Audiogenic Stress and Susceptibility to Infection

1970 ◽  
pp. 7-19 ◽  
Author(s):  
Marcus M. Jensen ◽  
A. F. Rasmussen
Keyword(s):  
Susceptibility To Infection ◽  
Audiogenic Stress

Gene Polymorphisms and Their Association to Coronavirus Family Infections: Susceptibility in Different Populations

2020 ◽  
Vol 5 ◽  
Keyword(s):  
Genetic Variants ◽  
Viral Infections ◽  
Human Leukocyte ◽  
Asian Population ◽  
African Region ◽  
Mediterranean Populations ◽  
Susceptibility To Infection ◽  
Asian Populations ◽  
Spread Pattern ◽  
Different Populations

Human leukocyte antigen (HLA) loci are highly polymorphic and determine differential features of the immune response in subjects from different regions. HLA genes have been proposed to determine genetic susceptibility to several diseases, particularly to viral infections. Moreover, it has been suggested that each ethnic group could have a different specificity of T-lymphocyte reactivity to the same viral infections. In this review, we analyzed the distribution of HLA types in countries of the Asian, European and North African region. Also, we studied the relation between these HLA polymorphisms and susceptibility to infection by the coronavirus. Our findings indicated that homozygosity would increase susceptibility to viral infections and, in some cases, to coronavirus infection. HLA types showing higher susceptibility were reported in Asian population, including China, Singapore, and Taiwan. In contrast, lower susceptibility HLA variants were detected among African populations, some Asian populations, and Mediterranean populations. The presented evidence along with the spread pattern of COVID-19 infection suggests that HLA genetic variants might be related to its infection susceptibility and severity. The investigation of HLA genetic variants distribution would be a useful tool to predict different populations’ susceptibility to viral infections.

Intestinal microbiota balance modulates host susceptibility to infection with enteric pathogenss

2007 ◽  
Vol 30 (4) ◽  
pp. 93
Author(s):  
I Sekirov ◽  
N Tam ◽  
M Robertson ◽  
C Lupp ◽  
B Finlay
Keyword(s):  
Intestinal Microbiota ◽  
Small Animal ◽  
Host Susceptibility ◽  
Morphological Development ◽  
Future Design ◽  
Susceptibility To Infection ◽  
Colonic Microbiota ◽  
Food Borne ◽  
Serovar Typhimurium ◽  
Intestinal Pathogens

Background: During our lifetimes we develop a very complex set of interactions with the multitude of microorganisms colonizing our bodies. In the gastrointestinal system, the microbiota is highly important for morphological development, nutrition, and protection against infectious diseases. The gastrointestinal pathogens, enterohemorrhagic and enteropathogenic Escherichia coli (EHEC and EPEC) and Salmonella enterica serovar Typhimurium (ST) are food-borne pathogens that cause much morbidity and mortality worldwide. Citrobacter rodentium (Cr) is a mouse pathogen that is used in small animal models to mimic EHEC and EPEC infections. Methods: We began to characterize the contribution of intestinal microbiota to the progression of these infections. Two main phyla comprise the majority of mouse intestinal microbiota: Bacteroidetes and Firmicutes. Bacteria from a number of additional phyla are also present in smaller numbers; among them γ-Proteobacteria class, belonging to Proteobacteria phylum, is note-worthy as this class harbours many intestinal pathogens, such as ST and Cr. The mouse intestinal microbiota was perturbed using tetracycline (Tet) and streptomycin (Sm) to increase the proportion of Bacteroidetes in the colonic microbiota, and using vancomycin (Vanc) to create a predominance of Firmicutes. The mice with this perturbed microbiota were infected with ST to investigate the resultant pathology and virulence characteristics, and any additional shifts in microbiota as a result of infection. Results: Treatment of mice with Sm and Vanc was found to decrease the resistance of mice to colonization with ST, while Tet-treated mice exhibited unchanged colonization resistance. Treatment of mice with gradually increasing doses of Sm, which gradually augmented the proportion of CFB bacteria in the microbiota, resulted in progressively increasing colonization of mice by ST, as well as a step-wise increase in the ST-induced typhlitis, associated with higher levels of inflammatory markers IL-6 and KC. The increasing levels of ST colonization following both Sm and Vanc treatment were associated with an increase in the proportion of γ-Proteobacteria in the cecal and colonic microbiota, as well as a decrease in the total bacterial numbers in both organs. Conclusions: It is evident that the intestinal microbiota plays a significant role in the host’s response to infection with enteric pathogens, and its composition and numbers are also affected by the offending bacteria. Elucidation of the details regarding the contribution of the microbiota to infectious disease progression will offer novel targets for the future design of superior prevention and treatment methods.

scholarly journals COVID-19 vaccines that reduce symptoms but do not block infection need higher coverage and faster rollout to achieve population impact

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
David A. Swan ◽  
Chloe Bracis ◽  
Holly Janes ◽  
Mia Moore ◽  
Laura Matrajt ◽  
...  
Keyword(s):  
Mathematical Model ◽  
No Reduction ◽  
King County ◽  
Symptomatic Disease ◽  
Population Impact ◽  
Susceptibility To Infection ◽  
Infection Susceptibility ◽  
Asymptomatic Infections ◽  
The U.S

AbstractTrial results for two COVID-19 vaccines suggest at least 90% efficacy against symptomatic disease (VEDIS). It remains unknown whether this efficacy is mediated by lowering SARS-CoV-2 infection susceptibility (VESUSC) or development of symptoms after infection (VESYMP). We aim to assess and compare the population impact of vaccines with different efficacy profiles (VESYMP and VESUSC) satisfying licensure criteria. We developed a mathematical model of SARS-CoV-2 transmission, calibrated to data from King County, Washington. Rollout scenarios starting December 2020 were simulated with combinations of VESUSC and VESYMP resulting in up to 100% VEDIS. We assumed no reduction of infectivity upon infection conditional on presence of symptoms. Proportions of cumulative infections, hospitalizations and deaths prevented over 1 year from vaccination start are reported. Rollouts of 1 M vaccinations (5000 daily) using vaccines with 50% VEDIS are projected to prevent 23–46% of infections and 31–46% of deaths over 1 year. In comparison, vaccines with 90% VEDIS are projected to prevent 37–64% of infections and 46–64% of deaths over 1 year. In both cases, there is a greater reduction if VEDIS is mediated mostly by VESUSC. The use of a “symptom reducing” vaccine will require twice as many people vaccinated than a “susceptibility reducing” vaccine with the same 90% VEDIS to prevent 50% of the infections and death over 1 year. Delaying the start of the vaccination by 3 months decreases the expected population impact by more than 50%. Vaccines which prevent COVID-19 disease but not SARS-CoV-2 infection, and thereby shift symptomatic infections to asymptomatic infections, will prevent fewer infections and require larger and faster vaccination rollouts to have population impact, compared to vaccines that reduce susceptibility to infection. If uncontrolled transmission across the U.S. continues, then expected vaccination in Spring 2021 will provide only limited benefit.

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