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Vector-borne diseases annually cause more than 700,000 deaths worldwide. In Colombia, infectious diseases are prevalent, being the Municipality of Santander de Quilichao (Cauca district) one of the most affected areas. This study aimed (a) to determine the abundance of species of mosquitoes with the potential capacity to transmit infectious diseases, in a school located in the Cauca district and (b) to teach students self-care and care for the environment to protect themselves from vector-borne diseases. During 2019 and 2020, in a dry and rainy season, manual collection of mosquitoes in four sites of the institution was conducted. Ecological statistical analyses were carried out. Mosquito species were grouped by similarity (abundance) using a dendrogram by area and a species rarefaction curve. A sociodemographic survey on knowledge, attitudes, and practices related to vector-borne diseases was carried out. An educational booklet was developed, and its impact was validated through the nonparametric Wilcoxon test. In total, 108 specimens were captured from four species: Aedes aegypti, Aedes albopictus, Culex quinquefasciatus, and Psorophora ferox. The greater presence of mosquitos was during the rainy season, being Aedes aegypti the most abundant species. According to Likert’s analysis, 59.6% of the students had a very favorable attitude toward the subject; the educational campaign significantly improved knowledge, attitudes, and practices of the students. Finally, the study presents entomological data of interest in public health. That makes it possible to establish prevention and control measures for vector-borne diseases in high schools, through environmental education.

Background Plasmodium vivax is predominant in the Amazon region, and enhanced knowledge of its development inside a natural vector, Anopheles aquasalis, is critical for future strategies aimed at blocking parasite development. The peritrophic matrix (PM), a chitinous layer produced by the mosquito midgut in response to blood ingestion, is a protective barrier against pathogens. Plasmodium can only complete its life-cycle, and consequently be transmitted to a new host, after successfully passing this barrier. Interestingly, fully engorged mosquitoes that had a complete blood meal form a thicker, well-developed PM than ones that feed in small amounts. The amount of red blood cells (RBC) in the blood meal directly influences the production of digestive enzymes and can protect parasites from being killed during the meal digestion. A specific study interrupting the development of the PM associated with the proteolytic activity inhibition, and distinct RBC concentrations, during the P. vivax infection of the New World malaria vector An. aquasalis is expected to clarify whether these factors affect the parasite development. Results Absence of PM in the vector caused a significant reduction in P. vivax infection. However, the association of chitinase with trypsin inhibitor restored infection rates to those of mosquitoes with a structured PM. Also, only the ingestion of trypsin inhibitor by non-chitinase treated mosquitoes increased the infection intensity. Moreover, the RBC concentration in the infected P. vivax blood meal directly influenced the infection rate and its intensity. A straight correlation was observed between RBC concentrations and infection intensity. Conclusions This study established that there is a balance between the PM role, RBC concentration and digestive enzyme activity influencing the establishment and development of P. vivax infection inside An. aquasalis. Our results indicate that the absence of PM in the midgut facilitates digestive enzyme dispersion throughout the blood meal, causing direct damage to P. vivax. On the other hand, high RBC concentrations support a better and thick, well-developed PM and protect P. vivax from being killed. Further studies of this complex system may provide insights into other details of the malaria vector response to P. vivax infection.

CAPES, FAPEAM, CNPq Universidade Federal do Rio de Janeiro. Hospital Universitário Clementino Fraga Filho. Serviço de Patologia Clínica. Laboratório de Infectologia e Parasitologia Molecular. Rio de Janeiro, RJ, Brasil Fundação Oswaldo Cruz. Centro de Pesquisa René Rachou. Laboratório de Malária. Belo Horizonte, MG, Brasil Fundação de Medicina Tropical Dr Heitor Vieira Dourado. Manaus, AM, Brasil Fundação de Medicina Tropical Dr Heitor Vieira Dourado. Manaus, AM, Brasil Fundação Oswaldo Cruz. Centro de Pesquisa René Rachou. Laboratório de Malária. Belo Horizonte, MG, Brasil Universidade Federal do Rio de Janeiro. Hospital Universitário Clementino Fraga Filho. Serviço de Patologia Clínica. Laboratório de Infectologia e Parasitologia Molecular. Rio de Janeiro, RJ, Brasil The molecular basis of Plasmodium vivax chloroquine (CQ) resistance is still unknown. Elucidating the mo¬lecular background of parasites that are sensitive or resistant to CQ will help to identify and monitor the spread of resistance. By genotyping a panel of molecular markers, we demonstrate a similar genetic variability between in vitro CQ-resistant and sensitive phenotypes of P. vivax parasites. However, our studies identified two loci (MS8 and MSP1-B10) that could be used to discriminate between both CQ-susceptible phenotypes among P. vivax iso¬lates in vitro. These preliminary data suggest that microsatellites may be used to identify and to monitor the spread of P. vivax-resistance around the world.