Canine visceral leishmaniasis due to Leishmania (L.) infantum chagasi in Amazonian Brazil: comparison of the parasite density from the skin, lymph node and visceral tissues between symptomatic and asymptomatic, seropositive dogs / Leishmaniose visceral canina causada por Leishmania (L.) infantum chagasi na Amazônia brasileira: comparação da densidade parasitária da pele, linfonodo e vísceras entre cães soropositivos, sintomáticos e assintomáticos

Canine visceral leishmaniasis (CVL) is recognizable by characteristic signs of disease and is highly lethal. The infection, however, may be quite inapparent in some seropositive dogs, and this has raised the polemic question as to whether or not such animals can be a source of infection for Lutzomyia longipalpis, the vector of American visceral leishmaniasis (AVL). In this study we have examined 51 dogs with acute CVL from an AVL area in Pará State, northern Brazil, and compared the parasite density, amastigotes of Leishmania (L.) infantum chagasi, in the skin, lymph node and viscera of symptomatic with that of nine asymptomatic but seropositive dogs (IFAT-IgG). Post-mortem biopsy fragments of these tissues were processed by immunohistochemistry, using a polyclonal antibody against Leishmania sp. The X² and Mann Whitney tests were used to evaluate the means of infected macrophage density (p < 0.05). There was no difference (p > 0.05) in the skin (10.7/mm² x 15.5/mm²) and lymph node (6.3/mm² x 8.3/mm²), between asymptomatic and symptomatic dogs, respectively. It was higher (p < 0.05), however, in the viscera of symptomatic (5.3/mm²) than it was in asymptomatic (1.4/mm²) dogs. These results strongly suggest that asymptomatic or symptomatic L. (L.) i. chagasi-infected dogs can serve as a source of infection, principally considering the highest (p < 0.05) parasite density from skin (10.7/mm² x 15.5/mm²), the place where the vetor L. longipalpis takes its blood meal, compared with those from lymph node (6.3/mm² x 8.3/mm²) and viscera (1.4/mm²x 5.3/mm²).

A leishmaniose visceral canina (LVC) é reconhecida pelas características clínicas da doença e é altamente letal. A infecção, entretanto, pode ser totalmente assintomática em alguns cães soropositivos, o que tem levantado questão polêmica sobre a possibilidade desses animais, serem ou não uma fonte importante da infecção para o flebotomíneo, Lutzomyia longipalpis, o principal vetor da leishmaniose visceral americana (LVA). Neste estudo foram examinados 51 cães com LVC aguda, provenientes de área endêmica de LVA no Estado do Pará, Brasil, e a carga parasitária, formas amastigotas de Leishmania (L.) infantum chagasi, na pele, linfonodo poplíteo e vísceras (fígado e baço) foi comparada com a de nove cães assintomáticos soropositivos (IFAT-IgG). Fragmentos de biópsia desses tecidos obtidos post-mortem foram processados para análise através de imunohistoquímica, usando um anticorpo policlonal contra Leishmania sp. Os testes do Qui-quadrado (X²) e Mann Whitney foram usados para avaliar as médias da densidade de macrófagos infectados (p < 0,05). Os resultados mostraram que não houve diferença (p > 0,05) na densidade de macrófagos infectados da pele (10,7/mm² x 15,5/mm²) e do linfonodo (6,3/mm² x 8,3/mm²) entre cães assintomáticos e sintomáticos. Entretanto, a densidade de macrófagos infectados da víscera de cães sintomáticos (5,3/mm²) foi maior (p < 0,05) que a de cães assintomáticos (1,4/mm²). Estes resultados sugerem, fortemente, que cães naturalmente infectados por L. (L.) i. chagasi, assintomáticos ou sintomáticos, podem servir como fonte de infecção, principalmente, considerando-se que a densidade de macrófagos infectados da pele (10,7/mm² x 15,5/mm²), local onde o flebotomíneo vetor Lu. longipalpis realiza a hematofagia, foi maior (p < 0,05) que as do linfonodo (6,3/mm² x 8.3/mm²) e vísceras (1,4/mm²x 5,3/mm²).

Fauna flebotomínica da Serra dos Carajás, Estado do Pará, Brasil, e sua possível implicação na transmissão da leishmaniose tegumentar americana / Phlebotominae fauna in Serra dos Carajás, Pará State, Brazil, and its possible implications for the transmission of American tegumentar leishmaniasis

A Serra dos Carajás, localizada no sudeste do Estado do Pará, Brasil, representa uma rica floresta tropical, onde são encontradas espécies de Leishmania sp. de interesse médico, como L. (V.) braziliensis, L. (V.) lainsoni, L. (V.) shawi e L. (L.)amazonensis, cuja transmissão é feita pelos flebotomíneos: Psychodopygus complexus ou Ps. wellcomei, Lutzomyia ubiquitalis, Lu. whitmani e Lu. flaviscutellata. Considerando o incremento de imigrantes na região do projeto Carajás, realizou-se estudo para avaliar a fauna de flebotomíneos e sua possível participação na transmissão da leishmaniose tegumentar americana (LTA). Os flebotomíneos foram capturados: i) Parque Zoobotânico de Parauapebas, ii) Área deproteção ambiental e, iii) Floresta Nacional de Tapirapé-Aquiri, de dezembro/2005 a setembro/2007, usando-se dez armadilhas luminosas tipo "CDC" (18 h às 6 h) e duas tipo Shannon (18 h às 20 h), durante 172 dias de coleta. Foram capturados 22.095 flebotomíneos, 6.789 (31 por cento) machos e 15.306 (69 por cento) fêmeas, pertencentes a 69 espécies e três gêneros: Psychodopygus, Lutzomyia e Brumptomyia. Foram detectadas 19 (0,16 por cento) infecções naturais nas seguintes espécies: Ps. davisi (4), Ps. h. hirsutus (3), Lu. umbratilis (3), Lu. richardward (2), Lu. brachipyga (2), Lu. ubiquitalis (2), Lu. trinidadenses (1) e Lu. migonei (1). Embora não tenha sido encontrada infecção em Ps. wellcomei/complexus, principalvetor da L. (V.) braziliensis na região, esta espécie foi a mais prevalente (16 por cento), seguida de Ps. davisi (15,4 por cento), Ps. carrerai (4,2 por cento), Lu. shawi (3,9 por cento), Lu. brachipyga (2,5 por cento) e Lu. richardward (1,2 por cento). Estes resultados evidenciam a importância destes flebotomíneos como possíveis vetores da LTA na Serra dos Carajás.

Serra dos Carajás, located in the southeast of Pará State, Brazil, is a rich tropical forest where species of Leishmania sp. of medical interest are found, such as Leishmania (V.) braziliensis, L. (V.) lainsoni, L. (V.) shawi and L. (L.) amazonensis. They are transmitted by the following phlebotomi: Psychodopygus complexus or Ps. wellcomei, Lutzomyia ubiquitalis, Lu. whitmani and Lu. flaviscutellata. Considering the increase of immigrants in the region of the Carajás project, this study aimed to assess the Phlebotominae fauna and their possible participation in the transmission of American cutaneous leishmaniasis (ACL). The phlebotomi were captured from December 2005 to September 2007 at the following locations: i)Parauapebas Botanical Park; ii) an environmental protection area; and iii) Tapirapé-Aquiri National Forest. During the 172 days of collection, 10 CDC (18 h to 6 h) and 2 Shannon (18 h to 20 h) light traps were used. Of the 22,095 phlebotomi captured, 6,789 (31 percent) were male and 15,306 (69 percent) were female, and they belonged to 69 species and three genera,including Psychodopygus, Lutzomyia and Brumptomyia. A total of 19 (0.16 percent) natural infections of the following species were detected: Ps. davisi (4), Ps. h. hirsutus (3), Lu. umbratilis (3), Lu. richardward (2), Lu. brachipyga (2), Lu. ubiquitalis (2),Lu. trinidadensis (1) and Lu. migonei (1). Although no infection was found in Ps. wellcomei/complexus, the main vector of L. (V.) braziliensis in the region, this species was the most prevalent (16 percent), followed by Ps. davisi (15.4 percent), Ps. carrerai (4.2percent), Lu. shawi (3.9 percent), Lu. brachipyga (2.5 percent) and Lu. richardward (1.2 percent). These results show the importance of these phlebotomi as possible vectors of ACL in Serra dos Carajás.

Novas evidências sobre o valor diagnóstico da reação de imunofluorescência indireta e reação intradérmica de hipersensibilidade tardia na infecção humana por Leishmania (L) infantum chagasi na Amazônia, Brasil / New evidences on the diagnostic value of indirect immunofluorescence test and delayed hypersensitivity skin test in human infection by Leishmania (L ) infantum chagasi in the Amazon, Brazil

Estudo prospectivo realizado no período de maio/2006-setembro/2008, numa coorte de 1.099 indivíduos, ambos os sexos, com idades de 1 a 84 anos (média 24, 4 anos), residente em área endêmica de leishmaniose visceral americana (LVA) no Município de Cametá, Pará, Brasil, objetivando analisar a prevalência e a incidência da infecção humana por Leishmania (L.) infantum chagasi, assim como a dinâmica da evolução dos seus perfis clínico-imunológicos previamente definidos: 1. Infecção assintomática (IA); 2. Infecção sintomática (IS=LVA); 3. Infecção subclínica oligossintomática (ISO); 4. Infecção subclínica resistente (ISR); e 5. Infecção inicial indeterminada (III). O diagnóstico da infecção baseou-se no uso simultâneo da reação de imunofluorescência indireta (RIFI) e reação intradérmica de hipersensibilidade tardia. Um total de 304 casos da infecção foi diagnosticado no período do estudo (187 na prevalência e 117 na incidência), gerando prevalência acumulada de 27,6 por cento, cuja distribuição no âmbito dos perfis clínico-imunológicos foi da seguinte ordem: IA 51,6 por cento, III 22,4 por cento, ISR 20,1 por cento, ISO 4,3 por cento e, IS (=LVA) 1,6 por cento. Com base na dinâmica da infecção, o principal achado recaiu no perfil III, que teve papel fundamental na evolução da infecção, dirigindo-a ora para o pólo imunológico de resistência, perfis ISR (21 casos - 30,8 por cento) e IA (30 casos - 44,1 por cento), ora para o polo imunológico de susceptibilidade, perfil IS (um caso -1,5 por cento); além destes, 16 casos mantiveram o perfil III até o fim do estudo. Concluiu-se que esta abordagem diagnóstica pode ajudar no monitoramento da infecção na área endêmica, visando, principalmente, prevenir a morbidade da LVA, assim como reduzir o tempo e despesas com o tratamento.

This is a prospective study on a cohort of 1099 individuals of both genders, aged 1-84 years (mean 24.4 years), living in an endemic area of American visceral leishmaniasis (AVL) in the Municipality of Cametá, Brazil, from May 2006 to September 2008. It aimed to analyze the prevalence and incidence rates of human infection by Leishmania (L.) infantum chagasi, as well as the evolutional process of its previously defined clinical and immunological profiles: 1. Asymptomatic infection (AI);2. Symptomatic infection (SI = AVL); 3. Subclinical oligosymptomatic infection (SOI); 4. Subclinical resistant infection (SRI); and 5. Indeterminate initial infection (III). The diagnosis was based on the simultaneous use of indirect immunofluorescence assay (IFA) and delayed hypersensitivity skin test. A total of 304 cases of infection were diagnosed during the period studied(187 for prevalence and 117 for incidence), generating an accumulated prevalence rate of 27.6 percent. The distribution regarding their clinical and immunological profiles presented the following order: AI 51.6 percent; III 22.4 percent; SRI 20.1 percent; SOI4.3 percent; and SI (= AVL) 1.6 percent. Based on the dynamics of the infection, the main discovery was about the III profile, which had an instrumental role in its evolution, directing it either to the resistant immunological pole – SRI (21 cases - 30.8 percent) and AI (30 cases - 44.1 percent) profiles – or to the susceptible immunological pole – SI (1 case - 1.5 percent) profile. In addition, 16 cases remained within the III profile until the end of the study. It was concluded that this diagnostic approach can help monitor the infection in endemic areas, aiming mainly at preventing morbidity caused by AVL, and reducing the treatment time and expenses.

The Neotropical Leishmania species: a brief historical review of their discovery, ecology and taxonomy / 117

This paper is a review of the major historical events leading to our present classification of the Neotropical Leishmania species, and apart from indicating the basic type of disease these different parasites may cause in humans, it does not discuss the clinical or epidemiological features of the leishmaniases. For each of these species, information is given on the known geographical distribution, recorded phlebotomine sand fly host(s) and the secondary, wild or domestic mammalian hosts. Reasons are given for regarding the parasite referred to as Leishmania (L.) infantum chagasi, the causative agent of American visceral leishmaniasis, as most probably indigenous to the Neotropics rather than imported during the Iberian colonisation...

Este artigo apresenta uma revisão dos mais importantes eventos históricos que levaram à atual classificação das espécies neotropicais de Leishmania e indica as doenças básicas causadas em seres humanos por estes diferentes parasitos, sem discutir os aspectos clínicos e epidemiológicos das leishmanioses. Para cada uma das espécies descritas, são fornecidas informações a respeito de sua conhecida distribuição geográfica, dos flebotomíneos hospedeiros registrados e de seus reservatórios mamíferos secundários, selvagens ou domésticos. Os dados apresentados levam à conclusão de que o parasito Leishmania (L.) infantum chagasi, agente causador da leishmaniose visceral americana, é provavelmente autóctone da região neotropical, e não importada durante a colonização ibérica...

Proven and putative vectors of American cutaneous leishmaniasis in Brazil: aspects of their biology and vectorial competence

The aim of the present review is to give relevant information on aspects of the biology and ecology, including the vectorial competence of Lutzomyia sand fly species suggested as vectors of American cutaneous leishmaniasis in Brazil. The disease, due to Leishmania (Viannia) braziliensis, has been registered in most municipalities in all the Brazilian states and its transmission is associated with more than one sand fly species in each geographical region. A variety of Leishmania species can be found in the Amazon basin, where different epidemiological chains have been detected with the participation of different phlebotomine vectors. Finally, a discussion is presented on some sand fly species found naturally infected by Leishmania, but for which there is as yet no evidence regarding their epidemiological importance.

Revisão sobre a patogenia da leishmaniose tegumentar americana na Amazônia, com ênfase à doença causada por Leishmania (V. ) braziliensis e Leishmania (L. ) amazonensis / Revisiting the pathogenesis of the american tegumentary leishmaniasis in Amazonian, with emphasis to the disease due to Leishmania (V. ) braziliensis and Leishmania (L.) amazonensis

A patogenia da leishmaniose tegumentar americana (LTA) na Amazônia foi revisada à luz dos mais recentes aspectos associados ao espectro clínico, histopatológico e imunopatológico da doença causada por Leishmania (V.) braziliensis e Leishmania (L.) amazonensis. Esta revisão mostrou a existência de uma dicotomia entre as duas espécies de Leishmania e a resposta imune celular; enquanto a L. (V.) braziliensis mostra forte tendência em dirigir a infecção, a partir da forma central do espectro clínico-imunológico, a leishmaniose cutânea localizada (LCL), para o pólo imunológico hiperreativo, representado pela leishmaniose cutâneo-mucosa (LCM), com exacerbação da hipersensibilidade e perfil da resposta CD4 tipo-Thl, a L. (L.) amazonensis mostra o oposto, dirige a infecção para o pólo imunológico hiporreativo, representado pela leishmaniose cutânea anérgica difusa (LCAD), com forte inibição da hipersensibilidade e perfil da resposta CD4 tipo- Th2. Entre a forma central LCL e as formas polares LCM e LCAD a infecção passa por uma fase intermediária, a leishmaniose cutânea disseminada borderline (LCDB), com inibição parcial da hipersensibilidade e peifil da resposta CD4 Thl + Th2. Estes são, provavelmente, os principais mecanismos imunológicos que modulam a patogenia da LTA causada por L. (V.) braziliensis e L. (L.) amazonensis.

The pathogenesis of American tegumentary leishmaniasis (ATL) was reviewed ifl the light of more recent features of clinical, histopathological and immunopathological spectrum of disease caused by Leishmania (V.) braziliensis and Leishmania (L.) amazonensis. This review has shown a dichotomy in the interaction between these two species of Leishmania with the human .cellular immune response; while L. (V.) braziliensis shows a clear tendency to direct infection, from the localized cutaneous leishmaniasis (LCL) in the center of the clinical-immunological spectrum of disease, to the hyperactive immunologic pole represented by mucocutaneous leishmaniasis (MCL), which shows exacerbated hypersensitivity reaction and CD4 Thl-type immune response, L. (L.) amazonensis shows the opposite,. directing infection to the hypoactive immunologic pole consisted by anergic diffuse cutaneous leishmaniasis (ADCL), associated with a marked inhibition of hypersensitivity reaction and CD4 Th2type immune response. Between the central LCL and thetwo polar MCL and ADCL forms the infection may present an intermediary phase, borderline disseminated cutaneous leishmaniasis (BDCL), which shows partial inhibition of hypersensitivity reaction and a mixed CD4 Thl plus Th2 immune response. These are probably the main immunological mechanisms regarding the immune response dichotomy that modulates the pathogenesis of ATL caused by these Leishmania parasites.

Lutzomyia (Nyssomyia) whitmani s.l. (Antunes & Coutinho, 1939)(Diptera: Psychodidae: Phlebotominae): geographical distribution and the epidemiology of American cutaneous leishmaniasis in Brazil Mini-review

The aim of the present study, in view of the widespread geographical distribution of Lutzomyia (Nyssomyia) whitmani s.l. in Brazil, in close association with the regions of transmission of Leishmania (Viannia) braziliensis and L. (V.) shawi, is to investigate the distribution of this sand fly species and American cutaneous leishmaniasis (ACL) in relationship to vegetation and landscape ecology throughout Brazil. Thematic maps were elaborated by the MapInfo programme, giving information on the spatial distribution of L. whitmani s.l., in accordance with types of vegetation and foci of ACL. With regards to the known areas of transmission of ACL in Brazil, it is notable that L. (N.) whitmani s.l. occurs in most of them, where it has been implicated as a possible vector of L. (V.) braziliensis. The presence of L. whitmani s.l. has been registered in 26 states, the one exception being Santa Catarina; in some states such as Roraima, Acre, Tocantins, and Mato Grosso do Sul this sand fly species has been recorded in a large number of municipalities. L. whitmani s.l. has been found in association with a variety of vegetation types, including the Amazonian forest, savanna ("campos cerrados"), and northeastern savanna ("caatingas nordestinas" or "savana estépica").

Theileria electrophorin.sp., a parasite of the electric eel Electrophorus electricus (Osteichthyes: Cypriniformes: Gymnotidae) from Amazonian Brazil

The name Theileria electrophori n.sp. is proposed for a small parasite described in the erythrocytes of the electric eel, Electrophorus electricus, from Amazonian Brazil. Division of the organism in the erythrocyte produces only four bacilliform daughter cells which become scattered in the host cell, without a cruciform or rosette-shaped disposition. Exoerythrocytic meronts producing a large number of merozoites were encountered in Giemsa-stained impression smears of the internal organs, principally in the liver, and are presumably the source of the intraerythrocytic forms of the parasite. This developmental pattern is characteristic of piroplasms within the family Theileriidae, where the author considers the parasite of E. electricus to most appropriately belong. It effectively distinguishes the organism from the dactylosomatid parasites Babesiosoma Jakowska and Nigrelli, 1956 and Dactylosoma Labbé, 1894 also found in fishes. This appears to be the second report of Theileria Bettencourt, Franca and Borges, 1907 in a fish.

Observations on Eimeria species of Dasyprocta leporina (Linnaeus, 1758)(Rodentia: Dasyproctidae) from the state of Pará, North Brazil

Redescriptions are given of the mature oocysts of Eimeria aguti Carini 1935, E. cotiae Carini, 1935 and E. paraensis Carini, 1935, in the faeces of five specimens of the rodent Dasyprocta leporina (Rodentia: Dasyproctidae) from the state of Pará, North Brazil. New information is provided on the sporulation time of these parasites and the prepatent period in experimentally infected D. leporina. Some endogenous stages of E. cotiae are described in the epithelial cells of the ileum, and the absence of any oocysts in the gall-bladder contents of the infected animals indicates that the intestine is also the site of development of E. aguti and E. paraensis. Difficulties in separating E. cotiae and E. paraensis on morphology of the oocysts are discussed. The oocysts of both parasites share many structural features and have a wide size range. It is concluded that although it is at present best to maintain these names, the possibility exists that they were separately given to oocysts of smaller dimensions (E. cotiae) and larger dimensions (E. paraensis) of a single parasite. Location of an endogenous site of development for E. paraensis that is distinctly separate from that of E. cotiae might establish more definitely the separate specific status of the two parasites.

Lutzomyia longipalpis and the eco - epidemiology of American visceral leishmaniasis, with particular reference to Brazil: a review

An historical review is given of American visceral leishmaniasis (AVL), with particular reference to the eco-epidemiology of the disease in Brazil. Following the first records of AVL in this country, in 1934, the sandfly Lutzomyia longipalpis (Lutz and Neiva, 1912) was incriminated as the principal vector. It is now generally accepted, however, that there exist a number of cryptic species under the name of Lu. longipalpis s.l. and that variations in the quantity of the vasodilatory peptide maxadilan in the saliva of flies from different populations of Lu. longipalpis s.l., may account for the variable clinical manifestations of AVL seen in different geographic regions. Distribution of AVL has been shown to extend throughout most of South and Central America, with the domestic dog serving as the principal reservoir of infection for man. However, while one hypothesis suggests that the causative parasite is Leishmania infantum, imported from Europe with the Portuguese and Spanish colonists, the demonstration of a high rate of benign, inapparent infection in foxes in Amazonian Brazil raised an opposing suggestion that the parasite is indigenous to the Americas. Recent reports of similar infections in native marsupials, and possibly rodents, tend to support this view, particularly as Lu. longipalpis is primordially a silvatic sandfly. Although effective control measures in foci of the disease will diminish the number of canine and human infections, the presence of such an enzootic in a variety of native animals will render the total eradication of AVL unlikely.

Further observations on clinical, histopathological, and immunological features of borderline disseminated cutaneous leishmaniasis caused by Leishmania (Leishmania) amazonensis

Leishmania (Leishmania) amazonensis has for some time been considered as the causative agent of two distinct forms of American cutaneous leishmaniasis (ACL): localized cutaneous leishmaniasis (LCL), and anergic diffuse cutaneous leishmaniasis (ADCL). Recently, a new intermediate form of disease, borderline disseminated cutaneous leishmaniasis (BDCL), was introduced into the clinical spectrum of ACL caused by this parasite, and in this paper we record the clinical, histopathological, and immunological features of eight more BDCL patients from Brazilian Amazonia, who acquired the disease in the Pará state, North Brazil. Seven of them had infections of one to two years' evolution and presented with primary skin lesions and the occurrence of metastases at periods varying from six to 12 months following appearance of the first lesion. Primary skin lesions ranged from 1-3 in number, and all had the aspect of an erythematous, infiltrated plaque, variously located on the head, arms or legs. There was lymphatic dissemination of infection, with lymph node enlargement in seven of the cases, and the delayed hypersensitivity skin-test (DTH) was negative in all eight patients prior to their treatment. After that, there was a conversion of DTH to positive in five cases re-examined. The major histopathological feature was a dermal mononuclear infiltration, with a predominance of heavily parasitized and vacuolated macrophages, together with lymphocytes and plasma cells. In one case, with similar histopathology, the patient had acquired his infection seven years previously and he presented with the largest number of disseminated cutaneous lesions. BDCL shows clinical and histopathological features which are different from those of both LCL and ADCL, and there is a good prognosis of cure which is generally not so in the case of frank ADCL.

The Genus Cyclospora (Apicomplexa: Eimeriidae), with a description of Cyclospora schneideri n.sp. in the snake Anilius scytale scytale (Aniliidae) from Amazonian Brazil: a review

A review is made of the recorded species of the coccidian genus Cyclospora and major events leading up to the discovery of C. cayetanensis, which is responsible for serious outbreaks of diarrhoea in man and is one of the aetiological agents of "traveller's diarrhoea". Humans appear to be the specific hosts, with the entire life-cycle in the intestine: to date there is no convincing evidence that the disease is a zoonosis. A description is given of oocysts and endogenous stages of C. schneideri n.sp., in the snake Anilius scytale scytale. Sporulation is exogenous and completed after about one week at 24-26°. Mature oocysts 19.8 Î 16.6 (15.1 Î 13.8-25.7 Î 20.1), shape-index 1.2 (1.0-1.3): no oocyst residuum or polar bodies. Oocyst wall a single colourless, smooth layer with no micropyle: it is rapidly deformed or broken. Sporocysts 13.6 Î 9.4 (11.3 Î 8.3-15.1 Î 9.9), shape-index 1.4 (1.2-1.5) with an inconspicuous Stieda body. Sporozoites 11-13 Î 2.5-3. Endogenous stages are intracytoplasmic in the epithelial cells of the small intestine and with the characters of the Eimeriorina.

Blood and intestinal parasites of squirrels (Rodentia: Sciuridae) in Amazonian Brazil

We report the result of an examination for blood and intestinal protozoa in 12 specimens of the red squirrel Sciurus spadiceus (Rodentia: Sciuridae) from Birroque, municipality of Plácido de Castro, state of Acre, Brazil. No parasites were detected in thin, Giemsa-stained blood films of the animals, but culture of the blood of three in Difco B45 medium blood-agar slants gave rise to isolates of epimastigotes. Inoculation of one isolate into laboratory mice resulted in the appearance of Trypanosoma cruzi-like trypomastigotes in their peripheral blood, and the other two isolates gave rise to transient infections with a T. lewisi-like parasite in inoculated mice and hamsters. The failure of the latter parasite to develop in the triatomine bug Rhodnius robustus suggests that it is probably not T. rangeli. This appears to be the first record of a T. lewisi-like trypanosome in neotropical squirrels. Oocysts of an Eimeria sp., were detected in the faeces of 10 animals (83.3 percent). The parasite develops in the epithelial cells of the intestine, where it may cause severe damage and sometimes results in death of the animal. No oocysts were detected in bile.

Clinical and immunopathological spectrum of American cutaneous leishmaniasis with special reference to the disease in Amazonian Brazil: a review

The wide variety of Leishmania species responsible for human American cutaneous leishmaniasis combined with the immune mechanisms of the host results in a large spectrum of clinical, histopathological, and immunopathological manifestations. At the middle of this spectrum are the most frequent cases of localized cutaneous leishmaniasis (LCL) caused by members of the subgenera Leishmania and Viannia, which respond well to conventional therapy. The two pathogenicity extremes of the spectrum generally recognized are represented at the hypersensitivity pole by mucocutaneous leishmaniasis (MCL) and at the hyposensitivity pole by anergic diffuse cutaneous leishmaniasis (ADCL). Following the present study on the clinical, histopathological and immunopathological features of cutaneous leishmaniasis in Amazonian Brazil, we propose the use of the term "borderline disseminated cutaneous leishmaniasis" for the disseminated form of the disease, due to parasites of the subgenera Leishmania and Viannia, which might be regarded as intermediate between LCL and the extreme pathogenicity poles MCL and ADCL.

Haematozoan parasites of the lizard Ameiva ameiva (Teiidae) from Amazonian Brazil: a preliminary note

Three different haematozoan parasites are described in the blood of the teiid lizard Ameiva ameiva Linn. from North Brazil: one in the monocytes and the other two in erythrocytes. The leucocytic parasite is probably a species of Lainsonia Landau, 1973 (Lankesterellidae) as suggested by the presence of sporogonic stages in the internal organs, morphology of the blood forms (sporozoites), and their survival and accumulation in macrophages of the liver. One of the erythrocytic parasites produces encapsulated, stain-resistant forms in the peripheral blood, very similar to gametocytes of Hemolivia Petit et al., 1990. The other is morphologically very different and characteristically adheres to the host-cell nucleus. None of the parasites underwent development in the mosquitoes Culex quinquefasciatus and Aedes aegypti and their behaviour in other haematophagous hosts is under investigation. Mixed infections of the parasites commonly occur and this often creates difficulties in relating the tissue stages in the internal organs to the forms seen in the blood. Concomitant infections with a Plasmodium tropiduri-like malaria parasite were seen and were sometimes extremely heavy.

Some coccidial parasites of the lizard Amphisbaena alba (Reptilia: Amphisbaenia: Amphisbaenidae)

Five parasites are described in the lizard Amphisbaena alba (Amphisbaenidae) from the state of Pará, North Brazil. Mature oocysts of Choleoeimeria amphisbaenae n. sp., are passed already mature in the faeces. They are ellipsoidal-cylindrical, average 33.7 x 22.8 æm and are devoid of micropyle, oocyst residuum or polar body. The colourless wall is smooth and of 2 layers. The 4 dizoic sporocysts have no Stieda body and average 13 x 9.3 æm. Endogenous stages develop in the epithelial cells of the gall-bladder in the manner described for the genus and may cause extensive tissue damage. Sporulation of Isospora capanemaensis n. sp., is completed 3 days after the oocysts are voided in the faeces. They average 14.8 x 14.5 æm and have no micropyle, oocyst residuum or polar body. The 2 tetrazoic sporocysts are pear-shaped, average 8.6 x 6.6 and have an inconspicuous Stieda body. Endogenous development is in the epithelial cells of the ileum, and heavy infections cause considerable tissue destruction. Multisporocystic oocysts passed in the faeces of one A. alba possibly originated from an invertebrate host ingested by the lizard. A globidium-like cyst in the digestive tract of A. alba measured 105 x 85 æm and contained many hundreds of merozoites. A stained kidney smear of the same lizard revealed the presence of an unidentified parasite producing multinucleate cyst-like stages.

Development of Hepatozoon caimani (Carini, 1909) Pessôa, De Biasi & De Souza, 1972 in the Caiman Caiman c. crocodilus, the frog Rana catesbeiana and the mosquito Culex fatigans

The sporogony of Hepatozoon caimani has been studied, by light microscopy, in the mosquito Culex fatigans fed on specimens of the caiman Caiman c. crocodilus showing gametocytes in their peripheral blood. Sporonts iniciate development in the space between the epithelium of the insect gut and the elastic membrane covering the haemocoele surface of the stomach. Sporulating oocysts are clustered on the gut, still invested by the gut surface membrane. Fully mature oocysts were first seen 21 days after the blood-meal. No sporogonic stages were found in some unidentified leeches fed on an infected caiman, up to 30 days following the blood-meal. When mosquitoes containing mature oocysts were fed to frogs (Leptodactylus fuscus and Rana catesbeiana), cysts containing cystozoites developed in the internal organs, principally the liver. Feeding these frogs to farm-bred caimans resulted in the appearance of gametocytes in their peripheral blood at some time between 59 and 79 days later, and the development of tissue cysts in the liver, spleen, lungs and kidneys. Transmission of the parasite was also obtained by feeding young caimans with infected mosquitoes and it is suggested that both methods occur in nature. The finding of similar cysts containing cystozoites in the semi-aquatic lizard Neusticurus bicarinatus, experimentally fed with infected C. fatigans, suggests that other secondary hosts may be involved