Serological and Molecular Survey of Rickettsial Agents in Wild Boars (Sus scrofa) from Midwestern Brazil.

Wild boars (Sus scrofa L.) are considered among the most harmful invasive species worldwide, causing irreversible ecosystem damage, acting as zoonotic spreaders and reservoirs, threatening human and animal health, and having an important economic impact. Accordingly, the present study has assessed the rickettsial exposure, tick infestation of wild boars, and rickettsial DNA presence in ticks from infested animals from the Cerrado biome in midwestern Brazil. Anti-Rickettsia spp. antibodies were detected in serum samples of wild boars by immunofluorescence assay. Overall, 106/285 (37.2%) wild boar serum samples from 13 to 18 (72.2%) municipalities showed seroreactivity to at least one of the four Rickettsia spp. antigens tested, the largest number of wild boars serologically tested to Rickettsia spp. in this type of study. Among the 106 seroreactive animals, 34 showed possible homologous reactions between R. parkeri, R. amblyommatis, and R. bellii, with endpoint titers between 128 and 512. A sample of 45 ticks collected from four culled wild boars was identified as Amblyomma sculptum, and all tested negative for rickettsial DNA presence. In conclusion, this study has provided a reliable sampling seroprevalence and indicated high exposure of wild boars to rickettsial agents, with a potential interaction with Rickettsia spp. from the spotted fever group within the Cerrado biome from midwestern Brazil.

Serosurvey of Coxiella burnetii in Descendants of Former Black Slaves (Quilombola Communities) of Southern Brazil.

Brazilian descendants of former Black-slave (quilombola) communities have been predisposed to several zoonotic diseases due to social vulnerability, characterized by subsistence and close contact with livestock and companion animals. Accordingly, the present study has assessed anti-Coxiella burnetii antibodies in 200 individuals and 20 dogs from four quilombola communities located in Paraná State, southern Brazil. Serum samples were tested by indirect immunofluorescence assay (IFA) using in-house and commercial diagnostic protocols, with analysis of seropositive titers and antibody type. Fisher's exact test was used to compare seropositivity to C. burnetti with binary variables, with variables with three or more possible responses submitted to logistic regression. In total, 44/200 (22%; 95% CI 16.82-28.24) people tested positive, and 4.5% had titers higher than 128, indicating a recent onset of C. burnetii infection. Seropositive individuals were statistically associated with the Limitão community (p = 0.0013), urban workers as occupations (p = 0.0475), consumption of undercooked meat (p = 0.0159), and contact with animal abortion (p = 0.0276). No seropositivity association was found for age, sex, education, habit of entering forest areas, consumption of game meat, consumption of raw milk, flea and tick bites, dog contact, or history of female miscarriage. Only one of 20 dogs was seropositive with a titer of 128, probably related to an acute animal infection. Despite the prevalence here being higher than previous Brazilian reports, including with symptomatic populations, the results were within range for worldwide outbreaks and occupational risk populations. To the reader's knowledge, this is the first human survey of Q fever in southern Brazil and should be considered a warning for C. burnetii in vulnerable populations, particularly Quilombola communities.

The Virus-Induced Cytopathic Effect.

The cytopathic effect comprises the set of cellular alterations produced by a viral infection. It is of great relevance since it constitutes a direct marker of infection. Likewise, these alterations are often virus-specific which makes them a phenotypic marker for many viral species. All these characteristics have been used to complement the study of the dynamics of virus-cell interactions through the kinetic study of the progression of damage produced by the infection. Various approaches have been used to monitor the cytopathic effect, ranging from light microscopy, immunofluorescence assays, and direct labeling with fluorescent dyes, to plaque assay for the characterization of the infection over time. Here we address the relevance of the study of cytopathic effect and describe different experimental alternatives for its application.

Seroprevalence and hematological abnormalities associated with Ehrlichia canis in dogs referred to a veterinary teaching hospital in central-western Brazil / Soroprevalência e alterações hematológicas associadas com Ehrlichia canis em cães encaminhados a um hospital veterinário-escola no centro-oeste do Brasil

Ticks are significant parasites of dogs in the tropics, where tick-borne pathogens are highly prevalent, especially in areas where tick control measures are frequently neglected. This study investigated the seroprevalence and hematological abnormalities associated with Ehrlichia canis in dogs referred to a veterinary teaching hospital in Central-western Brazil. Out of 264 dogs tested for anti-Ehrlichia canis antibodies by an indirect immunofluorescence assay (IFA), 59.1% (156/264) were positive. Seropositivity was significantly associated to anemia and thrombocytopenia, alone or in combination, and to leukopenia. Conversely, there were no differences in terms of seroprevalence according to sex, breed and age. This study demonstrated that dogs referred to a veterinary teaching hospital in Central-western Brazil are highly exposed to E. canis and that seropositive dogs are more likely to present hematological abnormalities, particularly anemia, thrombocytopenia and leukopenia. To our knowledge, this is the first study on detection of anti-E. canis antibodies by means of IFA among dogs in the state of Goiás. These findings highlighted the need for increasing awareness among dog owners regarding tick control measures in Central-western Brazil, ultimately to reduce the risk of exposure to E. canis and other tick-borne pathogens.

Carrapatos são importantes parasitos de cães nos trópicos, onde patógenos transmitidos por carrapatos são altamente prevalentes, especialmente em áreas onde as medidas de controle de carrapatos são frequentemente negligenciadas. O estudo investigou a soroprevalência e as anormalidades hematológicas associadas à Ehrlichia canis em cães encaminhados para um hospital veterinário-escola no Centro-oeste do Brasil. Dos 264 cães testados para anticorpos anti-Ehrlichia canis por meio da reação de imunofluorescência indireta (RIFI), 59.1% (156/264) foram positivos. A soropositividade foi associada significativamente à anemia e trombocitopenia, isoladamente ou em combinação, e à leucopenia. Por outro lado, não houve diferenças quanto à soroprevalência segundo sexo, raça e idade. Este estudo demonstrou que cães encaminhados a um hospital veterinário-escola na região Centro-oeste do Brasil são altamente expostos à E. canis, e que cães soropositivos têm maior probabilidade de apresentar alterações hematológicas, principalmente anemia, trombocitopenia e leucopenia. Para o nosso conhecimento, este é o primeiro estudo sobre a detecção de anticorpos anti-E. canis por meio da RIFI em cães do estado de Goiás. Essas descobertas destacam a necessidade de aumentar a conscientização entre os proprietários de cães em relação às medidas de controle do carrapato no Centro-oeste do Brasil, em última análise, para reduzir o risco de exposição ao E. canis e outros patógenos transmitidos por carrapatos.

How to report the antinuclear antibodies (anti-cell antibodies) test on HEp-2 cells: guidelines from the ICAP initiative.

Results of the anti-nuclear antibodies-indirect immunofluorescence assay (anti-cell antibodies test) on HEp-2 cell substrates should be communicated to clinicians in a standardized way, adding value to laboratory findings and helping with critical clinical decisions. This paper proposes a test report based on the practices informed by 118 laboratories in 68 countries, with recommendations from the International Consensus on ANA Patterns (ICAP) group. Major focus is placed on the report format containing endpoint titers, immunofluorescence patterns together with anti-cell (AC) nomenclature, remarks on follow-up or reflex testing, and possible other autoantibody associations. ISO 15,189 directives were integrated into the test report. Special situations addressed include serum screening dilutions and endpoint titers, relevance of immunofluorescence patterns with special attention to cytoplasmic patterns, mixed and compound patterns, and how to report different titers corresponding to multiple patterns or autoantibodies in the same sample. This paper suggests a subtitle for the HEp-2-IIFA, namely anti-cell antibodies test, which could gradually substitute the original outdated ANA nomenclature. This ICAP pro forma report represents a further step in harmonizing the way relevant clinical information could be provided by laboratories.

Spatial distribution of Toxoplasma gondii in cows and associated risk factors.

The aim of the present study was to evaluate the spatial distribution of the prevalence of T. gondii in cows using the indirect immunofluorescence assay and determine associated risk factors. Serum samples were collected from 2970 cows on 263 rural farms in 223 municipalities. A questionnaire was administered to herd owners to collect data for the evaluation of risk factors associated with this disease. Mean seroprevalence of T. gondii in cows was 8.48% (95% CI: 7.48 to 9.49). The microregions with the greatest likelihood (p ≤ 0.05) of having infected animals were Anápolis, Ceres, São Miguel do Araguaia, the Federal District, Anicuns, and Vão do Paraná. The purchase of females or males for reproductive/breeding purposes was significantly associated (p ≤ 0.05) with the prevalence of T. gondii in these regions. A positive correlation (0.7618; p = 0.047) was found between the prevalence of T. gondii and total area in hectares of forests in these regions, suggesting that wild cats may be disseminating T. gondii at these sites. The present results highlight the importance of considering the meat from these animals to be an important infection route for humans who eat raw or undercooked food.

Rickettsial pathogens circulating in urban districts of Rio de Janeiro, without report of human Brazilian Spotted Fever / Circulação de patógenos riquetsiais em bairros urbanos do Rio de Janeiro sem relatos humanos da Febre Maculosa Brasileira

Spotted fever group rickettsioses are emerging diseases. In some of these diseases, domestic dogs act as sentinels. Canine serological studies have demonstrated that rickettsial dispersion is concentrated in rural areas, seroprevalence being higher where human rickettsioses are endemic. In Rio de Janeiro, the Atlantic forest vegetation has been devastated by urbanization. In this context, we aimed to detect Rickettsia spp. in urban areas of the West Zone of Rio de Janeiro. Sera from 130 dogs were tested by Indirect Immunofluorescence Assay, and ticks collected from these dogs were tested by polymerase chain reaction. We found the rate of serological reactions against R. rickettsii and R. parkeri in our study area to exceed those of rural and non-endemic areas, highlighting the importance of dogs as urban sentinels. The possibility of contact with opossums and capybaras increased the chances of exposure to Rickettsia spp., reinforcing the hypothetical link between the landscape and the rickettsial wild cycle. Rhipicephalus sanguineus sensu lato was the tick most frequently observed. PCR-positive samples showed similarity with R. rickettsii and R. felis, an emerging pathogen rarely reported from ticks. We observed that rickettsiae circulate in urban places and ticks from indoor environments, which may be involved in bacterial epidemiology.(AU)

Riquetsioses do Grupo da Febre Maculosa são doenças emergentes. Em algumas destas doenças, os cães domésticos agem como sentinelas. Estudos sorológicos caninos têm demonstrado que a dispersão de patógenos rickettsiais está concentrada em áreas rurais, sendo a soroprevalência maior onde as rickettsioses humanas são endêmicas. Na cidade do Rio de Janeiro, a vegetação de Mata Atlântica vem sendo devastada pela urbanização. Nesse contexto, objetivou-se detectar a presença de Rickettsia spp. em áreas urbanas da Zona Oeste do Rio de Janeiro. Amostras de soro obtidas de 130 cães foram testadas, utilizando-se a Imunofluorescência Indireta. Carrapatos coletados desses cães foram testados, utilizando-se a reação em cadeia da polimerase. Observou-se que as taxas de reações sorológicas contra R. rickettsii e R. parkeri nessa área de estudo excederam a prevalência das áreas rurais e não endêmicas, destacando-se a importância dos cães como sentinelas urbanos das rickettsioses. A possibilidade de contato com capivaras e gambás favoreceu a exposição à Rickettsia spp., reforçando a hipótese de ligação entre a paisagem local e o ciclo silvestre de transmissão riquetsial. O carrapato Rhipicephalus sanguineus sensu lato foi encontrado com maior frequência. Amostras com positividade pela PCR mostraram similaridade com R. rickettsii e R. felis, um patógeno emergente raramente descrito em carrapatos. Observou-se circulação riquetsial em áreas urbanas e em carrapatos obtidos do ambiente doméstico, os quais podem estar envolvidos na epidemiologia dessas bactérias.(AU)

Rickettsial pathogens circulating in urban districts of Rio de Janeiro, without report of human Brazilian Spotted Fever / Circulação de patógenos riquetsiais em bairros urbanos do Rio de Janeiro sem relatos humanos da Febre Maculosa Brasileira

Abstract Spotted fever group rickettsioses are emerging diseases. In some of these diseases, domestic dogs act as sentinels. Canine serological studies have demonstrated that rickettsial dispersion is concentrated in rural areas, seroprevalence being higher where human rickettsioses are endemic. In Rio de Janeiro, the Atlantic forest vegetation has been devastated by urbanization. In this context, we aimed to detect Rickettsia spp. in urban areas of the West Zone of Rio de Janeiro. Sera from 130 dogs were tested by Indirect Immunofluorescence Assay, and ticks collected from these dogs were tested by polymerase chain reaction. We found the rate of serological reactions against R. rickettsii and R. parkeri in our study area to exceed those of rural and non-endemic areas, highlighting the importance of dogs as urban sentinels. The possibility of contact with opossums and capybaras increased the chances of exposure to Rickettsia spp., reinforcing the hypothetical link between the landscape and the rickettsial wild cycle. Rhipicephalus sanguineus sensu lato was the tick most frequently observed. PCR-positive samples showed similarity with R. rickettsii and R. felis, an emerging pathogen rarely reported from ticks. We observed that rickettsiae circulate in urban places and ticks from indoor environments, which may be involved in bacterial epidemiology.

Resumo Riquetsioses do Grupo da Febre Maculosa são doenças emergentes. Em algumas destas doenças, os cães domésticos agem como sentinelas. Estudos sorológicos caninos têm demonstrado que a dispersão de patógenos rickettsiais está concentrada em áreas rurais, sendo a soroprevalência maior onde as rickettsioses humanas são endêmicas. Na cidade do Rio de Janeiro, a vegetação de Mata Atlântica vem sendo devastada pela urbanização. Nesse contexto, objetivou-se detectar a presença de Rickettsia spp. em áreas urbanas da Zona Oeste do Rio de Janeiro. Amostras de soro obtidas de 130 cães foram testadas, utilizando-se a Imunofluorescência Indireta. Carrapatos coletados desses cães foram testados, utilizando-se a reação em cadeia da polimerase. Observou-se que as taxas de reações sorológicas contra R. rickettsii e R. parkeri nessa área de estudo excederam a prevalência das áreas rurais e não endêmicas, destacando-se a importância dos cães como sentinelas urbanos das rickettsioses. A possibilidade de contato com capivaras e gambás favoreceu a exposição à Rickettsia spp., reforçando a hipótese de ligação entre a paisagem local e o ciclo silvestre de transmissão riquetsial. O carrapato Rhipicephalus sanguineus sensu lato foi encontrado com maior frequência. Amostras com positividade pela PCR mostraram similaridade com R. rickettsii e R. felis, um patógeno emergente raramente descrito em carrapatos. Observou-se circulação riquetsial em áreas urbanas e em carrapatos obtidos do ambiente doméstico, os quais podem estar envolvidos na epidemiologia dessas bactérias.

Quantum dots-based fluoroimmunoassay for anti-Zika virus IgG antibodies detection.

Zika virus (ZIKV) has been declared a public health emergency of international concern. ZIKV has been associated with some neurological disorders, and their long-term effects are not completely understood. The majority of the methods for ZIKV diagnosis are based on the detection of IgM antibodies, which are the first signs of immunological response. However, the detection of IgG antibodies can be an important approach for ZIKV past infection diagnosis, especially for pregnant women, helping the comprehension/treatment of this disease. There has been a growing interest in applying nanoparticles for efficient ZIKV or antibodies detection. Quantum dots (QD) are unique fluorescent semiconductor nanoparticles, highly versatile for biological applications. In the present study, we explored the special QD optical properties to develop an immunofluorescence assay for anti-ZIKV IgG antibodies detection. Anti-IgG antibodies were successfully conjugated with QDs and applied in a fluorescence sensing nanoplatform. After optimization using IgG antibodies, the conjugates were employed to detect anti-ZIKV IgG antibodies in polystyrene microplates sensitized with ZIKV envelope E protein. The nanoplatform was able to detect anti-ZIKV IgG antibodies in a concentration at least 100-fold lower than the amount expected for protein E immune response. Moreover, conjugates were able to detect the antibodies for at least 4 months. Thus, our results showed that this QDs-based fluoroimmunoplatform can be considered practical, simple and promising to detect Zika past infections and/or monitoring immune response in vaccine trials.

Brazilian spotted fever serological investigation among equids at the Guarapiranga Dam area in the city of São Paulo, Brazil / Investigação sorológica da febre maculosa brasileira entre equídeos na área da represa de Guarapiranga, na cidade de São Paulo, Brasil

The Guarapiranga Dam region, in the metropolitan area of São Paulo, has been an endemic area for Brazilian spotted fever (BSF), a tick-borne disease caused by the bacterium Rickettsia rickettsii. In this particular area, R. rickettsii is known to be transmitted to humans by Amblyomma aureolatum, a typical dog tick that is not associated with horses. In other BSF-endemic areas, R. rickettsii transmission is associated with Amblyomma sculptum, a tick species that typically infest capybaras and horses. The Guarapiranga Dam bears abundant populations of capybaras and horses; however, since nothing is known about a possible cycle of transmission of R. rickettsii by A. sculptum in this area, this study evaluated such transmission by performing a serosurvey of horses living in the Guarapiranga Dam region. A total of 206 equids living in the margins of the Guarapiranga Dam were serologically tested for antibodies reactive to five Rickettsia species, four of the spotted fever group (R. rickettsii, R. parkeri, R. amblyommatis, R. rhipicephali) and one basal group species, R. bellii. Overall, 171 (83%) equids reacted positively to at least one Rickettsia species. A total of 160 (78%), 123 (60%), 80 (39%), 72 (35%), and 71 (34%), equid sera reacted to R. bellii, R. rickettsii, R. parkeri, R. rhipicephali, and R. amblyommatis, respectively, with endpoint titers ranging from 64 to 1024 for R

Na região da represa de Guarapiranga localizada na área metropolitana de São Paulo, têm sido relatados casos humanos de Febre Maculosa Brasileira (FMB), uma doença transmitida por carrapatos causada pela bactéria Rickettsia rickettsii. Nesta área de estudo, R. rickettsii é conhecida por ser transmitida aos seres humanos pelo Amblyomma aureolatum, um carrapato de cão que não está associado a cavalos. Em outras áreas endêmicas da FMB, a transmissão de R. rickettsii está associada ao Amblyomma sculptum, uma espécie de carrapato que normalmente infesta capivaras e cavalos. A represa de Guarapiranga possui populações abundantes de capivaras e cavalos; no entanto, como nada se sabe sobre um possível ciclo de transmissão de R. rickettsii por A. sculptum nessa área, este estudo avaliou essa transmissão realizando um levantamento sorológico em cavalos que vivem na região da represa de Guarapiranga. Um total de 206 equídeos que vivem nas margens da represa de Guarapiranga foram testados sorologicamente para cinco espécies de Rickettsia, sendo quatro do grupo da FMB (R. rickettsii, R. parkeri, R. amblyommatis, R. rhipicephali) e um do grupo basal (R. bellii). No geral, 171 (83%) equídeos reagiram positivamente a pelo menos uma espécie de Rickettsia. Um total de 160 (78%), 123 (60%), 80 (39%), 72 (35%) e 71 (34%), reagiram a R. bellii, R. rickettsii, R. parkeri, R. rhipicephali e R. amblyo

Brazilian spotted fever serological survey among equids at the Guarapiranga Dam area in the city of São Paulo, Brazil / Investigação sorológica da febre maculosa brasileira entre equídeos na área da represa de Guarapiranga, na cidade de São Paulo, Brasil

In the Guarapiranga dam region located in the metropolitan area of São Paulo, human cases have been reported of Brazilian spotted fever (BSF), a tick-borne disease caused by the bacterium Rickettsia rickettsii. In this area, R. rickettsii is known to be transmitted to humans by Amblyomma aureolatum, a typical dog tick that is not associated with horses. In other BSF-endemic areas, R. rickettsii transmission is associated with Amblyomma sculptum, a tick species that typically infest capybaras and horses. The Guarapiranga Dam bears abundant populations of capybaras and horses. However, since nothing is known about a possible cycle of transmission of R. rickettsii by A. sculptum in this area, this study evaluated such transmission by performing a serosurvey of horses living in the Guarapiranga Dam region. A total of 206 equids living in the margins of the Guarapiranga Dam were serologically tested for antibodies reactive to five Rickettsia species, four of the spotted fever group (R. rickettsii, R. parkeri, R. amblyommatis, R. rhipicephali) and one basal group species, R. bellii. Overall, 171 (83%) equids reacted positively to at least one Rickettsia species. A total of 160 (78%), 123 (60%), 80 (39%), 72 (35%), and 71 (34%), equid sera reacted to R. bellii, R. rickettsii, R. parkeri, R. rhipicephali, and R. amblyommatis, respectively, with endpoint titers ranging from 64 to 1024 for R. bellii, and 64 to 512 for the remaining four Rickettsia species. Endpoint titers to R. bellii (median: 256) was significantly higher (P<0.05) than the endpoint titers to the other four Rickettsia species, for which the median values varied from 64 to 128. A total of 65 (32%) equid sera showed endpoint titers to R. bellii at least 4-fold higher than those to any of the other four antigens, indicating that they have been exposed to R. bellii or a very closely related species. Our results provide serological evidence that the sampled equids were not frequently exposed to R. rickettsii-infected ticks. Since horses are a highly suitable sentinel for R. rickettsii transmission by A. sculptum, we conclude that this tick species has no epidemiological role in the transmission of R. rickettsii in the BSF-endemic area of the Guarapiranga Dam in the metropolitan area of São Paulo.(AU)

Na região da represa de Guarapiranga localizada na área metropolitana de São Paulo, têm sido relatados casos humanos de Febre Maculosa Brasileira (FMB), uma doença transmitida por carrapatos causada pela bactéria Rickettsia rickettsii. Nesta área de estudo, R. rickettsii é conhecida por ser transmitida aos seres humanos pelo Amblyomma aureolatum, um carrapato de cão que não está associado a cavalos. Em outras áreas endêmicas da FMB, a transmissão de R. rickettsii está associada ao Amblyomma sculptum, uma espécie de carrapato que normalmente infesta capivaras e cavalos. A represa de Guarapiranga possui populações abundantes de capivaras e cavalos; no entanto, como nada se sabe sobre um possível ciclo de transmissão de R. rickettsii por A. sculptum nessa área, este estudo avaliou essa transmissão realizando um levantamento sorológico em cavalos que vivem na região da represa de Guarapiranga. Um total de 206 equídeos que vivem nas margens da represa de Guarapiranga foram testados sorologicamente para cinco espécies de Rickettsia, sendo quatro do grupo da FMB (R. rickettsii, R. parkeri, R. amblyommatis, R. rhipicephali) e um do grupo basal (R. bellii). No geral, 171 (83%) equídeos reagiram positivamente a pelo menos uma espécie de Rickettsia. Um total de 160 (78%), 123 (60%), 80 (39%), 72 (35%) e 71 (34%), reagiram a R. bellii, R. rickettsii, R. parkeri, R. rhipicephali e R. amblyommatis, respectivamente, com títulos finais variando de 64 a 1024 para R. bellii e 64 a 512 para as quatro espécies restantes de Rickettsia. Os títulos finais para R. bellii (mediana: 256) foram significativamente maiores (P <0,05) do que os títulos para as outras quatro espécies de Rickettsia, para os quais os valores medianos variaram de 64 a 128. Um total de 65 (32%) equideos, os soros mostraram títulos finais para R. bellii pelo menos quatro vezes maior que os de qualquer um dos outros quatro antígenos, indicando que eles foram expostos a R. bellii ou a uma espécie muito próxima. Os resultados obtidos fornecem evidências sorológicas de que os equídeos amostrados não eram frequentemente expostos a carrapatos infectados por R. rickettsii. Como os cavalos são um sentinela altamente adequado para a transmissão de R. rickettsiipor A. sculptum, a conclusão obtida foi que essa espécie de carrapato não tem papel epidemiológico na transmissão da bactéria na área endêmica de FMB da represa de Guarapiranga na região metropolitana de São Paulo.(AU)

Circulation of spotted fever group rickettsiae among dogs seropositive for Leishmania spp. in an urban area of Brazil

Abstract INTRODUCTION: Dogs play an epidemiological role in several vector-borne diseases that affect human and animal health worldwide. We aimed to identify rickettsial circulation among dogs with canine visceral leishmaniasis (CVL) from a region endemic for both diseases. METHODS: CVL-seropositive dogs were screened for spotted fever group rickettsiae using an indirect immunofluorescence assay. RESULTS: Among the CVL-positive dogs, anti-Rickettsia rickettsii antibodies were identified in one asymptomatic and one oligosymptomatic dog. CONCLUSIONS: This study shows low circulation of antibodies to R. rickettsii in CVL-seropositive dogs. It is recommended that surveillance studies in dogs should continue in order to monitor this scenario.

Brazilian spotted fever serological survey among equids at the Guarapiranga Dam area in the city of São Paulo, Brazil / Investigação sorológica da febre maculosa brasileira entre equídeos na área da represa de Guarapiranga, na cidade de São Paulo, Brasil

In the Guarapiranga dam region located in the metropolitan area of São Paulo, human cases have been reported of Brazilian spotted fever (BSF), a tick-borne disease caused by the bacterium Rickettsia rickettsii. In this area, R. rickettsii is known to be transmitted to humans by Amblyomma aureolatum, a typical dog tick that is not associated with horses. In other BSF-endemic areas, R. rickettsii transmission is associated with Amblyomma sculptum, a tick species that typically infest capybaras and horses. The Guarapiranga Dam bears abundant populations of capybaras and horses. However, since nothing is known about a possible cycle of transmission of R. rickettsii by A. sculptum in this area, this study evaluated such transmission by performing a serosurvey of horses living in the Guarapiranga Dam region. A total of 206 equids living in the margins of the Guarapiranga Dam were serologically tested for antibodies reactive to five Rickettsia species, four of the spotted fever group (R. rickettsii, R. parkeri, R. amblyommatis, R. rhipicephali) and one basal group species, R. bellii. Overall, 171 (83%) equids reacted positively to at least one Rickettsia species. A total of 160 (78%), 123 (60%), 80 (39%), 72 (35%), and 71 (34%), equid sera reacted to R. bellii, R. rickettsii, R. parkeri, R. rhipicephali, and R. amblyommatis, respectively, with endpoint titers ranging from 64 to 1024 for R. bellii, and 64 to 512 for the remaining four Rickettsia species. Endpoint titers to R. bellii (median: 256) was significantly higher (P<0.05) than the endpoint titers to the other four Rickettsia species, for which the median values varied from 64 to 128. A total of 65 (32%) equid sera showed endpoint titers to R. bellii at least 4-fold higher than those to any of the other four antigens, indicating that they have been exposed to R. bellii or a very closely related species. Our results provide serological evidence that the sampled equids were not frequently exposed to R. rickettsii-infected ticks. Since horses are a highly suitable sentinel for R. rickettsii transmission by A. sculptum, we conclude that this tick species has no epidemiological role in the transmission of R. rickettsii in the BSF-endemic area of the Guarapiranga Dam in the metropolitan area of São Paulo.(AU)

Na região da represa de Guarapiranga localizada na área metropolitana de São Paulo, têm sido relatados casos humanos de Febre Maculosa Brasileira (FMB), uma doença transmitida por carrapatos causada pela bactéria Rickettsia rickettsii. Nesta área de estudo, R. rickettsii é conhecida por ser transmitida aos seres humanos pelo Amblyomma aureolatum, um carrapato de cão que não está associado a cavalos. Em outras áreas endêmicas da FMB, a transmissão de R. rickettsii está associada ao Amblyomma sculptum, uma espécie de carrapato que normalmente infesta capivaras e cavalos. A represa de Guarapiranga possui populações abundantes de capivaras e cavalos; no entanto, como nada se sabe sobre um possível ciclo de transmissão de R. rickettsii por A. sculptum nessa área, este estudo avaliou essa transmissão realizando um levantamento sorológico em cavalos que vivem na região da represa de Guarapiranga. Um total de 206 equídeos que vivem nas margens da represa de Guarapiranga foram testados sorologicamente para cinco espécies de Rickettsia, sendo quatro do grupo da FMB (R. rickettsii, R. parkeri, R. amblyommatis, R. rhipicephali) e um do grupo basal (R. bellii). No geral, 171 (83%) equídeos reagiram positivamente a pelo menos uma espécie de Rickettsia. Um total de 160 (78%), 123 (60%), 80 (39%), 72 (35%) e 71 (34%), reagiram a R. bellii, R. rickettsii, R. parkeri, R. rhipicephali e R. amblyommatis, respectivamente, com títulos finais variando de 64 a 1024 para R. bellii e 64 a 512 para as quatro espécies restantes de Rickettsia. Os títulos finais para R. bellii (mediana: 256) foram significativamente maiores (P <0,05) do que os títulos para as outras quatro espécies de Rickettsia, para os quais os valores medianos variaram de 64 a 128. Um total de 65 (32%) equideos, os soros mostraram títulos finais para R. bellii pelo menos quatro vezes maior que os de qualquer um dos outros quatro antígenos, indicando que eles foram expostos a R. bellii ou a uma espécie muito próxima. Os resultados obtidos fornecem evidências sorológicas de que os equídeos amostrados não eram frequentemente expostos a carrapatos infectados por R. rickettsii. Como os cavalos são um sentinela altamente adequado para a transmissão de R. rickettsiipor A. sculptum, a conclusão obtida foi que essa espécie de carrapato não tem papel epidemiológico na transmissão da bactéria na área endêmica de FMB da represa de Guarapiranga na região metropolitana de São Paulo.(AU)

Seroprevalence of Rickettsia rickettsii and Rickettsia parkeri in dogs during a Brazilian Spotted Fever outbreak in the State of Rio de Janeiro / Soroprevalência de Rickettsia rickettsii e Rickettsia parkeri em cães durante um surto de Febre Maculosa Brasileira no Estado do Rio de Janeiro

The present paper is the first to perform this evaluation in dogs from the cities of Natividade, Porciuncula and Varre-Sai. The aim of this study is to search for Spotted Fever Group Rickettsia in canine sera using indirect immunofluorescence assay and to identify the probable causative agent of sera reactions in animals. Of the 253 sampled canines, 67.59% (171/253) were seroreactive for Rickettsia rickettsii and 11.07% (28/253) for Rickettsia parkeri, both in dilution 1:64. Titration of tested sera against R. rickettsii antigens reached 1:131.072 and, for R. parkeri, 1:4.096. We conclude that dogs are important sentinels for R. rickettsii infection, and can be infected regardless of sex, age, the habit of visiting woodlands or being in direct contact with equines and capybaras. Serological diagnosis has highlighted many dogs infected by R. rickettsii, and ambient conditions, such as the presence of flowing water bodies, was important for the occurrence of Brazilian Spotted Fever in the northwestern of Rio de Janeiro State.(AU)

O presente trabalho é o primeiro a ser realizado com cães nos municípios de Natividade, Porciúncula e Varre-Sai e tem por objetivo pesquisar Rickettsias do Grupo da Febre Maculosa em soros de cães, por meio da reação de imunofluorescência indireta, e identificar o provável agente causador da reação sorológica nos animais. Dos caninos amostrados, 67,59% (171/253) foram sororreativos para Rickettsia rickettsii e 11,07% (28/253) para Rickettsia parkeri, ambos em diluição de 1:64. A titulação dos soros testados contra antígenos de R. rickettsii chegou a 1:131.072, e para R. parkeri, 1:4.096. Conclui-se que cães são importantes sentinelas para a infecção por R. rickettsii, independente de sexo, idade, hábito de visitar ambientes florestais ou de estarem em contato direto com equinos e capivaras. O diagnóstico sorológico permitiu evidenciar muitos cães infectados por R. rickettsii, e condições ambientais, como a presença de áreas ribeirinhas, foram importantes para a ocorrência de Febre Maculosa Brasileira na região noroeste do Estado do Rio de Janeiro.(AU)

Seroprevalence of Rickettsia rickettsii and Rickettsia parkeri in dogs during a Brazilian Spotted Fever outbreak in the State of Rio de Janeiro / Soroprevalência de Rickettsia rickettsii e Rickettsia parkeri em cães durante um surto de Febre Maculosa Brasileira no Estado do Rio de Janeiro

The present paper is the first to perform this evaluation in dogs from the cities of Natividade, Porciuncula and Varre-Sai. The aim of this study is to search for Spotted Fever Group Rickettsia in canine sera using indirect immunofluorescence assay and to identify the probable causative agent of sera reactions in animals. Of the 253 sampled canines, 67.59% (171/253) were seroreactive for Rickettsia rickettsii and 11.07% (28/253) for Rickettsia parkeri, both in dilution 1:64. Titration of tested sera against R. rickettsii antigens reached 1:131.072 and, for R. parkeri, 1:4.096. We conclude that dogs are important sentinels for R. rickettsii infection, and can be infected regardless of sex, age, the habit of visiting woodlands or being in direct contact with equines and capybaras. Serological diagnosis has highlighted many dogs infected by R. rickettsii, and ambient conditions, such as the presence of flowing water bodies, was important for the occurrence of Brazilian Spotted Fever in the northwestern of Rio de Janeiro State.(AU)

O presente trabalho é o primeiro a ser realizado com cães nos municípios de Natividade, Porciúncula e Varre-Sai e tem por objetivo pesquisar Rickettsias do Grupo da Febre Maculosa em soros de cães, por meio da reação de imunofluorescência indireta, e identificar o provável agente causador da reação sorológica nos animais. Dos caninos amostrados, 67,59% (171/253) foram sororreativos para Rickettsia rickettsii e 11,07% (28/253) para Rickettsia parkeri, ambos em diluição de 1:64. A titulação dos soros testados contra antígenos de R. rickettsii chegou a 1:131.072, e para R. parkeri, 1:4.096. Conclui-se que cães são importantes sentinelas para a infecção por R. rickettsii, independente de sexo, idade, hábito de visitar ambientes florestais ou de estarem em contato direto com equinos e capivaras. O diagnóstico sorológico permitiu evidenciar muitos cães infectados por R. rickettsii, e condições ambientais, como a presença de áreas ribeirinhas, foram importantes para a ocorrência de Febre Maculosa Brasileira na região noroeste do Estado do Rio de Janeiro.(AU)

Serologic Evidence of Scrub Typhus in the Peruvian Amazon.

Using a large, passive, febrile surveillance program in Iquitos, Peru, we retrospectively tested human blood specimens for scrub typhus group orientiae by ELISA, immunofluorescence assay, and PCR. Of 1,124 participants, 60 (5.3%) were seropositive, and 1 showed evidence of recent active infection. Our serologic data indicate that scrub typhus is present in the Peruvian Amazon.

Seropositivity for Rickettsia spp. and Ehrlichia spp. in the human population of Mato Grosso, Central-Western Brazil

Abstract INTRODUCTION The epidemiology of Rickettsia and Ehrlichia species infection is underestimated in Mato Grosso State. METHODS: Serum samples obtained during a Dengue outbreak in 2011-2012 were tested via indirect immunofluorescence and/or ELISA. RESULTS: Samples from 19/506 (3.8%) patients presented antibodies for at least one of three Rickettsia species; 2/506 (0.4%) samples reacted against Ehrlichia canis. Most afflicted patients are residents of cities from the south-central region of the state, where these diseases have been reported in animals. CONCLUSIONS: These results show serological evidence of human exposure to Rickettsia and Ehrlichia species in Mato Grosso State.

Spatial distribution and risk factors for Toxoplasma gondii seropositivity in cattle slaughtered for human consumption in Rondônia, North region, Brazil.

The present study aimed to evaluate Toxoplasma gondii seroprevalence in cattle slaughtered for human consumption from rural properties in the state of Rondônia, North region, Brazil; the seroprevalence was determined using indirect immunofluorescence assays (IFATs). Additionally, spatial distribution and risk factors associated with toxoplasmosis were also analyzed. Of the 1000 cattle serum samples examined, 53 (5.3%) were determined to be seropositive for T. gondii with antibody titers (IgG) ≥64. In regard to results of the studied risk factors (presence of cats, cats with free access to cattle, breeding system, animal's gender, consumption of raw milk by humans on the property and cattle abortion in the last 12 months) and the odds ratio (OR) of each of these factors influencing cattle to acquire toxoplasmosis, only animals raised on a feeder/stocker/backgrounder system presented a higher probability of being seropositive for T. gondii (OR≥1, P=0.04) than cattle raised only in a feeder/stocker system. There was no association between the occurrence of reproductive problems and T. gondii seropositivity. Based on results obtained in the Brazilian state of Rondônia, it could be concluded that the presence of cats and their contact with cattle on each property, cattle breeding purpose and cattle abortion in the last 12 months were not considered risk factors for T. gondii infection in cattle. Considering that the presence of T. gondii was detected in animals slaughtered in the state of Rondônia, consuming raw or undercooked meat from seropositive cattle should be considered a route of transmission of T. gondii to humans. However, the prevalence of toxoplasmosis diagnosed in cattle from this state (5.30%) is lower than the prevalence of toxoplasmosis observed in South, Southeast and Center-West regions of Brazil, which may vary between 48.5% and 71.0%. The low prevalence of toxoplasmosis in cattle is highlighted in Rondônia, which is the sixth largest state for cattle slaughtering in Brazil and is responsible for producing 20% of all cattle meat exported by Brazil.

Occurrence of anti-Toxoplasma gondii antibodies and parasite DNA in backyard chicken breeding in Northeast, Brazil / Ocorrência de anticorpos anti-Toxoplasma gondii e DNA do parasita em galinhas de criações domésticas no Nordeste, Brasil

The aim of the present study was to investigate the occurrence of anti-Toxoplasma gondii antibodies and parasite DNA in backyard chickens bred in the metropolitan area of Recife, Brazil. In total, 212 serum samples were collected from 16 properties, and 12 backyard chickens were collected in the six sanitary districts of Recife. An indirect immunofluorescence assay (IFA) was used to investigate the occurrence of anti-Toxoplasma gondii antibodies. Polymerase chain reaction (PCR) was used to detect T. gondii DNA in brain, heart, liver and lung specimens. Of the samples analyzed by serology, 86/212 (40.56%) were positive; of the samples analyzed by PCR, 2/12 (16.7%) were positive, with both samples positive by both tests (serological and molecular). The presence of antibody anti-T. gondii and parasite DNA in tissues of these animals are worrying aspects for public health because there is a risk of transmission of the parasite to humans through eating undercooked or raw meat. Based on the results, the adoption of preventive measures to prevent the cats access to the chickens creations should be encouraged, since these animals were identified in most of the studied properties.(AU)

O objetivo do presente estudo foi investigar a ocorrência de anticorpos anti-Toxoplasma gondii e de DNA do parasito em galinhas de criações domésticas, na região metropolitana de Recife, Brasil. No total, 212 amostras de soro foram coletadas de aves de 16 estabelecimentos e de 12 galinhas de criações domésticas nos seis distritos sanitários de Recife. Para a pesquisa de anticorpos anti-Toxoplasma gondii foi utilizada a Reação de Imunofluorescência Indireta (RIFI). A Reação em Cadeia da Polimerase (PCR) foi utilizada para detectar o DNA de T. gondii em fragmentos de cérebro, coração, fígado e pulmão. Das amostras analisadas por sorologia, 86/212 (40,56%) foram positivas. Das amostras analisadas por PCR, 2/212 (16,7%) foram positivas, em ambos os testes (sorológicos e moleculares). A presença de anticorpos anti-T. gondii e de DNA parasitário nos tecidos desses animais são aspectos preocupantes para saúde pública, porque há o risco de transmissão do parasita para humanos através da ingestão de carne mal cozida ou crua. Com base nos resultados obtidos, a adoção de medidas preventivas que evitem o acesso de gatos às criações de galinhas deve ser incentivada, uma vez que esses animais foram identificados na maioria das propriedades estudadas.(AU)

Occurrence of anti-Toxoplasma gondii antibodies and parasite DNA in backyard chicken breeding in Northeast, Brazil / Ocorrência de anticorpos anti-Toxoplasma gondii e DNA do parasita em galinhas de criações domésticas no Nordeste, Brasil

Abstract The aim of the present study was to investigate the occurrence of anti-Toxoplasma gondii antibodies and parasite DNA in backyard chickens bred in the metropolitan area of Recife, Brazil. In total, 212 serum samples were collected from 16 properties, and 12 backyard chickens were collected in the six sanitary districts of Recife. An indirect immunofluorescence assay (IFA) was used to investigate the occurrence of anti-Toxoplasma gondii antibodies. Polymerase chain reaction (PCR) was used to detect T. gondii DNA in brain, heart, liver and lung specimens. Of the samples analyzed by serology, 86/212 (40.56%) were positive; of the samples analyzed by PCR, 2/12 (16.7%) were positive, with both samples positive by both tests (serological and molecular). The presence of antibody anti-T. gondii and parasite DNA in tissues of these animals are worrying aspects for public health because there is a risk of transmission of the parasite to humans through eating undercooked or raw meat. Based on the results, the adoption of preventive measures to prevent the cats access to the chickens creations should be encouraged, since these animals were identified in most of the studied properties.

Resumo O objetivo do presente estudo foi investigar a ocorrência de anticorpos anti-Toxoplasma gondii e de DNA do parasito em galinhas de criações domésticas, na região metropolitana de Recife, Brasil. No total, 212 amostras de soro foram coletadas de aves de 16 estabelecimentos e de 12 galinhas de criações domésticas nos seis distritos sanitários de Recife. Para a pesquisa de anticorpos anti-Toxoplasma gondii foi utilizada a Reação de Imunofluorescência Indireta (RIFI). A Reação em Cadeia da Polimerase (PCR) foi utilizada para detectar o DNA de T. gondii em fragmentos de cérebro, coração, fígado e pulmão. Das amostras analisadas por sorologia, 86/212 (40,56%) foram positivas. Das amostras analisadas por PCR, 2/212 (16,7%) foram positivas, em ambos os testes (sorológicos e moleculares). A presença de anticorpos anti-T. gondii e de DNA parasitário nos tecidos desses animais são aspectos preocupantes para saúde pública, porque há o risco de transmissão do parasita para humanos através da ingestão de carne mal cozida ou crua. Com base nos resultados obtidos, a adoção de medidas preventivas que evitem o acesso de gatos às criações de galinhas deve ser incentivada, uma vez que esses animais foram identificados na maioria das propriedades estudadas.