Anti-tick monoclonal antibody applied by artificial capillary feeding in Rhipicephalus (Boophilus) microplus females

AbstractThe tick Rhipicephalus microplus is an ectoparasite harmful to livestock, a vector of disease agents that affects meat and milk production. However, resistance to acaricides reflects the need for alternative tick control methods, among which vaccines have gained increasing relevance. In this scenario, monoclonal antibodies can be used to identify and characterize antigens that can be used as vaccine immunogens. Capillary tube artificial feeding of partially engorged R. microplus females with monoclonal antibodies against proteins from the gut of tick were used to test the effects of immunoglobulins in the physiology of the parasite. The results of artificial feeding showed that female ticks over 25mg and under 60mg in weight performed better in the artificial feeding process, with a 94–168% weight increase after 24h of feeding. Results showed that artificial feeding of ticks proved to be a viable technique to study the effects of antibodies or drugs in the physiology of the parasite. One monoclonal antibody (BrBm2) induced decreased oviposition. Moreover, the antigen recognized by BrBm2 was identified as a 27-kDa protein and immunolabeled on digestive vesicles membranes of digestive cells of partially and fully engorged females

Raiva em herbívoros no estado do Pará, Brasil: estudo descritivo (2004 a 2013)

PARC/PROPESP and PAPQ/ PROPESPUniversidade Federal do Pará. Instituto de Medicina Veterinária. Laboratório de Epidemiologia e Geoprocessamento. Castanhal, PA, Brazil.Instituto Federal de Educação do Tocantins. Palmas, TO, Brazil.Universidade Federal do Pará. Instituto de Medicina Veterinária. Laboratório de Epidemiologia e Geoprocessamento. Castanhal, PA, Brazil.Universidade Federal de Mato Grosso. Graduate Program in Health Sciences. Sinop, MT, Brazil.Museu Paraense Emílio Goeldi - Campus de Pesquisa. Programa de Capacitação Institucional. Coordenação Ciências da Terra e Ecologia. Belém, PA, Brazil.Agência de Defesa Agropecuária do Pará. Belém, PA, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Geoprocessamento. Ananindeua, PA, Brasil.Universidade Federal do Pará. Instituto de Medicina Veterinária. Laboratório de Epidemiologia e Geoprocessamento. Castanhal, PA, Brazil.Rabies is an important zoonosis to public health associated with lethal encephalitis and economic losses. Analysis of its spatial distribution is a meaningful tool in understanding its dispersion, which may contribute to the control and prophylaxis of the disease. This study analyzed the spatial-temporal distribution of rabies outbreaks in livestock in Pará state, Brazil, from 2004 to 2013. We used records of neurological syndromes obtained from the state’s livestock authority (Adepará). The analysis recorded 711 neurological syndromes reports in livestock, of which 32.8% were positive for rabies. In 8% of the neurological syndromes (n=57) was not possible to perform the analysis because of bad-packaging conditions of the samples sent. Outbreaks involved at least 1,179 animals and cattle were the most affected animal species (76.8%). The numbers of reported neurological syndromes and of rabies outbreak shad strong positive correlation and exhibited decreasing linear trend. Spatially, most outbreaks occurred in two mesoregions in Pará (Northeast and Southeast). One of the justifications for this spatial distribution may be related with the distribution of the animals in the state, since these mesoregions are the largest cattle producers in Pará and have most of their territory deforested for pasture implementation

SUPLEMENTAÇÃO COM Bacillus toyonensis MODULA A PRODUÇÃO DE ANTICORPOS EM CAMUNDONGOS SENSIBILIZADOS COM ANTÍGENOS DE Leishmania (Leishmania) infatum chagasi

The aim of this study was to evaluate the effect of supplementation with the probiotic Bacillus toyonensis on the production of IgG, IgG1 and IgG2a antibodies against Leishmania (Leishmania) infantum chagasi antigens. Twenty-four female albino BALB/c mice, 21 days old, were immunized experimentally against L. (L.) infantum chagasi, divided into three experimental groups. Group A received no supplementation, group B was continuously supplemented until day 56 and in group C the probiotic was administered seven days before and seven days after each immunization for the same period. The experiment was conducted until day 84. Seroconversion was used to evaluate the humoral immune response. During the supplementation, all the animals presented total IgG seroconversion against the antigen used, without statistical difference (p>0.05) between the groups. In the isotype analysis, the group supplemented with probiotic in the continuous period presented seroconversion results of the upper IgG2a / IgG1 ray when compared to the control group (1.8 times) and to that supplemented seven days before and seven days after supplementation (1.2 times) on day 70, keeping their titre superior to the groups in question until the end of the experiment (1.2 times on day 84). Based on these results, it can observed a greater ability of the supplemented group to continuously modulate favorably the humoral immune response and to maintain the production of IgG2a isotype antibodies against the antigen in question.Keywords: Canine leishmaniasis; probiotic; immune response.O estudo teve como objetivo avaliar o efeito da suplementação com o probiótico Bacillus toyonensis na cinética da produção de anticorpos IgG, IgG1 e IgG2a contra antígenos de Leishmania (Leishmania) infatum chagasi. Foram utilizados 24 camundongos BALB/c, fêmeas, tendo em média 21 dias de idade, sensibilizados experimentalmente contra L. (L.) infantum chagasi, divididos em três grupos experimentais. O grupo A não recebeu suplementação, o grupo B foi suplementado de forma contínua até o dia 56 e no grupo C o probiótico foi administrado sete dias antes e sete dias após cada sensibilização, pelo mesmo período. O experimento foi conduzido até o dia 84. Foi utilizada a soroconversão para avaliação da resposta imune humoral. Durante a suplementação todos os animais apresentaram soroconversão de IgG total contra o antígeno utilizado, sem ser identificada diferença estatística (p<0,05) entre os grupos. Na análise de isotipagem, o grupo suplementado com probiótico no período contínuo apresentou resultados de soroconversão da razão IgG2a/IgG1 superior quando comparado ao grupo controle (1,8 vezes) e ao suplementado sete dias antes e sete dias após a suplementação (1,2 vezes) no dia 70, mantendo o seu título superior aos grupos em questão até o final do experimento (1,2 vezes no dia 84). Com base nesses resultados, pode-se observar maior habilidade do grupo suplementado continuamente modular favoravelmente a resposta imune humoral e manter a produção de anticorpos do isotipo IgG2a contra o antígeno em questão.Palavras-chave: Leishmaniose canina, probiótico, resposta imunológica

Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017

Background The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 comparative risk assessment (CRA) is a comprehensive approach to risk factor quantification that offers a useful tool for synthesising evidence on risks and risk–outcome associations. With each annual GBD study, we update the GBD CRA to incorporate improved methods, new risks and risk–outcome pairs, and new data on risk exposure levels and risk–outcome associations. Methods We used the CRA framework developed for previous iterations of GBD to estimate levels and trends in exposure, attributable deaths, and attributable disability-adjusted life-years (DALYs), by age group, sex, year, and location for 84 behavioural, environmental and occupational, and metabolic risks or groups of risks from 1990 to 2017. This study included 476 risk–outcome pairs that met the GBD study criteria for convincing or probable evidence of causation. We extracted relative risk and exposure estimates from 46 749 randomised controlled trials, cohort studies, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. Using the counterfactual scenario of theoretical minimum risk exposure level (TMREL), we estimated the portion of deaths and DALYs that could be attributed to a given risk. We explored the relationship between development and risk exposure by modelling the relationship between the Socio-demographic Index (SDI) and risk-weighted exposure prevalence and estimated expected levels of exposure and risk-attributable burden by SDI. Finally, we explored temporal changes in risk-attributable DALYs by decomposing those changes into six main component drivers of change as follows: (1) population growth; (2) changes in population age structures; (3) changes in exposure to environmental and occupational risks; (4) changes in exposure to behavioural risks; (5) changes in exposure to metabolic risks; and (6) changes due to all other factors, approximated as the risk-deleted death and DALY rates, where the risk-deleted rate is the rate that would be observed had we reduced the exposure levels to the TMREL for all risk factors included in GBD 2017. Findings In 2017, 34·1 million (95% uncertainty interval [UI] 33·3–35·0) deaths and 1·21 billion (1·14–1·28) DALYs were attributable to GBD risk factors. Globally, 61·0% (59·6–62·4) of deaths and 48·3% (46·3–50·2) of DALYs were attributed to the GBD 2017 risk factors. When ranked by risk-attributable DALYs, high systolic blood pressure (SBP) was the leading risk factor, accounting for 10·4 million (9·39–11·5) deaths and 218 million (198–237) DALYs, followed by smoking (7·10 million [6·83–7·37] deaths and 182 million [173–193] DALYs), high fasting plasma glucose (6·53 million [5·23–8·23] deaths and 171 million [144–201] DALYs), high body-mass index (BMI; 4·72 million [2·99–6·70] deaths and 148 million [98·6–202] DALYs), and short gestation for birthweight (1·43 million [1·36–1·51] deaths and 139 million [131–147] DALYs). In total, risk-attributable DALYs declined by 4·9% (3·3–6·5) between 2007 and 2017. In the absence of demographic changes (ie, population growth and ageing), changes in risk exposure and risk-deleted DALYs would have led to a 23·5% decline in DALYs during that period. Conversely, in the absence of changes in risk exposure and risk-deleted DALYs, demographic changes would have led to an 18·6% increase in DALYs during that period. The ratios of observed risk exposure levels to exposure levels expected based on SDI (O/E ratios) increased globally for unsafe drinking water and household air pollution between 1990 and 2017. This result suggests that development is occurring more rapidly than are changes in the underlying risk structure in a population. Conversely, nearly universal declines in O/E ratios for smoking and alcohol use indicate that, for a given SDI, exposure to these risks is declining. In 2017, the leading Level 4 risk factor for age-standardised DALY rates was high SBP in four super-regions: central Europe, eastern Europe, and central Asia; north Africa and Middle East; south Asia; and southeast Asia, east Asia, and Oceania. The leading risk factor in the high-income super-region was smoking, in Latin America and Caribbean was high BMI, and in sub-Saharan Africa was unsafe sex. O/E ratios for unsafe sex in sub-Saharan Africa were notably high, and those for alcohol use in north Africa and the Middle East were notably low. Interpretation By quantifying levels and trends in exposures to risk factors and the resulting disease burden, this assessment offers insight into where past policy and programme efforts might have been successful and highlights current priorities for public health action. Decreases in behavioural, environmental, and occupational risks have largely offset the effects of population growth and ageing, in relation to trends in absolute burden. Conversely, the combination of increasing metabolic risks and population ageing will probably continue to drive the increasing trends in non-communicable diseases at the global level, which presents both a public health challenge and opportunity. We see considerable spatiotemporal heterogeneity in levels of risk exposure and risk-attributable burden. Although levels of development underlie some of this heterogeneity, O/E ratios show risks for which countries are overperforming or underperforming relative to their level of development. As such, these ratios provide a benchmarking tool to help to focus local decision making. Our findings reinforce the importance of both risk exposure monitoring and epidemiological research to assess causal connections between risks and health outcomes, and they highlight the usefulness of the GBD study in synthesising data to draw comprehensive and robust conclusions that help to inform good policy and strategic health planning

Epidemiological scenarios for human rabies exposure notified in Colombia during ten years: A challenge to implement surveillance actions with a differential approach on vulnerable populations.

Based on notified cases of human rabies exposure and human deaths by rabies to Colombia public health surveillance system between 2007 and 2016, we conducted a spatiotemporal analysis to identify epidemiological scenarios of high human rabies exposure due to dogs, cats, bats, or farm animals (n = 666,411 cases). The incidence rate of human rabies exposures was analyzed by using geographical information system (spatiotemporal distribution and Cluster and Outlier Analysis (Anselin Local Moran's I)) data for all Colombian cities. The incidence rate of human rabies exposures due to dogs and cats showed an increasing trend, while aggression due bats and farm animals fluctuated throughout the analyzed period. Human deaths by rabies transmitted by cat and bat occurred in the Andean and Orinoquia regions, which had urban and rural scenarios. The urban scenario showed the highest exposure to human rabies due to cats and dogs in cities characterized with high human population density and greater economic development. In contrary, the highest human rabies exposure in the rural scenario was observed due to contact of mucosa or injured skin with the infected saliva of farm animals with the rabies virus, principally among workers in the agroforestry area. The inequality scenario showed some outlier cities with high human rabies exposure due to farm animals principally in the Pacific region (characterized by the highest poverty rates in Colombia), being Afro-descendant and indigenous population the most exposed. The highest exposure due to bats bite was observed among indigenous people residing in cities of the Amazon region as a dispersed population (Amazonian scenario). None of the high exposure scenarios were related to human deaths by rabies due to dogs aggression. The identified scenarios can help develop better surveillance systems with a differential approach to the vulnerable population and strengthening them in areas with rabies viral circulation

Artificial feeding of partially engorged Amblyomma sculptum females through capillaries*

ABSTRACT. Abel I., Cunha N.C., Rangel C.P., Corrêa F.N. & Fonseca A.H. Artificial feeding of partially engorged Amblyomma sculptum females through capillaries. [Alimentação artificial de fêmeas parcialmente ingurgitadas de Amblyomma sculptum, por meio de tubos capilares]. Revista Brasileira de Medicina Veterinária, 38(supl. 3): 211-217, 2016. Departamento de Epidemiologia e Saúde Pública, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, BR 465, km 7, Campus Seropédica 23897-970, Seropédica, RJ, Brazil. E-mail: [email protected] This study presents the standardization of an artificial feeding technique using capillaries and discusses its effects on biological parameters of partially engorged Amblyomma sculptum females. Partially engorged females were sorted for mean baseline weight (71.94 mg, group I; 167.58 mg, group II). Females were detached from rabbits after 7 days of feeding and then exposed to capillary tubes containing citrated bovine blood for 6, 12, and 24 h. Biological parameters were analyzed for each weight group, after each period. All ticks fed on this system took blood meal. Weights before and after artificial feeding were compared, and significant difference was observed. Mean weight gain for group I females artificially fed for 6, 12, and 24 h was 56.05, 86.75 and 192.89 mg, respectively. Weight gain in group II females fed for 6, 12 and 24 h was 133.73, 182.09 and 368.77 mg. Results indicate that capillary feeding may be used routinely in studies on pathogen transmission by A. sculptum females. The ideal initial weight range is discussed in terms of the kind of study design

Artificial feeding of Amblyomma cajennense (Acari: Ixodidae) fasting females through capillary tube technique

The present study aimed to adjust the artificial feeding technique through capillaries and to verify its influence over the biology of Amblyomma cajennense females. Five groups of 20 female ticks were formed. Females were starved for 45 days and then fed with citrated bovine blood using capillary tubes in different periods of time. Females were divided in five experimental groups with 20 individuals each and fed as follows: groups uninterruptedly fed for 12, 24, and 48 hours and groups fed 2 and 6 h a day, for a period of 8 days. Subsequently, ticks were exposed to rabbits for complementary feeding and their biological parameters were analyzed. TIcks were capable of feeding, showing rounded idiosoma, visible even to naked eyes, following the feeding period. The groups fed for 24 hours, 2 hours/day for eight consecutive days or 6h/day for eight consecutive days presented greater weight gain, without statistically significant differences. These results suggested that 24 hours of artificial feeding were enough for fasting females to increase weight by 2.43 mg. Artificial feeding through capillaries did not interfere with parasitic and non-parasitic phases of A. cajennense females