Risk Of Infectious Diseases Research Articles

Evaluation of the knowledge, attitudes, vaccine hesitancy, and behaviors of anesthesia technicians on adult vaccination

Background: Anesthesia technicians work in places with a high risk of infectious diseases. Vaccination is one of the most essential methods that protect society and healthcare workers against infectious diseases. This study aims to determine anesthesia technicians' knowledge, behavior, attitude, and vaccine hesitancy. Methods: A cross-sectional web-based study was conducted between October 2021 and February 2022 at the Ankara Yildirim Beyazit University, Turkiye. A semi-structured and self-reported online survey was recruited to collect data from the Turkish anesthesia technicians’ community. Data of 1600 participants have undergone descriptive and univariate analyses to evaluate the differences in mean scores on knowledge, attitudes, and vaccine hesitancy. Results: The mean age of respondents was 24 years (±6.15). More than two-thirds (79.2%) were females, single (84.9%), aged less than 30 years (88.4%), and unemployed (61.1%); however, 12.4% had chronic diseases. The mean knowledge, attitude, and vaccine hesitancy score were 13.24± 3.22 (range: 0-21), 11.19 ± 3.19 (range: 0-15), and 28.67± 6.64, range: 12–60), respectively. Most respondents had information (1458, 91.1%) about COVID-19 vaccines, and 1247(77.9%) had been vaccinated. However, 240 (16.3%) did not receive vaccines at all compared to 59 (3.7%) who completed the thirteen recommended vaccines in Turkiye. The mean of vaccine hesitancy was significantly higher among females (P=0.001), unemployed (P=0.007), residents in Southeast Anatolia (P=0.001), and those who did not use medication continuously (P=0.016). However, participants aged 40 years and above (P=0.013) showed the lowest mean of vaccine hesitancy than the other age groups. Conclusion: Appropriate training and guidance might increase the vaccination information and enhance the vaccination rates among anesthesia technicians.

Latency period of PROM at term and the risk of neonatal infectious diseases

To find the risk of time thresholds of PROM for infectious diseases of term neonates. A multi-center prospective cohort study including pregnancies with PROM at term with a single fetus were conducted. Time thresholds of the duration from PROM to delivery were examined in 2-h increments to assess the rates of infectious neonatal diseases. 7019 pregnancies were included in the study. Neonatal pneumonia and sepsis were most frequent infectious diseases in neonates born from mother with PROM at term. Rates of early-onset pneumonia varied significantly when comparing length of time of PROM greater than 16 h vs. less than 16 h (for EOP in 3 days of life, adjusted OR 1.864, 95% CI 1.159 ~ 2.997, p = 0.010; for EOP in 7 days of life, adjusted OR 1.704, 95% CI 1.104 ~ 2.628, p = 0.016). Neonates born from mother of whom the length of time from PROM to delivery ≥ 16 h were at a higher risk of acquiring EOP.

Neonatal Antibiotic Treatment Can Affect Stool Pattern and Oral Tolerance in Preterm Infants.

Preterm neonates are at high risk of infectious and inflammatory diseases which require antibiotic treatment. Antibiotics influence neonatal gut microbiome development, and intestinal dysbiosis has been associated with delayed gastrointestinal transit. Neonates who take less time to pass meconium have a better tolerance to enteral feeding. We analyzed the effect of neonatal antibiotic treatment on the stool pattern and oral tolerance in 106 preterm infants < 33 weeks gestational age. Neonates were classified in 3 groups according to neonatal antibiotic (ABT) treatment days: no antibiotics, 3–7 d ABT, and ≥8 d ABT. Preterm infants from the ≥8 d ABT group took longer to pass meconium and to start green and yellow stools, took longer to reach 100 and 150 mL/kg/day, and reached reduced volumes in enteral feeds at day of life 14 and 28 than infants from no ABT and 3–7 d ABT groups. Multiple linear regression models showed that neonatal antibiotic treatment, birth weight, invasive mechanical ventilation, surfactant, enteral feeding start day, neonatal parenteral nutrition, and neonatal fasting days are associated with the stool pattern and oral tolerance in preterm infants.

Factors influencing emergency nurses’ infection control practices related to coronavirus disease 2019 in Korea

BackgroundWhen an infectious disease breaks out, emergency nurses are the front-line specialists. Infection control by emergency nurses is important to minimize the risk of infectious disease and to improve the infection control practices of emergency nurses. Therefore, it is crucial to identify the factors influencing infection control practice related to COVID-19. MethodsFor this cross-sectional study design used survey methods for data collection, a questionnaire survey was conducted with 161 emergency nurses working in five hospitals selected through convenience sampling. Data were collected from November 10 to November 26 in 2020. ResultsInfection control practice related to COVID-19 was affected by the infection prevention environment (β = 0.24, p = .002), monitoring of wearing Personal Protective Equipment (β = 0.19, p = .006), knowledge about COVID-19 (β = 0.18, p = .009), perceived severity related to COVID-19 (β = 0.18, p = .010), and perceived barrier related to COVID-19 (β = −0.15, p = .033). ConclusionCreating safe infection prevention measures and revitalizing personal protective equipment monitoring are necessary to improve infection control practices. A systematic infection control education program is needed to improve knowledge about COVID-19, emphasize its perceived severity, and identify and eliminate perceived barriers.

The Relationship between Vector Species Richness and the Risk of Vector-Borne Infectious Diseases

AbstractInfectious diseases can impact human welfare and impede wildlife management. Much recent research explores whether biodiversity increases or decreases infectious disease risk. Here, we theoretically study the relationship between vector species richness and the risk of vector-borne diseases using an epidemiological model of a single host and multiple vectors. The model considers that vectors are involved in interspecific feeding interference that causes transmission interference and in interspecific recruitment competition that mediates susceptible vector regulation. The model reveals three possible shapes of the vector richness-disease risk relationship: monotonic amplification, hump-shaped, and monotonic dilution patterns. The monotonic amplification pattern occurs across a wide parameter region. The hump-shaped and monotonic dilution patterns are found when transmission interference is strong and recruitment competition is weak. Unexpectedly, susceptible vector regulation not only promotes dilution but can strengthen amplification if coupled with strong transmission interference. Our results suggest that vector richness might be more likely to cause amplification rather than dilution, and shifts in the community mean trait values of vectors could also affect disease risk along the vector richness gradient.

The association between fetal gender in twin pregnancies and the risk of pediatric infectious diseases of the offspring: A population-based cohort study with long-term follow up.

We aimed to study the association between fetal gender in twin pregnancies and the risk for childhood infectious morbidity of the offspring. A population-based cohort analysis was performed comparing total and subtypes of infectious related pediatric hospitalizations among males versus females offspring of twin pregnancies. The analysis included all dichorionic twins born between the years 1991-2021. A Kaplan-Meier survival curve was used to compare the cumulative infectious morbidity incidence, and a Cox proportional hazards model was constructed to adjust for confounders. The study population included 4222 newborns (2111 males and 2111 females). Males had higher rates of infectious-related hospitalizations using a Cox proportional hazards model, an independent association was shown between male gender and infectious related hospitalizations of the offspring (Adjusted HR = 1.2, 95% CI: 1.1-1.4; p < 0.001). Male gender in twin pregnancies is associated with an increased risk for long-term pediatric infectious morbidity.

Aerosol emissions from wind instruments: effects of performer age, sex, sound pressure level, and bell covers

Aerosol emissions from wind instruments are a suspected route of transmission for airborne infectious diseases, such as SARS-CoV-2. We evaluated aerosol number emissions (from 0.25 to 35.15 μm) from 81 volunteer performers of both sexes and varied age (12 to 63 years) while playing wind instruments (bassoon, clarinet, flute, French horn, oboe, piccolo, saxophone, trombone, trumpet, and tuba) or singing. Measured emissions spanned more than two orders of magnitude, ranging in rate from < 8 to 1,815 particles s−1, with brass instruments, on average, producing 191% (95% CI 81–367%) more aerosol than woodwinds. Being male was associated with a 70% increase in emissions (vs. female; 95% CI 9–166%). Each 1 dBA increase in sound pressure level was associated with a 28% increase (95% CI 10–40%) in emissions from brass instruments; sound pressure level was not associated with woodwind emissions. Age was not a significant predictor of emissions. The use of bell covers reduced aerosol emissions from three brass instruments tested (trombone, tuba, and trumpet), with average reductions ranging from 53 to 73%, but not for the two woodwind instruments tested (oboe and clarinet). Results from this work can facilitate infectious disease risk management for the performing arts.

Comparison of Bacterial Risk in Cryo AHF and Pathogen Reduced Cryoprecipitated Fibrinogen Complex.

Until November 2020, cryoprecipitated antihaemophilic factor (cryo AHF) was the only United States Food and Drug Administration (FDA)-approved fibrinogen source to treat acquired bleeding. The post-thaw shelf life of cryo AHF is limited, in part, by infectious disease risk. Concerns over product wastage demand that cryo AHF is thawed as needed, with thawing times delaying the treatment of coagulopathic patients. In November 2020, the FDA approved Pathogen Reduced Cryoprecipitated Fibrinogen Complex for the treatment and control of bleeding, including massive hemorrhage, associated with fibrinogen deficiency. Pathogen Reduced Cryoprecipitated Fibrinogen Complex (also known as INTERCEPT® Fibrinogen Complex, IFC) has a five-day post-thaw room-temperature shelf life. Unlike cryo AHF, manufacturing of IFC includes broad spectrum pathogen reduction (Amotosalen + UVA), enabling this extended post-thaw shelf life. In this study, we investigated the risk of bacterial contamination persisting through the cryoprecipitation manufacturing process of cryo AHF and IFC. Experiments were performed which included spiking plasma with bacteria prior to cryoprecipitation, and bacterial survival was analyzed at each step of the manufacturing process. The results show that while bacteria survive cryo AHF manufacturing, IFC remains sterile through to the end of shelf life and beyond. IFC, with a five-day post-thaw shelf life, allows the product to be sustainably thawed in advance, facilitating immediate access to concentrated fibrinogen and other key clotting factors for the treatment of bleeding patients.

Risk of Severe Coronavirus Disease 2019 Disease in Individuals With Down Syndrome: A Matched Cohort Study From a Large, Integrated Health Care System.

BackgroundDown syndrome (DS) is associated with an increased risk of infections attributed to immune defects. Whether individuals with DS are at an increased risk of severe coronavirus disease 2019 (COVID-19) remains unclear.MethodsIn a matched cohort study, we evaluated the risk of COVID-19 infection and severe COVID-19 disease in individuals with DS and their matched counterparts in a pre-COVID-19 vaccination period at Kaiser Permanente Southern California. Multivariable Cox proportion hazard regression was used to investigate associations between DS and risk of COVID-19 infection and severe COVID-19 disease.ResultsOur cohort included 2541 individuals with DS and 10 164 without DS matched on age, sex, and race/ethnicity (51.6% female, 53.3% Hispanic, median age 25 years [interquartile range, 14–38]). Although the rate of COVID-19 infection in individuals with DS was 32% lower than their matched counterparts (adjusted hazard ratio [aHR], 0.68; 95% confidence interval [CI], .56–.83), the rate of severe COVID-19 disease was 6-fold higher (aHR, 6.14; 95% CI, 1.87–20.16).ConclusionsAlthough the risk of COVID-19 infection is lower, the risk of severe disease is higher in individuals with DS compared with their matched counterparts. Better infection monitoring, early treatment, and promotion of vaccine for COVID-19 are warranted for DS populations.

Investigating associations between nematode infection and three measures of sociality in Asian elephants

Frequent social interactions, proximity to conspecifics, and group density are main drivers of infections and parasite transmissions. However, recent theoretical and empirical studies suggest that the health benefits of sociality and group living can outweigh the costs of infection and help social individuals fight infections or increase their infection-related tolerance level. Here, we combine the advantage of studying artificially created social work groups with different demographic compositions with free-range feeding and social behaviours in semi-captive Asian elephants (Elephas maximus), employed in timber logging in Myanmar. We examine the link between gastro-intestinal nematode load (strongyles and Strongyloides spp.), estimated by faecal egg counts, and three different aspects of an elephant’s social world: individual solitary behaviour, work group size, and work group sex ratio. Controlling for sex, age, origin, time since last deworming treatment, year, human sampler bias, and individual identity, we found that infection by nematodes ranged from 0 to 2720 eggs/g between and within 26 male and 45 female elephants over the 4-year study period. However, such variation was not linked to any investigated measures of sociality in either males or females. Our findings highlight the need for finer-scale studies, establishing how sociality is limited by, mitigates, or protects against infection in different ecological contexts, to fully understand the mechanisms underlying these pathways.Significance statementBeing social involves not only benefits, such as improved health, but also costs, including increased risk of parasitism and infectious disease. We studied the relationship between and three different sociality measures—solitary behaviour, group size, and the proportion of females to males within a group—and infection by gut nematodes (roundworms), using a unique study system of semi-captive working Asian elephants. Our system allows for observing how infection is linked to sociality measures across different social frameworks. We found that none of our social measures was associated with nematode infection in the studied elephants. Our results therefore suggest that here infection is not a large cost to group living, that it can be alleviated by the benefits of increased sociality, or that there are weak infection–sociality associations present which could not be captured and thus require finer-scale measures than those studied here. Overall, more studies are needed from a diverse range of systems that investigate specific aspects of social infection dynamics.

Study and comparison of population density indices of Ixodes ticks of different biotopes of Kyiv and Cherkasy regions

Ixodes ticks play an important role in the spread of various infectious diseases. Representatives of the Ixodes family carry a large number of pathogens. Zoonotic infections, such as tick-borne borreliosis, tick-borne encephalitis, ehrlichiosis, anaplasmosis, etc., are especially dangerous. Areas of distribution of Ixodes ticks are quite diverse: forests, meadows, shrubs, city parks and various types of green spaces in cities. The study of the quantitative and species composition of ticks in natural foci of infectious diseases is an important component of assessing the epizootiological biopotential and forecasting the risks of infectious diseases in certain areas. In the studies, we studied and compared the distribution of Ixodes ticks based on the population density index of Ixodes ricinus and Dermacentor reticulatus in two different habitats: anthropogenically transformed semi-natural forest environment and meadow-type with pastures. The first – the forest area is located in the forest park tract "Golendernya" in Bila Tserkva, Kyiv region. The second – a natural meadow area is located in the Cherkasy region, Lysyansk United Territorial Community (OTG), village Zhabianka. Collection of Ixodes was performed by the usual method on the flag. The population density index is expressed in relation to the number of ticks per 1 m2 of the surveyed area with a correction factor of 1.2. A total of 12,000 m2 of total habitat area was surveyed, 572 specimens of Ixodes ticks were collected, including 393 Ixodes ricinus and Dermacentor reticulatus 179, respectively. 356 Ixodes ticks were collected in the Golendernia tract, of which 339 were Ixodes ricinus and only 17 were Dermacentor reticulatus. Accordingly, in Golendernia tract the population density index of the surveyed area of 6 thousand m2 Ixodes ricinus is 0.07 specimens/m2 (95.9%) and Dermacentor reticulatus – 0.003 specimens/m2 (4.1%). 216 specimens of Ixodes ticks were collected in the natural meadow biotope, of which 162 – Dermacentor reticulatus and 54 – Ixodes ricinus. The population density index of the surveyed area of 6 thousand m2 in the meadow biotope with mites of the species Dermacentor reticulatus is 0.03 specimens/m2 (75.0%), and with mites of the species Ixodes ricinus – 0.01 specimens/m2. (25.0%). Population density indices between Ixodes ricinus and Dermacentor reticulatus have a statistically significant difference (p &lt;0.01) which is due to the types of habitats. Key words: Ixodes tiks, Ixodes ricinus, Dermacentor reticulatus, population density index, habitats.

Social Network Analysis on the Mobility of Three Vulnerable Population Subgroups: Domestic Workers, Flight Crews, and Sailors during the COVID-19 Pandemic in Hong Kong.

Background: Domestic workers, flight crews, and sailors are three vulnerable population subgroups who were required to travel due to occupational demand in Hong Kong during the COVID-19 pandemic. Objective: The aim of this study was to explore the social networks among three vulnerable population subgroups and capture temporal changes in their probability of being exposed to SARS-CoV-2 via mobility. Methods: We included 652 COVID-19 cases and utilized Exponential Random Graph Models to build six social networks: one for the cross-sectional cohort, and five for the temporal wave cohorts, respectively. Vertices were the three vulnerable population subgroups. Edges were shared scenarios where vertices were exposed to SARS-CoV-2. Results: The probability of being exposed to a COVID-19 case in Hong Kong among the three vulnerable population subgroups increased from 3.38% in early 2020 to 5.78% in early 2022. While domestic workers were less mobile intercontinentally compared to flight crews and sailors, domestic workers were 1.81-times in general more likely to be exposed to SARS-CoV-2. Conclusions: Vulnerable populations with similar ages and occupations, especially younger domestic workers and flight crew members, were more likely to be exposed to SARS-CoV-2. Social network analysis can be used to provide critical information on the health risks of infectious diseases to vulnerable populations.

Real-time Monitoring of the Environment Gases within the UV-NIR Regions

Indoor air quality and environmental monitoring, particularly during the coronavirus (COVID-19) pandemic are vital and in need. The main purpose of monitoring the air quality is that the infected area may increase the risk of spreading infectious diseases of COVID-19. Therefore, real-time and non-contact measurements are more necessary for the current situation to monitor the indoor area air quality. In this study, we propose an optical method for monitoring indoor air quality in fast and accurate tracking of ultraviolet (UV), visible, and near-infrared (IR) indoor atmospheric gases using the natural sunlight and spectrometer. The proposed method is portable, non-contact, and real-time spectroscopy screening of the Oxygen (O2), Ozone (O3), and water vapour through the analysis of their absorption characteristics. The absorption peaks and light intensities of O2 at 630 nm, 685 nm, and 758; O3 at 380 nm, 390 nm, 427 nm, 481 nm, 522 nm; and H2O at 718 nm and 820 nm have been monitored at different weather conditions. Further to provide air pollution’s effect through tracking the absorption peaks and intensity for each gas, the proposed method might help identify the infected area potential of COVID-19 under practical scenarios such as pre-inspection in houses, shops, hospitals, and schools. The data are of great importance, particularly for population groups and individuals most vulnerable to COVID-19. Considering factors such as safety, stability, and price, this simple technology is the most suitable for real applications.

Optimization of ventilation performance of side air supply for large indoor spaces using deflectors and slot air outlets

Due to the large height and span of indoor spaces, efficient indoor ventilation performance may be difficult to achieve using the side air supply for large halls, to control the indoor air pollutants or reduce the infection risk, such as the transmission of COVID-19 within the breathing zone of occupants. An efficient Ventilation Mode with Deflector and Slot air outlets (VMDS) was developed by this study. The use of a deflector with slot air outlets was introduced by utilizing jet collision and adhesion effect to accentuate the ventilation performance of the side air supply for the large space. The numerical simulation model used in this study was validated experimentally. The VMDS was compared with three other side air supply modes used in large spaces, and the results were evaluated comprehensively. The results show that VMDS is effective in reducing indoor air pollutant concentrations and transmission of infectious diseases in large spaces while satisfying the energy efficiency and thermal comfort requirements. Compared with the common side-supply and side-return ventilation modes, VMDS can reduce indoor air pollutant concentration by nearly 40%, reduce the transmission risk of infectious disease to less than 1% at a low air change rate and increase the ventilation efficiency from about 0.85 to about 1.2. In addition, VMDS can theoretically reduce ventilation energy consumption by about 85%.

Cascading Risks for Preventable Infectious Diseases in Children and Adolescents during the 2022 Invasion of Ukraine

Russia’s military incursion into Ukraine triggered the mass displacement of two-thirds of Ukrainian children and adolescents, creating a cascade of population health consequences and producing extraordinary challenges for monitoring and controlling preventable pediatric infectious diseases. From the onset of the war, infectious disease surveillance and healthcare systems were severely disrupted. Prior to the reestablishment of dependable infectious disease surveillance systems, and during the early months of the conflict, our international team of pediatricians, infectious disease specialists, and population health scientists assessed the health implications for child and adolescent populations. The invasion occurred just as the COVID-19 Omicron surge was peaking throughout Europe and Ukrainian children had not received COVID-19 vaccines. In addition, vaccine coverage for multiple vaccine-preventable diseases, most notably measles, was alarmingly low as Ukrainian children and adolescents were forced to migrate from their home communities, living precariously as internally displaced persons inside Ukraine or streaming into European border nations as refugees. The incursion created immediate impediments in accessing HIV treatment services, aimed at preventing serial transmission from HIV-positive persons to adolescent sexual or drug-injection partners and to prevent vertical transmission from HIV-positive pregnant women to their newborns. The war also led to new-onset, conflict-associated, preventable infectious diseases in children and adolescents. First, children and adolescents were at risk of wound infections from medical trauma sustained during bombardment and other acts of war. Second, young people were at risk of sexually transmitted infections resulting from sexual assault perpetrated by invading Russian military personnel on youth trapped in occupied territories or from sexual assault perpetrated on vulnerable youth attempting to migrate to safety. Given the cascading risks that Ukrainian children and adolescents faced in the early months of the war—and will likely continue to face—infectious disease specialists and pediatricians are using their international networks to assist refugee-receiving host nations to improve infectious disease screening and interventions.

Wastewater surveillance for rapid identification of infectious diseases in prisons

Wastewater surveillance for rapid identification of infectious diseases in prisons

Clinical and financial burden of spinal infections in people who inject drugs.

People who inject drugs (PWID) are known to be at increased risk of infectious diseases including bacterial and blood-borne viral infections. However, there is limited literature surrounding the burden of spinal infections as a complication of injecting drug use (IDU). To quantify the clinical and financial burden of IDU-related spinal infections. Retrospective chart review of adult PWID with spinal infections requiring hospital admission to a tertiary health service in Melbourne, Australia between 2011 and 2019. Fifty-seven PWID with 63 episodes of spinal infections were identified with a median hospital stay of 47 days (interquartile range (IQR) 16; range 4-243 days). One-third of episodes required neurosurgical intervention and 11 (17%) episodes required intensive care unit admission (range 2-17 days). Staphylococcus aureus was the most common causative pathogen, present in three-quarters of all episodes (n=47). The median duration of antibiotic regime was 59 days (IQR 42) and longer courses were associated with known bacteraemia (P=0.048), polymicrobial infections (P=0.001) and active IDU (P=0.066). Predictors of surgery include neurological symptoms at presentation (relative risk (RR) 2.6; P=0.010), inactive IDU status (RR 3.0; P=0.002), a diagnosis of epidural abscess (RR 4.1; P=0.001) and spinal abscess (RR ∞; P < 0.001). Completion of planned antimicrobial therapy was reported in 51 (82%) episodes. Average expenditure per episode was A$61 577. Spinal infections in PWID are an underreported serious medical complication of IDU. Although mortality is low, there is significant morbidity with prolonged admissions, large antimicrobial requirements and surgical interventions generating a substantial cost to the health system.

Ethical considerations during a pioneering surgical procedure: porcine cardiac xenotransplantation.

Preclinical advances in life-sustaining porcine cardiac xenotransplantation from donor pigs to baboons have paved the way for the performance of porcine cardiac xenotransplantation in a human. This procedure was performed with emergency use authorisation granted by the United States Food and Drug Administration under the umbrella of investigational new drug use on compassionate grounds. The patient was denied candidacy for durable mechanical circulatory support and heart transplantation as a result of non-adherence to medical advice. Successful porcine cardiac xenotransplantation in humans will significantly increase the availability of potential donor organs for long-term management of end-stage heart failure. Human porcine cardiac xenotransplantation is associated with ethical conflicts encompassing multiple ethical principles which are not mutually exclusive and are sometimes conflicting. This article focuses on some of the ethical conflicts encountered in relation to the use of mechanical circulatory support, pretransplant evaluation, shared decision making during informed consent, infectious disease risk, preclinical and clinical testing, and the role of regulatory bodies during performance of the first human porcine cardiac xenotransplantation. An increase in human trials of xenotransplantation procedures is imminent. Potential ethical conflicts associated with xenotransplantation should be addressed appropriately.

Effects of dietary Hericium erinaceus powder on growth, hematology, disease resistance, and expression of genes related immune response against thermal challenge of Nile tilapia (Oreochromis niloticus)

Functional feed additives have been promising possibilities for improving fish immune function. The present study attempts to investigate the effect of dietary Hericium erinaceus (HE) supplementation on growth performance, hematology, disease resistance, and expression of genes related immune response against thermal challenge in Nile tilapia. Four isonitrogenous and isolipidic diets were prepared: a control diet without HE supplementation (HE0), HE supplementation at 5 g/kg (HE5), 10 g/kg (HE10), and 20 g/kg (HE20). Each diet was fed to quadruplicate groups of Nile tilapia (9.96 ± 0.01 g/fish) to apparent satiation two times daily for 10 weeks. The dietary HE supplementation promoted protein productive value with a quadratic effect (P = 0.002) although it had no significant effect on other growth and feed utilization parameters (P > 0.05). In addition, the dietary HE supplementation linearly increased red blood cell count, hematocrit, and hemoglobin content (P ≤ 0.001) and quadratically increased the contents of protein and albumin, as well as the alkaline phosphatase activity (P < 0.05). The aspartate aminotransferase activity was linearly and quadratically decreased (P = 0.037, 0.017), and the plasma cortisol level was linearly decreased by increasing HE levels (P = 0.001). The microbial resistance of Nile tilapia against Streptococcus agalactiae increased in all HE-supplemented groups compared to the control group in association with the significant increases in hepatic mRNA levels of genes related immunity, including TNF-α, IL-1β, IL-6, IL-10, and TGF-β. The dietary HE supplementation did not significantly affect the pre-thermal challenge expression of HSP70cB1 mRNAs (P > 0.05), but significantly decreased HSP70cB1 transcripts and plasma cortisol levels after thermal stress challenge (P < 0.05). Therefore, it is suggested that HE at 10 g/kg can be used as a feed additive that enhances the immunity response, reduces the risk of infectious diseases caused by S. agalactiae, and improved thermal stress resistance in Nile tilapia culture.

Understanding the relative risks of zoonosis emergence under contrasting approaches to meeting livestock product demand.

It has been argued that intensive livestock farming increases the risk of pandemics of zoonotic origin because of long-distance livestock movements, high livestock densities, poor animal health and welfare, low disease resistance and low genetic diversity. However, data on many of these factors are limited, and analyses to date typically ignore how land use affects emerging infectious disease (EID) risks, and how these risks might vary across systems with different yields (production per unit area). Extensive, lower yielding practices typically involve larger livestock populations, poorer biosecurity, more workers and more area under farming, resulting in different, but not necessarily lower, EID risks than higher yielding systems producing the same amount of food. To move this discussion forward, we review the evidence for each of the factors that potentially link livestock production practices to EID risk. We explore how each factor might vary with yield and consider how overall risks might differ across a mix of production systems chosen to reflect in broad terms the current livestock sector at a global level and in hypothetical low- and high-yield systems matched by overall level of production. We identify significant knowledge gaps for all potential risk factors and argue these shortfalls in understanding mean we cannot currently determine whether lower or higher yielding systems would better limit the risk of future pandemics.