significantly. Again, all six goats on which six infected G.pallidipes fed singly (three tsetse per colony) became infected. If the observed differences in susceptibility of the two G.pallidipes colonies reflect transmission of trypanosomes by the two allopatric populations of tsetse in the field, then the epidemiology of congolense-trypanosomiasis in livestock must differ between these two areas of Kenya endemic for trypanosomiasis.

[Metacyclics of Leishmania mexicana in the hypopharynx of Lutzomyia youngi experimentally infected]. / Metaciclicos de Leishmania mexicana en la hipofaringe de Lutzomyia youngi experimentalmente infectada.

Although it has been postulated that the natural transmission of leishmaniasis occurs by regurgitation of the parasites from contaminated proboscis of phlebotomine vector recent experimental results seems to oppose this thesis. Wild-caught and laboratory-reared females of Lutzomyia youngi, vector of Leishmania mexicana in the Venezuelan Andes, were infected on tarsal lesion of hamsters, inoculated 6 weeks previously s.c. with 2 x 10(4) amastigotes of L. mexicana s.l., isolated from Venezuelan case of diffuse leishmaniasis. The insects were kept at 23 degrees C and 80% R.H., on a 50% (v:v) solution of "unrefined" cane sugar. The parasites developed through 3 stages: i) differentiation of the amastigotes and exponential growth in the number of promastigotes, ending between 60 and 108 hrs, with a massive fecal elimination of large promastigotes; ii) a stationary phase in growth with flagellar adhesion to the cuticle of the stomodeum and synthesis of a gel that formed a plug between 60 and 120 hrs; iii) differentiation of metacyclics, which invade the hypopharyngeal duct in 7% of the insects, from the 5th day post-infection, and most frequently between the 6th and 9th day. The metacyclics measured 4.2/microns in body length, 1.07/microns in maximum with and the flagellum was 8.8/microns long. The parasites swam freely in the saliva of the hypopharyngeal duct (lumen 6/microns in diameter), from the apex to union with the salivary duct, without invading the latter. Similar results has been obtained in the same vector experimentally infected with other two strains of L. mexicana isolated respectively from wild Lu. flaviscutellata and from another case of diffuse leishmaniasis.(ABSTRACT TRUNCATED AT 250 WORDS)

Extrachromosomal inheritance of susceptibility to trypanosome infection in tsetse flies. I. Selection of susceptible and refractory lines of Glossina morsitans morsitans.

Differences in susceptibility to infection with Trypanosoma congolense between F1 families of Glossina morsitans morsitans indicated that susceptibility is maternally inherited in this species of tsetse fly. Twelve F1 families, six selected for susceptibility and six selected for refractoriness to infection, have been bred for up to 13 generations. The reciprocal differences demonstrated in the F1 generation persisted in these selected families over many generations, indicating that susceptibility/refractoriness to T. congolense infection is extrachromosomally inherited in G. m. morsitans. Repeated 'backcrossing' to males of the opposite strain showed that infection rates within families were independent of the contribution of the male parent. Susceptible families had a mean midgut infection rate of 76.9% and a mature (hypopharyngeal) infection rate of 47.9%. In the refractory families 88.9% of the flies failed to develop an infection, 11.1% had midgut infections and only 6.3% developed mature infections. Levels of midgut infection remained remarkably constant within families over generations, whether refractory or susceptible, while maturation rates varied between generations and between sexes. Males matured a significantly greater proportion of midgut infections than females in the susceptible families. It is suggested that the inheritance of susceptibility/refractoriness relates primarily to the establishment of midgut infections in G. m. morsitans, and that maturation of midgut infections is dependent upon environmental factors such as diet, and differences between sexes probably reflecting differences in rates of bloodmeal digestion.(ABSTRACT TRUNCATED AT 250 WORDS)

Absence of a surface coat from metacyclic Trypanosoma vivax: possible implications for vaccination against vivax trypanosomiasis.

Trypomastigotes attached to the wall of the hypopharynx in tsetse flies infected with Trypanosoma vivax are believed to represent the true metacyclic stage of this trypanosome. Electron microscopy demonstrates that attachment is mediated by hemidesmosome-like junctions along the flagellar membrane and that none of the trypomastigotes, either attached or free in the hypopharynx lumen, possesses a surface coat comparable with that on the metacyclics of T. brucei and T. congolense and on the bloodstream stages of all salivarian trypanosomes. As the variable antigen of bloodstream and metacyclic T. brucei is located in the surface coat, the absence of the coat from metacyclic T. vivax suggests that the mechanism of antigenic variation in this species may be somewhat different from that of antigenic variation in T. brucei, and that vaccination of cattle against T. vivax may prove a simpler proposition than vaccination against T. brucei.