BackgroundThis study aims to describe the epidemiological and entomological factors associated with a recent malaria outbreak that occurred in 2012 in a socially marginalized population from Guna Yala Comarca in Panama.MethodsA descriptive and observational study was conducted by analysing demographic and epidemiological data from all malaria cases registered during 2012 in the Comarca Guna Yala, Panama. Malaria intensity indicators were calculated during the study period. Entomological evaluations were performed monthly, from October to December 2012, in the three communities that presented the most intense malaria transmission during the first semester of 2012. Anopheles breeding habitats were also characterized.ResultsDuring the studied period, 6754 blood smears were examined (17.8 % of the total population), and 143 were confirmed as positive for Plasmodium vivax. A significant increase of malaria transmission risk indicators (API: 3.8/1000, SPR: 2.1 %) was observed in Guna Yula, when compared with previous years, and also in comparison with estimates from the whole country. Anopheles albimanus was the most abundant and widespread (877; 72.0 %) vector species found in the three localities, followed by Anopheles punctimacula (231; 19.0 %) and Anopheles aquasalis (110; 9.0 %). Three An. albimanus pools were positive for P. vivax, showing an overall pooled prevalence estimate of 0.014.ConclusionsData analysis confirmed that during 2012 a malaria epidemic occurred in Guna Yala. Panama. This study provides baseline data on the local epidemiology of malaria in this vulnerable region of Panamá. This information will be useful for targeting control strategies by the National Malaria Control Programme.

Hantavirus cardiopulmonary syndrome (HCPS), which is caused by infection with Choclo virus, is uncommon in Panama, yet seropositivity among rural residents is as high as 60%. To clarify the environmental risk factors favoring rodent-to-human transmission, we tested serum from 3,067 rodents captured over a five-year period for antibodies against recombinant N protein of hantavirus by enzyme immunoassay and strip immunoblot. Among 220 seropositive rodents, Oligoryzomys fulvescens, the reservoir of Choclo virus, had the highest overall seroprevalence (23.5%); more abundant rodents (Zygodontomys brevicauda and Sigmodon hirsutus) had lower seroprevalences. In the mixed (combined modern and traditional) productive agroecosystem, the highest seroprevalence was among O. fulvescens captured in residences and in crops grown within 40 meters of a residence, with significantly lower seroprevalence in adjacent pasture and non-productive vegetation. Thus, crop habitats may serve as refugia for invasion into adjacent human residences and suggests several interventions to reduce human infection.

The natural transmission of dengue virus from an infected female mosquito to its progeny, namely the vertical transmission, was researched in wild caught Aedes aegypti during an important outbreak in the town of Santa Cruz de la Sierra, Bolivia. Mosquitoes were collected at the preimaginal stages (eggs, larvae and pupae) then reared up to adult stage for viral detection using molecular methods. Dengue virus serotypes 1 and 3 were found to be co-circulating with significant higher prevalence in male than in female mosquitoes. Of the 97 pools of Ae. aegypti (n = 635 male and 748 female specimens) screened, 14 pools, collected in February-May in 2007, were found positive for dengue virus infection: five DEN-1 and nine DEN-3. The average true infection rate (TIR) and minimum infection rate (MIR) were respectively 1.08% and 1.01%. These observations suggest that vertical transmission of dengue virus may be detected in vectors at the peak of an outbreak as well as several months before an epidemic occurs in human population.

Introduction. The COVID-19 pandemic, originated in China, has affected millions of people worldwide, leading to various situations such as psychological disorders and diseases that affect people’s physical and mental health, and disrupt their quality of life. Objective. To analyze stress levels during social distancing due to COVID-19 by gender and to determine the moderating effect of adaptability to the situation. Method. The study is cross-sectional and quantitative, with a descriptive-correlational scope. The sample consisted of 1,173 Mexican subjects (522 males [44.5%] and 651 females [22.5%]) with an average age of 25.99 years (DT = 11.19; range = 12 - 77 years). Adaptability and perceived stress were measured, obtaining reliability from appropriate instruments. Results. The results indicated that the greater the number of weeks of social distancing, the higher the perceived level of stress. Also, the better people adapt to social distancing, the less stress occurs. Women were observed to have higher levels of stress compared to men. Discussion and conclusion. The findings highlight the importance of adaptability to the stressful situation of the pandemic, because the effect of severe stress on women largely disappears when there is a high level of adaptability to the event.

Background: The population of older adults is increasing worldwide, which brings attention to the importance of healthy aging. Adoption of healthy lifestyle activities such as participating in physical activity on a daily basis is key to maintaining physical and mental health. The aim of this study was to investigate the effects of participation in a 12-week multidimensional exercise program on health behavior and biopsychological factors of older adults living in Northeastern Mexico. Methods: A quasi-experimental study was conducted with 45 older adults (35 females and 10 males; M = 67.24 ± 5.73 years). The participants were assigned to an experimental group (EG; n = 23) that participated in a 12-week exercise program and a control group (CG; n = 22). Pre-and post-analyses of the exercise intervention data were carried out to investigate the participants' health-related variables including physical activity levels, blood pressure, self-esteem, depressive symptoms, and blood lipids profiles. Results: The results indicated that the exercise intervention contributed to significant improvements in the older adults' health-related variables for the EG when contrasted with the control group. For instance, the EG significantly improved systolic (p < 0.001) and diastolic (p < 0.027) blood pressure, blood lipids [e.g., cholesterol (p < 0.05)], triglycerides (p < 0.05), self-esteem (p < 0.005), and depressive symptoms (p < 0.002) as well as physical activity (p < 0.001) levels. The results also demonstrated that only those individuals in the EG diagnosed with disease benefited from improved self-esteem and physical activity levels when contrasted with their healthy counterparts.

In this paper we revisit the classification of the gauge transformations in the Euler top system using the generalized classical Hamiltonian dynamics of Nambu. In this framework the Euler equations of motion are bi-Hamiltonian and SL(2, R) linear combinations of the two Hamiltonians leave the equations of motion invariant, although belonging to inequivalent Lie-Poisson structures. Here we give the explicit form of the Hamiltonian vector fields associated to the components of the angular momentum for every single Lie-Poisson structure including both the asymmetric rigid bodies and its symmetric limits. We also give a detailed classification of the different Lie-Poisson structures recovering all the ones reported previously in the literature.

Contribución de los autores:Todos los autores contribuyeron en la redacción y corrección del manuscrito, análisis e interpretación de los datos, verificación de referencias bibliográficas, observaciones y revisión crítica del mismo. ARTÍCULO ORIGINAL Biomédica 2012;32:557-69 doi: http://dx.doi.org/10.7705/biomedica.v32i4.773 Caracterización de la transmisión de la malaria por Plasmodium vivax en la región fronteriza de Panamá con Costa Rica en el municipio de Barú, Panamá Characterization of Plasmodium vivax malaria transmission at the border of Panamá and Costa RicaIntroduction. Few studies have described the factors associated with Plasmodium vivax transmission dynamics in endemic regions from Panamá. Objective. Malaria transmission dynamics produced by P. vivax were characterized at the border between Panamá and Costa Rica. Materials and methods. In the municipality of Barú, an observational, descriptive and cross-sectional study was undertaken to measure the annual parasite index (API), slide positivity index (SPR), and the annual blood examination rate (ABER). The most frequent symptoms and signs in malaria patients were recorded. The anopheline species were identified in the area and the preferred larval habitats, the density of larval populations in the larval habitats and the bites/human/night were characterized. Results. Of a total of 10,401 thick smear blood samples, 83 were positive for P. vivax. Of these, 84% came from rural areas and 79% were from economically active individuals. The median and average ages were 36 and 30 years, respectively, and 58.5% of the malaria cases were male. API was 4.1/1,000 inhabitants; SPR was 0.8% and ABER was 51.9%. Of the diagnosed cases, 54% showed blood parasitemias ranging between 100-2,000 parasites/µl. The majority of the cases were observed in May and June. Two mosquito vector species were identified--Anopheles albimanus and An. punctimacula. Conclusion. These observations indicate the advisibility of continued entomological studies, strengthening of epidemiological surveillance, consideration of additional risk factors and evaluation

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