Ornithodoros cf. mimon infected with a spotted fever group Rickettsia in Brazil.

Ornithodoros mimon is an argasid tick primarily associated with bats that also infest other animals including birds, opossums and humans. In this paper, we report the finding of an argasid species resembling O. mimon, which similarly may be found in human dwellings and parasitize humans in Brazil. We also provide molecular evidence that this argasid tick species may carry a rickettsial organism, whose pathogenicity remains unknown. A total of 16 ticks (two females, two males and 12 nymphs) were collected in the bedroom and in the attic of a human house, where cases of "insect" bites have been recurrent. These ticks were identified morphologically and genetically as Ornithodoros cf. mimon. Upon PCR testing, four of these ticks (one female and three nymphs) were positive for human blood and for a bacterium closely related to "Candidatus Rickettsia paranaensis". In conclusion, we report for the first time in Brazil an argasid tick species morphologically and genetically related to O. mimon, which feeds on humans and carry a rickettsial organism belonging to the spotted fever group. Further studies are needed to formally assess the taxonomic status of this tick species and also to investigate the pathogenicity of its associated rickettsial organism.

Parasite species variation and impact of spatial displacement of the population on cutaneous leishmaniasis in Rio de Janeiro, Brazil.

BACKGROUND: Cutaneous leishmaniasis results from complex interactions between human beings, vectors and the environment. Parasitic species differ in epidemiological and geographical contexts. METHODS: We studied a retrospective cohort of 696 patients with cutaneous leishmaniasis treated at a reference centre in the state of Rio de Janeiro, Brazil, between 2000 and 2015. We analysed displacements due to work, leisure and migrations with identification of Leishmania species. RESULTS: The geographic distribution of autochthonous cases showed that >95% of infections occurred in urban areas. In the state of Rio de Janeiro, most cases were concentrated in the cities surrounding forest parks and nature conservation areas. The same applies to the city of Rio de Janeiro, where these infections occurred in the neighbourhoods surrounding some mountain and forest areas. The non-displacement group included 575 (82.6%) patients and the displacement group included 121 (17.4%) patients. Leishmania (Viannia) braziliensis predominated in both groups. Other species were found in the displacement group. CONCLUSIONS: The disordered urbanization of the state of Rio de Janeiro in recent decades has created conditions for the emergence of urban foci of transmission close to forest areas. Changes in the environment, movement of infected individuals and adaptation of sandflies may have contributed to this.

Trypanosoma caninum, a new parasite described in dogs in Brazil: aspects of natural infection.

Trypanosoma caninum constitutes the most recent trypanosomatid species infecting dogs in Brazil. Due to the limited data available about this parasite, this study aims to disclose clinical and laboratory findings from 14 dogs naturally infected. The dogs were diagnosed during a cross-sectional survey in Cuiabá (Mato Grosso, Brazil) and followed up at an interval of 3, 6, and 12 mo in order to evaluate the clinical evolution and to investigate the parasite, the DNA, or both in different biological samples (intact skin, cutaneous scar, blood, bone marrow, and lymph node aspirate) by parasitological (culture and smear exam) and molecular (DNA-based tests) methods. Specific anti-T. caninum and anti-Leishmania antibody production was also evaluated. Ten of 14 dogs infected by T. caninum showed a good general state at the time of diagnosis, and this status did not vary during the follow-up. Anti-T. caninum and anti-Leishmania IgG antibodies were detected by IFAT in 10 and 2 animals, respectively. Concomitant infection by Leishmania chagasi was confirmed in 2 dogs, indicating an overlap of endemic areas in Cuiabá. Trypanosoma caninum (parasite or DNA) was found only in the intact skin in all animals examined. Our results suggest that T. caninum infection can be manifested as an asymptomatic case with low humoral immune response.

A questão do controle das leishmanioses no Brasil / The issue of control of leishmaniasis in Brazil

O controle de endemia de ocorrência nacional, atingindo regiões de características diferentes, embora implique principalmente o conhecimento de suas formas de transmissão nos diferentes contextos, além de frequência, distribuição e outros aspectos ecoepidemiológicos pertinentes, requer também informações que vão desde as manifestações clínicas e os diagnósticos de suspeição e confirmatórios, ao acesso à atenção e resposta à terapêutica. Apesar da abordagem delicada ou difícil das leishmanioses, sob qualquer desses aspectos, a complexidade do controle destaca-se pela grande multiplicidade de elementos envolvidos na transmissão e a consequente produção de infecção e doença. (AU)

Use of ELISA employing homologous and heterologous antigens for the detection of IgG and subclasses (IgG1 and IgG2) in the diagnosis of canine visceral leishmaniasis.

Indirect immunofluorescence is the method recommended for the diagnosis of visceral leishmanisis in dogs, however, the accuracy of this technique is low and its use on a large scale is limited. Since ELISA does not present these limitations, this technique might be an option for the detection of IgG or specific IgG1 and IgG2 subclasses. Canine ehrlichiosis is an important differential diagnosis of American Visceral Leishmaniasis (AVL). The present study compared ELISA using Leishmania chagasi and Leishmania braziliensis antigen for the detection of anti-Leishmania IgG and subclasses in serum samples from 37 dogs naturally infected with L. chagasi (AVL) and in samples from four dogs co-infected with L. braziliensis and L. chagasi (CI). The occurrence of cross-reactivity was investigated in control serum samples of 17 healthy dogs (HC) and 35 infected with Ehrlichia canis (EC). The mean optical density obtained for the detection of IgG was significantly higher when L. chagasi antigen was used, and was also higher in subgroup VLs (symptomatic) compared to subgroup Vla (asymptomatic). The correlation between IgG and IgG1 was low. The present results suggest that IgG ELISA using homologous antigen yields the best results, permitting the diagnosis of asymptomatic L. chagasi infection and the discrimination between cases of AVL and ehrlichiosis in dogs.

Use of elisa employing homologous and heterologous antigens for the detection of IgG and subclasses (IgG1 and IgG2) in the diagnosis of Canine visceral leishmaniasis / A utilização do ELISA empregando antígenos homólogos e heterólogos para a detecção de IgG e subclasses (IgG1 e IgG2) no diagnóstico de Leishmaniose visceral canina

Indirect immunofluorescence is the method recommended for the diagnosis of visceral leishmanisis in dogs, however, the accuracy of this technique is low and its use on a large scale is limited. Since ELISA does not present these limitations, this technique might be an option for the detection of IgG or specific IgG1 and IgG2 subclasses. Canine ehrlichiosis is an important differential diagnosis of American Visceral Leishmaniasis (AVL). The present study compared ELISA using Leishmania chagasi and Leishmania braziliensis antigen for the detection of anti-Leishmania IgG and subclasses in serum samples from 37 dogs naturally infected with L. chagasi (AVL) and in samples from four dogs co-infected with L. braziliensis and L. chagasi (CI). The occurrence of cross-reactivity was investigated in control serum samples of 17 healthy dogs (HC) and 35 infected with Ehrlichia canis (EC). The mean optical density obtained for the detection of IgG was significantly higher when L. chagasi antigen was used, and was also higher in subgroup VLs (symptomatic) compared to subgroup Vla (asymptomatic). The correlation between IgG and IgG1 was low. The present results suggest that IgG ELISA using homologous antigen yields the best results, permitting the diagnosis of asymptomatic L. chagasi infection and the discrimination between cases of AVL and ehrlichiosis in dogs.

A imunofluorescência indireta é o método recomendado para o diagnóstico de leishmaniose visceral em cães, entretanto, a acurácia dessa técnica é baixa e seu uso em grande escala é limitado. Uma vez que o ELISA não apresenta essas limitações, essa técnica poderia ser uma opção para a detecção de IgG ou subclasses IgG1 e IgG2 específicas. A ehrlichiose canina é um importante diagnóstico diferencial de Leishmaniose Visceral Americana (LVA). O presente estudo comparou o ELISA usando antígenos de Leishmania chagasi e Leishmania braziliensis para a detecção de IgG e subclasses anti-Leishmania em amostras de soro de 37 cães naturalmente infectados com L. chagasi (LVA) e em amostras de quatro cães co-infectados (CI). A ocorrência de reatividade cruzada foi investigada em amostras de soro controle de 17 animais saudáveis (HC) e 35 de infectados por Ehrlichia canis (EC). A média de densidade óptica obtida para a detecção de IgG foi significantemente maior quando o antígeno de L. chagasi foi usado e também mais elevada no subgrupo LVs (sintomático) quando comparado ao subgrupo LVa (assintomático). A correlação entre IgG e IgG1 foi baixa. O presente resultado sugere que ELISA IgG empregando antígeno homólogo, produz os melhores resultados, permitindo o diagnóstico de infecção assintomática por L. chagasi e a discriminação entre casos de LVA e ehrlichiose em cães.

Endemic tegumentary leishmaniasis in Brazil: correlation between level of endemicity and number of cases of mucosal disease.

The purpose of this study was to establish a correlation between the endemic level of tegumentary leishmaniasis in different regions of Brazil during 2002-2009 and the number of cases of mucosal or mucocutaneous leishmaniasis. The proportion of mucosal leishmaniasis was inversely correlated with prevalence of infection. In areas with a lower infection prevalence, the proportion of mucosal leishmaniasis increased (P < 0.05). The hypothesis of an Amazonian origin and dissemination through human migration is considered. Our results show that in regions with lower prevalence and endemically younger, the proportion of cases that evolve to the mucosal form is higher than in regions with higher prevalence and endemically older.

Evaluation of polymerase chain reaction in the routine diagnosis for tegumentary leishmaniasis in a referral centre.

The present study investigated the diagnostic value of polymerase chain reaction (PCR) performed in parallel to conventional methods at an American tegumentary leishmaniasis (ATL) referral centre for diagnosis. Accuracy parameters for PCR were calculated using 130 patients with confirmed ATL (ATL group), 15 patients established with other diseases and 23 patients with a lesion suggestive of ATL, but without parasitological confirmation (NDEF group). PCR showed 92.3% sensitivity, 93.3% specificity, a 99.2% positive predictive value and a 13.84 positive likelihood ratio. In the NDEF group, PCR confirmed ATL in 13 of the 23 patients, seven of whom responded to leishmaniasis treatment and six who presented spontaneous healing of the lesion. PCR should be included in the routine diagnostic procedures for ATL, especially for cases found to be negative by conventional methods.

First encounter of subclinical human Leishmania (Viannia) infection in State of Rio Grande do Sul, Brazil

The objective of the present study was to evaluate the specificity of the Montenegro skin test (MST) in an area in Brazil, state of Grande do Sul State (RS), which was considered to be non-endemic for leishmaniasis. Sixty subjects presented a positive MST and were reevaluated by clinical examination, serology and polymerase chain reaction (PCR) of peripheral blood for the detection of subclinical Leishmania infection. None of the subjects presented clinical signs or symptoms of current leishmaniasis or a history of the disease.Leishmania (Viannia) DNA was detected in blood by PCR and hybridization in one subject. The PCR skin test-positive individual remained asymptomatic throughout the study. Clinical examination showed no scars suggestive of past cutaneous leishmaniasis. Human subclinical infection with Leishmania (Viannia) in RS was confirmed by PCR. This is the first report of subclinical infection with this parasite in the human population of this area.

Use of ELISA employing Leishmania (Viannia) braziliensis and Leishmania (Leishmania) chagasi antigens for the detection of IgG and IgG1 and IgG2 subclasses in the diagnosis of American tegumentary leishmaniasis in dogs.

American tegumentary leishmaniasis (ATL) shows a reduced humoral response in dogs and levels of specific antibodies may therefore not be detected by indirect immunofluorescence. Although the sensitivity of enzyme-linked immunosorbent assay (ELISA) is higher than that of indirect immunofluorescence, the best antigen for the diagnosis of ATL in dogs has not been defined. The detection of IgG subclasses represents an alternative to increase the efficiency of the serological diagnosis. In Rio de Janeiro, sporotrichosis is the main differential diagnosis of ATL in dogs, and a sensitive, specific and little invasive method that permits the discrimination of the two diseases is desired. In the present study, 69 serum samples, 34 obtained from dogs with ATL and 35 from dogs with sporotrichosis, all of them with a confirmed etiological diagnosis, were tested. The samples were analyzed by ELISA using Leishmania (Viannia) braziliensis and L. (L.) chagasi antigens for the detection of anti-Leishmania IgG, IgG1 and IgG2. The use of L. (V.) braziliensis antigens for the detection of IgG and IgG2 yielded the best results. Using L. (L.) chagasi antigen, the sensitivity and specificity for the detection of IgG were 82.4% and 100%, respectively, whereas both sensitivity and specificity were 97.1% with the L. (V.) braziliensis antigen. No improvement in the performance of the test was observed when IgG2 was analyzed separately. The IgG1 assays presented low accuracy, irrespective of the antigen used: sensitivity and specificity of 58.8% and 60% for L. (V.) braziliensis and of 64.7% and 77.1% for L. (L.) chagasi, respectively. The present results suggest that IgG ELISA using the L. (V.) braziliensis shows the best performance for the diagnosis of ATL, permitting the discrimination between cases of ATL and sporotrichosis in dogs.

Skin reactivity to thimerosal and phenol-preserved Montenegro antigen in Brazil.

A randomized double-blind trial was performed to determine the frequency of positive reactions to the Montenegro antigen (leishmanin) preserved in thimerosal (Merthiolate) 1:10,000 or phenol 0.4%. The respective products were tested separately in 400 young healthy individuals from a non-endemic area for Leishmaniases. Each volunteer received one of the following reagents: merthiolated antigen, phenolated antigen, merthiolated saline, or phenolated saline. The frequency of positive responses to each reagent after the first application was as follows: 0% (phenolated saline), 9.2% (merthiolated saline), 34.6% (antigen in phenolated saline), and 41.1% (antigen in merthiolated saline). After 1 week, volunteers who had tested positive for merthiolated or phenolated antigen were retested with the respective preservative, while negatives were retested with the preservative they had not received during the first test. In all, 331 volunteers who received merthiolated saline during the study, of whom 41 (12.4%) tested positive. Meanwhile, 326 volunteers who received phenolated saline, 4 (1.2%) tested positive. Positive reactions in each group were similar in relation to gross appearance skin reactions. Considering the high frequency of hypersensitivity to thimerosal in the study population, it is recommended that this compound should be replaced as a preservative of the leishmanin antigen. Almost 30% of positive reactions to Montenegro antigen in what is considered a non-endemic region was surprising and will be the object of future studies.

First encounter of subclinical human Leishmania (Viannia) infection in State of Rio Grande do Sul, Brazil.

The objective of the present study was to evaluate the specificity of the Montenegro skin test (MST) in an area in Brazil, state of Grande do Sul State (RS), which was considered to be non-endemic for leishmaniasis. Sixty subjects presented a positive MST and were reevaluated by clinical examination, serology and polymerase chain reaction (PCR) of peripheral blood for the detection of subclinical Leishmania infection. None of the subjects presented clinical signs or symptoms of current leishmaniasis or a history of the disease. Leishmania (Viannia) DNA was detected in blood by PCR and hybridization in one subject. The PCR skin test-positive individual remained asymptomatic throughout the study. Clinical examination showed no scars suggestive of past cutaneous leishmaniasis. Human subclinical infection with Leishmania (Viannia) in RS was confirmed by PCR. This is the first report of subclinical infection with this parasite in the human population of this area.

Post mortem parasitological evaluation of dogs seroreactive for Leishmania from Rio de Janeiro, Brazil.

A parasitological study was conducted on 66 dogs seroreactive for Leishmania captured as a control measure of visceral leishmaniasis in the State of Rio de Janeiro, Brazil. Biological samples from different anatomical sites were collected during autopsy of the animals and cultured on biphasic medium (NNN/Schneider). The Leishmania isolates were characterized by isoenzyme electrophoresis. Leishmania was isolated from 80.3% of the animals: 12 animals with Leishmania (Viannia) braziliensis isolated exclusively from cutaneous lesions, 39 with L. (L.) chagasi isolated from different sites in the same animal, and 2 with simultaneous isolation of L. (V.) braziliensis from cutaneous lesions and L. (L.) chagasi from different sites. Isolation in culture revealed the absence of Leishmania parasites in 13 animals. The results obtained confirm the existence of mixed infections in dogs in Rio de Janeiro and indicate the need to complement the investigation of seroreactive dogs using methods for the parasitological diagnosis and identification of Leishmania species.

Is Leishmania (Viannia) braziliensis preferentially restricted to the cutaneous lesions of naturally infected dogs?

Nineteen dogs naturally infected with Leishmania (Viannia) braziliensis were studied in order to determine the presence of the parasite outside cutaneous lesions. Eleven (57.9%) animals showed single cutaneous or mucosal lesions and eight (42.1%) presented two or three lesions. Twenty-eight active lesions were biopsied. Isolation in culture and characterization by enzyme electrophoresis were possible in 100% of cases and amastigote forms were visualized upon histopathological examination in three samples (n=25, 12%). Isolation of the parasite in culture from peripheral blood and intact skin fragments obtained from the scapular region was negative in all animals, as was the histopathological analysis of skin from this region. Serological reactivity determined by an immunofluorescent antibody test and/or enzyme-linked immunosorbent assay was demonstrated in 15 animals. The results obtained suggest that L. braziliensis preferentially remains at the site of lesion, in contrast to the systemic distribution of parasites observed in dogs infected with L. (Leishmania) chagasi. A better understanding of this aspect may help direct diagnostic and control strategies applicable to areas characterized by the simultaneous occurrence of the cutaneous and visceral forms of leishmaniasis, as is the case for the Municipality of Rio de Janeiro, Brazil.

Sobre a origem e dispersão das leishmanioses cutânea e mucosa com base em fontes históricas pré e pós-colombianas / On the origin and spread of cutaneous and mucosal leishmaniasis, based on pre-and post- Colombian historical sources

Concentra-se sobre a origem, difusão e história das leishmanioses tegumentares americanas (LTA), com especial enfoque sobre a leishmaniose mucosa (LM) no continente sul-americano, cuja análise foi feita através de fontes históricas.

Sobre a origem e dispersäo das leishmanioses cutânea e mucosa com base em fontes históricas pré e pós-colombianas / On the origin and spread of cutaneous and mucosal leishmaniasis, based on pre-and post- Colombian historical sources

Concentra-se sobre a origem, difusäo e história das leishmanioses tegumentares americanas (LTA), com especial enfoque sobre a leishmaniose mucosa (LM) no continente sul-americano, cuja análise foi feita através de fontes históricas. (AU)

[On the origin and spread of cutaneous and mucosal leishmaniasis, based on pre- and post- colombian historical source]. / Sobre a origem e dispersão das leishmanioses cutânea e mucosa com base em fontes históricas pré e pós-colombianas.

Drawing from four sixteenth-century sources, the article reports some apparent incidents of American Tegumentary Leishmaniasis within the territory of the Andes. Reinterpretation of these sources affords a look at the longstanding issue of the origin of espundia,or mucosal Leishmaniasis (ML). The study reinforces the hypothesis that ML originated in the western Amazon region, from there climbing into the high forests and later into hot inter-Andean lands via Bolivia's and Peru's borders with Brazil, above al through human migration. dating to archeological times, this process intensified during the Inca period under the social policies of the mitmaq or mitimaes. These events transpired within the historical and social context of the fall of the Inca Empire and the advent of Spanish colonization.

Parasite genotypically related to a monoxenous trypanosomatid of dog's flea causing opportunistic infection in an HIV positive patient

An HIV positive patient presenting a clinical picture of visceral leishmaniasis co-infection was submitted to a bone marrow aspiration after admission to hospital. Amastigotes forms were seen in the bone marrow aspirate and the parasite grew in culture as promastigotes. Molecular analyses showed that the flagellates isolated did not belong to the genera Leishmania, Trypanosoma or Sauroleishmania. It was not possible to establish infection in laboratory animals. In vitro culture of mouse peritoneal macrophages revealed the invasion of the host cells by the flagellates and their killing 48 hr after infection. Opportunistic infection with an insect trypanosomatid was suspected. Further hybridization analyses against a pannel of different monoxenous and heteroxenous trypanosomatids showed kDNA cross-homology with Leptomonas pulexsimulants a trypanosomatid found in the dog's flea.

Phase 1 study of an inactivated vaccine against American tegumentary leishmaniasis in normal volunteers in Brazil

A phase 1 double-blind placebo-controlled study was performed to evaluate a vaccine against American tegumentary leishmaniasis in 61 healthy male volunteers. Side effects and the immune response to the vaccine were evaluated, with 1- and 2- dose schemes, with intervals of 7 or 21 days, each dose containing 1440 mg of protein N antigen of a single strain of Leishmania amazonensis (PH 8) diluted in merthiolated saline (1:10,000). Merthiolated saline and an inert substance were used as placebos. No significant clinical alterations were found following the respective injections in the vaccinated individuals as compared to the placebos, except for local pain, which was associated significantly with injection of the vaccine. The laboratory alterations we observed bore no association with the clinical findings and were unimportant. We observed no differences between the groups with regard to seroconversion or the Montenegro skin test. However, the group that received a single dose of the vaccine and the one that received two doses with a 21-day interval displayed cutaneous induration significantly larger than in the control group, with 100 per cent and 66 per cent conversion in the skin test, respectively. We concluded that the vaccine does not present any major side effect that would contraindicate its use in healthly individuals.

Estudo histopatológico do sistema nervoso periférico na doença de Chagas experimental / Histopathological study of the peripheral nervous system in experimental Chagas' Disease

Com a finalidade de estudar o comprometimento do sistema nervoso periférico na doença de Chagas experimental, foram inoculados grupos de camundongos machos adultos com 10 elevado a quinta potência tripomastigotas sangüíneos da cepa Colombiana e uma cepa de Tripanosoma cruzi proveniente de triatomíneos do Município de Säo Rauimundo Nonato, Piauí - Brasil, por via intraperitoneal. A necrópsia destes animais ocorreu entre o 21§ dia e 8§ mês de infecçäo, quando foram retirados o nervo ciático, músculo esquelético da coxa e coraçäo. Em seguida, os fragmentos foram fixados em formol a 10 por cento para exame histopatológico de rotina e imuno-histoquímico. Além desses tecidos, examinamos o corçäo para confirmaçäo da infecçäo. O exame microscópico do nervo ciático corado pela hematoxilina-eosina de todos os animais atresentou infiltrado inflamatório formado de linfócitos e plasmócitos localizados no endoneuro, e com maior prevalência no perineuro dos nervos ciáticos, originando um processo de neurite intersticial ou perineurite na fase aguda ou crônica de ambas as cepas. Constatou-se, também um intenso processo de vascularite no nervo ciático e músculo esquelético da coxa na fase crônica e, ocasionalmente, necrose das paredes vasculares com a cepa Colombiana. Alguns camundongos crônicos, infectados com a cepa Colombiana, exibiram sinais de paresia ou paralisia dos menbros posteriores e a presença de amastigotas nos nervos dos animais paralíticos. Nestes animais, encontramos lesöes do nervo ciático associado ao comprometimento do músculo esquelético da coxa onde é evidente a miosite, surgirndo, esporadicamente, a miosite calcificante em alguns camundongos crônicos. Os camundongos apresentaram miocardite, pericardite e endocardite. No entanto, a presença de amastigotas foram observadas freqüentemente na fase aguda. Os resultados da imunoperoxidase apresentaram amastigotas ou antígenos parasitários nos cortes histológicos do coraçäo, nervo ciático e músculo esquelético da coxa, os quais foram semelhantes ao observado pelos tecidos corados pela HE