Occurrence Of Infectious Diseases Research Articles

Antimicrobial Resistance in Equines: A Growing Threat to Horse Health and Beyond—A Comprehensive Review

The equine industry holds substantial economic importance not only in the USA but worldwide. The occurrence of various infectious bacterial diseases in horses can lead to severe health issues, economic losses, and restrictions on horse movement and trade. Effective management and control of these diseases are therefore crucial for the growth and sustainability of the equine industry. While antibiotics constitute the primary treatment strategy for any bacterial infections in horses, developing resistance to clinically important antibiotics poses significant challenges to equine health and welfare. The adverse effects of antimicrobial overuse and the escalating threat of resistance underscore the critical importance of antimicrobial stewardship within the equine industry. There is limited information on the epidemiology of antimicrobial-resistant bacterial infections in horses. In this comprehensive review, we focus on the history and types of antimicrobials used in horses and provide recommendations for combating drug-resistant bacterial infections in horses. This review also highlights the epidemiology of antimicrobial resistance (AMR) in horses, emphasizing the public health significance and transmission dynamics between horses and other animals within a One Health framework. By fostering responsible practices and innovative control measures, we can better help the equine industry combat the pressing threat of AMR and thus safeguard equine as well as public health.

Childhood PFAS exposure and immunotoxicity: a systematic review and meta-analysis of human studies

BackgroundExposure to poly- and perfluoroalkyl substances (PFAS) may affect infant and childhood health through immunosuppression. However, the findings of epidemiological literature examining relationships between prenatal/childhood PFAS exposure and vaccine response and infection in humans are still inconclusive. The aim of this review was to examine the effects of PFAS exposure on vaccine antibody response and infection in humans.MethodsThe MEDLINE/Pubmed database was searched for publications until 1 February 2023 to identify human studies on PFAS exposure and human health.Eligible for inclusion studies had to have an epidemiological study design and must have performed logistic regression analyses of gestational or childhood exposure to PFAS against either antibody levels for pediatric vaccines or the occurrence of children’s infectious diseases. Information on baseline exposure to PFAS (in ng/mL), the age of PFAS exposure (gestational or in years), and the outcome was measured, potentially leading to multiple exposure-outcome comparisons within each study was collected. Percentage change and standard errors of antibody titers and occurrence of infectious diseases per doubling of PFAS exposure were calculated, and a quality assessment of each study was performed.ResultsSeventeen articles were identified matching the inclusion criteria and were included in the meta-analysis. In general, a small decrease in antibody response and some associations between PFAS exposure and childhood infections were observed.ConclusionsThis meta-analysis summarizes the findings of PFAS effects on infant and childhood immune health. The immunosuppression findings for infections yielded suggestive evidence related to PFAS exposure, particularly PFOS, PFOA, PFHxS, and PFNA but moderate to no evidence regarding antibody titer reduction.Systematic review registrationThe research protocol of this systematic review is registered and accessible at the Open Science Framework (https://doi.org/10.17605/OSF.IO/5M2VU).

Childhood PFAS exposure and immunotoxicity: a systematic review and meta-analysis of human studies

BackgroundExposure to poly- and perfluoroalkyl substances (PFAS) may affect infant and childhood health through immunosuppression. However, the findings of epidemiological literature examining relationships between prenatal/childhood PFAS exposure and vaccine response and infection in humans are still inconclusive. The aim of this review was to examine the effects of PFAS exposure on vaccine antibody response and infection in humans.MethodsThe MEDLINE/Pubmed database was searched for publications until 1 February 2023 to identify human studies on PFAS exposure and human health.Eligible for inclusion studies had to have an epidemiological study design and must have performed logistic regression analyses of gestational or childhood exposure to PFAS against either antibody levels for pediatric vaccines or the occurrence of children’s infectious diseases. Information on baseline exposure to PFAS (in ng/mL), the age of PFAS exposure (gestational or in years), and the outcome was measured, potentially leading to multiple exposure-outcome comparisons within each study was collected. Percentage change and standard errors of antibody titers and occurrence of infectious diseases per doubling of PFAS exposure were calculated, and a quality assessment of each study was performed.ResultsSeventeen articles were identified matching the inclusion criteria and were included in the meta-analysis. In general, a small decrease in antibody response and some associations between PFAS exposure and childhood infections were observed.ConclusionsThis meta-analysis summarizes the findings of PFAS effects on infant and childhood immune health. The immunosuppression findings for infections yielded suggestive evidence related to PFAS exposure, particularly PFOS, PFOA, PFHxS, and PFNA but moderate to no evidence regarding antibody titer reduction.Systematic review registrationThe research protocol of this systematic review is registered and accessible at the Open Science Framework (https://doi.org/10.17605/OSF.IO/5M2VU).

Impact of extreme weather events on the occurrence of infectious diseases in Belgium from 2011 to 2021.

The role of meteorological factors, such as rainfall or temperature, as key players in the transmission and survival of infectious agents is poorly understood. The aim of this study was to compare meteorological surveillance data with epidemiological surveillance data in Belgium and to investigate the association between intense weather events and the occurrence of infectious diseases. Meteorological data were aggregated per Belgian province to obtain weekly average temperatures and rainfall per province and categorized according to the distribution of the variables. Epidemiological data included weekly cases of reported pathogens responsible for gastroenteritis, respiratory, vector-borne and invasive infections normalized per 100 000 population. The association between extreme weather events and infectious events was determined by comparing the mean weekly incidence of the considered infectious diseases after each weather event that occurred after a given number of weeks. Very low temperatures were associated with higher incidences of influenza and parainfluenza viruses, Mycoplasma pneumoniae, rotavirus and invasive Streptococcus pneumoniae and Streptococcus pyogenes infections, whereas very high temperatures were associated with higher incidences of Escherichia coli, Salmonella spp., Shigella spp., parasitic gastroenteritis and Borrelia burgdorferi infections. Very heavy rainfall was associated with a higher incidence of respiratory syncytial virus, whereas very low rainfall was associated with a lower incidence of adenovirus gastroenteritis. This work highlights not only the relationship between temperature or rainfall and infectious diseases but also the most extreme weather events that have an individual influence on their incidence. These findings could be used to develop adaptation and mitigation strategies.

Occurrence of major infectious diseases and healthcare seeking among young children with disabilities in Sierra Leone using cross-sectional population-based survey data

BackgroundChildren with disabilities are at risk of worse health outcomes compared to children without functional difficulties. Sierra Leone has one of the world’s highest prevalences of functional difficulties among children,...

Effect of Drying Methods on the Total Phenolic of Maman Plant (Cleome gynandra L.) from Riau

Maman plant (Cleome gynandra L.) is an underutilised leafy vegetable that has a high nutritive value and contains phenolic compounds that are essential in reducing or preventing the occurrence of chronic and infectious diseases. In this study, we investigate the effect of drying methods on the total phenolic content of maman plant from Riau. The drying treatment process for maman leafs was tried using three methods: room air-dried without sunlight exposure at 21-24oC for seven days, freeze-dried at -40oC for four days, and oven-drying at 40oC for three days. Freeze-dried maman leafs exhibited significantly (p < 0.05) higher total phenolics (5,90 mgGAE/g) than those dried using other methods, followed by oven-dried (5,14 mgGAE/g) and room-air dried (4,50 mgGAE/g). Drying maman leaves for further research is recommended using the freeze-dried method to obtain optimal phytochemical content.

Contribution of Particulates to Airborne Disease Transmission and Severity: A Review.

The emergence of coronavirus disease 2019 (COVID-19) has catalyzed great interest in the spread of airborne pathogens. Airborne infectious diseases are classified into viral, bacterial, and fungal infections. Environmental factors can elevate their transmission and lethality. Air pollution has been reported as the leading environmental cause of disease and premature death worldwide. Notably, ambient particulates of various components and sizes are harmful pollutants. There are two prominent health effects of particles in the atmosphere: (1) particulate matter (PM) penetrates the respiratory tract and adversely affects health, such as heart and respiratory diseases; and (2) bioaerosols of particles act as a medium for the spread of pathogens in the air. Particulates contribute to the occurrence of infectious diseases by increasing vulnerability to infection through inhalation and spreading disease through interactions with airborne pathogens. Here, we focus on the synergistic effects of airborne particulates on infectious disease. We outline the concepts and characteristics of bioaerosols, from their generation to transformation and circulation on Earth. Considering that microorganisms coexist with other particulates as bioaerosols, we investigate studies examining respiratory infections associated with airborne PM. Furthermore, we discuss four factors (meteorological, biological, physical, and chemical) that may impact the influence of PM on the survival of contagious pathogens in the atmosphere. Our review highlights the significant role of particulates in supporting the transmission of infectious aerosols and emphasizes the need for further research in this area.

The influence of job category (rank) in the occurrence of infectious diseases among police personnel in south eastern Nigeria from 2012 to 2021

The occurrence of infectious diseases among police officers is one of the neglected areas in health and scientific research. The aim of this study is to ascertain and assess the influence of job category (rank) in the occurrence of infectious diseases among police personnel in south eastern Nigeria from 2012 to 2021. The study was designed as a retrospective study using data from the central police clinics/hospitals for the period of ten years covering 2012 – 2021. The study population comprised all the recorded infectious disease data in the three police clinics/hospitals of study for police personnel documented from January 2011 to December 2021. Occurrences of infectious diseases were analysed through descriptive techniques such as construction of the frequency distribution and distribution charts. Chi-square test was performed to test for associating variables of interest in the study. The probability value (P) was used to interpret the significance level at 5% and P value less than 0.05 was considered statistically significant. The study found the overall rate of occurrence infectious diseases among police officers as 21.1% in the study area. Significant associating factors of infectious diseases occurrence among police personnel found in the study for job category is (P < 0.0001, χ2=74.91, df = 1). Police officers at junior category were the most affected (24.1%) compared to the officers at senior category (11.9%). the rate of occurrence of infectious diseases is significant among junior category (rank) police personnel in the South Eastern Nigeria.

Kano Model for Apartment-Unit Specialized Planning Guidelines to Prevent Infectious Diseases

Owing to the continued occurrence of infectious diseases, proactive prevention and management plans are required. This study aimed to develop design guidelines to effectively respond to infectious diseases based on the needs of apartment residents, which focused on a South Korean setting. The research method included a literature review to identify apartment planning concepts for preventing and managing infectious diseases, a survey of 300 participants using the Kano model, and an analysis of the quality attributes (QAs) of the survey results to prioritize design guidelines. After reviewing 20 studies, 65 items related to apartment-unit planning for infectious disease prevention, including 108 keywords, were identified. Using thematic analysis, the keywords converged into three planning concepts: hygiene, convenience, and comfort. Based on the literature review, 27 survey questions were derived, and a Kano model QA analysis was performed. As a result, 17 attractive QAs, two one-dimensional QAs, seven indifferent QAs, and one reverse QA were identified. Among these, 13 items that had a significant impact on residents’ satisfaction were classified as essential requirements, and the remaining 14 items were classified as recommended design guidelines. The results of this study provide insights into an evidence-based framework for complex building design guidelines to prevent the spread of infectious diseases.

Fluoride promotes the secretion of inflammatory factors in microglia through NLRP3/Caspase-1/GSDMD pathway.

It is widespread of endemic fluorosis in China, and the exposure of excessive fluoride will cause nervous system disease and activate microglia. However, the mechanism of the damage is not clear. It is well-known that NLRP3/Caspase-1/GSDMD pathway, a classic pyroptosis pathway, is widely involved in the occurrence and development of nervous system-related diseases, infectious diseases, and atherosclerotic diseases. This research aimed to explore the molecular mechanism of sodium fluoride on inflammation and pyroptosis in BV2 microglia based on the NLRP3/Caspase-1/GSDMD signaling pathway. BV2 microglia was treated with sodium fluoride at the dose of 0.25, 1, and 2mmol/L for 24, 48, and 72h, respectively. Cell viability, cell morphology, lactate dehydrogenase content, and related proteins and genes were examined to investigate if sodium fluoride caused damage to BV2 microglia through the pyroptosis pathway. Dithiolam (5μmol/L), a pyroptosis inhibitor, was added for further verification. NaF could induced BV2 cells injury in a dose-dependent fashion through disrupting the integrity of cell membranes and increasing IL-1β via upregulating NLRP3, Caspase-1, and its downstream protein GSDMD. Disulfiram couldimprove these changes caused by NaF. In conclusion, our results suggested that NLRP3/Caspase-1/GSDMD-mediated classical pyroptosis pathway was involved in fluoride-induced BV2 microglia damage.

Association between Acute and Chronic Inflammatory States: A Case-Control Study.

Fever is the hallmark of efficient acute inflammatory response, which may be disrupted in chronic inflammatory conditions. The "continuum theory" proposes that the return of acute inflammatory states with high fever predicts improvement in chronic diseases during treatment. Our objective was to investigate the observation made, during classical homeopathic treatment, that such an association exists between chronic inflammation and efficient acute inflammation. In a case-control study, the reports of patients diagnosed with chronic inflammatory conditions with at least 6 months of follow-up under homeopathic treatment were retrospectively sampled from homeopathic medical practices from Greece, India, Romania and Russia. Twenty patients who improved under homeopathic treatment and 20 age-matched controls of those who did not improve were selected. The occurrence of common acute infectious diseases with fever during the follow-up period was investigated. The average age of the cases and controls was 28.4 (SD: 16.64) and 27.9 (SD: 17.19) years respectively. 18/20 cases and 4/20 controls developed common infectious diseases with fever. Cramer's V co-efficient value was found to be 0.551 (p < 0.01), indicating that improvement was more in patients with fever than without. Odds ratio of improving with respect to development of acute infectious diseases was 36.0 (95% CI: 5.8 to 223.5). The binary logistic regression model indicated significant contribution of occurrence of acute infections with fever as a predictor for improvement in chronic inflammatory disease. Classical homeopathic clinical observations indicate an association between chronic inflammatory status in the body and the ability to mount efficient acute inflammation. In this case-control study, the occurrence of common infections with fever during treatment heralded improvement in chronic inflammatory disease. Further powered studies are necessary to substantiate this finding.

Effects of public health interventions and zero COVID policy on paediatric diseases: A Southern China study.

With the spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in schools and communities, clinical evidence is needed to determine the impact of the pandemic and public health interventions under the zero coronavirus disease policy on the occurrence of common infectious diseases and non-infectious diseases among children. The current study was designed to analyse the occurrence of common infectious diseases before and after the pandemic outbreak in southern China. Data was obtained for 1 801 728 patients admitted into children's hospitals in Guangzhou between January 2017 and July 2022. Regression analysis was performed for data analysis. The annual occurrence of common paediatric infectious diseases remarkably decreased after the pandemic compared to the baseline before the pandemic and the monthly occurrence. Cases per month of common paediatric infectious diseases were significantly lower in five periods during the local outbreak when enhanced public health measures were in place. Cases of acute non-infectious diseases such as bone fractures were not reduced. Non-pharmaceutical interventions decreased annual and monthly cases of paediatric respiratory and intestinal infections during the coronavirus disease 2019 (COVID-19) pandemic, especially when enhanced public health interventions were in place. Our findings provide clinical evidence that public health interventions under the dynamic zero COVID policy in the past three years had significant impacts on the occurrence of common respiratory and intestinal infectious diseases among children and adolescents but little impact on reducing non-infectious diseases such as leukaemia and bone fracture.

Generation and Application of Monoclonal Antibodies against Porcine S100A8, S100A9, and S100A12 Proteins Using Hybridoma Technology.

S100A8, S100A9, and S100A12 proteins are important members of the S100 protein family, act primarily as congenital immunomodulators, and are closely related to the occurrence of infectious diseases. There have been few reports on the functional properties of S100A8, S100A9, and S100A12 proteins in swine, but it is certain that porcine S100A8, S100A9, and S100A12 proteins are highly expressed in diseased swine. To address the current lack of reliable and timely detection tools for these three proteins, we generated monoclonal antibodies specific to the porcine S100A8, S100A9, and S100A12 proteins using hybridoma technology. The results of serum sample testing showed that the above monoclonal antibodies specifically recognize the proteins S100A8, S100A9, and S100A12 in the serum and were able to evaluate the content change of these proteins during the infection process. This provides the basis for the use of porcine S100A8, S100A9, and S100A12 in the surveillance and diagnosis of swine diseases and laid a foundation for further understanding their roles in infection, immunity, and inflammation, as well as their potential applications in preventing or treating gastrointestinal tract or inflammatory diseases in swine.

SARS-CoV-2 vaccination and risk of infectious diseases in hospitalized older patients.

Vaccinations, for example flu vaccine, may be a cause of cross-reactive immunostimulation that prevents a larger spectrum of infections. However, whether SARS-CoV-2 vaccinations may also determine this effect is unclear. This study aims, first, to assess the incidence of infections at hospital admission and during the hospitalization in older inpatients vaccinated and unvaccinated against SARS-CoV-2; second, to compare length of hospital stay and in-hospital mortality between vaccinated and unvaccinated individuals. This retrospective study included 754 older inpatients admitted to the Geriatrics and Orthogeriatrics Units of the University Hospital of Ferrara (Italy) between March 2021 and November 2021. Sociodemographic and health-related data, and the diagnosis of infections at hospital admission and during hospitalization were collected from medical records. The sample's mean age was 87.2years, 59.2% were females, and 75.5% were vaccinated against SARS-CoV-2. Vaccinated individuals had 36% lower odds of intra-hospital infections (OR = 0.64, 95%CI 0.44-0.94) and 39% lower in-hospital death (HR = 0.61, 95%CI 0.39-0.95), also after adjusting for potential confounders, while no significant results emerged about infections at hospital admission. Considering the hospitalization's endpoints, SARS-CoV-2 vaccination was associated with a lower probability of being transferred to long-term care or other hospital departments than returning home (OR = 0.63, 95%CI 0.40-0.99). In older inpatients, SARS-CoV-2 vaccination seems to be associated with a lower likelihood of intra-hospital infectious diseases not caused by SARS-CoV-2 and all-cause in-hospital mortality. The vaccination coverage in the older population could limit not only the onset and severity of COVID-19 but also the occurrence of other infectious diseases.

Scientific and production substantiation of the effectiveness of the product for dry hoof baths

This paper presents the results of a study of the adsorption activity of a developed complex product for the treatment and prevention of diseases of the distal extremities of cattle and its effectiveness with individual and group use using the method of dry hoof baths in a number of agricultural enterprises with tethered and freestall housing of cattle. It was shown that the developed product has a porous structure and a wide range of adsorption. The main cause of infection causing mass lesions of the fingers and hooves of cattle in the surveyed agricultural enterprises was an increase in the threshold number of the diversity of saprophytic and opportunistic microorganisms transmitted directly from one animal to another. Associations of bacteria and micromycetes determined the cause of the occurrence and spread of infectious diseases of the fingers and hooves. The test results of the developed complex product, which includes inorganic adsorbents and active substances with pronounced fungicidal, bactericidal and anti-inflammatory properties indicate the possibility of its introduction into the system of control measures with diseases of fingers and hooves in disadvantaged agricultural enterprises with both tethered and free-stall livestock keeping.

The involvement of reactive oxygen species in causing chronic cardiovascular and neurodegenerative diseases and some cancers

An increase in the occurrence of different infectious and chronic diseases as well as aging population has resulted in poor human health and decline in the quality of life all over the world. In fact, chronic diseases, which are partially resistant to currently available drugs are long lasting health hazards and require ongoing medical attention. Major causes of increase in these diseases are considered to be changes in the environment as well as diets and lifestyle. Particularly, there has been changes from a simple, nutritious, lowcalorie diet and active lifestyle to a complex and processed food rich in high calories accompanied by a sedentary lifestyle and unhealthy living habits. Since high-calorie diets and inactive lifestyle are known to promote the production of reactive oxygen species (ROS) in the body, it is likely that oxidative stress and associated inflammation may be intimately involved in enhancing the resistance of several disorders to the existing therapeutic interventions and thus promoting the occurrence of chronic diseases. A thorough review of literature regarding the pathogenesis of some major chronic diseases including cardiovascular disease like heart failure, neurodegenerative disorder like Alzheimer's disease and various types of cancer has revealed that these health hazards are associated with increased oxidative stress, production of pro-inflammatory chemicals such as nitric oxide and some cytokines, as well as formation of some toxic substances such as advanced glycation end products. It is thus evident that extensive research work by employing genetic, immunological and nutraceutical approaches, needs to be carried out for developing some novel antioxidants with anti-inflammatory activities for reducing the incidence of chronic diseases. In the meantime, it would be prudent for patients with chronic diseases to pursue the preventive measures involving reduced intake of high calorie diet and following an active lifestyle

Interrupting Effect of Social Distancing on Ischemic Heart Disease, Asthma, Stroke, and Suicide Attempt Patients by PM2.5 Exposure.

This study aimed to examine the interrupting effect of social distancing (SD) on emergency department (ED) patients with ischemic heart disease (IHD), stroke, asthma, and suicide attempts by PM2.5 exposure in eight Korean megacities from 2017 to 2020. The study used National Emergency Department Information System and AirKorea data. A total of 469014 patients visited EDs from 2017 to 2020. Interrupted time series analysis was employed to examine changes in the level and slope of the time series, relative risk, and confidence intervals (CIs) by PM2.5 exposure. The SD level was added to the sensitivity analysis. The interrupted time series analysis demonstrated a significant increase in the ratio of relative risk (RRR) of IHD patients in Seoul (RRR=1.004, 95% CI: 1.001, 1.006) and Busan (RRR=1.007, 95% CI: 1.002, 1.012) post-SD. Regarding stroke, only patients in Seoul exhibited a significant decrease post-SD (RRR=0.995, 95% CI: 0.991, 0.999). No significant changes were observed for asthma in any of the cities. In the case of suicide attempts, Ulsan demonstrated substantial pre-SD (RR=0.827, 95% CI: 0.732, 0.935) and post-SD (RRR=1.200, 95% CI: 1.057, 1.362) differences. While the interrupting effect of SD was not as pronounced as anticipated, this study did validate the effectiveness of SD in modifying health behaviors and minimizing avoidable visits to EDs in addition to curtailing the occurrence of infectious diseases.

Prediction of visceral leishmaniasis incidence using the Seasonal Autoregressive Integrated Moving Average model (SARIMA) in the state of Maranhão, Brazil.

Visceral leishmaniasis (VL) is an infectious disease predominant in countries located in the tropics. The prediction of occurrence of infectious diseases through epidemiologic modeling has revealed to be an important tool in the understanding of its occurrence dynamic. The objective of this study was to develop a forecasting model for the incidence of VL in Maranhão using the Seasonal Autoregressive Integrated Moving Average model (SARIMA). We collected monthly data regarding VL cases from the National Disease Notification System (SINAN) corresponding to the period between 2001 and 2018. The Box-Jenkins method was applied in order to adjust a SARIMA prediction model for VL general incidence and by sex (male or female) for the period between January 2019 and December 2013. For 216 months of this time series, 10,431 cases of VL were notified in Maranhão, with an average of 579 cases per year. With regard to age range, there was a higher incidence among the pediatric public (0 to 14 years of age). There was a predominance in male cases, 6437 (61.71%). The Box-Pierce test figures for overall, male and female genders supported by the results of the Ljung-Box test suggest that the autocorrelations of residual values act as white noise. Regarding monthly occurrences in general and by gender, the SARIMA models (2,0,0) (2,0,0), (0,1,1) (0,1,1) and (0,1,1) (2, 0, 0) were the ones that mostly adjusted to the data respectively. The model SARIMA has proven to be an adequate tool for predicting and analyzing the trends in VL incidence in Maranhão. The time variation determination and its prediction are decisive in providing guidance in health measure intervention.

Pyroptosis in microbial infectious diseases.

Pyroptosis is a gasdermins-mediated programmed cell death that plays an essential role in immune regulation, and its role in autoimmune disease and cancer has been studied extensively. Increasing evidence shows that various microbial infections can lead to pyroptosis, associated with the occurrence and development of microbial infectious diseases. This study reviews the recent advances in pyroptosis in microbial infection, including bacterial, viral, and fungal infections. We also explore potential therapeutic strategies for treating microbial infection-related diseases by targeting pyroptosis.

Effect of killed autogenous polyvalent vaccines against Vibrio harveyi, V. alginolyticus and Streptococcus iniae on survival and immunogenicity of Asian seabass (Latescalcarifer)

Vibriosis and Streptococcosis are the most important bacterial diseases that infect Asian seabass (Lates calcarifer) in various stages of its life cycle. Vaccination is a cost-effective strategy to prevent the occurrence of infectious diseases and increase sustainability in the aquaculture industry. This study was aimed to develop and evaluate a killed polyvalent vaccine against Vibrio harveyi, V. alginolyticus and Streptococcus iniae, delivered by intraperitoneal injection in Asian seabass. The fish were divided into three groups with 60 fish in triplicate: I) a control group injected with phosphate-buffered saline (PBS), II) a group vaccinated by polyvalent vaccine (V. alginolyticus + V. harveyi + S. iniae) and III) a group vaccinated with the same polyvalent vaccine plus an oral booster. Immunological parameters and antibody titer were measured before and at three, five-, and eight-weeks post-vaccination. The efficacy of the killed vaccine was assessed five weeks post-vaccination by challenging with each isolate separately. The vaccinated groups had higher survival rate than control group. The highest relative percentage survival rate, 85.71 ± 3.57 % was observed in group III when challenged with V. harveyi. The vaccinated fish produced significantly higher antibody titers against V. alginolyticus, V. harveyi and S. iniae than the control group (P < 0.05). Non-specific immune parameters were significantly enhanced in the vaccinated groups, especially group III, compared to the control. The results demonstrated that the administration of a killed polyvalent vaccine can effectively protect Asian seabass against V. alginolyticus, V. harveyi and S. iniae.