The Evolution of Entomological Research with Focus on Emerging and Re-emerging Mosquito-Borne Infections in the Philippines

This paper presented previous and current research efforts for medically important mosquitoes that serve as vectors of emerging and re-emerging diseases in the Philippines, in light of identifying the research gap that exists in the field of public health entomology in the country. This extensive review of the past and current research studies with regard to medical entomology and vector control also attempted to provide proper direction and insights for effective implementation of the country’s vector control programs. All research studies conducted in the Philippines from 1958 up to the present that are related to the paper’s interest and are available on Philippines’ Department of Science and Technology and RITM databases were tracked. Results from this analysis imply that studies on public health entomology in the Philippines have evolved and have gone through various stages of development over time. However, the magnitude of research on medically important mosquitoes in the country is still insufficient for it to contribute comprehensively to integrated methods of vector management and totally eliminate mosquito-borne infections in the Philippines. It is recommended for researchers to work on the continuity of vector researches and explore further the diversity of the entomological aspects of the control of vector-borne diseases

Capacitación laboral y la inserción laboral de los beneficiarios del Programa Jóvenes Productivos, sede Lima, 2016

En relación a la metodología empleada, la investigación fue de un enfoque cuantitativo, de tipo de estudio básico, por su profundidad la investigación fue de nivel correlacional. En relación al diseño de investigación fue no experimental y de corte transversal. La población de estudio fue 250 beneficiarios del Programa Jóvenes Productivos sede Lima 2016. La técnica de muestreo utilizado fue el muestreo probabilístico aleatorio simple. La muestra seleccionada fue de 152 beneficiarios. La técnica y el instrumento de recolección de datos, fueron la encuesta y el cuestionario. Cada variable de investigación tuvo su propio cuestionario con preguntas cerradas del tipo escala de Likert. Para validar el instrumento se empleó la técnica de juicio de expertos, los cuales dieron conformidad a la validez de los instrumentos. La investigación se basó en las teorías humanista sustentada por Maslow para la variable capacitación laboral y la teoría del capital humano sustentado por Schultz para la variable inserción laboral. La investigación concluye que se encontró una relación lineal estadísticamente significativa, alta y directamente proporcional entre la capacitación laboral y la inserción laboral del Programa Jóvenes Productivos se de Lima 2016 (rs = 0.813, p<0.000). Asimismo, se encontró una relación estadísticamente significativa y moderada (rs = 0.796, p<0.000) entre la dimensión evaluación de competencias y la inserción laboral y una relación estadísticamente significativa y moderada (rs = 0.663, p<0.000) entre la dimensión satisfacción de la capacitación y la inserción laboral

Community-based dengue vector control : experiences in behavior change in Metropolitan Manila, Philippines

Dengue is the most important mosquito-borne disease in the Philippines, especially in Metropolitan Manila where communities are socially and economically diverse, and city governments struggle to provide basic services such as continuously available, piped water supply to residents. We examined responses to introducing water container management to control dengue vectors in two diverse communities in Masagana City: Village A (gated community) and Village B (informal settlers community). The roll out of the intervention was carried out by the study team, dengue control personnel and local health workers (BHWs). A behavioural change framework was used to describe the community responses to the introduction of a new vector control intervention - household water containermanagement. Although, the desired outcome was not achieved during the study’s timeline, observation on processes of behaviour change underscored the importance of understanding the social nature of the urban communities, often overlooked structures when dengue control program and researchers introduce new dengue control interventions

Fabrication of a Nanoparticle-based Sensor for the Detection of Dengue Virus-3 in Aedes aegypti

The nanoparticle-based sensor was found to be serotype-specific for DENV-3 by demonstrating a positive result only with DENV-3. This was performed using extracted RNA of different dengue serotypes from A. aegypti. In this study, the fabricated nanoparticle-based sensor can detect target concentration for as low as 0.1 ?M using synthetic DENV-3 target and 5 x 102 PFU/mL using extracted RNA from A. aegypti. The nanobiosensor presented in this study provides a simple, faster

High relative humidity might trigger the occurrence of the second seasonal peak of dengue in the Philippines.

BACKGROUND: Dengue in some regions has a bimodal seasonal pattern, with a first big seasonal peak followed by a second small seasonal peak. The factors associated with the second small seasonal peak remain unclear. METHODS: Monthly data on dengue cases in the Philippines and its 17 regions from 2008 to 2017 were collected and underwent a time series seasonal decomposition analysis. The associations of monthly average mean temperature, average relative humidity, and total rainfall with dengue in 19 provinces were assessed with a generalized additive model. Logistic regression and a classification and regression tree (CART) model were used to identify the factors associated with the second seasonal peak of dengue. RESULTS: Dengue incidence rate in the Philippines increased substantially in the period 2013-2017, particularly for the regions in south Philippines. Dengue peaks in south Philippines predominantly occurred in August, with the peak in the national capital region (NCR) (i.e., Metropolitan Manila) occurring in September. The association between mean temperature and dengue appeared J-shaped or upside-down-V-shaped, and the association between relative humidity (or rainfall) and dengue was heterogeneous across different provinces (e.g., J shape, reverse J shape, or upside-down V shape, etc). Relative humidity was the only factor associated with the second seasonal peak of dengue (odds ratio: 1.144; 95% confidence interval: 1.023-1.279; threshold: 77%). CONCLUSIONS: Dengue control and prevention resources are increasingly required in regions beyond the NCR, and relative humidity can be used as a predictor of the second seasonal peak of dengue in the Philippines

Determining the density of states for classical statistical models: A random walk algorithm to produce a flat histogram

We describe an efficient Monte Carlo algorithm using a random walk in energy space to obtain a very accurate estimate of the density of states for classical statistical models. The density of states is modified at each step when the energy level is visited to produce a flat histogram. By carefully controlling the modification factor, we allow the density of states to converge to the true value very quickly, even for large systems. This algorithm is especially useful for complex systems with a rough landscape since all possible energy levels are visited with the same probability. In this paper, we apply our algorithm to both 1st and 2nd order phase transitions to demonstrate its efficiency and accuracy. We obtained direct simulational estimates for the density of states for two-dimensional ten-state Potts models on lattices up to $200 \times 200$ and Ising models on lattices up to $256 \times 256$. Applying this approach to a 3D $\pm J$ spin glass model we estimate the internal energy and entropy at zero temperature; and, using a two-dimensional random walk in energy and order-parameter space, we obtain the (rough) canonical distribution and energy landscape in order-parameter space. Preliminary data suggest that the glass transition temperature is about 1.2 and that better estimates can be obtained with more extensive application of the method.Comment: 22 pages (figures included

A call to protect non-clinical frontliners in the fight against COVID-19: evidence from a seroprevalence study in the Philippines.

Since the COVID-19 pandemic started in 2020, healthcare workers (HCW) and other hospital personnel have been regarded as “frontliners”, and at increased risk of SARS-CoV-2 infection compared to the general population. As such, testing only symptomatic individuals or regular testing of HCWs who directly attend to COVID-19 patients or specimens may underestimate the extent of infection, and actual SARS-CoV-2 seroprevalence. Because of this, the World Health Organization has called for seroepidemiological surveys to assess the extent of infection amongst HCW and other populations to provide timely estimates of COVID-19 virus infection severity and inform public health responses and evidence-based policy decisions

The seasonal dynamics and biting behavior of potential Anopheles vectors of Plasmodium knowlesi in Palawan, Philippines.

BACKGROUND: A small number of human cases of the zoonotic malaria Plasmodium knowlesi have been reported in Palawan Island, the Philippines. Identification of potential vector species and their bionomics is crucial for understanding human exposure risk in this setting. Here, we combined longitudinal surveillance with a trap-evaluation study to address knowledge gaps about the ecology and potential for zoonotic spillover of this macaque malaria in Palawan Island. METHODS: The abundance, diversity and biting behavior of human-biting Anopheles mosquitoes were assessed through monthly outdoor human landing catches (HLC) in three ecotypes representing different land use (forest edge, forest and agricultural area) across 8 months. Additionally, the host preference and biting activity of potential Anopheles vectors were assessed through comparison of their abundance and capture time in traps baited with humans (HLC, human-baited electrocuting net-HEN) or macaques (monkey-baited trap-MBT, monkey-baited electrocuting net-MEN). All female Anopheles mosquitoes were tested for the presence of Plasmodium parasites by PCR. RESULTS: Previously incriminated vectors Anopheles balabacensis and An. flavirostris accounted for > 95% of anophelines caught in longitudinal surveillance. However, human biting densities were relatively low (An. balabacensis: 0.34-1.20 per night, An. flavirostris: 0-2 bites per night). Biting densities of An. balabacensis were highest in the forest edge, while An. flavirostris was most abundant in the agricultural area. The abundance of An. balabacensis and An. flavirostris was significantly higher in HLC than in MBT. None of the 357 female Anopheles mosquitoes tested for Plasmodium infection were positive. CONCLUSIONS: The relatively low density and lack of malaria infection in Anopheles mosquitoes sampled here indicates that exposure to P. knowlesi in this setting is considerably lower than in neighboring countries (i.e. Malaysia), where it is now the primary cause of malaria in humans. Although anophelines had lower abundance in MBTs than in HLCs, An. balabacensis and An. flavirostris were caught by both methods, suggesting they could act as bridge vectors between humans and macaques. These species bite primarily outdoors during the early evening, confirming that insecticide-treated nets are unlikely to provide protection against P. knowlesi vectors

SARS-CoV-2 seroprevalence and infection rate in Manila, Philippines prior to national vaccination program implementation: a repeated cross-sectional analysis

Background: SARS-CoV-2 seroepidemiological studies are used to guide public health decision making and to prepare for emerging infectious diseases. Disease occurrence estimates are limited in the Philippines, the country with the highest reported number of coronavirus disease-related deaths in the Western Pacific region. We aimed to estimate SARS-CoV-2 seroprevalence and infection rate among outpatient clinic attendees in Metro Manila prior to the implementation of the national coronavirus disease vaccination program. Methods: We conducted repeated cross-sectional surveys at the animal bite clinic in San Lazaro Hospital, Manila, the Philippines across four periods, 3 months apart, between May 2020 and March 2021. Multivariable logistic regression was used to assess associations between different characteristics and infection status including seropositivity.Results: In total 615 participants were enrolled, ranging from 115 to 174 per period. Seroprevalence quadrupled between the first (11.3%) and second (46.8%) periods and plateaued thereafter (third—46.0%, fourth—44.6%). Among seropositive participants, total antibody concentration was comparable throughout the first to third periods but declined between the third and fourth periods. Infection prevalence was comparable across enrollment periods (range 2.9–9.5%). Post-secondary education [aOR 0.42 (95% CI 0.26, 0.67)] was protective, and frontline work [aOR 1.81 (95% CI 1.18, 2.80)] was associated with increased odds of seropositivity. Frontline work status [aOR 2.27 (95% CI 1.10, 4.75)] and large household size [aOR 2.45 (95% CI 1.18, 5.49)] were associated with increased odds of infection.Conclusions: The quadrupling of seroprevalence over 3 months between the first and second enrollment periods coincided with the high burden of infection in Metro Manila in early 2020. Our findings suggest a limit to the rise and potential decline of population-level SARS-CoV-2 infection-induced immunity without introduction of vaccines. These results may add to our understanding of how immunity develops against emerging infectious diseases including coronaviruses

SARS-CoV-2 seroprevalence and infection rate in Manila, Philippines prior to national vaccination program implementation: a repeated cross-sectional analysis.

BACKGROUND: SARS-CoV-2 seroepidemiological studies are used to guide public health decision making and to prepare for emerging infectious diseases. Disease occurrence estimates are limited in the Philippines, the country with the highest reported number of coronavirus disease-related deaths in the Western Pacific region. We aimed to estimate SARS-CoV-2 seroprevalence and infection rate among outpatient clinic attendees in Metro Manila prior to the implementation of the national coronavirus disease vaccination program. METHODS: We conducted repeated cross-sectional surveys at the animal bite clinic in San Lazaro Hospital, Manila, the Philippines across four periods, 3 months apart, between May 2020 and March 2021. Multivariable logistic regression was used to assess associations between different characteristics and infection status including seropositivity. RESULTS: In total 615 participants were enrolled, ranging from 115 to 174 per period. Seroprevalence quadrupled between the first (11.3%) and second (46.8%) periods and plateaued thereafter (third-46.0%, fourth-44.6%). Among seropositive participants, total antibody concentration was comparable throughout the first to third periods but declined between the third and fourth periods. Infection prevalence was comparable across enrollment periods (range 2.9-9.5%). Post-secondary education [aOR 0.42 (95% CI 0.26, 0.67)] was protective, and frontline work [aOR 1.81 (95% CI 1.18, 2.80)] was associated with increased odds of seropositivity. Frontline work status [aOR 2.27 (95% CI 1.10, 4.75)] and large household size [aOR 2.45 (95% CI 1.18, 5.49)] were associated with increased odds of infection. CONCLUSIONS: The quadrupling of seroprevalence over 3 months between the first and second enrollment periods coincided with the high burden of infection in Metro Manila in early 2020. Our findings suggest a limit to the rise and potential decline of population-level SARS-CoV-2 infection-induced immunity without introduction of vaccines. These results may add to our understanding of how immunity develops against emerging infectious diseases including coronaviruses