Identification of thresholds on population density for understanding transmission of COVID-19

Pathways of transmission of coronavirus (COVID-19) disease in the human population are still emerging. However, empirical observations suggest that dense human settlements are the most adversely impacted, corroborating a broad consensus that human-to-human transmission is a key mechanism for the rapid spread of this disease. Here, using logistic regression techniques, estimates of threshold levels of population density were computed corresponding to the incidence in the human population. Regions with population densities greater than 3000 person per square mile in the United States have about 95% likelihood to get infected with COVID-19. Since case numbers of COVID-19 dynamically changed each day until November 30, 2020, ca. 4% of US counties were at 50% or higher risk of COVID-19 transmission. While threshold on population density is not the sole indicator for predictability of coronavirus in human population, yet it is one of the key variables on understanding and rethinking human settlement in urban landscapes. Plane language SummaryPopulation density is certainly one of the key factors influencing the transmission of infectious diseases like COVID-19. It is approximated that in continental United States, population density of 1192 per square mile and higher presents 50% probability of getting infected with COVID-19. Key PointsO_LIBased on data from the USA, the population density of 1192 persons per square mile represented a 50% or higher probability of risk of transmission of COVID-19. C_LIO_LIAbout 35 counties in the USA are at very high risk of transmission potential (95% or higher) for COVID-19. C_LIO_LIAnalysis shows the vulnerability of urban towns to respiratory infectious disease C_LI

The Content and Implementation of Policies and Programs on Adolescent Sexual and Reproductive Health in Vietnam: Results and Challenges.

In Vietnam, great efforts have been made in sexual and reproductive health (SRH) information provision, education, communication, as well as service provision for the adolescent and youth (A&Y) over the last 10 years. This paper aimed to examine the content and implementation of SRH policies for A&Y between 2006 and 2017. Case studies were conducted, including interviews and historical documentation. Qualitative data were collected in Hai Duong, Hue, and Dong Thap provinces through 34 in-depth interviews with representatives of central/provincial agencies and 9 focus group discussions with representatives of communal agencies and beneficiaries. SRH policies for A&Y during 2006 to 2017, along with other related national policies, were developed cohesively, however, the gaps in information provision, education, communication as well as service provision remained unresolved. The contents of policies and program implementation did not cover comprehensively, especially regarding disadvantaged groups such as disabled people, migrants, ethnic minorities, and people aged 10 to 14 years. The A&Y SRH policies and program implementation had faced some challenges relating to governance, service delivery, health workforce, health information system, and health financing. The SRH policy for A&Y in the next period needs to be focused on interventions/services for disadvantaged groups. While the human resource is of great importance for the capacity and feasibility to tackle SRH's challenges, strengthening the advocacy to ensure policies/programs should be prioritized and committed for effective implementation. An appropriate financing system to run information provision, education, communication, and support services for A&Y must be considered during policy development and implementation.

Prevalence of smoking among health science students in Vietnam in 2018 and associated factors: A cross-sectional study.

Smoking is a global health problem among health science students. The objectives of this study were to estimate the prevalence of smoking and to examine associated factors among health science students from five universities in Vietnam. Among 5946 participants (95.0% response rate), the smoking prevalence was 19.2% (95% CI:17.4-21.0%) among male students and 2.9% (95% CI:2.4-3.5%) among female students. In the multivariable regression models, significant factors for smoking were the perceived financial burden, the respondent's year in university, a non-self-determined motivation profile, self-reported depression and/or anxiety, the level of vigorous physical activity, and alcohol drinking.

Pregnancy health literacy among teenagers in Kaysone district, Savannakhet Province, Lao PDR.

BACKGROUND: Pregnancy health literacy (PHL) among teenagers is considered a major protective factor for teenage pregnancy. In Lao PDR, 18% of girls aged 15-19 have begun childbearing and 15% of maternal deaths occur to teenage girls, particularly in rural areas. OBJECTIVE: The aim of this study was to describe PHL and its related factors among teenagers in Kaysone district. METHOD: This was a cross-sectional study conducted at Oudomvilay and Kheuakhaokat in Kaysone district in January 2019. The Teenage Pregnancy Health Literacy (TPHL) score was collected via face to face interviews covering 33 items with 262 adolescents. Calculation of the TPHL index score was based on the European Health Literacy Survey (HLS-EU) index formula. The TPHL index was also based on the HLS-EU standard level and descriptive statistics were used to explain the score and levels. Descriptive analyses were performed to analyse the individual, family, peer and school variables and to investigate level of TPHL and linear regression was used to identify factors related to TPHL. RESULTS: The overall score for TPHL was a mean of 27/50. Most (60%) of the adolescents had problematic TPHL levels and only 0.4% had excellent TPHL levels. TPHL was positively and significantly associated with living in urban areas (ß = 2.42; p = 0.002), higher education (ß = 2.93; p = 0.004), schooling (ß = 0.96; p = 0.018), being single (ß = 2.9; p = 0.029) and attending classes where sex education content was included (ß = 4.72; p < 0.001). CONCLUSION: Low TPHL scores show the importance of improving sex education for adolescents as a means of increasing TPHL for better health outcomes in Lao PDR.

A new species of Psydrax (Vanguerieae, Rubiaceae) from the Gia Lai Plateau, southern Vietnam.

A new species of Rubiaceae, Psydrax gialaiensis B.H.Quang, T.B.Tran & V.S.Dang, sp. nov., is described and illustrated from the Kon Chu Rang Nature Reserve, Gia Lai Province, southern Vietnam. This species is characterized by having strigose branches and leaves, a conspicuously bulging, short corolla tube, an accrescent nectary disc and a style with a dense tuft of hairs, which clearly distinguishes it from the other species in the genus. A description, vernacular name, conservation assessment, illustration, photographs, and a key to the species of Psydrax in Vietnam are provided.

Particulate air pollution in Ho Chi Minh city and risk of hospital admission for acute lower respiratory infection (ALRI) among young children.

High levels of air pollutants in Vietnam, especially particulate matters including PM2.5, can be important risk factors for respiratory diseases among children of the country. However, few studies on the effects of ambient air pollution on human health have been conducted in Vietnam so far. The aim of this study is to examine the association between PM2.5 and hospital admission due to acute lower respiratory infection (ALRI) among children aged < 5 years old in Ho Chi Minh city, the largest city of Vietnam. Data relating PM2.5 and hospital admission were collected from February 2016-December 2017 and a time series regression analysis was performed to examine the relationship between PM2.5 and hospital admission including the delayed effect up to three days prior to the admission. We found that each 10 µg/m3 increase in PM2.5 was associated with an increase of 3.51 (95%CI: 0.96-6.12) risk of ALRI admission among children. According to the analysis, male children are more sensitive to exposure to PM2.5 than females, while children exposed to PM2.5 are more likely to be infected with acute bronchiolitis than with pneumonia. The study demonstrated that young children in HCMC are at increased risk of ALRI admissions due to the high level of PM2.5 concentration in the city's ambient air.

Hepatic myofibroblasts promote the progression of human cholangiocarcinoma through activation of epidermal growth factor receptor.

UNLABELLED: Intrahepatic cholangiocarcinoma (CCA) is characterized by an abundant desmoplastic environment. Poor prognosis of CCA has been associated with the presence of alpha-smooth muscle actin (α-SMA)-positive myofibroblasts (MFs) in the stroma and with the sustained activation of the epidermal growth factor receptor (EGFR) in tumor cells. Among EGFR ligands, heparin-binding epidermal growth factor (HB-EGF) has emerged as a paracrine factor that contributes to intercellular communications between MFs and tumor cells in several cancers. This study was designed to test whether hepatic MFs contributed to CCA progression through EGFR signaling. The interplay between CCA cells and hepatic MFs was examined first in vivo, using subcutaneous xenografts into immunocompromised mice. In these experiments, cotransplantation of CCA cells with human liver myofibroblasts (HLMFs) increased tumor incidence, size, and metastatic dissemination of tumors. These effects were abolished by gefitinib, an EGFR tyrosine kinase inhibitor. Immunohistochemical analyses of human CCA tissues showed that stromal MFs expressed HB-EGF, whereas EGFR was detected in cancer cells. In vitro, HLMFs produced HB-EGF and their conditioned media induced EGFR activation and promoted disruption of adherens junctions, migratory and invasive properties in CCA cells. These effects were abolished in the presence of gefitinib or HB-EGF-neutralizing antibody. We also showed that CCA cells produced transforming growth factor beta 1, which, in turn, induced HB-EGF expression in HLMFs. CONCLUSION: A reciprocal cross-talk between CCA cells and myofibroblasts through the HB-EGF/EGFR axis contributes to CCA progression.

Immunohistochemical profile of ezrin and radixin in human liver epithelia during fetal development and pediatric cholestatic diseases.

AIM: Ezrin and radixin are actin-binding proteins that contribute to the integrity of epithelia. Abnormalities of bile secretion occur primarily in cholestatic liver diseases and are associated with changes in cell cytoskeleton. Expression of these proteins during liver development and in cholestatic liver diseases remains poorly investigated. METHODS: Ezrin and radixin expression was analyzed in fetal, adult and pediatric cholestatic human liver (i.e. biliary atresia, sclerosing cholangitis) by immunohistochemistry. RESULTS: In adult and fetal livers, ezrin was expressed exclusively in the cells of the biliary lineage (i.e. biliary epithelial cells and ductal cells) whereas radixin was located not only in hepatocytes but also in cells of the biliary lineage. In the lobule of mature livers, radixin displayed a zonal distribution with predominant expression in the periportal region. In cholestatic diseases, both proteins were expressed in cells of the ductular reaction. An aberrant expression of ezrin was detected in hepatocytes of cirrhotic nodules with a CK7-positive pattern and in malignant hepatocytes in a course of cholestatic disease toward cancer. CONCLUSIONS: Among the components of the liver epithelial cells, ezrin was exclusively expressed in biliary phenotype cells, while radixin was found in biliary and hepatocytic lineages, with a periportal zonal expression. In cholestatic diseases, ezrin was expressed in hepatocytes supporting the appearance of a biliary phenotype.