Coinfection by Toxoplasma gondii and Leishmania spp. in domestic cats (Felis catus) in State of Mato Grosso do Sul

Introduction Leishmaniasis and toxoplasmosis are important to public health. Methods Antibodies for Toxoplasma gondii and Leishmania spp. were evaluated in cats from Campo Grande, State of Mato Grosso do Sul, Brazil, a region endemic for canine visceral leishmaniasis. Serum samples from 50 asymptomatic cats were titrated for T. gondii by the immunofluorescence antibody test and modified agglutination test and for Leishmania spp. by the immunofluorescence antibody test. Results These two agents coinfected two (4%) of the 50 tested animals. Conclusions These findings demonstrate the concomitant presence of two important zoonoses in cats from Brazilian endemic regions for canine visceral leishmaniasis.

Impact of the antipneumococcal conjugate vaccine on the occurrence of infectious respiratory diseases and hospitalization rates in children

INTRODUCTION: In 2010, to reduce the occurrence of serious pneumococcal disease, the Ministry of Health in Brazil incorporated the 10-valent pneumococcal vaccine in the immunization schedule of children younger than two years of age. The objective of this study was to evaluate the impact of vaccination on the incidence of infectious respiratory diseases in infants before and after the introduction of the 10-valent pneumococcal vaccine. METHODS: This cross-sectional study involved primary care and hospital networks from a city in Minas Gerais State, Brazil, between 2009 and 2012. RESULTS: A 40% reduction in the prevalence of community-acquired pneumonia (CAP) was observed after introducing the pneumococcal conjugate vaccine. Male children were 28% more likely to develop the disease. The prevalence ratio ([PR] = 1.96, 95% CI: 1.52 to 2.53, p < 0.05) suggested that not being vaccinated was associated with the occurrence of pneumonia. The prevalence of CAP was 70% lower (PR 0.30, 95% CI: 0.24 to 0.37, p<0.05) in children vaccinated as recommended compared to children with delayed vaccination, suggesting that the updated vaccine schedule improves protection. CONCLUSIONS: Immunization with the 10-valent pneumococcal vaccine appeared to reduce the number of pneumonia cases in children during the study period. Prospective studies are needed to confirm the efficacy of the vaccine against the occurrence of pneumococcal pneumonia.

Leishmania, Babesia and Ehrlichia in urban pet dogs: co-infection or cross-reaction in serological methods?

INTRODUCTION: The present study was designed to assess the occurrence of co-infection or cross-reaction in the serological techniques used for detecting the anti-Leishmania spp., -Babesia canis vogeli and -Ehrlichia canis antibodies in urban dogs from an area endemic to these parasites. METHODS: The serum samples from dogs were tested for the Babesia canis vogeli strain Belo Horizonte antigen and Ehrlichia canis strain São Paulo by immunofluorescence antibody test (IFAT) and by anti-Leishmania immunoglobulin G (IgG) antibody detection to assess Leishmania infection. We used the following four commercial kits for canine visceral leishmaniasis: ELISA, IFAT, Dual Path Platform (DPP) (Bio Manguinhos(r)/FIOCRUZ/MS) and a rK39 RDT (Kalazar Detect Canine Rapid Test; Inbios). RESULTS : Of 96 serum samples submitted to serological assays, 4 (4.2%) were positive for Leishmania as determined by ELISA; 12 (12.5%), by IFAT; 14 (14.6%) by rK39 RDT; and 20 (20.8%), by DPP. Antibodies against Ehrlichia and Babesia were detected in 23/96 (23.9%) and 30/96 (31.2%) samples, respectively. No significant association was identified between the results of tests for detecting Babesia or Ehrlichia and those for detecting Leishmania (p-value>0.05). CONCLUSIONS: In the present study, we demonstrated co-infection with Ehrlichia or Babesia and Leishmania in dogs from Minas Gerais (Brazil); we also found that the serological tests that were used did not cross-react.

The effectiveness of a rotavirus vaccine in preventing hospitalizations and deaths presumably due to acute infectious diarrhea in Brazilian children: a quasi-experimental study

INTRODUCTION: Rotavirus is the main etiologic agent of acute infectious diarrhea in children worldwide. Considering that a rotavirus vaccine (G1P8, strain RIX4414) was added to the Brazilian vaccination schedule in 2006, we aimed to study its effectiveness and safety regarding intestinal intussusception. METHODS: A quasi-experimental trial was performed in which the primary outcome was the number of hospitalizations that were presumably due to acute infectious diarrhea per 100,000 children at risk (0-4 years old). The secondary outcomes included mortality due to acute infectious diarrhea and the intestinal intussusception rates in children in the same age range. We analyzed three scenarios: Health Division XIII of the State of São Paulo (DRS XIII) from 2002 to 2008, the State of São Paulo, and Brazil from 2002 to 2012. RESULTS: The averages of the hospitalization rates for 100,000 children in the pre- and post-vaccination periods were 1,413 and 959, respectively, for DRS XIII (RR=0.67), 312 and 249, respectively, for the State of São Paulo (RR=0.79), and 718 and 576, respectively, for Brazil (RR=0.8). The mortality rate per 100,000 children in the pre- and post-vaccination periods was 2.0 and 1.3, respectively, for DRS XIII (RR=0.66), 5.5 and 2.5, respectively, for the State of São Paulo (RR=0.47), and 15.0 and 8.0, respectively, for Brazil (RR=0.53). The average annual rates of intussusception for 100,000 children in DRS XIII were 28.0 and 22.0 (RR=0.77) in the pre- and post-vaccination periods, respectively. CONCLUSIONS: A monovalent rotavirus vaccine was demonstrated to be effective in preventing the hospitalizations and deaths of children that were presumably due to acute infectious diarrhea, without increasing the risk of intestinal intussusception.

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.

Polymerase chain reaction-based method for the identification of Leishmania (Viannia) braziliensis and Leishmania (Viannia) guyanensis in mucosal tissues conserved in paraffin

ABSTRACTINTRODUCTION: In the Americas, mucosal leishmaniasis is primarily associated with infection by Leishmania (Viannia) braziliensis. However, Leishmania (Viannia) guyanensis is another important cause of this disease in the Brazilian Amazon. In this study, we aimed at detecting Leishmaniadeoxyribonucleic acid (DNA) within paraffin-embedded fragments of mucosal tissues, and characterizing the infecting parasite species.METHODS: We evaluated samples collected from 114 patients treated at a reference center in the Brazilian Amazon by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analyses.RESULTS: Direct examination of biopsy imprints detected parasites in 10 of the 114 samples, while evaluation of hematoxylin and eosin-stained slides detected amastigotes in an additional 17 samples. Meanwhile, 31/114 samples (27.2%) were positive for Leishmania spp. kinetoplast deoxyribonucleic acid (kDNA) by PCR analysis. Of these, 17 (54.8%) yielded amplification of the mini-exon PCR target, thereby allowing for PCR-RFLP-based identification. Six of the samples were identified as L. (V.) braziliensis, while the remaining 11 were identified as L. (V.) guyanensis.CONCLUSIONS: The results of this study demonstrate the feasibility of applying molecular techniques for the diagnosis of human parasites within paraffin-embedded tissues. Moreover, our findings confirm that L. (V.) guyanensisis a relevant causative agent of mucosal leishmaniasis in the Brazilian Amazon.

Expression of annexin A1 in Leishmania-infected skin and its correlation with histopathological features

ABSTRACTINTRODUCTION:The aim of this study was quantify annexin A1 expression in macrophages and cluster of differentiation 4 (CD4) + and cluster of differentiation 8 (CD8)+ T cells from the skin of patients with cutaneous leishmaniasis (n=55) and correlate with histopathological aspects.METHODS:Infecting species were identified by polymerase chain reaction-restriction fragment length polymorphism, and expression of annexin A1 was analyzed by immunofluorescence.RESULTS:All patients (n = 55) were infected with Leishmania braziliensis . Annexin A1 was expressed more abundantly in CD163 + macrophages in infected skin (p < 0.0001) than in uninfected skin. In addition, macrophages in necrotic exudative reaction lesions expressed annexin A1 at higher levels than those observed in granulomatous (p < 0.01) and cellular lesions p < 0.05). This difference might be due to the need to clear both parasites and necrotic tissue from necrotic lesions. CD4 + cells in cellular lesions expressed annexin A1 more abundantly than did those in necrotic (p < 0.05) and granulomatous lesions (p < 0.01). Expression in CD8 + T cells followed the same trend. These differences might be due to the pervasiveness of lymphohistiocytic and plasmacytic infiltrate in cellular lesions.CONCLUSIONS:Annexin A1 is differentially expressed in CD163 + macrophages and T cells depending on the histopathological features of Leishmania -infected skin, which might affect cell activation.

Presence of anti-Leishmania (Viannia) braziliensis antibodies in blood donors in the West-Central region of the State of Paraná, Brazil

ABSTRACTINTRODUCTION:Serological screening in blood banks does not include all transmittable diseases. American cutaneous leishmaniasis (ACL) has a high detection rate in the municipalities of the State of Paraná.METHODS:This study analyzed the presence of anti- Leishmania braziliensisantibodies in 176 blood donors who live in these endemic areas. The variables were analyzed with the χ2 test and Stata 9.1 software. RESULTS: Twenty (11.4%) samples were positive for the presence of anti- L. braziliensisantibodies. CONCLUSIONS: The high percentage of donors with anti- Leishmania spp. antibodies indicates the need to study the risk of ACL transmission through blood donors.

Detection of Leishmania (Viannia) DNA in leucocytes from the blood of patients with cutaneous leishmaniasis

ABSTRACTINTRODUCTION:Cutaneous leishmaniasis (CL) is a serious and global public health issue, with the potential of developing a mucosal form, occurring as subclinical cases, and showing recurrence despite previous treatment.METHODS:Polymorphonuclear and mononuclear DNA obtained from 49 patients was subjected to polymerase chain reaction for detection of Leishmania (Viannia).RESULTS:DNA was detected in mononuclear cells from two patients with active primary lesions positive for CL, with infection periods of 3 and 6 months, respectively.CONCLUSIONS:The DNA of Leishmania (Viannia) indicates probable parasite dissemination possibly explaining subclinical case emergence, lesion recurrence, and mucosal lesion appearance.

Predictive factors for Leishmania infantum infection in dogs examined at a veterinary teaching hospital in Teresina, State of Piauí, Brazil

Abstract: INTRODUCTION: In Brazil, culling of seropositive dogs is one of the recommended strategies to control visceral leishmaniasis. Since infectiousness is correlated with clinical signs, control measures targeting symptomatic dogs could be more effective. METHODS: A cross-sectional study was carried out among 1,410 dogs, predictive models were developed based on clinical signs and an indirect immunofluorescence antibody test. RESULTS: The validated predictive model showed sensitivity and specificity of 86.5% and 70.0%, respectively. CONCLUSIONS: Predictive models could be used as tools to aid control programs in focusing on a smaller fraction of dogs contributing more to infection dissemination.

Vaccine-associated paralytic Poliomyelitis: a case report of domiciliary transmission

Poliomyelitis associated with live strain vaccine is defined as the paralytic form of the acute anterior poliomyelitis related to the vaccine strain. Since these strains behave similarly to the wild-type virus, we can differentiate, epidemiologically, two types of vaccine-associated poliomyelitis: cases in which the patient was vaccinated and cases in which the patient had had contact with vaccinated individuals. We herein present the case of an unvaccinated child, with a clinical picture of an acute anterior poliomyelitis associated with the live strain vaccine, whose brother received the Sabin vaccine 20 days before the onset of the symptoms. Vaccine strain of the type 3 poliovirus was isolated in fecal culture and a presented mutation in nucleotide 472 (C®U) in the 5' non-coding region, which is strongly related to the higher strain virulence.

Comportamento biológico "in vitro" de "novas espécies" de Leishmania no Velho Mundo

As leishmanioses são um grupo de doenças causadas pelo parasita protozoário Leishmania sp. Na Bacia mediterrânica, Leishmania infantum, é a principal espécie causadora de leishmaniose visceral, a forma mais severa da doença, sendo L. major um dos agentes etiológicos da leishmaniose cutânea. Apesar de se considerar que estes parasitas têm uma reprodução essencialmente clonal, nos últimos 20 anos tem vindo a ser descrita a recombinação genética entre diferentes estirpes e espécies, com ocorrência de híbridos naturais, quer no Velho quer no Novo Mundo. Recentemente, em Portugal, foram isoladas e identificadas pela primeira vez, estirpes híbridas de L. infantum/L. major. O presente estudo teve como principais objetivos, a pesquisa de “novas espécies” de Leishmania e a análise do comportamento “in vitro” de estirpes parentais e híbridas de L. infantum e L. major. Numa primeira parte do trabalho efetuou-se a cultura e pesquisa de DNA de Leishmania sp., em amostras de sangue medular de 229 cães provenientes de uma região endémica de Portugal, utilizando diferentes marcadores moleculares (kDNA, ITS1 e SSU rRNA) e protocolos de PCR. Não foi encontrado DNA de espécies híbridas, tendo-se no entanto, identificado DNA de Leishmania sp. em 45,85% (105/229) das amostras, incluindo cães sem sinais clínicos. Na segunda parte do trabalho, realizaram-se diversos ensaios “in vitro” com estirpes híbridas naturais L. infantum/L. major e parentais L. infantum e L. major. Em condições normais de crescimento, observou-se um padrão de crescimento distinto para cada estirpe estudada. Em condições de “stress” oxidativo, destacou-se uma diferença significativa entre as duas estirpes híbridas estudadas. Em condições de “stress” nutricional, as estirpes não apresentaram diferenças entre si. Após avaliação da suscetibilidade das estirpes na presença de Anfotericina B, todas se mostraram suscetíveis, com concentrações inibitórias (CI50) entre 0.21 e 1.15 μg/mL. Após infeção em linhas celulares monocíticas, não se verificaram diferenças estatisticamente significativas na taxa e intensidade de infeção das estirpes híbridas em comparação às putativas parentais. Os resultados obtidos, contribuíram para um melhor conhecimento sobre o comportamento biológico destas estirpes híbridas naturais L. infantum/L. major. Estas demonstraram um comportamento “in vitro” intermédio, relativamente às estirpes parentais. Estes resultados poderão servir de base para o desenvolvimento de outros estudos com estas “novas espécies”, nomeadamente estudos de patogenicidade “in vivo” e o papel de biomarcadores de virulência, que permitam um potencial prognóstico da infeção e avaliação do seu risco epidemiológico.

Estudo dos flebótomos (Diptera, Phlebotominae), vectores de Leishmania sp. No Concelho de Torres Novas, Portugal

Os flebótomos são insectos vectores de vários agentes patogénicos, dos quais se destacam os protozoários do Género Leishmania. Em Portugal, as leishmanioses, canina e humana, são causadas por L. infantum, sendo o cão o principal reservatório e Phlebotomus perniciosus e P. ariasi os vectores comprovados do parasita. São conhecidos três focos de doença, mas casos de leishmaniose canina têm sido reportados em outras regiões nas quais se desconhecem as espécies flebotomínicas presentes e respectivas taxas de infecção. Neste trabalho, efectuou-se a primeira prospecção flebotomínica no Concelho de Torres Novas, Distrito de Santarém, localizado na região Centro de Portugal. Os principais objectivos foram determinar a fauna flebotomínica do Concelho, os aspectos bioecológicos, as taxas de infecção por Leishmania e os factores de risco para a transmissão vectorial. De Junho a Novembro de 2010, 275 biótopos foram prospectados com armadilhas CDC. As capturas foram realizadas em 91 localidades, nas 17 freguesias do Concelho, e incluíram habitats domésticos, peridomésticos e silváticos. Os exemplares capturados foram identificados morfologicamente, as fêmeas utilizadas para detecção molecular de DNA de Leishmania e identificação das refeições sanguíneas. Análises de regressão simples e múltipla foram utilizadas para avaliação dos factores de risco para a presença das várias espécies flebotomínicas. Testes não paramétricos foram usados para comparar densidades. Dos 1262 flebótomos capturados, quatro espécies foram assinaladas com as seguintes abundâncias relativas: P. perniciosus 73,69%, P. ariasi 8,16%, P. sergenti 6,58% e Sergentomyia minuta 11,57%. Em 82% das localidades prospectadas foi detectada pelo menos uma espécie flebotomínica e em 71,4% destas foi capturada pelo menos uma das espécies comprovadamente vectoras de L. infantum. P. perniciosus foi assinalado em todas as 17 freguesias do Concelho. Os factores de risco identificados foram: temperaturas elevadas e humidades relativas baixas, locais abrigados e ausência de vento forte, presença de pinheiros como vegetação dominante, biótopos peridomésticos, particularmente currais de ovelhas e coelheiras, ou na proximidade de ovelhas, aves de capoeira e ninhos com andorinhas. A taxa de infecção flebotomínica por L. infantum foi de 4% para P. ariasi e de 0,32% para o total de fêmeas capturadas. A maioria das fêmeas para as quais se identificou a origem da refeição sanguínea pertencia a P. perniciosus. Esta espécie apresentou um comportamento oportunista, alimentando-se numa grande variedade de hospedeiros vertebrados. A elevada abundância e distribuição das espécies vectoras, juntamente com a seroprevalência de Leishmania nos cães do Distrito (5-10%), e a captura de uma fêmea grávida de P. ariasi (infectante), sugerem que o Concelho de Torres Novas é um foco de leishmaniose no país. A maior abundância relativa de P. sergenti, comparando com prospecções realizadas noutras áreas da região Centro de Portugal, sugere que este potencial vector esteja a expandir-se para latitudes mais elevadas, aumentando o risco de introdução de L. tropica no território, por contacto com imigrantes ou viajantes infectados de áreas endémicas. A monitorização flebotomínica, e dos hospedeiros vertebrados, deverá ser continuada no Concelho para que medidas eficazes de controlo possam ser definidas e implementadas.

Intradermorreação de Montenegro em cães (Mammalia: Canidae) experimentalmente inoculados por Leishmaniaguyanensis e Leishmania braziliensis (Kinetoplastida: Trypanosomatidae), principais agentes causadores de Leishmaniose Tegumentar na Amazônia

O teste de intradermorreação de Montenegro é utilizado para detectar infecção por Leishmania em humanos. A técnica se baseia numa reação de hipersensibilidade tardia. Os antígenos de Montenegro utilizados no experimento são soluções de antígenos homólogos brutos de Leishmania (Viannia) braziliensis e L.(V)guyanensis. Este experimento demonstrou que os animais inoculados com as espécies de Leishmania inoculadas desenvolveram enduração no local do teste mais acentuada que os animais controle. Os resultados sugerem que o teste cutâneo pode vir a ser indicado como método auxiliar de diagnóstico em cães infectados por Leishmania sp.

The spiny rat Proechimys guyannensis (Rodentia: Echimydae) fails to respond to intradermal inoculation with Leishmania (Viannia) braziliensis

Leishmaniasis a disease of worldwide occurrence is caused by protozoa of the Leishmania genus. In Brazil, Leishmania (Viannia) braziliensis is the main parasite responsible for the American cutaneous leishmaniasis. Main hosts of this protozoa are small wild mammals particularly marsupials and rodents. The aim of this study was to evaluate if spiny rat Proechimys guyannensis (Rodentia: Echimydae) has role in the cycle of the American cutaneous leishmaniasis caused by L. (V.) braziliensis. Thus, promastigotes (the flagellate stage) of Leishmania (Viannia) braziliensis were used to inoculate seven spiny rats (Proechimys guyannensis). After inoculated intradermal at the ear pinna, nose and plantar pad, the rats were monitored for 180 days. Tissue samples collected at 90 and 180 days from the rats proved to be negative for the presence of genetic material from the parasite. After euthanasia, the protozoa also failed to growth in culture medium containing tissue samples collected from the rats showing that there was no infection. These results fail to prove that spiny rat has a role in the cycle of the American cutaneous leishmaniasis caused by L. (V.) braziliensis.