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1.
Proc Natl Acad Sci U S A ; 119(14): e2106005119, 2022 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-35344423

RESUMO

SignificanceSome viruses that infect bacteria, temperate bacteriophages, can confer immunity to infection by the same virus. Here we report λ-immune bacteria could protect λ-sensitive bacteria from killing by phage λ in mixed culture. The protection depended on the extent to which the immune bacteria were able to adsorb the phage. Reconciling modeling with experiment led to identifying a decline in protection as bacteria stopped growing. Adsorption of λ was compromised by inhibition of bacterial energy metabolism, explaining the loss of protection as bacterial growth ceased.


Assuntos
Bacteriófagos , Bacteriófago lambda/genética , Escherichia coli/metabolismo
2.
J Infect Dis ; 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38470214

RESUMO

BACKGROUND: In Denmark, a girls-only human papillomavirus (HPV) vaccination program was initiated in 2008-2009. The study aim was to assess the HPV prevalence and type distribution in younger men prior to HPV vaccination in men. METHODS: The study population was younger men who attended information days regarding military service. At random days (2019-2020), 280 men were included. We collected questionnaire data regarding risk factors for HPV infection and a penile swab for HPV testing. We compared results in this study with those from a previous study of young men (2006-2007). RESULTS: The majority of participants (94%) were 18-20 years old. The median number of lifetime sexual partners was 4. Altogether, 130 men (46.4%) were HPV positive. No infections with HPV types 6, 11, 16, 18, 31, and 45 were detected. The most frequent type was HPV-51 (detected in 11.1%). Comparison showed that the odds of high-risk HPV type infection were higher in 2019-2020 (prevalence odds ratio [POR], 1.7 [95% confidence interval {CI}, 1.1-2.7]) compared with 2006-2007. In contrast, the odds were lower (POR, 0.3 [95% CI, .1-.6]) for HPV types targeted by the 9-valent HPV vaccine. CONCLUSIONS: The multicohort girls-only vaccination program has to a large degree protected young men against the HPV types included in the licensed vaccines. This does not speak against gender-neutral vaccination as the HPV prevalence is still high, although consisting largely of less carcinogenic HPV types.

3.
J Infect Dis ; 229(1): 59-63, 2024 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-37402631

RESUMO

Many countries affected by the global outbreak of mpox in 2022 have observed a decline in cases. Our mathematical model accounting for heavy-tailed sexual partnership distributions suggests that mpox epidemics can hit the infection-derived herd immunity threshold and begin to decline, with <1% of sexually active men who have sex with men infected regardless of interventions or behavioral changes. We consistently found that many countries and US states experienced an epidemic peak, with cumulative cases of around 0.1% to 0.5% among men who have sex with men. The observed decline in cases may not necessarily be attributable to interventions or behavioral changes primarily.


Assuntos
Mpox , Minorias Sexuais e de Gênero , Masculino , Humanos , Homossexualidade Masculina , Comportamento Sexual , Surtos de Doenças
4.
Clin Infect Dis ; 78(4): 976-982, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-37738564

RESUMO

BACKGROUND: Widespread outbreaks of person-to-person transmitted hepatitis A virus (HAV), particularly among people who inject drugs (PWID), continue across the United States and globally. However, the herd immunity threshold and vaccination coverage required to prevent outbreaks are unknown. We used surveillance data and dynamic modeling to estimate herd immunity thresholds among PWID in 16 US states. METHODS: We used a previously published dynamic model of HAV transmission calibrated to surveillance data from outbreaks involving PWID in 16 states. Using state-level calibrated models, we estimated the basic reproduction number (R0) and herd immunity threshold for PWID in each state. We performed a meta-analysis of herd immunity thresholds to determine the critical vaccination coverage required to prevent most HAV outbreaks among PWID. RESULTS: Estimates of R0 for HAV infection ranged from 2.2 (95% confidence interval [CI], 1.9-2.5) for North Carolina to 5.0 (95% CI, 4.5-5.6) for West Virginia. Corresponding herd immunity thresholds ranged from 55% (95% CI, 47%-61%) for North Carolina to 80% (95% CI, 78%-82%) for West Virginia. Based on the meta-analysis, we estimated a pooled herd immunity threshold of 64% (95% CI, 61%-68%; 90% prediction interval, 52%-76%) among PWID. Using the prediction interval upper bound (76%) and assuming 95% vaccine efficacy, we estimated that vaccination coverage of 80% could prevent most HAV outbreaks. CONCLUSIONS: Hepatitis A vaccination programs in the United States may need to achieve vaccination coverage of at least 80% among PWID in order to prevent most HAV outbreaks among this population.


Assuntos
Usuários de Drogas , Vírus da Hepatite A , Abuso de Substâncias por Via Intravenosa , Humanos , Estados Unidos/epidemiologia , Imunidade Coletiva , Abuso de Substâncias por Via Intravenosa/complicações , Abuso de Substâncias por Via Intravenosa/epidemiologia , Vacinação
5.
J Theor Biol ; 587: 111815, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38614211

RESUMO

In the current paper we analyse an extended SIRS epidemic model in which immunity at the individual level wanes gradually at exponential rate, but where the waning rate may differ between individuals, for instance as an effect of differences in immune systems. The model also includes vaccination schemes aimed to reach and maintain herd immunity. We consider both the informed situation where the individual waning parameters are known, thus allowing selection of vaccinees being based on both time since last vaccination as well as on the individual waning rate, and the more likely uninformed situation where individual waning parameters are unobserved, thus only allowing vaccination schemes to depend on time since last vaccination. The optimal vaccination policies for both the informed and uniformed heterogeneous situation are derived and compared with the homogeneous waning model (meaning all individuals have the same immunity waning rate), as well as to the classic SIRS model where immunity at the individual level drops from complete immunity to complete susceptibility in one leap. It is shown that the classic SIRS model requires least vaccines, followed by the SIRS with homogeneous gradual waning, followed by the informed situation for the model with heterogeneous gradual waning. The situation requiring most vaccines for herd immunity is the most likely scenario, that immunity wanes gradually with unobserved individual heterogeneity. For parameter values chosen to mimic COVID-19 and assuming perfect initial immunity and cumulative immunity of 12 months, the classic homogeneous SIRS epidemic suggests that vaccinating individuals every 15 months is sufficient to reach and maintain herd immunity, whereas the uninformed case for exponential waning with rate heterogeneity corresponding to a coefficient of variation being 0.5, requires that individuals instead need to be vaccinated every 4.4 months.


Assuntos
COVID-19 , Epidemias , Imunidade Coletiva , Vacinação , Humanos , Imunidade Coletiva/imunologia , COVID-19/imunologia , COVID-19/epidemiologia , COVID-19/prevenção & controle , SARS-CoV-2/imunologia
6.
Stat Med ; 43(15): 2853-2868, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38726590

RESUMO

Assessing population-level effects of vaccines and other infectious disease prevention measures is important to the field of public health. In infectious disease studies, one person's treatment may affect another individual's outcome, that is, there may be interference between units. For example, the use of bed nets to prevent malaria by one individual may have an indirect effect on other individuals living in close proximity. In some settings, individuals may form groups or clusters where interference only occurs within groups, that is, there is partial interference. Inverse probability weighted estimators have previously been developed for observational studies with partial interference. Unfortunately, these estimators are not well suited for studies with large clusters. Therefore, in this paper, the parametric g-formula is extended to allow for partial interference. G-formula estimators are proposed for overall effects, effects when treated, and effects when untreated. The proposed estimators can accommodate large clusters and do not suffer from the g-null paradox that may occur in the absence of interference. The large sample properties of the proposed estimators are derived assuming no unmeasured confounders and that the partial interference takes a particular form (referred to as 'weak stratified interference'). Simulation studies are presented demonstrating the finite-sample performance of the proposed estimators. The Demographic and Health Survey from the Democratic Republic of the Congo is then analyzed using the proposed g-formula estimators to assess the effects of bed net use on malaria.


Assuntos
Malária , Estudos Observacionais como Assunto , Humanos , Malária/prevenção & controle , Mosquiteiros Tratados com Inseticida/estatística & dados numéricos , Modelos Estatísticos , Simulação por Computador , República Democrática do Congo/epidemiologia
7.
Network ; : 1-39, 2024 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-38400837

RESUMO

Plant diseases are rising nowadays. Plant diseases lead to high economic losses. Internet of Things (IoT) technology has found its application in various sectors. This led to the introduction of smart farming, in which IoT has been utilized to help identify the exact spot of the diseased affected region on the leaf from the vast farmland in a well-organized and automated manner. Thus, the main focus of this task is the introduction of a novel plant disease detection model that relies on IoT technology. The collected images are given to the Image Transmission phase. Here, the encryption task is performed by employing the Advanced Encryption Standard (AES) and also the decrypted plant images are fed to the pre-processing stage. The Mask Regions with Convolutional Neural Networks (R-CNN) are used to segment the pre-processed images. Then, the segmented images are given to the detection phase in which the Adaptive Dense Hybrid Convolution Network with Attention Mechanism (ADHCN-AM) approach is utilized to perform the detection of plant disease. From the ADHCN-AM, the final detected plant disease outcomes are obtained. Throughout the entire validation, the offered model shows 95% enhancement in terms of MCC showcasing its effectiveness over the existing approaches.

8.
Proc Natl Acad Sci U S A ; 118(36)2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34413212

RESUMO

Recent evidence suggests that vaccination hesitancy is too high in many countries to sustainably contain COVID-19. Using a factorial survey experiment administered to 20,500 online respondents in Germany, we assess the effectiveness of three strategies to increase vaccine uptake, namely, providing freedoms, financial remuneration, and vaccination at local doctors. Our results suggest that all three strategies can increase vaccination uptake on the order of two to three percentage points (PP) overall and five PP among the undecided. The combined effects could be as high as 13 PP for this group. The returns from different strategies vary across age groups, however, with older cohorts more responsive to local access and younger cohorts most responsive to enhanced freedoms for vaccinated citizens.


Assuntos
Vacinas contra COVID-19/administração & dosagem , COVID-19/prevenção & controle , COVID-19/psicologia , Vacinação em Massa/psicologia , Motivação/ética , Recusa de Vacinação/psicologia , Adulto , Fatores Etários , Idoso , COVID-19/epidemiologia , COVID-19/virologia , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Vacinação em Massa/economia , Pessoa de Meia-Idade , Modelos Psicológicos , SARS-CoV-2/patogenicidade , Inquéritos e Questionários
9.
Proc Natl Acad Sci U S A ; 118(1)2021 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-33443183

RESUMO

Vaccination yields the direct individual benefit of protecting recipients from infectious diseases and also the indirect social benefit of reducing the transmission of infections to others, often referred to as herd immunity This research examines how prosocial concern for vaccination, defined as people's preoccupation with infecting others if they do not vaccinate themselves, motivates vaccination in more and less populated regions of the United States. A nationally representative, longitudinal survey of 2,490 Americans showed that prosocial concern had a larger positive influence on vaccination against influenza in sparser regions, as judged by a region's nonmetropolitan status, lesser population density, and lower proportion of urban land area. Two experiments (total n = 800), one preregistered, provide causal evidence that drawing attention to prosocial (vs. individual) concerns interacted with social density to affect vaccination intentions. Specifically, prosocial concern led to stronger intentions to vaccinate against influenza and COVID-19 but only when social density was low (vs. high). Moderated mediation analyses show that, in low-density conditions, the benefits of inducing prosocial concern were due to greater perceived impact of one's vaccination on others. In this light, public health communications may reap more benefits from emphasizing the prosocial aspects of vaccination in sparser environments.


Assuntos
Vacinas contra COVID-19/administração & dosagem , COVID-19/epidemiologia , Vacinas contra Influenza/administração & dosagem , Influenza Humana/epidemiologia , Adolescente , Adulto , COVID-19/prevenção & controle , COVID-19/transmissão , COVID-19/virologia , Feminino , Humanos , Influenza Humana/prevenção & controle , Influenza Humana/transmissão , Influenza Humana/virologia , Estudos Longitudinais , Masculino , Orthomyxoviridae/genética , Orthomyxoviridae/imunologia , Densidade Demográfica , Probabilidade , Saúde Pública , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Estados Unidos/epidemiologia , Vacinação , Adulto Jovem
10.
J Dairy Sci ; 107(6): 3824-3835, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38211691

RESUMO

This closed cohort study aimed to identify the associations between dairy calf management practices and herd-level perinatal calf mortality risk. From February 2020 to June 2021, predominantly Holstein dairy farms in Québec (n = 1,832) and New Brunswick (n = 52), Canada, that were registered in the dairy herd improvement program were visited once. A questionnaire covering all aspects of precalving, calving, and colostrum management was administered. Data regarding perinatal mortality were retrieved from the dairy herd improvement program database for each farm for 2021. Perinatal mortality was calculated for each farm as the proportion of calves dead at birth or dying within 24 h after birth. A multivariable negative binomial model was used to assess herd-level factors associated with the risk of perinatal mortality. The final model included the lying surface in the calving area, the typical time to first colostrum intake, typical cow-calf contact time, the proportion of males born, the proportion of assisted calvings, and herd size. Herd-level perinatal mortality risk ranged from 0% to 38.1% (mean ± SE = 7.6% ± 0.1%). A greater proportion of males born, a higher proportion of assisted calvings, and delayed colostrum feeding were associated with increased herd-level perinatal mortality. Factors associated with a decreased herd-level perinatal mortality risk were having a typical cow-calf contact time between 7 and 12 h after calving compared with reduced cow-calf contact time, soft lying surfaces in the calving area compared with concrete and mat-lying surfaces, and an increased number of calvings per year. Our results show that although some of the significant risk factors are not well understood (i.e., calving area lying surface, typical cow-calf contact time), Canadian farmers could focus on the factors under their control (i.e., time to first colostrum feeding, proportion of difficult calvings, males born, and calvings per year) to reduce the risk of perinatal mortality. Future work should focus on qualitative research to understand the dairy farmer motivations and limitations to implementing practices identified in this and other studies to reduce perinatal mortality.


Assuntos
Criação de Animais Domésticos , Bovinos , Indústria de Laticínios , Mortalidade Perinatal , Feminino , Masculino , Criação de Animais Domésticos/estatística & dados numéricos , Roupas de Cama, Mesa e Banho/estatística & dados numéricos , Roupas de Cama, Mesa e Banho/veterinária , Canadá/epidemiologia , Estudos de Coortes , Abrigo para Animais/estatística & dados numéricos , Modelos Estatísticos , Novo Brunswick/epidemiologia , Morte Perinatal , Quebeque/epidemiologia , Fatores de Risco , Natimorto/veterinária , Inquéritos e Questionários , Animais
11.
J Dairy Sci ; 107(1): 459-475, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37690715

RESUMO

This observational study aimed to determine the association of cow-level factors and herd-level housing and management practices during the dry period with indicators of udder health in early-lactation cows in automated milking system (AMS) herds. Data were collected from 166 commercial AMS dairy farms (mean ± standard deviation = 116 ± 111 milking cows; range = 39 to 1,200) across Canada between October 2018 and September 2020. Information on herd demographics, housing, and management practices was obtained on each farm using 2 surveys. On each farm, we selected all cows that had available Dairy Herd Improvement (DHI) somatic cell count (SCC) data for their last milk test before dry-off (>250 d in milk) and their first milk test after calving (5-45 d in milk). Data from 14,007 cows were included after excluding cows with a dry period of <30 d and >120 d. Using the SCC data, we calculated for each cow the somatic cell score (SCS) for the last milk test before dry-off (PreSCS) and the first milk test after calving (PostSCS), which we then averaged per herd at a test-day level. Intramammary infection (IMI) was estimated using cow SCC data. Each cow was classified as not infected (SCC <200,000 cells/mL) or infected (SCC ≥200,000 cells/mL) at her last milk test before dry-off and her first milk test after calving. Based on this classification, cows were further categorized as never infected, always infected, new IMI, or cured IMI. At the cow level, a higher PostSCS was associated with longer dry periods. The odds of having a new IMI were higher for cows of higher parity and that had lower 305-d milk yield before dry-off. Cows with lower parity were more likely to cure an IMI. At the herd level, a higher 305-d milk yield before dry-off was associated with a lower incidence of new IMI and a higher incidence of cured IMI. Separating cows into a different pen as preparation for dry-off tended to be associated with a lower PostSCS and incidence of new IMI. At dry-off, herds that used teat sealants and blanket antibiotic dry cow therapy also had lower PostSCS. During the dry period, housing cows in different groups was associated with a higher PostSCS and a lower incidence of cured IMI, while housing cows in both pack pens and stalls compared with only pack pens was associated with a lower incidence of new IMI. Finally, placing cows onto the AMS to be milked one or more days after calving tended to be associated with a lower PostSCS compared with placing them in the AMS within the first day postpartum. In summary, indicators of udder health in early-lactation cows in AMS herds were associated with several cow-level factors and herd-level housing and management practices before dry-off, at dry-off, during the dry period, and at the beginning of lactation. Thus, if some of the associations identified are causal, AMS producers may be able to improve udder health through modifications of housing and management practices.


Assuntos
Doenças dos Bovinos , Mastite Bovina , Feminino , Bovinos , Animais , Leite , Glândulas Mamárias Animais , Mastite Bovina/epidemiologia , Lactação , Antibacterianos , Contagem de Células/veterinária , Indústria de Laticínios
12.
J Dairy Sci ; 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38788844

RESUMO

The present study demonstrates successful herd sanitation and eradication of contagious mastitis caused by Staphylococcus aureus genotype B (S. aureus GTB) in an entire Swiss district (Ticino) including 3,364 dairy cows from 168 farms. Herd sanitation included testing of all cows using a highly GTB specific and sensitive qPCR assay, implementation of related on-farm measures, appropriate antibiotic therapy of GTB-positive cows and culling of therapy-resistant animals, respectively. A treatment index was used as an objective criterion to select GTB-positive cows eligible for culling and replacement payment. 62 herds (37%) were initially GTB-positive with a cow prevalence between 10% and 100% and were submitted to sanitation. Twenty mo after the start of the campaign, all these herds were free from S. aureus GTB, whereby 73% of them were sanitized during the first 7 mo. At the cow level, a total of 343 animals were infected. 50 of them were immediately culled and financially compensated based on their treatment index value. The remaining 293 cows were intramammarily treated with antibiotics either during lactation using the combination of cephalexin-kanamycin or penicillin-gentamicin or at dry-off using cloxacillin. Out of these cows, 275 (93.9%) were treated successfully meaning that their milk was twice GTB-negative by qPCR after therapy. For lactational treatment, control samples were taken ≥10 and ≥20 d after treatment, for dry off treatment ≥14 and ≥24 d after parturition. Neither lactation number nor SCC before treatment of the cow nor the type of therapy were associated with therapeutic cure. Using data of 30 GTB-positive and 71 GTB-negative herds (1855 observations), the impact of GTB sanitation on bulk tank milk SCC (BTSCC) was evaluated applying a linear mixed statistical model. In the year before sanitation, BTSCC was always higher in GTB positive than in GTB negative herds. After the start of the campaign, BTSCC declined rapidly in the herds under GTB sanitation and achieved values that no longer differed statistically from those of GTB-free herds after only 2 mo, remaining very similar for the rest of the campaign. The farmers were very satisfied with the outcome of the campaign as all GTB positive herds could be sanitized rapidly, sanitation was sustainable, and milk quality increased.

13.
J Dairy Sci ; 107(6): 3899-3915, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38216037

RESUMO

Acidogenic boluses can mitigate potential negative effects of high milk yield at dry-off on udder health. This randomized controlled trial aimed to investigate the effect of administering acidogenic boluses at dry-off on dry period intramammary infection (IMI) dynamics and on milk production parameters, somatic cell count linear score (LSCC), clinical mastitis (CM), and herd removal in the next lactation. A total of 901 cows from 3 dairy farms were randomly allocated to a control (CON, n = 458; no administration of acidogenic boluses at dry-off) or treatment group (TRT, n = 443; administration of 2 acidogenic boluses at dry-off). Quarter milk samples were collected at dry-off and after calving and submitted for bacteriological milk culture. The effects of treatment on the presence of quarter-level postpartum IMI, cure of existing IMI, and acquisition of new IMI, and on the prevalence of cow-level high LSCC (LSCC ≥4) in the first 30 days in milk (DIM) were analyzed using mixed effects logistic regression. Mixed linear regression was used to analyze cow-level milk production parameters (i.e., milk yield, fat corrected milk, fat and protein yield, and LSCC) in the first 90 DIM and until 300 DIM. For CM and herd removal, Cox proportional hazard regression models were used. In addition to treatment group, lactation group at dry-off, presence of high LSCC in the last test-day, average milk yield in the week before dry-off, presence of CM in the lactation of enrollment, and biologically relevant interactions were offered in all models. There was no evidence of a difference in IMI dynamics or in milk, fat corrected milk, protein or fat yields in the subsequent lactation between groups. The TRT group had a lower LSCC in the first 2 mo postpartum compared with the CON group (2.58 ± 0.3 vs. 2.92 ± 0.3 and 2.42 ± 0.3 vs. 2.81 ± 0.3, for first and second month postpartum). The prevalence of high LSCC in the first 30 DIM was 9.1% lower in the TRT compared with the CON group (16.3% vs. 25.5%; risk difference: -9.2; 95% confidence interval [CI]: -15.8, -2.5). Cows in the TRT group exhibited reduced hazards of CM in the subsequent lactation compared with cows in the CON group (hazard ratio: 0.75; 95% CI: 0.63, 0.89) as well as a reduced hazard of herd removal (hazard ratio: 0.82, 95% CI: 0.77, 0.88). The administration of acidogenic boluses as a component of dry-off management is a promising approach to maintain good udder health and reduce the hazard of CM and herd removal during the subsequent lactation.


Assuntos
Lactação , Glândulas Mamárias Animais , Mastite Bovina , Leite , Animais , Bovinos , Feminino , Contagem de Células/veterinária
14.
J Dairy Sci ; 107(8): 6052-6064, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38554821

RESUMO

The use of sensor-based measures of rumination time as a parameter for early disease detection has received a lot of attention in scientific research. This study aimed to assess the accuracy of health alerts triggered by a sensor-based accelerometer system within 2 different management strategies on a commercial dairy farm. Multiparous Holstein cows were enrolled during the dry-off period and randomly allocated to conventional (CON) or sensor-based (SEN) management groups at calving. All cows were monitored for disorders for a minimum of 10 DIM following standardized operating procedures (SOP). The CON group (n = 199) followed an established monitoring protocol on the farm. The health alerts of this group were not available during the study but were later included in the analysis. The SEN group (n = 197) was only investigated when the sensor system triggered a health alert, and a more intensive monitoring approach was implemented according to the SOP. To analyze the efficiency of the health alerts in detecting disorders, the sensitivity (SE) and specificity (SP) of health alerts were determined for the CON group. In addition, all cows were divided into 3 subgroups based on their health status and the status of the health alerts in order to retrospectively compare the course of rumination time. Most health alerts (87%, n = 217) occurred on DIM 1. For the confirmation of diagnoses, health alerts showed SE and SP levels of 71% and 47% for CON cows. In SEN cows, SE of 71% and 75% and SP of 48% and 43% were found for the detection of ketosis and hypocalcemia, respectively. The rumination time of the subgroups was affected by DIM and the interaction between DIM and the status of health alert and health condition.


Assuntos
Parto , Animais , Bovinos , Feminino , Doenças dos Bovinos/diagnóstico , Indústria de Laticínios/métodos , Gravidez , Lactação
15.
J Dairy Sci ; 107(5): 2983-2998, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-37977443

RESUMO

The cost benefits of herd genotyping and the benefits of using sexed semen have been affected by recent improvements in sexing technologies, incorporation of direct health traits in the German total merit index for Holstein cattle, deteriorating prices for purebred heifer calves and bull calves, and introduction of herd genotyping programs. Inseminating genetically superior dams with female-sexed Holstein semen increases the mean breeding value of heifer calves and can produce more Holstein heifer calves than are needed for replacement. This provides an opportunity to increase the selection response in health and production traits at the farm level. A deterministic model is introduced that predicts the increase or decrease in net profit when a farmer takes part in a herd genotyping program and follows a certain insemination strategy. The types of semen allocated to cows and heifers may be sexed or unsexed and Holstein or beef breed. Genetically superior heifers and cows are inseminated with female-sexed Holstein semen, intermediate dams with unsexed Holstein semen, and genetically inferior dams with unsexed or male-sexed beef breed semen. In general, participating in a herd genotyping program is beneficial for German Holstein breeders. The optimum proportions of cows and heifers that should be inseminated with a certain type of semen are sensitive to farm-specific peculiarities. A small price difference between crossbred bull calves and crossbred heifer calves often makes the use of male-sexed beef breed semen uneconomic. Under the conditions considered, it was found to be advantageous to inseminate approximately 50% of heifers and 10% of cows with the highest genetic merit with female-sexed Holstein semen. The optimum proportion of cows that should be inseminated with unsexed beef breed semen was found to be approximately 40%. In a herd with a low replacement rate, the selected heifers can exhibit their genetic superiority over a longer period of time, and a larger proportion of cows can be inseminated with beef breed semen. Participation in a herd genotyping program is, therefore, particularly beneficial for herds with low replacement rates.

16.
J Dairy Sci ; 107(6): 3941-3958, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38246554

RESUMO

On-farm welfare assessment is time-consuming and costly. Assessing welfare using routinely collected herd data has been proposed as a more economical alternative. The online Animal Welfare Indicator (AWI), developed by a Norwegian dairy cooperative, applies an algorithm to routinely collected health, production, and management data to "indicate" aspects of animal welfare at herd level. The overall AWI score is based on 10 AWI subindicator scores, representative of elements of animal welfare such as claw health, udder health, and mortality. Our cross-sectional study explored 2 ways in which the AWI may enable more efficient welfare assessment of Norwegian dairy herds. First, we investigated using the AWI to reduce the duration of on-farm assessments by replacing on-farm measures. Second, we examined reducing the number of on-farm welfare assessments by using the AWI to predict which herds have poorer welfare with respect to specific on-farm measures. Using Spearman rank analyses, we investigated if the AWI scores for 157 herds were associated with 24 on-farm welfare variables measured contemporaneously by Welfare Quality assessment. The mortality AWI subindicator score and the percentage mortality in the previous 12 mo were moderately correlated, as were the udder health AWI subindicator score and the percentage high somatic cell count (SCC) in the previous 3 recordings. Only negligible or weak correlations were found between the other AWI scores and the on-farm assessment variables. We built Generalized Linear Models using AWI scores as independent variables to predict herds with poorer welfare. Herds were classified as having poorer welfare based on their results in specific on-farm welfare measures. We evaluated the models' predictive ability and accuracy. Moderately accurate models were built for predicting poorer herds with respect to high SCC, mortality, and moderate or severe lameness. The other models were less accurate. The AWI scores were generally unsuitable as replacements of on-farm welfare measures. The AWI subindicators for udder health and mortality could replace the on-farm welfare measures related to those 2 topics, but there was some overlap in the data used to calculate them. Despite a lack of independence, the use of those 2 AWI subindicators may marginally reduce the duration of on-farm assessments. A prediction model based on AWI scores showed potential for identifying herds with poorer welfare in terms of moderate or severe lameness, facilitating more efficient use of resources for on-farm lameness assessment. As a consequence of the data used in the AWI, it was only reflective of health-related welfare outcomes.


Assuntos
Algoritmos , Bem-Estar do Animal , Indústria de Laticínios , Animais , Bovinos , Feminino , Estudos Transversais
17.
Cent Eur J Public Health ; 32(1): 58-62, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38669159

RESUMO

Regarding the vaccination of children, it can be said that there are basically three vaccination policies in the world, one of which is usually used in particular country depending on the national legislation. These are the mandatory vaccination policy, mandatory vaccination policy for school entry and recommended vaccination policy. The mandatory vaccination policy and the mandatory vaccination policy for school entry face obstacles consisting of conflicts between fundamental human rights and freedoms. This is, for example, a conflict between the right to health and the right to life on the one hand and the right to protect the inviolability of the person and body integrity or the right to personal freedom, freedom of movement, residence, etc., on the other. Another issue is the right to undisrupted school attendance, based on both compulsory schooling and the right to education. This article looks at different approaches to the vaccination of children in different countries. It provides an illustrative comparison of approaches to vaccination of children in selected countries. It is obvious that the essential problems with organizing and ensuring the vaccination of children are and will be associated with the indicated conflicts of fundamental human rights. It is therefore necessary to search and try to find the optimal policy for undergoing the necessary vaccinations and thereby creating herd immunity, of course for those infectious diseases where this is possible. These efforts are necessary for sufficiently effective protection of individual and public health.


Assuntos
Direitos Humanos , Vacinação Compulsória , Criança , Humanos , Política de Saúde , Direitos Humanos/legislação & jurisprudência , Programas de Imunização/legislação & jurisprudência , Vacinação Compulsória/legislação & jurisprudência , Instituições Acadêmicas/legislação & jurisprudência
18.
Am Nat ; 202(4): E104-E120, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37792913

RESUMO

AbstractMany animals lay their eggs in clusters. Eggs on the periphery of clusters can be at higher risk of mortality. We asked whether the most commonly occurring clutch sizes in pentatomid bugs could result from geometrical arrangements that maximize the proportion of eggs in the cluster's interior. Although the most common clutch sizes do not correspond with geometric optimality, stink bugs do tend to lay clusters of eggs in shapes that protect increasing proportions of their offspring as clutch sizes increase. We also considered whether ovariole number, an aspect of reproductive anatomy that may be a fixed trait across many pentatomids, could explain observed distributions of clutch sizes. The most common clutch sizes across many species correspond with multiples of ovariole number. However, there are species with the same number of ovarioles that lay clutches of widely varying size, among which multiples of ovariole number are not overrepresented. In pentatomid bugs, reproductive anatomy appears to be more important than egg mass geometry in determining clutch size uniformity. In addition, our analysis demonstrates that groups of animals with little variation in ovariole number may nonetheless lay a broad range of clutch shapes and sizes.


Assuntos
Tamanho da Ninhada , Animais , Fenótipo
19.
Annu Rev Microbiol ; 72: 521-549, 2018 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-30200849

RESUMO

Streptococcus pneumoniae (the pneumococcus) is a nasopharyngeal commensal and respiratory pathogen. Most isolates express a capsule, the species-wide diversity of which has been immunologically classified into ∼100 serotypes. Capsule polysaccharides have been combined into multivalent vaccines widely used in adults, but the T cell independence of the antibody response means they are not protective in infants. Polysaccharide conjugate vaccines (PCVs) trigger a T cell-dependent response through attaching a carrier protein to capsular polysaccharides. The immune response stimulated by PCVs in infants inhibits carriage of vaccine serotypes (VTs), resulting in population-wide herd immunity. These were replaced in carriage by non-VTs. Nevertheless, PCVs drove reductions in infant pneumococcal disease, due to the lower mean invasiveness of the postvaccination bacterial population; age-varying serotype invasiveness resulted in a smaller reduction in adult disease. Alternative vaccines being tested in trials are designed to provide species-wide protection through stimulating innate and cellular immune responses, alongside antibodies to conserved antigens.


Assuntos
Infecções Pneumocócicas/microbiologia , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/imunologia , Streptococcus pneumoniae/classificação , Streptococcus pneumoniae/imunologia , Anticorpos Antibacterianos/sangue , Cápsulas Bacterianas/imunologia , Portador Sadio/imunologia , Portador Sadio/microbiologia , Portador Sadio/prevenção & controle , Humanos , Imunidade Celular , Imunidade Coletiva , Imunidade Inata , Infecções Pneumocócicas/imunologia , Vacinas Pneumocócicas/administração & dosagem , Vacinas Pneumocócicas/isolamento & purificação , Dinâmica Populacional , Sorogrupo , Vacinas Conjugadas/administração & dosagem , Vacinas Conjugadas/imunologia , Vacinas Conjugadas/isolamento & purificação
20.
Theor Popul Biol ; 152: 23-38, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37150257

RESUMO

Health perceptions and health-related behaviors can change at the population level as cultures evolve. In the last decade, despite the proven efficacy of vaccines, the developed world has seen a resurgence of vaccine-preventable diseases (VPDs) such as measles, pertussis, and polio. Vaccine hesitancy, which is influenced by historical, political, and socio-cultural forces, is believed to be a primary factor responsible for decreasing vaccine coverage, thereby increasing the risk and occurrence of VPD outbreaks. Behavior change models have been increasingly employed to understand disease dynamics and intervention effectiveness. However, since health behaviors are culturally influenced, it is valuable to examine them within a cultural evolution context. Here, using a mathematical modeling framework, we explore the effects of cultural evolution on vaccine hesitancy and vaccination behavior. With this model, we shed light on facets of cultural evolution (vertical transmission, community influences, homophily, etc.) that promote the spread of vaccine hesitancy, ultimately affecting levels of vaccination coverage and VPD outbreak risk in a population. In addition, we present our model as a generalizable framework for exploring cultural evolution when humans' beliefs influence, but do not strictly dictate, their behaviors. This model offers a means of exploring how parents' potentially conflicting beliefs and cultural traits could affect their children's health and fitness. We show that vaccine confidence and vaccine-conferred benefits can both be driving forces of vaccine coverage. We also demonstrate that an assortative preference among vaccine-hesitant individuals can lead to increased vaccine hesitancy and lower vaccine coverage.


Assuntos
Evolução Cultural , Vacinas , Criança , Humanos , Hesitação Vacinal , Aceitação pelo Paciente de Cuidados de Saúde , Modelos Teóricos , Vacinação
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