Impact of a research-action on vaccination indicators in the state of Minas Gerais, Brazil.

OBJECTIVE: Analyze the impact of the state research-action project on immunization indicators (vaccination coverage - VC, homogeneity of vaccination coverage - HVC, dropout rate - DR, and risk rating) before and after the intervention in municipalities and priority Regional Health Administrations/Regional Health Superintendencies (RHA/RHS). METHODS: The state research-action project was a before-after community clinical trial conducted in 212 municipalities belonging to eight RHA/RHS in the state of Minas Gerais, Brazil. The study sample comprised RHA/RHS with a decreasing trend for routine vaccination coverage in children under one year from 2015 to 2020. This study used secondary VC and DR data from 10 immunobiologicals recommended for children younger than two years from January to December 2021 (pre-intervention period, prior to the state research-action project) and from January to December 2022 (post-intervention period). The categorical variables were presented in proportions, and initially, a comparison was made between those of DR, HVC, and the risk rating for the transmission of vaccine-preventable diseases, according to the two periods (2021 and 2022), using the McNemar test. RESULTS: All immunization indicators increased after conducting the research-action project. In 2021, 80.66% of the state's municipalities had a risk rating for the transmission of vaccine-preventable diseases as "high and very high." In 2022, the value reduced to 68.40%. CONCLUSIONS: Risk rating for the transmission of vaccine-preventable diseases is an important mechanism to assist managers in defining priorities. The state research-action project used a method that enabled the construction and execution of unique action plans for each municipality, directing the improvement of immunization indicators in the state.

Impact of a research-action on vaccination indicators in the state of Minas Gerais, Brazil / Impacto de uma pesquisa-ação nos indicadores vacinais em Minas Gerais

ABSTRACT OBJECTIVE Analyze the impact of the state research-action project on immunization indicators (vaccination coverage - VC, homogeneity of vaccination coverage - HVC, dropout rate - DR, and risk rating) before and after the intervention in municipalities and priority Regional Health Administrations/Regional Health Superintendencies (RHA/RHS). METHODS The state research-action project was a before-after community clinical trial conducted in 212 municipalities belonging to eight RHA/RHS in the state of Minas Gerais, Brazil. The study sample comprised RHA/RHS with a decreasing trend for routine vaccination coverage in children under one year from 2015 to 2020. This study used secondary VC and DR data from 10 immunobiologicals recommended for children younger than two years from January to December 2021 (pre-intervention period, prior to the state research-action project) and from January to December 2022 (post-intervention period). The categorical variables were presented in proportions, and initially, a comparison was made between those of DR, HVC, and the risk rating for the transmission of vaccine-preventable diseases, according to the two periods (2021 and 2022), using the McNemar test. RESULTS All immunization indicators increased after conducting the research-action project. In 2021, 80.66% of the state's municipalities had a risk rating for the transmission of vaccine-preventable diseases as "high and very high." In 2022, the value reduced to 68.40%. CONCLUSIONS Risk rating for the transmission of vaccine-preventable diseases is an important mechanism to assist managers in defining priorities. The state research-action project used a method that enabled the construction and execution of unique action plans for each municipality, directing the improvement of immunization indicators in the state.

RESUMO OBJETIVO Analisar o impacto do projeto estadual de pesquisa-ação nos indicadores de imunização (coberturas vacinais - CV, homogeneidade de cobertura vacinal - HCV, taxa de abandono - TA e classificação de risco) antes e após a intervenção em municípios e Gerências Regionais de Saúde/Superintendências Regionais de Saúde (GRS/SRS) prioritários. MÉTODOS O projeto estadual de pesquisa-ação foi um ensaio clínico comunitário, do tipo antes-depois, realizado em 212 municípios pertencentes a oito GRS/SRS do estado de Minas Gerais, Brasil. Compuseram a amostra do estudo as SRS/GRS com tendência decrescente para a cobertura vacinal de rotina em crianças menores de 1 ano, no período de 2015 a 2020. Neste estudo, foram utilizados dados secundários de CV e TA de 10 imunobiológicos recomendados para crianças menores de 2 anos, no período de janeiro a dezembro de 2021 (período pré-intervenção, anterior ao projeto estadual de pesquisa-ação) e de janeiro a dezembro de 2022 (período pós-intervenção). As variáveis categóricas foram apresentadas em proporções e, inicialmente, realizou-se a comparação entre as de TA, HCV e a classificação de risco para a transmissão de doenças imunopreveníveis, segundo os dois períodos (2021 e 2022), utilizando-se o teste McNemar. RESULTADOS Observou-se um aumento de todos os indicadores de imunização após a realização do projeto de pesquisa-ação. No ano de 2021, 80,66% dos municípios do estado tiveram a classificação de risco para transmissão de doenças imunopreveníveis como "alto e muito alto risco". Em 2022, o valor foi reduzido para 68,40%. CONCLUSÕES A classificação de risco para transmissão de doenças imunopreveníveis é um mecanismo importante para auxiliar os gestores na definição de prioridades. O projeto estadual de pesquisa-ação empregou um método que possibilitou a construção e a execução de planos de ação singulares a cada município, direcionando a melhoria dos indicadores de imunização no estado.

Estratégias cooperativas para melhorar a cobertura vacinal em crianças no estado de Minas Gerais, Brasil / Cooperative strategies to improve vaccination coverage in children in the state of Minas Gerais, Brazil / Estrategias cooperativas para mejorar la cobertura de vacunación infantil en el estado de Minas Gerais (Brasil)

Objetivo: relatar a experiência das oficinas de uma pesquisa-ação do tipo intervenção elaborada para aumento da cobertura vacinal de crianças em municípios do estado de Minas Gerais. Método: relato de experiência sobre a metodologia empregada nas oficinas organizadas com objetivo de aumentar a cobertura vacinal no estado de Minas Gerais, Brasil. As oficinas foram compostas em quatro etapas: momento motivacional, núcleo contextual, núcleo integrador/planejamento e núcleo integrador/resultados. Resultados: As oficinas mostraram-se potentes na sensibilização e na indução da discussão dos indicadores de cobertura vacinal, evidenciando, inconsistências entre o Sistema de Informação do Programa Nacional de Imunizações e os registros internos dos municípios. Para além dos indicadores, as oficinas, permitiram troca de experiências entre os representantes municipais, discussão de recursos financeiros, estruturação de salas de vacina, aquisição de veículos, contratação de profissionais, entre outros. Considerações Finais: As oficinas mostram-se capaz de evidenciar a realidade dos municípios, para além do reconhecimento das necessidades para melhoria dos processos de imunização, mas também no desenvolvimento de estratégias, capazes de promover aumento das coberturas vacinais.

Objective: to report the experience of workshops of an action research designed to increase vaccination coverage of children in municipalities of the state of Minas Gerais. Method: experience report on the methodology used in the workshops organized to increase vaccination coverage in the state of Minas Gerais, Brazil. The workshops were composed in four stages: motivational moment, contextual core, integrative core/planning and integrative core/results. Results: The workshops proved powerful in raising awareness and inducing discussion of vaccination coverage indicators, evidencing, inconsistencies between the National Immunization Program Information System and the internal records of the municipalities. In addition to the indicators, the workshops allowed the exchange of experiences among municipal representatives, discussion of financial resources, structuring of vaccine rooms, acquisition of vehicles, hiring of professionals, among others. Final Considerations: The workshops are able to highlight the reality of the municipalities, in addition to recognizing the needs for improvement of immunization processes, but also in developing strategies to promote increased vaccination coverage.

Objetivo: relatar la experiencia de los talleres de una investigación-acción diseñada para aumentar la cobertura de vacunación infantil en municipios del estado de Minas Gerais. Método: informe de experiencia sobre la metodología utilizada en los talleres organizados para aumentar la cobertura de vacunación en el estado de Minas Gerais, Brasil. Los talleres constaron de cuatro etapas: momento motivacional, núcleo contextual, núcleo integrador/planificación y núcleo integrador/resultados. Resultados: Los talleres demostraron ser potentes para sensibilizar e inducir la discusión de los indicadores de cobertura de vacunación, evidenciando, inconsistencias entre el Sistema de Información del Programa Nacional de Inmunizaciones y los registros internos de los municipios. Además de los indicadores, los talleres permitieron el intercambio de experiencias entre representantes municipales, discusión de recursos financieros, estructuración de salas de vacunas, adquisición de vehículos, contratación de profesionales, entre otros. Consideraciones Finales: Los talleres se mostraron capaces de evidenciar la realidad de los municipios, más allá del reconocimiento de las necesidades de mejora de los procesos de inmunización, pero también en el desarrollo de estrategias, capaces de promover el aumento de la cobertura de vacunación.

Triatomines (Hemiptera, Reduviidae) blood intake: Physical constraints and biological adaptations.

In order to efficiently obtain blood from their vertebrate hosts, bloodsucking arthropods have undergone an evolutionary selection process leading to specialist adaptations in their feeding apparatus (mouthparts and suction pumps) and salivary molecules. These adaptations act to counteract haemostasis, inflammation, and immune responses in their vertebrate hosts. The association of haematophagous arthropods with vertebrate hosts during a blood feed allows the transmission of pathogens between their hosts and vectors in a tripartite interaction. Feeding mechanisms in haematophagous arthropod species have been the subject of studies over at least eight decades worldwide, as a consequence of the importance of vector-borne diseases and their impact on human health. Here we review studies of the feeding mechanisms of triatomine bugs, with a particular focus on factors that influence their feeding performance when obtaining a blood meal from different vertebrate hosts.

Physiological characterization of the hematophagy of Ornithodoros rostratus (Acari: Argasidae) on live hosts.

Ornithodoros rostratus is an argasid tick and its importance is based on its hematophagy and the resulting transmission of pathogens such as Rickettsia rickettsii and Coxiella burnetii to its vertebrate hosts. In the face of a lack of physiological studies related to hematophagy in argasid ticks, this paper aims to identify and characterize the events that occur throughout the feeding by O. rostratus on live hosts. Electrical signals and alterations on the feeding site were monitored using intravital microscopy and electromyography. The analyses allowed for the characterization of four distinct events: suction, salivation, chelicerae movements and inactivity. Feeding was divided into two distinct phases: (1) penetration of mouthparts (when only salivation and chelicerae movements occurred) and the formation of the feeding pool (salivation and chelicerae movements with the first signs of suction) and (2) engorgement, during which chelicerae movements ceased and blood intake took place in feeding complexes (salivation followed by suction). Variations in patterns of the electrical signals, suction frequency and salivation showed four distinct sub-phases: (2a) suction with electrical signals of irregular shape, increased suction frequency and decreased salivation frequency throughout blood feeding; (2b) suction with electrical signals of symmetrical shape, high suction rates (3.8 Hz on average) and feeding complexes lasting for 7.7 s; (2c) suction with electrical signals of irregular shape, high suction frequency and feeding complex lasting 11.5 s; and (2d) electrical signals with no profile and the longest feeding complexes (14.5 s). Blood feeding ended with the withdrawal of the mouthparts from the host's skin.

Life cycle of Ornithodoros rostratus (Acari: Argasidae) ticks feeding on mice under laboratory conditions.

Ornithodoros rostratus Aragão is an argasid tick found in Bolivia, Paraguay, Argentina and Brazil. Only limited studies about O. rostratus have been conducted and several aspects of their life cycle differ among studies or remain unexplored. In order to better elucidate the biology of O. rostratus, the present work describes its life cycle when feeding on mice under laboratory conditions. To complete their life cycle on mice, O. rostratus goes through a larval stage, 3-6 nymphal instars (nymph 1-6) and adult male and female. Adults can be originated from nymph 3-6. Nymphs 4 with higher weight after feeding tend to originate adults. Adults originated from early instars tended to be lighter. Females tended to be heavier than males. Larvae needed on average 2.7 days to complete their blood meal whereas other instars ranged from 17.3 to 78.3 min. The capacity to ingest blood was higher in larvae and females in comparison to males. The preecdysis period ranged from 5 to 12.5 days. After one blood meal, females remain on average 15.2 ± 5.8 days laying 276.8 ± 137.2.9 eggs. Females originated from nymph 4 had similar oviposition time, egg incubation and conversion ingested blood/number of eggs produced, but presented lower initial weigh and weigh gain, generating fewer eggs. Our results added novel information on O. rostratus biology and was discussed considering the variability of argasid populations and in context with the differences about their life cycle described in previous works.

Intravital microscopy and image analysis of Rhodnius prolixus (Hemiptera: Reduviidae) hematophagy: the challenge of blood intake from mouse skin.

Hematophagous insects transmit many of the most dangerous parasitic diseases. The transmission usually occurs during hematophagy or just after as this is when the vector and the host are in contact. The contact time is determined by the feeding performance of the insect in each host. In triatomines, feeding performance interferes with both their life cycle and the vectorial competence to transmit the hemoflagellate Trypanosoma cruzi. Triatomine bugs are vessel feeders, obtaining their blood meals directly from the vessels (venules or arterioles) of their vertebrate hosts. The host blood intake rate is not constant during the feeding, and the sucking frequency of triatomines tends to be higher and to contain fewer interruptions in pigeons than in mice. To identify the difficulties encountered by triatomine bugs in obtaining blood meals from mouse skin, we used intravital microscopy techniques associated with electromyograms of the cibarial pump. To monitor the vibration of the cannulated vessels and the blood flow through the head of the insect during the engorgement phase, we introduced a novel method for image analysis. The mean number of vessels used during a Rhodnius prolixus blood meal was 3.4±1.2, and the insects fed more in venules (63%) than in arterioles (37%). An important increase in vascular permeability was observed throughout the feeding. Platelet aggregation, rolling and leukocyte adherence were analyzed on the venular endothelium, showing remarkable increases for some time following the R. prolixus feeding. The reduction in sucking frequency that was observed during insect feeding was likely due to the increased cibarial pump filling time. The monitoring of the vessel wall pulsation also permitted the registration of regurgitation-like movements during blood pumping, with these movements being recorded mostly during the second half of the feeding. The evaluation of blood flow through the head of the insect suggested that the regurgitation-like movements were not true regurgitations and were caused by abrupt difficulties in the function of the cibarial pump. The role of the platelet plugs and the changes in blood viscosity at the R. prolixus feeding site are discussed. The method introduced in the present study to analyze the images brings new insights into the interaction between hematophagous vectors and their hosts, reinforcing the importance of insect saliva throughout the feeding process.

Salivation pattern of Rhodnius prolixus (Reduviidae; Triatominae) in mouse skin.

The objective of this work was to study the pattern of salivation of triatomines during feeding in mouse skin. Rhodnius prolixus was fed with a solution of the dye acridine orange or fluorescein. The saliva was efficiently labelled with acridine orange, probably due to the difference in pH between the salivary gland (6.0) and the hemolymph (6.5-7.0). This procedure was not effective at labelling the saliva of Triatoma infestans, however, fluorescent labelling of R. prolixus saliva allowed us to demonstrate that salivation occurs during entire feeding process. The saliva is released soon after the bite. In the probing phase, saliva is pumped continuously in the host skin, including around the blood vessels. During the engorgement phase, saliva is observed in a bolus within the blood vessel and some of it is sucked up by the insect, together with blood. The frequency of saliva emission inside the vessels was low (0.51+/-0.18 Hz). The saliva deposition in the microcirculation is continuous and modulated by the frequency of the cibarial pump because, when functioning at high frequency, cibarial pump sucks almost all saliva to the insect gut. This mechanism would determine the quantity of saliva deposited in the microcirculation as necessary, and consequently minimizing the host's immune response to salivary antigens.