Increasing potential risk for American visceral leishmaniasis in Amapá, Brazil

Abstract: INTRODUCTION: The present note discusses some evidence on the increasing potential risk for American visceral leishmaniasis (AVL) transmission in the Northern Brazilian State of Amapá, the Guianan-Amazon biome. METHODS Early and present data about AVL were collected, including our recent entomological findings. RESULTS: The spread of the sand fly vector Lutzomyia longipalpis, and a sylvatic reservoir host, the crab-eating fox Cerdocyon thous in that region represents important findings related to the epidemiology of AVL in the Guianan-Amazon biome. CONCLUSIONS: These observations suggest that Brazilian authorities need to develop surveillance strategies in these risk areas.

Lutzomyia longipalpis urbanisation and control

Since the description of Lutzomyia longipalpis by Lutz and Neiva more than 100 years ago, much has been written in the scientific literature about this phlebotomine species. Soares and Turco (2003) and Lainson and Rangel (2005) have written extensive reviews focused on vector-host-parasite interactions and American visceral leishmaniasis ecology. However, during the last two decades, the success of Lu. longipalpis in colonising urban environments and its simultaneous geographical spreading have led to new theoretical and operational questions. Therefore, this review updates the general information about this species and notes the more challenging topics regarding the new scenario of urbanisation-spreading and its control in America. Here, we summarise the literature on these issues and the remaining unsolved questions, which pose recommendations for operational research.

An atypical Toxoplasma gondii genotype in a rural Brazilian dog co-infected with Leishmania (Viannia) braziliensis

Toxoplasmosis and leishmaniasis are two worldwide zoonoses caused by the protozoan parasites Toxoplasma gondii and Leishmania spp., respectively. This report describes the clinical and laboratorial findings of a co-infection with both parasites in a 4-year-old female dog suspected of ehrlichiosis that presented anemia, thrombocytopenia, hypoalbuminemia, hyperglobulinemia, tachyzoite-like structures to the lung imprints, and polymerase chain reaction (PCR) results positive for T. gondii (kidney, lung, and liver) and Leishmania spp. Co-infection with Toxoplasma gondii and Leishmania braziliensis was confirmed by sequencing; restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) confirmed an atypical T. gondii genotype circulating in dogs that has been reported to cause human congenital toxoplasmosis.

Studies on Phlebotominae (Diptera: Psychodidae) in the Campus FIOCRUZ Mata Atlântica, Jacarepaguá, in the City of Rio de Janeiro, Brazil

INTRODUCTION: The presence of American cutaneous leishmaniasis (ACL) in the communities of the Campus FIOCRUZ Mata Atlântica (CFMA) in the City of Rio de Janeiro initiated the investigation of the Phlebotominae fauna in the Atlantic Forest to determine the occurrence of putative ACL vectors associated with the enzootic cycle. METHODS: For 24 consecutive months, sand flies were captured inside the forest and in the border area near the communities. RESULTS: The following sand fly species were identified: Brumptomyia brumpti, Brumptomyia cunhai, Brumptomyia nitzulescui, Lutzomyia edwardsi, Lutzomyia pelloni, and Lutzomyia quinquefer. Other identified sand fly vectors, such as Lutzomyia intermedia (the predominant species), Lutzomyia migonei, Lutzomyia whitmani, Lutzomyia fischeri, and Lutzomyia hirsuta hirsuta, are associated with ACL transmission, and the vector for American visceral leishmaniases (AVL), Lutzomyia longipalpis, was also found. CONCLUSIONS: All sand fly vectors were found in both studied environments except for Lutzomyia whitmani, which was only identified in the forest. This study represents the first identification of Lutzomyia longipalpis in the CFMA, and the epidemiological implications are discussed. .

Validity of the polymerase chain reaction in the diagnosis of clinically suspected cases of American visceral leishmaniasis

To test the validity of the polymerase chain reaction for diagnosing American visceral leishmaniasis, 88 suspected cases were studied. Diagnosis was confirmed in 47 (53.5%) and ruled out in 41 (46.5%) patients. Samples of bone marrow and peripheral blood were processed by polymerase chain reaction to evaluate the sensitivity and specificity of the test and its agreement beyond chance with microscopy examination. The polymerase chain reaction was positive in bone marrow of 100% of the patients with amastigotes seen with microscopy examination, and in 59.5% in those where no parasite were seen. Agreement beyond chance between visualization of the parasite in bone marrow aspirates and polymerase chain reaction was considered weak (Kappa = 0.41). Concordance between polymerase chain reaction of bone marrow aspirates and of peripheral blood was considered excellent (Kappa = 0.88). The test turned out positive in all bone marrow aspirates of those with the disease and whereas the positivity rate was 58.5% among those without the disease, with specificity rate of 41.5%.

The distribution pattern of Lutzomyia longipalpis (Diptera: Psychodidae) in the peridomiciles of a sector with canine and human visceral leishmaniasis transmission in the municipality of Dracena, São Paulo, Brazil

The specimen distribution pattern of a species can be used to characterise a population of interest and also provides area-specific guidance for pest management and control. In the municipality of Dracena, in the state of São Paulo, we analysed 5,889 Lutzomyia longipalpis specimens collected from the peridomiciles of 14 houses in a sector where American visceral leishmaniasis (AVL) is transmitted to humans and dogs. The goal was to analyse the dispersion and a theoretical fitting of the species occurrence probability. From January-December 2005, samples were collected once per week using CDC light traps that operated for 12-h periods. Each collection was considered a sub-sample and was evaluated monthly. The standardised Morisita index was used as a measure of dispersion. Adherence tests were performed for the log-series distribution. The number of traps was used to adjust the octave plots. The quantity of Lu. longipalpis in the sector was highly aggregated for each month of the year, adhering to a log-series distribution for 11 of the 12 months analysed. A sex-stratified analysis demonstrated a pattern of aggregated dispersion adjusted for each month of the year. The classes and frequencies of the traps in octaves can be employed as indicators for entomological surveillance and AVL control.

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.

Aspectos clínicos da leishmaniose visceral canina no distrito de Monte Gordo, Camaçari (BA) / Clinical aspects of canine visceral leishmaniasis in the district of monte gordo, camaçari (BA) / Aspectos clínicos de la leishmaniosis visceral canina en el distrito de monte gordo, camaçari (BA)

No Brasil, a Leishmaniose Visceral Americana ocorre de forma zoonótica, acometendo humanos e tendo como reservatório principal o cão. O diagnóstico e a eliminação precoce dos animais soropositivos são elementares nos processos de formulação dos Programas de Controle da doença. Dada a importância do sorodiagnóstico, o presente estudo objetivouidentificar caninos positivos para a Leishmaniose Visceral Americana pela técnica sorológica Enzime-Linked Immunosorbent Assay (ELISA) no distrito de Monte Gordo, zona litorânea de intenso turismo do município de Camaçari (BA), e classificá-los de acordo com a sintomatologia clínica. O inquérito sorológico foi realizado em 358 cães e a soroprevalência encontrada foi de 14,8 porcento. A significância estatística ocorreu entre sorologia positiva e as variáveis: comportamento apático, estado nutricional caquético, onicogrifose, pelagem ruim, linfadenopatia presente e coloração pálida das mucosas.

In Brazil, American Visceral Leishmaniasis is characterized by a zoonotic cycle that affects humans with canines as the main reservoir. Early diagnosis and elimination of seropositive animals are fundamental for devising control programs for this disease. Given the importance of serodiagnosis, the purpose of this study was to identify positive canines for AmericanVisceral Leishmaniasis through the Enzyme-Linked Immunosorbent Assay (ELISA) technique in the district of Monte Gordo, a coastal zone with intense tourist activity in the municipality of Camaçari (BA). This study also aimed to classify the canine cases based on their clinical symptoms. Serological surveillance was performed in 358 dogs and the seroprevalence reached 14.8%. Statistical significance was found between positive serology and the following variables: apathetic behavior, cachexia, onynchogryphosis, bad hair, lymphoadenopathy, and pale mucous membrane.

En Brasil, la Leishmaniosis Visceral Americana ocurre de forma zoonótica, afectando a los humanos y teniendo, como reserva principal, al perro. El diagnóstico y la eliminación rápida de los animales seropositivos son elementales en los procesos de formulación de los programas de control de la enfermedad. Dada la importancia del serodiagnóstico, el presente estudio objetivó identificar a los perros positivos para la Leishmaniosis Visceral Americana usando la técnica serológica Enzime-Linked Immunosorbent Assay (ELISA) en el distrito de Monte Gordo, zona costera de intenso turismo en el municipio de Camaçari (BA), y clasificarlos de acuerdo con la sintomatología clínica. La investigación serológica fue realizada con 358 perros encontrándose una seroprevalencia de 14.8%. Estadísticamente hubo una diferencia significativa entre los resultados de serología positiva y las siguientes variables: comportamiento apático, estado nutricional caquéctico,onicogrifosis, pelaje pobre, linfadenopatía presente y palidez en las superficies mucosas.

Flebotomíneos de áreas com notificações de casos autóctones de leishmaniose visceral canina e leishmaniose tegumentar americana em Angra dos Reis, Rio de Janeiro, Brasil / Phlebotomine fauna in areas of autochthonous cases of canine visceral leishmaniasis and American cutaneous leishmaniasis in Angra dos Reis, Rio de Janeiro, Brazil

Flebótomos de áreas com notificações de casos autóctones de leishmaniose visceral canina e leishmaniose tegumentar americana em Angra dos Reis, Rio de Janeiro, Brasil. O município de Angra dos Reis apresenta casos humanos de leishmaniose tegumentar americana desde 1945. Inquéritos flebotomínicos realizados em 1978 revelaram a presença de Nyssomyia intermedia e a primeira notificação de Lutzomyia longipalpis no Rio de Janeiro, Ilha Grande, Angra dos Reis. Em agosto de 2002 foi notificado o primeiro caso canino de leishmaniose visceral na Ilha Grande, Angra dos Reis. Inquéritos flebotomínicos realizados nos peridomicílios, no período de novembro de 2002 a maio de 2003, em quatro localidades de Angra dos Reis, resultaram em 12.554 flebotomíneos e a presença de nove espécies: Brumptomyia sp.; Nyssomyia intermedia, Migonemyia migonei, Micropygomyia schreiberi, Pintomyia fischeri, Psychodopygus davisi, Psychodopygus ayrosai, Evandromyia tupinambay, Psathyromyia pelloni. foi Nyssomyia intermedia, predominante em todas as localidades, seguida por M.migonei. O principal vetor da LVA, Lutzomyia longipalpis, não foi detectado nas localidades, incluindo áreas do entorno, onde um cão infectado residia.

The city of Angra dos Reis presents human cases of American cutaneous leishmaniasis since 1945. Phlebotomine surveys in 1978 had disclosed the presence of Nyssomyia intermedia and the first notification of Lutzomyia longipalpis in Rio de Janeiro, Ilha Grande, Angra dos Reis. In August of 2002 the first canine case of visceral leishmaniasis in the Ilha Grande, Angra dos Reis was notified. Surveys of phlebotomines in the peridomiciliary areas, in the period of November, 2002, through May, 2003, in four localities of Angra dos Reis, resulted in 12,554 specimens belonging to nine species: Brumptomyia sp. Nyssomyia intermedia, Migonemyia migonei, Micropygomyia schreiberi, Pintomyia fischeri, Psychodopygus davisi, Psychodopygus ayrosai, Evandromyia tupinambay, Psathyromyia pelloni. Nyssomyia intermedia was predominant in all localities, followed by M. migonei. The main vector of the AVL, L. longipalpis, was not detected in the localities, including their surroundings, where an infected dog inhabited.

Avaliação das Técnicas de ELISA e “Immunoblotting” (IgG e subclasses específicas) no diagnóstico da infecção por Leishmania (Viannia) braziliensis e Leishmania (Leishmania) chagasi em cães / Evaluation of ELISA techniques and \"Immunoblotting\" (IgG subclasses and specific) in the diagnosis of infection with Leishmania (V.) braziliensis and Leishmania (Leishmania) chagasi in dogs

As leishmanioses são enfermidades infecciosas de importância em Saúde Pública. A identificação e retirada de cães infectados é uma medida de controle controversa. A reação de imunofluorescência, utilizada na rotina de diagnóstico, apresenta limitações quanto à sensibilidade e especificidade. Tais limitações podem implicar na manutenção de animais infectados nas áreas endêmicas ou na indicação de eutanásias desnecessárias. Por apresentarem elevadas sensibilidade e especificidade, as técnicas de ELISA e “immunoblotting” deveriam ser melhor avaliadas. A utilização de antígeno homólogo e a detecção de subclasses de IgG têm sido relatadas como alternativas para a obtenção de melhores resultados no diagnóstico sorológico. Este estudo teve como objetivo avaliar os parâmetros de acurácia de ELISA IgG e subclasses em soros de cães infectados por Leishmania (Viannia) braziliensis e Leishmania (Leishmania) chagasi (sintomáticos e assintomáticos) e identificar e caracterizar, por “immunoblotting”, bandas de L. (V.) braziliensis e de L. (L.) chagasimais freqüentemente reconhecidas por IgG e subclasses nesses soros. Foram estudadas 162 amostras de soro, sendo 34 de cães com leishmaniose tegumentar americana (LTA), 37 com leishmaniose visceral americana (LVA) (sintomáticos e assintomáticos), 4 com infecção mista (Leishmania (Viannia) braziliensis e Leishmania (Leishmania) chagasi) e 87 amostras de soros controle de cães residentes fora de área endêmica de leishmanioses, sendo 17 cães saudáveis e 70 com doenças que necessitam diagnóstico diferencial com LTA (esporotricose 35) ou com LVA (ehrlichiose 35). As médias de densidade ótica (D.O.) obtidas para detecção de IgG nos soros de cães com LTA ou com LVA foram estatisticamente mais elevadas com os respectivos antígenos homólogos, havendo um equilíbrio da resposta humoral nos animais com infecção mista...

Entretanto, a técnica não permitiu discriminar entre um caso individual de LTA e de LVA. A média de D.O. nos cães com LVA sintomáticos foi mais elevada que nos assintomáticos. IgG1 não revelou resultados promissores, com baixas médias de D.O. e reduzido reconhecimento antigênico nos cães infectados por Leishmania sp., independente da presença de sinais clínicos. As freqüências de detecção de IgG e IgG2, tanto por ELISA quanto por “immunoblotting” foram semelhantes. Não foi observada reatividade cruzada com L. (L.) chagasi no “immunoblotting”. Esses resultados sugerem que a utilização de antígenos homólogos para a detecção de IgG por ELISA elevaram a acurácia do teste e que em áreas com sobreposição de transmissão de L. (V.) braziliensis e de L. (L.) chagasi, seria indicado empregar o ELISA com ambos os antígenos. Além disso, o emprego do antígeno de L. (L.) chagasi elevou a especificidade dos testes de ELISA e de “immunoblotting”, permitindo a discriminação entre casos de leishmaniose e controles...

Flebotominos en dos focos endémicos de leishmaniasis visceral americana en el municipio torres, estado lara, venezuela. / Phlebotomine Sand Flies in Two Endemic Foci of American Visceral Leishmaniasis at Torres Municipality, Lara State, Venezuela.

Se realizó un estudio entomológico con el fin de conocer las especies flebotominas presentes en dos focos endémicos de leishmaniasis visceral americana (LVA) del estado Lara, Venezuela. Las capturas de flebotominos se realizaron, de enero 1998 a marzo 2000, en dos áreas endémicas localizadas en el municipio Torres: La Rinconada (10° 15’ N-69° 57’ W) y San Esteban (10° 54’ N-69° 55’ W). Para ello se colocó la trampa de luz Shannon, entre las 19: 00 y 22: 00 h, y 4 trampas de luz CDC durante toda la noche en el peridomicilio y, además, se realizó la búsqueda activa manual en sus refugios naturales. En La Rinconada se capturaron 7.488 ejemplares, pertenecientes a ocho especies flebotominas, de los cuales 6.782 fueron hembras y 706, machos. Lutzomyia pseudolongipalpis fue la especie predominante (94,59%). En San Esteban fueron capturados 1.032 ejemplares, de los cuales 842 fueron hembras y 190 machos. El 97,96% de los ejemplares fueron identificados como L. pseudolongipalpis. Ninguna de las hembras capturadas en las localidades endémicas estudiadas mostró la presencia de promastigotes de Leishmania spp. en su tracto digestivo. Debido al marcado predominio de L. pseudolongipalpis y la escasa presencia de L. evansi en estas áreas endémicas, L. pseudolongipalpis pudiera tener un rol importante en la transmisión de la leishmaniasis visceral en las localidades estudiadas.

An entomological study was undertaken to know the presence of phlebotomine species in two endemic foci of American Visceral Leishmaniasis (AVL) at Lara State, Venezuela. The captures of phlebotomine sand flies were carried out, from January 1998 to March 2000, in two endemic areas localized at the Torres municipality: La Rinconada (10° 15’ N-69° 57’ W) and San Esteban (10° 54’ N-69° 55’ W). For this purpose the Shannon light trap was used, between 19: 00 and 22: 00 h, and 4 CDC light traps left overnight at the peridomicily and, besides, active manual searches in its natural refuges was carried out. At La Rinconada, 7,488 specimens of eight phlebotomine species were caught out of which 6,782 were females and 706, males. Lutzomyia pseudolongipalpis was the predominant species (94.59%). At San Esteban 1,032 specimens were captured of which 842 were females and 190 males. The 97.96% of the specimens were identified as L. pseudolongipalpis. None of the females captured at the endemic localities that were studied showed the presence of Leishmania spp. promastigotes in their digestive tract. Due to the predominance of L. pseudolongipalpis and the low presence of L. evansi at these endemic areas, L. pseudolongipalpis should be regarded as having an important role in the transmission of American visceral leishmaniasis in the localities that were studied.