scholarly journals Exogenous glucocorticoids amplify the costs of infection by reducing resistance and tolerance, but effects are mitigated by co-infection

2019 ◽  
Vol 286 (1900) ◽  
pp. 20182913 ◽  
Author(s):  
Laura A. Schoenle ◽  
Ignacio T. Moore ◽  
Alana M. Dudek ◽  
Ellen B. Garcia ◽  
Morgan Mays ◽  
...  
Keyword(s):  
Individual Variation ◽  
Disease Transmission ◽  
Scale Up ◽  
Agelaius Phoeniceus ◽  
Negative Consequences ◽  
Glucocorticoid Treatment ◽  
Glucocorticoid Hormone ◽  
Haemosporidian Parasites ◽  
Inflammatory Immune Response ◽  
Resistance To Infection

Individual variation in parasite defences, such as resistance and tolerance, can underlie heterogeneity in fitness and could influence disease transmission dynamics. Glucocorticoid hormone concentrations often change in response to fluctuating environmental conditions and mediate changes in immune function, resource allocation and tissue repair. Thus, changes in glucocorticoid hormone concentrations might mediate individual variation in investment in resistance versus tolerance. In this study, we experimentally increased glucocorticoid concentrations in red-winged blackbirds ( Agelaius phoeniceus ) that were naturally infected with haemosporidian parasites, and assessed changes in resistance and tolerance of infection. Glucocorticoid treatment increased burdens of Plasmodium , the parasite causing avian malaria, but only in the absence of co-infection with another Haemosporidian, Haemoproteus . Thus, glucocorticoids might reduce resistance to infection, but co-infection can mitigate the negative consequences of increased hormone concentrations. Glucocorticoid treatment also decreased tolerance of infection. We found no evidence that the inflammatory immune response or rate of red blood cell production underlie the effects of glucocorticoids on resistance and tolerance. Our findings suggest that exogenous glucocorticoids can increase the costs of haemosporidian infections by both increasing parasite numbers and reducing an individual's ability to cope with infection. These effects could scale up to impact populations of both host and parasite.

scholarly journals Barriers to timely disclosure of HIV serostatus: A qualitative study at care and treatment centers in Dar es Salaam, Tanzania

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256537
Author(s):  
Neelam Ismail ◽  
Nancy Matillya ◽  
Riaz Ratansi ◽  
Columba Mbekenga
Keyword(s):  
Social Status ◽  
Disease Transmission ◽  
Qualitative Content Analysis ◽  
Dar Es Salaam ◽  
Hiv Care ◽  
People Living With Hiv ◽  
Negative Consequences ◽  
Hiv Serostatus ◽  
Care And Treatment ◽  
Living With Hiv

Introduction Disclosure of Human Immunodeficiency Virus (HIV) status is important to prevent the spread of HIV and maintain the health of people living with HIV, their spouses, and the community. Despite the benefits of disclosure, many people living with HIV delay disclosing their status to those close to them thereby increasing the risk for disease transmission. This study aimed to determine the barriers to timely disclosure of HIV serostatus for people living with HIV in Dar es Salaam, Tanzania, and identify what motivated disclosure. Methods A qualitative descriptive study using in-depth individual interviews was conducted with10 participants attending HIV care and treatment centers in Dar es Salaam. The participants were people living with HIV who had delayed disclosing their serostatus for more than one month after diagnosis. Data was analyzed using qualitative content analysis. Results Three categories emerged from the analysis: Barriers hindering timely disclosure, motivation for disclosure of serostatus, and consequences of delayed disclosure. Barriers to timely disclosure included denial of one’s status, the fear of stigmatization, fear of being separated or divorced, the need to protect loved ones, and lack of adequate knowledge about the disease. Reasons that motivated disclosure included gaining social support, preventing disease transmission and wanting to be at peace. Conclusion Timely disclosure is hindered by stigma because HIV is negatively perceived by the public. People living with HIV prefer not to disclose to avoid the negative consequences of disclosure, especially because of fear of being discriminated against and losing their social status, which plays a major role in social status in Tanzania. Trust and adequate counseling from health care workers helps prompt disclosure.

scholarly journals Beyond the Core: Who Has Larger Social Networks?

Social Forces ◽  
2020 ◽  
Author(s):  
Bas Hofstra ◽  
Rense Corten ◽  
Frank van Tubergen
Keyword(s):  
Social Networks ◽  
Individual Variation ◽  
Bayesian Modeling ◽  
State Of The Art ◽  
Scale Up ◽  
Network Size ◽  
Future Research ◽  
Social Contacts ◽  
Core Networks ◽  
Social Network Size

Abstract The sociological literature on social networks overwhelmingly considers the number of core social contacts. Social networks, however, reach far beyond this small number of social ties. We know little about individual variation in the size of such extended social networks. In this study, we move beyond core networks and explain individual variation in the extended social network size among youth. We use survey data of Dutch adolescents (N = 5,921) and use two state-of-the-art measurements to compute extended network sizes: network scale-up methods through Bayesian modeling and the observed number of contacts on Facebook. Among both measurements, we find that extended networks are larger among ethnic majority members, girls, and those who often engage in social foci. This highlights a crucial role for preferences and opportunity in the genesis of extended networks. Additionally, we find that differences between both network sizes (scale-up and Facebook) are smaller for girls and higher educated. We discuss the implications of these findings and suggest directions for future research.

Application of aerated biofilters for production of high quality water for industrial reuse in West Basin

2000 ◽  
Vol 41 (4-5) ◽  
pp. 417-424 ◽  
Author(s):  
V. Lazarova ◽  
J. Perera ◽  
M. Bowen ◽  
P. Sheilds
Keyword(s):  
Scale Up ◽  
Treatment Plant ◽  
Cooling Water ◽  
Free Water ◽  
Ammonia Removal ◽  
Negative Consequences ◽  
High Quality ◽  
Oil Refineries ◽  
Industrial Reuse ◽  
West Basin

The results of 5 years operation of 8 full-scale up-flow aerated Biofor® biofilters, installed at the West Basin Recycling Plant treatment plant (California), demonstrated the efficiency and reliability of this technology in the production of high quality ammonia free water for industrial reuse as cooling water in oil refineries. High nitrification rates up to 0.75 kg d−1 m−3 (0.047 lb d−1 ft−3) were obtained atwater velocities of 6.7 m h−1 (867.5 gpm). The hydraulic retention time in the biofilters was short without any negative consequences on the process. During all five years of operation, all Biofor® units demonstrated very reliable performances with 100% ammonia removal efficiency and very low residual suspended solids concentration of about 4.0 mg TSS L−1.

scholarly journals Infection prevention guidelines and considerations for paediatric risk groups when reopening primary schools during COVID-19 pandemic, Norway, April 2020

2020 ◽  
Vol 25 (22) ◽  
Author(s):  
Tone Bjordal Johansen ◽  
Elisabeth Astrup ◽  
Solveig Jore ◽  
Hege Nilssen ◽  
Bente Barton Dahlberg ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Primary Schools ◽  
Prevention And Control ◽  
Infection Prevention ◽  
Risk Groups ◽  
Infection Prevention And Control ◽  
Negative Consequences ◽  
School Closures ◽  
Prevention Guidelines ◽  
And Control

In response to the coronavirus disease (COVID-19) pandemic, most countries implemented school closures. In Norway, schools closed on 13 March 2020. The evidence of effect on disease transmission was limited, while negative consequences were evident. Before reopening, risk-assessment for paediatric risk groups was performed, concluding that most children can attend school with few conditions requiring preventative homeschooling. We here present infection prevention and control guidelines for primary schools and recommendations for paediatric risk groups.

scholarly journals Dissecting genetic and sex-specific sources of host heterogeneity in pathogen shedding and spread

2021 ◽  
Vol 17 (1) ◽  
pp. e1009196
Author(s):  
Jonathon A. Siva-Jothy ◽  
Pedro F. Vale
Keyword(s):  
Viral Load ◽  
Individual Variation ◽  
Disease Transmission ◽  
Genetic Background ◽  
Pathogen Transmission ◽  
Published Data ◽  
Virus Shedding ◽  
Transmission Potential ◽  
Sources Of Variation ◽  
Host Heterogeneity

Host heterogeneity in disease transmission is widespread but precisely how different host traits drive this heterogeneity remains poorly understood. Part of the difficulty in linking individual variation to population-scale outcomes is that individual hosts can differ on multiple behavioral, physiological and immunological axes, which will together impact their transmission potential. Moreover, we lack well-characterized, empirical systems that enable the quantification of individual variation in key host traits, while also characterizing genetic or sex-based sources of such variation. Here we used Drosophila melanogaster and Drosophila C Virus as a host-pathogen model system to dissect the genetic and sex-specific sources of variation in multiple host traits that are central to pathogen transmission. Our findings show complex interactions between genetic background, sex, and female mating status accounting for a substantial proportion of variance in lifespan following infection, viral load, virus shedding, and viral load at death. Two notable findings include the interaction between genetic background and sex accounting for nearly 20% of the variance in viral load, and genetic background alone accounting for ~10% of the variance in viral shedding and in lifespan following infection. To understand how variation in these traits could generate heterogeneity in individual pathogen transmission potential, we combined measures of lifespan following infection, virus shedding, and previously published data on fly social aggregation. We found that the interaction between genetic background and sex explained ~12% of the variance in individual transmission potential. Our results highlight the importance of characterising the sources of variation in multiple host traits to understand the drivers of heterogeneity in disease transmission.

scholarly journals Quantifying superspreading for COVID-19 using Poisson mixture distributions

2020 ◽  
Author(s):  
Cécile Kremer ◽  
Andrea Torneri ◽  
Sien Boesmans ◽  
Hanne Meuwissen ◽  
Selina Verdonschot ◽  
...  
Keyword(s):  
Negative Binomial Distribution ◽  
Individual Variation ◽  
Disease Transmission ◽  
Lognormal Distribution ◽  
Binomial Distribution ◽  
Negative Binomial ◽  
Mixture Distributions ◽  
Poisson Mixture ◽  
Transmission Process ◽  
The One

AbstractThe number of secondary cases is an important parameter for the control of infectious diseases. When individual variation in disease transmission is present, like for COVID-19, the number of secondary cases is often modelled using a negative binomial distribution. However, this may not be the best distribution to describe the underlying transmission process. We propose the use of three other offspring distributions to quantify heterogeneity in transmission, and we assess the possible bias in estimates of the offspring mean and its overdispersion when the data generating distribution is different from the one used for inference. We find that overdispersion estimates may be biased when there is a substantial amount of heterogeneity, and that the use of other distributions besides the negative binomial should be considered. We revisit three previously analysed COVID-19 datasets and quantify the proportion of cases responsible for 80% of transmission, p80%, while acknowledging the variation arising from the assumed offspring distribution. We find that the number of secondary cases for these datasets is better described by a Poisson-lognormal distribution.

The relationship between the use of sharp instruments and the risks associated with health service workers: a systematic review protocol

2021 ◽  
Vol 14 (3) ◽  
pp. 116-119
Author(s):  
Trajano Felipe Barrabas Xavier da Silva ◽  
Humberto Costa ◽  
Marcelo Montebello Ribeiro
Keyword(s):  
Systematic Review ◽  
Disease Transmission ◽  
Daily Practice ◽  
Relevant Information ◽  
Hospital Environment ◽  
Occupational Accidents ◽  
Negative Consequences ◽  
Systematic Review Protocol ◽  
Service Workers ◽  
Review Protocol

Work accidents are characterized as those resulting from the exercise of work in the service of a company, which can harm the worker. health care workers suffer from the risk of exposure to contaminants and sharps in their daily practice. The handling of perforating material predominates as a situation of exposure to occupational accidents among health professionals, being the main source of disease transmission within the hospital environment. Thus, a systematic review is proposed to obtain relevant information on these risks in order to plan appropriate future interventions to avoid related negative consequences. Thus, following the preferred reporting items for systematic reviews and meta-analyzes protocols (PRISMA-P), this systematic review protocol was developed in order to provide guidelines appropriate for the development of research that can deliver results to meet objective sought. Five databases will be accessed (SCOPUS, PubMed, Science Direct, EBSCOhost and Web of Science) and a total of 9 keyword combinations will be used. 

scholarly journals Stress, song and survival in sparrows

2009 ◽  
Vol 5 (6) ◽  
pp. 746-748 ◽  
Author(s):  
S. A. MacDougall-Shackleton ◽  
L. Dindia ◽  
A. E. M. Newman ◽  
D. A. Potvin ◽  
K. A. Stewart ◽  
...  
Keyword(s):  
Stress Response ◽  
Stress Responses ◽  
Individual Variation ◽  
Stress Reactivity ◽  
Negative Consequences ◽  
Transient Stress ◽  
Fitness Consequences ◽  
Stress Responsiveness ◽  
Song Development ◽  
Early Developmental

The stress response—increases in circulating glucocorticoids following a stressor—is typically considered adaptive, but few studies address the fitness consequences of individual variation in stress response. Generally, due to negative consequences of prolonged elevation of glucocorticoids, animals should have a transient stress response just sufficient to cope with the stressor. In rodents, stress responsiveness is affected by early developmental experience, and hyper-responsiveness to stress is linked to morbidity and mortality. We assessed individual variation in stress responses in free-living song sparrows, Melospiza melodia , in relation to fitness-related measures including song and overwinter survival. Birds with greater increases in corticosterone 30 min following restraint stress were less likely to return to breed the following year. Stress responsiveness was also correlated with song complexity: males with fewer syllables in their song repertoires had greater stress reactivity. Our findings support the hypothesis that developmental stressors both impair song development and affect the adult stress response. Thus, individual variation in the stress response may relate to variation in fitness.

scholarly journals Rural prioritization may increase the impact of COVID-19 vaccines in Sub-Saharan Africa due to ongoing internal migration: A modeling study

2021 ◽  
Author(s):  
Prashanth Selvaraj ◽  
Bradley G Wagner ◽  
Dennis L Chao ◽  
Maina L'Azou Jackson ◽  
J. Gabrielle Breugelmans ◽  
...  
Keyword(s):  
Internal Migration ◽  
Disease Transmission ◽  
Vaccination Campaign ◽  
Scale Up ◽  
Sub Saharan Africa ◽  
Age Group ◽  
Migration Rates ◽  
Urban Rural ◽  
Sub Saharan ◽  
The Impact

How COVID-19 vaccine is distributed within low- and middle-income countries has received little attention outside of equity or logistical concerns but may ultimately affect campaign impact in terms of infections, severe cases, or deaths averted. In this study we examined whether subnational (urban-rural) prioritization may affect the cumulative two-year impact on disease transmission and burden of a vaccination campaign using an agent-based model of COVID-19 in a representative Sub-Saharan Africa country setting. We simulated a range of vaccination strategies that differed by urban-rural prioritization, age group prioritization, timing of introduction, and final coverage level. Urban prioritization averted more infections in only a narrow set of scenarios, when internal migration rates were low and vaccination was started by day 30 of an outbreak. Rural prioritization was the optimal strategy for all other scenarios, e.g., with higher internal migration rates or later start dates, due to the presence of a large immunological naive rural population. Among other factors, timing of the vaccination campaign was important to determining maximum impact, and delays as short as 30 days prevented larger campaigns from having the same impact as smaller campaigns that began earlier. The optimal age group for prioritization depended on choice of metric, as prioritizing older adults consistently averted more deaths across all of the scenarios. While guidelines exist for these latter factors, urban-rural allocation is an orthogonal factor that we predict to affect impact and warrants consideration as countries plan the scale-up of their vaccination campaigns.

scholarly journals A Man, Who Never Stopped Dreaming of Humane India: Swami Agnivesh

2020 ◽  
Vol 8 (2) ◽  
pp. 74-83
Author(s):  
Venkat Rao Pulla ◽  
Bharath Bhushan Mamidi
Keyword(s):  
Social Activism ◽  
Scale Up ◽  
The Political ◽  
Contemporary History ◽  
Negative Consequences ◽  
Social Activists ◽  
History Of ◽  
The Common ◽  
The Government ◽  
Definition Of

We share two observations based on what we have seen in India. First, that the hegemonic politics in India ushered in institutional and structural inequalities in their wake and second, that the political leadership continued to be aspirational irrespective of ideologies desiring to scale up in the hierarchy of global economic and political power. These two observations pertain to the contemporary history of five decades of development in India. As a result of the above two observations, we make a further two observations that for the Aām Aādmi (the common man), the political parties that sit in the government and their respective ideologies do not matter. And for the state and the political elites, the negative consequences such as marginalisation, exclusion and desperation of the common folks that emanate from the models chosen for development do not matter.   It is in such contexts, social activists argue for a legitimate space for the vying intersects of poverty, caste, class, occupations, habitats amidst such motivated globalisation. They also continue to raise difficult conversations around patriarchy, religious hierarchy, bonded labour, and the girl child.  One such social activist that was concerned about all the above issues was Swami Agnivesh.  He was not antigovernment, anti-democracy, anti-institutional, anti-hierarchy, anti-religious. He sought to restore a new and deeper meaning of freedom (democracy), a new meaning of hierarchy, social care, and even a new definition of spirituality that is social. He was a man who never stopped dreaming of humanising India. In this article, we reminisce about our association with Swami Agnivesh and attempt to espouse his thought based on our hearing, reading, and reflection.    Briefly, we present his life, achievements, and social activism, and more importantly, we attempt to interpret his conception of social spirituality and the ‘power of love’.

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