Association between telomere length and anorexia of ageing: a cross-sectional study conducted with community-dwelling older people.

BACKGROUND: To verify whether shorter telomere length is associated with anorexia of ageing in community-dwelling older people. METHODS: Conducted as a cross-sectional investigation, the study enrolled 448 participants residing in an urban area of a municipality in Brazil. Relative telomere length in blood samples was measured using quantitative polymerase chain reaction (qPCR), whereas the presence of anorexia of ageing was determined using the Simplified Appetite Nutritional Questionnaire. Data analysis employed multiple logistic regression. RESULTS: Among the 448 older individuals surveyed, 70.69% were female, and the predominant age bracket ranged from 60 to 69 years (45.08%). Approximately 25% exhibited the shortest telomeric length, with a corresponding anorexia of ageing prevalence of 41.16%. Older individuals with diminished telomere lengths displayed an increased likelihood of experiencing anorexia of ageing (odds ratio [OR] = 1.92; 95% confidence interval [CI] = 1.12-3.29), independent of factors such as gender, age group, depressive symptoms, pain and performance in basic daily life activities. CONCLUSIONS: The observed association between anorexia of ageing and a telomeric biomarker underscores the imperative to meticulously evaluate the nutritional dimensions of older people, with a view to implementing interventions that may enhance their overall health status.

Monastrol suppresses invasion and metastasis in human colorectal cancer cells by targeting fascin independent of kinesin-Eg5 pathway.

Rearrangement of the actin cytoskeleton is a prerequisite for carcinoma cells to develop cellular protrusions, which are required for migration, invasion, and metastasis. Fascin is a key protein involved in actin bundling and is expressed in aggressive and invasive carcinomas. Additionally, fascin appears to be involved in tubulin-binding and microtubule rearrangement. Pharmacophoric-based in silico screening was performed to identify compounds with better fascin inhibitory properties than migrastatin, a gold-standard fascin inhibitor. We hypothesized that monastrol displays anti-migratory and anti-invasive properties via fascin blocking in colorectal cancer cell lines. Biophysical (thermofluor and ligand titration followed by fluorescence spectroscopy), biochemical (NMR), and cellular assays (MTT, invasion of human tissue), as well as animal model studies (zebrafish invasion) were performed to characterize the inhibitory effect of monastrol on fascin activity. In silico analysis revealed that monastrol is a potential fascin-binding compound. Biophysical and biochemical assays demonstrated that monastrol binds to fascin and interferes with its actin-bundling activity. Cell culture studies, including a 3D human myoma disc model, showed that monastrol inhibited fascin-driven cytoplasmic protrusions as well as invasion. In silico, confocal microscopy, and immunoprecipitation assays demonstrated that monastrol disrupted fascin-tubulin interactions. These anti-invasive effects were confirmed in vivo. In silico confocal microscopy and immunoprecipitation assays were carried out to test whether monastrol disrupted the fascin-tubulin interaction. This study reports, for the first time, the in vitro and in vivo anti-invasive properties of monastrol in colorectal tumor cells. The number and types of interactions suggest potential binding of monastrol across actin and tubulin sites on fascin, which could be valuable for the development of antitumor therapies.

Changing Clinical Epidemiology of Plasmodium vivax Malaria as Transmission Decreases: Population-Based Prospective Panel Survey in the Brazilian Amazon.

BACKGROUND: Malarial infections are often missed by microscopy, and most parasite carriers are asymptomatic in low-endemicity settings. Whether parasite detectability and its ability to elicit symptoms change as transmission declines remains unclear. METHODS: We performed a prospective panel survey with repeated measurements on the same participants over 12 months to investigate whether Plasmodium vivax detectability by microscopy and risk of symptoms upon infection varied during a community-wide larviciding intervention in the Amazon basin of Brazil that markedly reduced vector density. We screened 1096 to 1400 residents in the intervention site for malaria by microscopy and quantitative TaqMan assays at baseline and twice during intervention. RESULTS: We found that more P vivax infections than expected from their parasite densities measured by TaqMan assays were missed by microscopy as transmission decreased. At lower transmission, study participants appeared to tolerate higher P vivax loads without developing symptoms. We hypothesize that changes in the ratio between circulating parasites and those that accumulate in the bone marrow and spleen, by avoiding peripheral blood microscopy detection, account for decreased parasite detectability and lower risk of symptoms under low transmission. CONCLUSIONS: P vivax infections are more likely to be subpatent and remain asymptomatic as malaria transmission decreases.

Ankyloglossia and Breastfeeding Duration: A Multicenter Birth Cohort Study.

Background and Objective: The prevalence of ankyloglossia and its impact on breastfeeding practices may be overestimated, leading to surgical overtreatment in newborns. The study was conducted to estimate the prevalence of ankyloglossia in the first year of life and investigate the association with exclusive and total breastfeeding duration in different regions of Brazil. Materials and Methods: This multicenter prospective cohort study involved the recruitment of mother-infant pairs soon after childbirth in public hospitals in three state capitals in Brazil. Interviews were held with the mothers after birth, at 6 and 12 months to collect sociodemographic variables and data on exclusive and total breastfeeding duration. At 12 months of age, the children were submitted to a dental examination for classification of the lingual frenulum using the Bristol Tongue Assessment Tool. Data analysis involved Poisson regression with robust variance, with the calculation of unadjusted and adjusted relative risk (RR). Results: The final sample was composed of 293 children. The prevalence of defined and suspected ankyloglossia was 1% and 4.8%, respectively, totaling 5.8% (confidence interval [95% CI]: 3.1-8.5). No significant difference was found in the prevalence of exclusive and total breastfeeding at 1, 4, and 6 months between children with defined/suspected ankyloglossia and those without ankyloglossia. The multivariable analysis showed that the probability of the child achieving 6 months of breastfeeding did not differ between groups (RR = 0.98; 95% CI: 0.79-1.23; p = 0.907). Conclusion: The prevalence of defined ankyloglossia was very low and defined/suspected ankyloglossia was not associated with exclusive or total breastfeeding duration. Clinical Trial Registration: Registered with clinicaltrials.gov (n° NCT03841123).

Detection of herpes simplex virus in oral tongue squamous cell carcinoma.

Introduction: Oral tongue squamous cell carcinoma (OTSCC) is the most common cancer of the oral cavity. Contradictory results have been observed on the involvement of herpes simplex virus 1 (HSV-1) in oral squamous cell carcinomas. Here, we aimed to study the predominance of HSV-1 or HSV-2 in oral HSV infections and to investigate the presence of HSV-1 in OTSCC and its effect on carcinoma cell viability and invasion. Methods: The distribution of HSV types one and two in diagnostic samples taken from suspected oral HSV infections was determined from the Helsinki University Hospital Laboratory database. We then analysed 67 OTSCC samples for HSV-1 infection using immunohistochemical staining. We further tested the effects of HSV-1 using six concentrations (0.00001-1.0 multiplicity of infection [MOI]) on viability and two concentrations (0.001 and 0.1 MOI) on invasion of highly invasive metastatic HSC-3 and less invasive primary SCC-25 OTSCC cell lines using MTT and Myogel-coated Transwell invasion assays. Results: Altogether 321 oropharyngeal samples were diagnosed positive for HSV during the study period. HSV-1 was the predominant (97.8%) HSV type compared with HSV-2 (detected in 2.2% of samples). HSV-1 was also detected in 24% of the OTSCC samples and had no association with patient survival or recurrence. OTSCC cells were viable even after 6 days with low viral load (0.00001, 0.0001, 0.001 MOI) of HSV-1. In both cell lines, 0.001 MOI did not affect cell invasion. However, 0.1 MOI significantly reduced cell invasion in HSC-3 cells. Discussion: HSV-1 infection is predominant compared with HSV-2 in the oral cavity. HSV-1 is detected in OTSCC samples without clinical significance, and OTSCC cell survival or invasion was not affected at low doses of HSV-1.

Primary Dentition Caries Patterns as Predictors of Permanent Dentition Caries: A Prospective Cohort Study.

The aims of this study were to estimate the risk of caries in the permanent teeth at 12 years of age and to describe the diagnostic accuracy of caries patterns in the primary dentition at age 4 years to predict caries at age 12 years. A prospective cohort study followed children from birth to age 12 years in the city of São Leopoldo, Brazil. Sociodemographic variables were collected at birth, and dental caries was measured at 4 and 12 years of age (n = 204). At 4 years, children were classified according to the presence of caries (cavitated and non-cavitated lesions), number of lesions, affected segment (anterior or posterior), and affected surface (occlusal, smooth, or proximal). Prediction of permanent dentition caries occurrence (DMFT ≥1) (primary outcome) involved Poisson regression with robust variance and standard diagnostic accuracy measures. The prevalences of caries at age 4 years (including non-cavitated lesions) and 12 years were 61.8% and 42.2%, respectively. All caries patterns in the primary dentition were associated with caries in the permanent dentition. In multivariable analysis, the strongest associations were carious lesions on the primary posterior teeth (RR 2.2; 95% CI 1.5-3.2) and occlusal surfaces (RR 2.1; 95% CI 1.4-3.0). Among patterns evaluated, the presence of any tooth with caries (cavitated or non-cavitated) had the highest sensitivity (73%), but any tooth with cavitated decay had the highest accuracy (67%). In conclusion, any dental caries experience in early childhood is strongly predictive of dental caries experience in early adolescence. Primary dentition carious lesions on the posterior teeth or occlusal surfaces and the presence of cavitated lesions were stronger predictors.

Adaptation and clinical application of assistive device chair for bedside sitting in acute stroke phase: two case reports.

PURPOSE: This report presents the adaptation of an assistive device chair for bedside sitting and its application in two patients with trunk control impairment in the acute stroke phase. MATERIALS AND METHODS: The device was built with polyvinylchloride (PVC) pipes and designed by a team of mechanical engineers and physiotherapists to maintain a prolonged sitting position with less demand from therapists. To test the device, two patients were followed up during the acute phase of stroke. Both patients underwent an early mobilization program (30 min, twice a day, for three days) with an assistive device chair for bedside sitting. Patients were evaluated using the National Institutes of Health Stroke Scale (NIHSS), Trunk Impairment Scale (TIS), and International Classification of Functioning, Disability, and Health (ICF) checklist (b: body function; d: activity and participation). RESULTS: The adaptations generated the following equipment: 1) foldable, 2) three levels of backrest inclination, and 3) a safety anterior support or an activity table. Both patients showed clinical improvement after the intervention period, with NIHSS score reduction, TIS improvement, and greater functionality and independence on the ICF framework. CONCLUSION: The equipment with adaptations seems to be functional, easy to handle, and can potentially contribute to clinical and functional improvements in patients with trunk control deficits after stroke.

The assistive device chair has a low manufacturing cost, and allow an easy handling and storageThe assistive device chair has been adapted to facilitate sitting posture;The assistive device chair can be used as an auxiliary tool in early mobilizations protocols and contemporary rehabilitation approaches;The early mobilization protocol associated with the assistive device chair can generate clinical improvements in acute stroke.The mobilization protocol associated with the assistive device chair can promote improvement in International Classification of Functioning, Disability, and Health domains in acute stroke.

Clinically silent Plasmodium vivax infections in native Amazonians of northwestern Brazil: acquired immunity or low parasite virulence?

BACKGROUND: Malaria remains common among native Amazonians, challenging Brazil's elimination efforts. OBJECTIVES: We examined the epidemiology of malaria in riverine populations of the country's main hotspot - the upper Juruá Valley in Acre state, close to the Brazil-Peru border, where Plasmodium vivax accounts for > 80% of cases. METHODS: Participants (n = 262) from 10 villages along the Azul River were screened for malaria parasites by microscopy and genus-specific, cytochrome b (cytb) gene-based polymerase chain reaction. Positive samples were further tested with quantitative TaqMan assays targeting P. vivax- and P. falciparum-specific cytb domains. We used multiple logistic regression analysis to identify independent correlates of P. vivax infection. FINDINGS: Microscopy detected only one P. vivax and two P. falciparum infections. TaqMan assays detected 33 P. vivax infections (prevalence, 11.1%), 78.1% of which asymptomatic, with a median parasitaemia of 34/mL. Increasing age, male sex and use of insecticide-treated bed nets were significant predictors of elevated P. vivax malaria risk. Children and adults were similarly likely to remain asymptomatic once infected. MAIN CONCLUSIONS: Our findings are at odds with the hypothesis of age-related clinical immunity in native Amazonians. The low virulence of local parasites is suggested as an alternative explanation for subclinical infections in isolated populations.

Malaria Resilience in South America: Epidemiology, Vector Biology, and Immunology Insights from the Amazonian International Center of Excellence in Malaria Research Network in Peru and Brazil.

The 1990s saw the rapid reemergence of malaria in Amazonia, where it remains an important public health priority in South America. The Amazonian International Center of Excellence in Malaria Research (ICEMR) was designed to take a multidisciplinary approach toward identifying novel malaria control and elimination strategies. Based on geographically and epidemiologically distinct sites in the Northeastern Peruvian and Western Brazilian Amazon regions, synergistic projects integrate malaria epidemiology, vector biology, and immunology. The Amazonian ICEMR's overarching goal is to understand how human behavior and other sociodemographic features of human reservoirs of transmission-predominantly asymptomatically parasitemic people-interact with the major Amazonian malaria vector, Nyssorhynchus (formerly Anopheles) darlingi, and with human immune responses to maintain malaria resilience and continued endemicity in a hypoendemic setting. Here, we will review Amazonian ICEMR's achievements on the synergies among malaria epidemiology, Plasmodium-vector interactions, and immune response, and how those provide a roadmap for further research, and, most importantly, point toward how to achieve malaria control and elimination in the Americas.

Mother's education and family relations protect children from dental caries experience: a salutogenic approach.

The objective of this study was to identify dental caries-protective factors among 5-year-old children using the salutogenic theory. A cross-sectional study was conducted in a small-sized municipality in the Southeast region of Brazil, with a representative sample of 247 children registered in preschool and their respective mothers. The data were collected through questionnaires administered to the mothers about the socioeconomic, behavioral, and biological aspects of the mother and children. Additionally, the collections included validated instruments concerning psychosocial aspects, such as a sense of coherence, resilience, family cohesion and religiosity, and intraoral examinations of the children through the decayed-missing-filled primary teeth (dmft) index. All examinations were performed by a trained and calibrated examiner. The non-adjusted and adjusted odds ratios (OR) and their respective confidence intervals (CI) were estimated using multiple logistic regression with a hierarchical model. Among the examined children, 41.7% were caries-free. In the final model, the chances of the absence of dental caries experience (dmft = 0) were greater in children with mothers who had higher education levels (> 8 years of study) (OR = 2.55 [95%CIi:1.42-4.59]) and those who lived in an environment of high family cohesion (OR = 3.66 [95%CI: 1.19-11.29]). The results indicated that mothers' level of education and family relationships are protective factors against dental caries in 5-year-old children, which overlapped with behavioral and biological factors.

Simultaneous distribution of aflatoxins B1 and B2, and fumonisin B1 in corn fractions during dry and wet-milling.

One of the limitations of the use of corn in the food chain is its contamination with mycotoxins. Reduction in their levels can be achieved by processing the grain, which in the case of corn can be achieved by wet or dry milling. The aim of this study was to compare the distribution of aflatoxins B1 and B2, and fumonisin B1 in corn fractions obtained by dry and wet milling, aiming to identify conditions to mitigate the risk of exposure to these contaminants. Naturally, contaminated corn kernels were subjected to laboratory milling. The wet-milling conditions containing 1% lactic acid in the steeping solution and 18 h of steeping were the most efficient for mycotoxin reduction in the endosperm fraction, reducing aflatoxins B1 and B2 contamination to levels below the limit of quantification. Dry-milling reduced the concentration of these mycotoxins in the endosperm (98-99%). Fumonisin B1 contamination increased in the germ and pericarp fraction by more than three times in both dry and wet milling. Dry-milling reduced fumonisin B1 contamination in the endosperm to levels below the limit of quantitation. Wet and dry milling processes can be an efficient control method to reduce aflatoxins and fumonisin in the corn endosperm fraction. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-022-05373-9.

Analysis of Verticality Perception in Older Adults With and Without Acute Stroke in Half-Lying Versus Sitting Positions.

Currently, there is no research consensus regarding the influence of body position on verticality perception in acute stroke. In this study, we aimed to compare the influence of half-lying and sitting positions on measurements of the subjective visual vertical (SVV) and the subjective haptic vertical (SHV) of individuals in the acute stroke phase. In this cross-sectional study, we compared these positional experiences in two groups of participants: adults in the acute stroke phase and elderly individuals without stroke. Independent variables were stroke versus no-stroke groups, in half-lying versus sitting positions. Analyzed variables of related interest were cognition (Mini-Mental State Examination or MMSE), stroke severity (National Institutes of Health Stroke Scale or NIHSS), and trunk control (Trunk Impairment Scale or TIS). Dependent variables were visual and haptic verticality, as evaluated by SVV and SHV. There were observed differences in absolute SVV in sitting position between groups (p = 0.021), absolute SVV in half-lying position between groups (p = 0.033), absolute SHV in sitting position between groups (p = 0.003), absolute SHV in half-lying position between groups (p = 0.002), and constant SVV in half-lying position between groups (p = 0.007). In the stroke group there was a higher coefficient of variation of SVV and SHV in the half-lying position compared to sitting position. In the sitting position, we observed a very strong correlation between the TIS and absolute SHV (p = 0.008). We concluded that individuals in the acute phase of stroke had greater misperceptions of visual and haptic verticality than older adults without strokes and that individuals in the acute phase of stroke showed less variability in visual and haptic vertical perception in the sitting position than in the half-lying position. By implication, we should encourage the sitting position in the acute stroke phase and develop early strategies to increase the verticality perception.

Epidemiology of COVID-19 after Emergence of SARS-CoV-2 Gamma Variant, Brazilian Amazon, 2020-2021.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Gamma variant has been hypothesized to cause more severe illness than previous variants, especially in children. Successive SARS-CoV-2 IgG serosurveys in the Brazilian Amazon showed that age-specific attack rates and proportions of symptomatic SARS-CoV-2 infections were similar before and after Gamma variant emergence.

DTI-derived parameters differ between moderate and severe traumatic brain injury and its association with psychiatric scores.

BACKGROUND AND AIM: Diffusion tensor imaging (DTI) parameters in the corpus callosum have been suggested to be a biomarker for prognostic outcomes in individuals with diffuse axonal injury (DAI). However, differences between the DTI parameters on moderate and severe trauma in DAI over time are still unclear. A secondary goal was to study the association between the changes in the DTI parameters, anxiety, and depressive scores in DAI over time. METHODS: Twenty subjects were recruited from a neurological outpatient clinic and evaluated at 2, 6, and 12 months after the brain injury and compared to matched age and sex healthy controls regarding the DTI parameters in the corpus callosum. State-Trace Anxiety Inventory and Beck Depression Inventory were used to assess psychiatric outcomes in the TBI group over time. RESULTS: Differences were observed in the fractional anisotropy and mean diffusivity of the genu, body, and splenium of the corpus callosum between DAI and controls (p < 0.02). Differences in both parameters in the genu of the corpus callosum were also detected between patients with moderate and severe DAI (p < 0.05). There was an increase in the mean diffusivity values and the fractional anisotropy decrease in the DAI group over time (p < 0.02). There was no significant correlation between changes in the fractional anisotropy and mean diffusivity across the study and psychiatric outcomes in DAI. CONCLUSION: DTI parameters, specifically the mean diffusivity in the corpus callosum, may provide reliable characterization and quantification of differences determined by the brain injury severity. No correlation was observed with DAI parameters and the psychiatric outcome scores.

Clinically silent Plasmodium vivax infections in native Amazonians of northwestern Brazil: acquired immunity or low parasite virulence?

BACKGROUND Malaria remains common among native Amazonians, challenging Brazil′s elimination efforts. OBJECTIVES We examined the epidemiology of malaria in riverine populations of the country′s main hotspot - the upper Juruá Valley in Acre state, close to the Brazil-Peru border, where Plasmodium vivax accounts for > 80% of cases. METHODS Participants (n = 262) from 10 villages along the Azul River were screened for malaria parasites by microscopy and genus-specific, cytochrome b (cytb) gene-based polymerase chain reaction. Positive samples were further tested with quantitative TaqMan assays targeting P. vivax- and P. falciparum-specific cytb domains. We used multiple logistic regression analysis to identify independent correlates of P. vivax infection. FINDINGS Microscopy detected only one P. vivax and two P. falciparum infections. TaqMan assays detected 33 P. vivax infections (prevalence, 11.1%), 78.1% of which asymptomatic, with a median parasitaemia of 34/mL. Increasing age, male sex and use of insecticide-treated bed nets were significant predictors of elevated P. vivax malaria risk. Children and adults were similarly likely to remain asymptomatic once infected. MAIN CONCLUSIONS Our findings are at odds with the hypothesis of age-related clinical immunity in native Amazonians. The low virulence of local parasites is suggested as an alternative explanation for subclinical infections in isolated populations.

Avaliação de prescrições pediátricas de hidroxiureia para pacientes com doença falciforme / Evaluation of pediatric hydroxyurea prescriptions for patients with sickle cell disease

A hidroxiureia (HU) constituiu um dos principais avanços no tratamento da doença falciforme. O uso do medicamento em crianças no Brasil ainda é off label e está disponível somente na forma farmacêutica sólida. O objetivo do presente trabalho é avaliar as estratégias de adaptação da forma farmacêutica sólida para o uso em crianças com doença falciforme. Trata-se de estudo descritivo, com análise de prescrições pediátricas de HU e aplicação de questionários aos responsáveis no período de janeiro a março de 2018. Foram analisadas 43 prescrições e identificadas duas formas de adaptação 1) diluição convencional: diluição do medicamento em quantidade pré-determinada de água, seguido de administração de parte da solução obtida (22) (51%) e 2) uso da recomendação posológica "holiday" ou intermitente (21) (49%). Todos os pacientes que utilizavam a estratégia de diluição convencional descartavam o restante do medicamento da rede de esgoto doméstica. Além disso, identificou-se administração incorreta do medicamento em um paciente. A falta de forma farmacêutica apropriada para população pediátrica pode levar a riscos de administração incorreta e gastos desnecessários com o descarte de medicamentos, além de descarte inadequado que compromete fatores ambientais. O estudo reforça a necessidade de desenvolvimentos de formas farmacêuticas mais adequadas ao público infantil.

Hydroxyurea (HU) was one of the main advances in the treatment of sickle cell disease. The use of the drug in children in Brazil is still off-label and is only available in solid pharmaceutical form. The objective of the present study is to evaluate the strategies for adapting the solid dosage form for use in children with sickle cell disease. This is a descriptive study, with the analysis of pediatric HU prescriptions and the application of questionnaires to those responsible in the period from January to March 2018. 43 prescriptions were analyzed, and two forms of adaptation were identified, 1) conventional dilution: dilution of the drug in a pre-prescribed quantity - determined amount of water, followed by administration of part of the solution obtained (22) (51%), and 2) use of the holiday or intermittent dose recommendation (21) (49%). All patients using the conventional dilution strategy discarded the remainder of the drug from the domestic sewage system. In addition, incorrect administration of the drug was identified in one patient. The lack of an appropriate pharmaceutical form for the pediatric population can lead to risks of incorrect administration and unnecessary expenses with drug disposal, in addition to improper disposal that compromises environmental factors. This study reinforces the need to develop pharmaceutical forms that are more suitable for children.

Mother's education and family relations protect children from dental caries experience: a salutogenic approach

Abstract The objective of this study was to identify dental caries-protective factors among 5-year-old children using the salutogenic theory. A cross-sectional study was conducted in a small-sized municipality in the Southeast region of Brazil, with a representative sample of 247 children registered in preschool and their respective mothers. The data were collected through questionnaires administered to the mothers about the socioeconomic, behavioral, and biological aspects of the mother and children. Additionally, the collections included validated instruments concerning psychosocial aspects, such as a sense of coherence, resilience, family cohesion and religiosity, and intraoral examinations of the children through the decayed-missing-filled primary teeth (dmft) index. All examinations were performed by a trained and calibrated examiner. The non-adjusted and adjusted odds ratios (OR) and their respective confidence intervals (CI) were estimated using multiple logistic regression with a hierarchical model. Among the examined children, 41.7% were caries-free. In the final model, the chances of the absence of dental caries experience (dmft = 0) were greater in children with mothers who had higher education levels (> 8 years of study) (OR = 2.55 [95%CIi:1.42-4.59]) and those who lived in an environment of high family cohesion (OR = 3.66 [95%CI: 1.19-11.29]). The results indicated that mothers' level of education and family relationships are protective factors against dental caries in 5-year-old children, which overlapped with behavioral and biological factors.

Cohort profile: the Mâncio Lima cohort study of urban malaria in Amazonian Brazil.

PURPOSE: This population-based open cohort study aims to investigate biological and sociodemographic drivers of malaria transmission in the main urban hotspot of Amazonian Brazil. PARTICIPANTS: Nearly 20% of the households in the northwestern town of Mâncio Lima were randomly selected and 2690 participants were enrolled since April 2018. Sociodemographic, housing quality, occupational, behavioural and morbidity information and travel histories were collected during consecutive study visits. Blood samples from participants>3 months old were used for malaria diagnosis and human genetic studies; samples from participants with laboratory-confirmed malaria have been cryopreserved for genetic and phenotypic characterisation of parasites. Serology was introduced in 2020 to measure the prevalence and longevity of SARS-CoV-2 IgG antibodies. FINDINGS TO DATE: Malaria prevalence rates were low (up to 1.0% for Plasmodium vivax and 0.6% for P. falciparum) during five consecutive cross-sectional surveys between April-May 2018 and October-November 2020; 63% of infections diagnosed by microscopy were asymptomatic. Malaria risk is heterogeneously distributed, with 20% study participants contributing 86% of the overall burden of P. vivax infection. Adult males are at greatest risk of infection and human mobility across the urban-rural interface may contribute to sustained malaria transmission. Local P. vivax parasites are genetically diverse and fragmented into discrete inbred lineages that remain stable across space and time. FUTURE PLANS: Two follow-up visits, with similar study protocols, are planned in 2021. We aim to identify high-risk individuals that fuel onwards malaria transmission and represent a priority target for more intensive and effective control interventions. TRIAL REGISTRATION NUMBER: NCT03689036.

Ongoing host-shift speciation in Plasmodium simium.

Plasmodium simium, a malaria parasite that infects platyrrhine monkeys and humans in the New World, is nearly identical to Plasmodium vivax. Recent genomic comparative analyses of these sister species have identified elevated divergence in a gene that may underlie P. simium adaptation to non-human primates during its gradual speciation process.

Monthly biological larviciding associated with a tenfold decrease in larval density in fish farming ponds and reduced community-wide malaria incidence in northwestern Brazil.

BACKGROUND: Larvicides are typically applied to fixed and findable mosquito breeding sites, such as fish farming ponds used in commercial aquaculture, to kill immature forms and thereby reduce the size of adult malaria vector populations. However, there is little evidence suggesting that larviciding may suppress community-wide malaria transmission outside Africa. Here, we tested whether the biological larvicide VectoMax FG applied at monthly intervals to fish farming ponds can reduce malaria incidence in Amazonian Brazil. METHODS: This study was carried out in Vila Assis Brasil (VAB; population 1700), a peri-urban malaria hotspot in northwestern Brazil with a baseline annual parasite incidence of 553 malaria cases per 1000 inhabitants. The intervention consisted of monthly treatments with 20 kg/ha of VectoMax FG of all water-filled fish ponds in VAB (n ranging between 167 and 170) with a surface area between 20 and 8000 m2, using knapsack power mistblowers. We used single-group interrupted time-series analysis to compare monthly larval density measurements in fish ponds during a 14-month pre-intervention period (September 2017-October 2018), with measurements made during November 2018-October 2019 and shortly after the 12-month intervention (November 2019). We used interrupted time-series analysis with a comparison group to contrast the malaria incidence trends in VAB and nearby nonintervention localities before and during the intervention. RESULTS: Average larval densities decreased tenfold in treated fish farming ponds, from 0.467 (95% confidence interval [CI], 0.444-0.490) anopheline larvae per dip pre-intervention (September 2017-October 2018) to 0.046 (95% CI, 0.041-0.051) larvae per dip during (November 2018-October 2019) and shortly after the intervention (November 2019). Average malaria incidence rates decreased by 0.08 (95% CI, 0.04-0.11) cases per 100 person-months (P < 0.0001) during the intervention in VAB and remained nearly unchanged in comparison localities. We estimate that the intervention averted 24.5 (95% CI, 6.2-42.8) malaria cases in VAB between January and December 2019. CONCLUSIONS: Regular larviciding is associated with a dramatic decrease in larval density and a modest but significant decrease in community-wide malaria incidence. Larviciding may provide a valuable complementary vector control strategy in commercial aquaculture settings across the Amazon.