Virus Type Research Articles

Comparison of headache and facial pain prevalence and phenotype in upper respiratory tract infections of differing origins - a cross-sectional study.

This study aimed to compare headache and facial pain prevalence and headache phenotype among people with common upper respiratory tract infections (URTIs). Headache is a common symptom in viral URTI, but its phenotyping has so far been limited to coronavirus disease 2019 (COVID-19) and influenza. Additionally, the prevalence of facial pain in URTIs has only rarely been discussed in scientific publications. Patients with acute URTI symptoms were evaluated for headache phenotype using a semi-structured questionnaire. Antigen swab tests were performed in all participants. The analysis included 276 URTI/APVRS (acute post-viral rhinosinusitis) episodes in 223 patients (136 women, 60.1%) aged 18-73 [mean 41.3 / median (25th, 75th) 40 / standard deviation 15.1]. Participants were diagnosed with: COVID-19 - 107/276 (38.8%); 'common cold' - 103/276 (37.3%); influenza - 36/276 (13.0%); or APVRS - 30/276 (10.9%). Headache was present in 183/276 (66.3%) and URTIs and facial pain in 107/276 (38.8%). Predictors of headache in URTIs included sinonasal symptoms (odds ratio (OR) 10.70, p < 0.001) and fever (OR 2.9, p = 0.004). Headache more often (p = 0.030) had a migraine-like phenotype in COVID-19 (27.4% (20/73) vs. 9.1% (10/110) and tension-type headache (TTH)-like phenotype in 'common cold' (75.4%, 49/64 vs. 61.3%, 73/119). Previous COVID-19 immunisation (vaccination or infection) was associated (p = 0.004) with a lower prevalence of migraine-like headache [6.3% (1/16) vs. 32.8% (19/58)]. Headache and facial pain are prevalent during URTIs, and are associated with general and sinonasal immune response rather than virus type. Headache phenotype may depend on the causative microorganism, but it can evolve in response to previous immunisation. Our study supports vaccination against COVID-19, as people with prior immunisation are probably less likely to experience migraine-like headache.

A preregistered meta-meta-analysis on the global distribution of Hepatotropic Viruses.

Hepatotropic viruses (HAV, HBV, HCV, HDV, and HEV) significantly impact global health, with varying prevalence across regions. This study aims to systematically consolidate data from diverse meta-analyses to provide a contemporary reference on virus distribution and prevalence. Adhering to PRISMA guidelines, the study utilized a mixed effects model for data integration. Quality evaluation was carried out with QUOROM and AMSTAR tools, with heterogeneity assessed via the Higgins I2 statistic, Q-statistic and Tau squared (τ2) values. The study analyzed 86 meta-analyses from 56 studies (2017-2022) with minimal overlap. Prevalence rates by region were as follows: MENA - 29.2%, Afghanistan - 9.14%, Africa - 8.10%. Prevalence rates by virus type: HAV - 82.5%, HBV - 8.6%, HCV - 15.1%, HDV - 8.9%, HEV - 13.9%, dual HBV-HCV coinfection - 2.2%. Prevalence rates by risk groups: general population - 8.3%, healthcare workers - 4.0%. Continent-specific HBV-HCV prevalence rates: Africa - 9.2%, China - 6.9%, others. HCVprevalence rates among at-risk groups: healthcare workers - 5.58%, hemodialysis patients - 34.8%. Regional HCV rates: Africa - 7.42%, Middle East - 25.30%. Diverse global hepatotropic virus prevalence patterns are influenced by multifaceted factors. MENA faces higher rates due to healthcare challenges, while Africa struggles with limited resources. Tailored public health strategies, including vaccination and awareness campaigns, are essential to alleviate burdens and enhance global health. This consolidated data serves as a valuable resource for informed decision-making.

The burden of HIV-1 and HIV-2 epidemics in Ivory Coast.

Simian immunodeficiency viruses (SIV) infecting chimpanzees (SIVcpz) and sooty mangabeys (SIVsm) are, respectively, the biological precursors of human immunodeficiency viruses (HIV) Types 1 and 2. Former French colonies in West Africa are the regions where retroviruses first jumped from primates to humans. Ivory Coast is nowadays a country of over 29 million people, being 2% (580,000) persons living with HIV (PLWH). However, one-quarter remains undiagnosed. Heterosexual transmission is by far the most frequent mechanism of HIV acquisition and women exhibit higher rates of infection than men. Despite preventive measures, HIV infection in children throughout breastfeeding remains significant. The proportion of PLWH carrying HIV-1 is rising whereas conversely HIV-2 carriers are steadily declining. A nationwide survey conducted on earlier 2024 showed that a total of 188,880 PLWH were on follow-up. HIV-1 infection was found in 163,947, HIV-2 in 5,114, and coinfection in 3,182. HIV type was not reported for 7,500. Antiretroviral therapy with tenofovir, lamivudine, and dolutegravir is by far the most frequently prescribed regimen in Ivory Coast (n = 168,543). Viral suppression is recognized in 94.3% of treated PLWH, despite one-third acknowledging unwanted treatment interruptions after failure of stock supplies. Given shared transmission routes with HIV, coinfection with other human retroviruses such as Human T-lymphotropic virus type-1 (HTLV-1) and/or hepatitis viruses B, C, and delta are frequent in Ivory Coast. Coinfections remain largely undiagnosed and poorly managed. In summary, the HIV pandemic caused by both HIV-1 and HIV-2 is a major public health challenge in Ivory Coast, where strategies for expanding diagnosis, sustain antiretroviral treatment, and manage coinfections warrant further efforts.

Estimated Effectiveness of Influenza Vaccines in Preventing Secondary Infections in Households

Influenza vaccine effectiveness (VE) is commonly assessed against prevention of illness that requires medical attention. Few studies have evaluated VE against secondary influenza infections. To determine the estimated effectiveness of influenza vaccines in preventing secondary infections after influenza was introduced into households. During 3 consecutive influenza seasons (2017-2020), primary cases (the first household members with laboratory-confirmed influenza) and their household contacts in Tennessee and Wisconsin were enrolled into a prospective case-ascertained household transmission cohort study. Participants collected daily symptom diaries and nasal swabs for up to 7 days. Data were analyzed from September 2022 to February 2024. Vaccination history, self-reported and verified through review of medical and registry records. Specimens were tested using reverse transcription-polymerase chain reaction to determine influenza infection. Longitudinal chain binomial models were used to estimate secondary infection risk and the effectiveness of influenza vaccines in preventing infection among household contacts overall and by virus type and subtype and/or lineage. The analysis included 699 primary cases and 1581 household contacts. The median (IQR) age of the primary cases was 13 (7-38) years, 381 (54.5%) were female, 60 (8.6%) were Hispanic, 46 (6.6%) were non-Hispanic Black, 553 (79.1%) were Non-Hispanic White, and 343 (49.1%) were vaccinated. Among household contacts, the median age was 31 (10-41) years, 833 (52.7%) were female, 116 (7.3%) were Hispanic, 78 (4.9%) were non-Hispanic Black, 1283 (81.2%) were non-Hispanic White, 792 (50.1%) were vaccinated, and 356 (22.5%) had laboratory-confirmed influenza during follow-up. The overall secondary infection risk of influenza among household contacts was 18.8% (95% CI, 15.9% to 22.0%). The risk was highest among children and was 20.3% (95% CI, 16.4% to 24.9%) for influenza A and 15.9% (95% CI, 11.8% to 21.0%) for influenza B. The overall estimated VE for preventing secondary infections among unvaccinated household contacts was 21.0% (95% CI, 1.4% to 36.7%) and varied by type; estimated VE against influenza A was 5.0% (95% CI, -22.3% to 26.3%) and 56.4% (95% CI, 30.1% to 72.8%) against influenza B. After influenza was introduced into households, the risk of secondary influenza among unvaccinated household contacts was approximately 15% to 20%, and highest among children. Estimated VE varied by influenza type, with demonstrated protection against influenza B virus infection.

Matrine relieved DHAV-1-induced hepatocyte excessive interferon and pyroptosis by activating mitophagy

Duck hepatitis A virus type 1 (DHAV-1) is a significant pathogen affecting ducklings, capable of causing rapid mortality and adversely impacting the development of the duck industry. Matrine, the primary active ingredient in various Chinese herbal medicines, has demonstrated antiviral and anti-inflammatory properties. Nevertheless, the effects and mechanisms of action of matrine against DHAV-1 infection remain unclear. This research investigates the effects of matrine on DHAV-1 infection and elucidates the mechanisms involved. We found that matrine mitigated the excessive retinoic acid-inducible gene I (RIG-I)-like receptor (RLR) signaling response, pyroptosis, and mitochondrial damage induced by DHAV-1 in duckling livers and duck embryonic hepatocytes (DEHs). Additionally‌, by incorporating the autophagy inhibitor chloroquine, we observed that the effects of matrine on the regulation of excessive interferon (IFN) production, pyroptosis, mitochondrial damage, and oxidative stress were reversed. Overall, matrine inhibited excessive IFN production and pyroptosis by promoting mitophagy, suggesting that matrine may act as a possible therapeutic agent for addressing DHAV-1 infection and other viral hepatitis.

Risks of Cervical Cancer Recurrence After Fertility-Sparing Surgery and the Role of Human Papillomavirus Infection Types.

Cervical cancer is a largely preventable malignancy of the uterine cervix. The tendencies in cervical cancer morbidity and mortality have remained similar for the past decade, albeit with increasing frequency in low- and middle-income countries (LMICs). Moreover, in the majority of LMICs, cervical cancer is the second most prevalent cancer and the second most common cause of cancer-related death among reproductive-age women. High-risk human papillomavirus (HR-HPV) infections have been proven to be associated with up to 95% of cervical cancer cases, with HPV-16 and HPV-18 types being responsible for approximately 70% of all cervical cancers, with the other high-risk HPV types accounting for up to a further 25%. More recently, the latest data appear to confirm there is a change in the frequency of HR-HPV occurrence, especially HPV-16 and HPV-18, as a reflection of the implementation of preventive vaccination programs. Owing to the growing incidence of cervical cancer among reproductive-age women and with the development of cancer management approaches, fertility-sparing options have been proposed for early-stage cervical cancer management as an option for young women, especially those with unaccomplished reproductive desires. However, methods applied for this purpose (cold-knife conization, loop electrosurgical excision, trachelectomy) have variable outcomes and do not prevent risks of relapse. Multiple factors are involved in cervical cancer recurrence, even in cases treated at the early stage of the disease. In this review, the authors unveil whether HPV infection and virus type could be one of the key factors associated with cervical cancer recurrence after fertility-sparing surgery. Reviews of the literature reveal that recurrent and persistent HR-HPV infection is a strong predictor of cervical lesions' relapse. In particular, HPV-16 and HPV-18 infections and their persistence have been reported to be associated with cervical cancer recurrence. HR-HPV genotyping before and after fertility-sparing surgery for cervical cancer could facilitate a personalized approach and improve the overall survival rate. Screening for HR-HPV is essential during the follow-up of cervical cancer-treated women and will help to predict possible cancer recurrence.

Antibiotic Overuse in Pediatric Patients Hospitalized with RSV, COVID-19, and Influenza

Abstract Background Children hospitalized with viral respiratory tract infections (RTIs) are often treated with antibiotics due to concern for bacterial co-infection, although most do not have concurrent bacterial infections. This practice leads to unnecessary antibiotic treatment, which can lead to development of resistant bacteria and adverse events. The extent of antibiotic overuse in hospitalized children with community-onset viral RTI has not been well-quantified in recent years and may have worsened during the COVID-19 pandemic. The objectives of this study were to quantify and compare the extent of antibiotic overtreatment and to determine predictors of antibiotic use post-COVID-19 pandemic in children hospitalized with RSV, COVID-19, and influenza. Methods We performed a single center retrospective study evaluating percentages of antibiotic use and bacterial co-infection among children and adolescents aged &amp;lt;19 years old, hospitalized with respiratory syncytial virus (RSV), influenza, or SARS-CoV-2 between April 2020 and May 2023. Bacterial infection was defined as growth of bacteria from any specimen source, including blood, urine, pleural fluid, cerebrospinal fluid, and respiratory secretions, excluding common contaminants like coagulase-negative Staphylococci. Predictors of antibiotic treatment were determined using multivariable logistic regression. Results During the study period 1,718 patients were included (1022 with RSV, 188 with influenza, 535 with COVID-19). RSV patients were younger and more likely to be in the ICU than influenza or COVID-19 patients. The overall proportion of patients with culture-confirmed bacterial co-infection was low at 8% and did not differ greatly by virus type (8% for influenza, 6.9% for RSV, 10.3% for COVID-19, p=0.03). The proportion of children receiving antibiotics was higher for influenza than for other viruses (60.6% for influenza, 41.2% for RSV, and 48.6% for COVID-19, p &amp;lt; 0.001). Among patients with the lowest severity of illness (with normal inflammatory markers [PCT &amp;lt;0.5 ug/mL or CRP &amp;lt;50 mg/L] and not admitted to the ICU), 7.3% had a culture-confirmed bacterial infection while 48.1% received antibiotics. Independent predictors for receiving antibiotics were elevated inflammatory markers (C-reactive protein or procalcitonin), having &amp;gt;3 comorbidities, mechanical ventilation, and influenza diagnosis. Conclusion In children hospitalized with community-onset viral RTIs, antibiotic treatment is substantially higher than the burden of culture-confirmed bacterial infection, suggesting antibiotic overuse. Antibiotic use was greater for patients with influenza than for those with RSV or COVID-19. Antibiotic overuse was estimated to occur in over 40% of patients with low severity of illness. Stewardship programs can use this data to design interventions to promote more judicious antibiotic use. Figure 1. Rates of bacterial co-infection and antibiotic utilization among patients hospitalized with influenza, RSV, and COVID. Blue, percentage of patients who had a culture-confirmed bacterial infection; orange, percentage of patients who received any antibiotics; green, percentage of patients who received &amp;gt;3 days of antibiotics.

Evaluation and control strategy analysis of influenza cases in Jiujiang City, Jiangxi Province, China from 2018 to 2022.

According to World Trade Organization (WTO) statistics, the incidence of seasonal influenza in China has been on the rise since 2018. The aim of this study was to identify and investigate the influence of factors related to the incidence of four common types of influenza viruses. Data of patients with common cold and associated virus infections are described, and a logistic regression model based on gender, age and season was established. The relationship between virus type and the above three factors was analyzed in depth and significant (p<0.05) associations noted. We noted a fluctuation trend, with the infection rate of influenza virus showing an upward trend from 2018 to 2019 and from 2021 to 2022 and a downward trend from 2019 to 2021. The total number of cases in adolescents aged 18-30 years was higher than that in the elderly. The impact of different types of influenza virus on the population ranked from large to small, with special roles played by Influenza B/Victoria, H3N2, Influenza A/H1N1 pdm and Influenza B/Yamagata.

Quality of Caregiver-Adolescent Relationship on HIV, Herpes Simplex Virus Type-2, and on Pregnancy Among Young Women in South Africa Enrolled in HIV Prevention Trials Network 068

PurposeAdolescent girls and young women (AGYW) are at an increased risk of acquiring HIV and HSV-2, and unintended pregnancies are high in AGYW. Despite the protective impact of caregiver-adolescent relationships on risk behaviors, less attention has been paid to the association of these relationships and sexually transmitted infections (STIs) and pregnancy. MethodsWe used longitudinal data from HIV Prevention Trial Network 068, which was conducted among 2,533 AGYW (13 – 20 years) over 5 years in Agincourt, South Africa. Kaplan-Meier and Cox models were used to estimate the effect of quality of caregiver-adolescent relationships (caring and closeness) on STIs and pregnancy. Also, we assessed effect measure modification by age (14–19 vs. 20–25 years) for STI risk using stratum-specific estimates and likelihood ratio tests, with a p value <.1 indicative of effect measure modification. ResultsThere were no significant differences in the hazard of HIV by our exposures (caring: hazard ratio (HR): 1.03, 95% CI: 0.75, 1.42; closeness: HR: 0.80, 95% CI: 0.57, 1.11). Among 14–19-year-olds, those who reported caregiver caring were less likely to acquire HSV-2 (HR: 0.69, 95% CI: 0.51, 0.94, likelihood ratio tests= 3.89, p-value = .0487), in contrast, there were no significant differences among 20 – 25-year-olds. AGYW who reported high-quality relationships had a lower hazard of pregnancy incidence (caring: HR: 0.79, 95% CI: 0.68, 0.93; closeness: HR: 0.76; 95% CI: 0.64, 0.91). DiscussionPositive caregiver-adolescent relationships are associated with reduced risk of HSV-2 among younger AGYW and pregnancy incidence.

Evaluation of physical, chemical, and microbiological characteristics of waste stabilization ponds, Giza, Egypt

Wastewater treatment plants (WWTPs) contain a diverse array of microbes, underscoring the need for regular monitoring to ensure treatment efficacy and protect health. However, detailed studies on waste stabilization ponds (WSPs) are scarce. This study evaluates a full-scale WSP, located in Giza Governorate, Egypt, including anaerobic, facultative, and maturation ponds, examining an array of parameters such as enteric viruses, microeukaryotes (protozoa and algae), bacterial indicators, bacterial pathogens, and physicochemical characteristics. Utilizing multivariate statistical models, we identified significant distinctions in physicochemical parameters and microbial communities, primarily driven by treatment stages rather than temporal variations. In addition, seven viruses (human rotavirus, adenovirus, norovirus, astrovirus, hepatitis A virus, polyomavirus, and papillomavirus) were detected during the different stages (inlet, anaerobic, facultative, and outlet) of the WSP, except norovirus and papillomavirus were absent in the outlet stage. The viral log means reductions ranged from 1.24 to 5.94, depending on the stage and virus type. The removal efficiency of bacterial pathogens was more than 99%. High throughput 18S rRNA gene amplicon sequencing indicated the dominance of animal parasitic Apicomplexa species and Vermamoeba spp. in the WSP. Network analysis indicated significant roles for Ciliophora in virus reduction. Notably, the maturation pond's outlet was dominated by Spirulina maxima, whose mat-forming tendencies may inhibit pathogen removal by providing protective shelters. Although the WSP effectively reduced pathogen levels, the high initial loads resulted in considerable concentrations in the final effluent, posing ongoing public health concerns. This study highlights the imperative of including pathogen standards in national regulations for wastewater reuse.

Establishment and Application of Mismatch Amplification Mutation Assay-PCR for Rapid Detection and Differentiation of Duck Hepatitis A Virus-1 Attenuated Vaccine and Wild Strains.

Duck hepatitis A virus type 1 (DHAV-1) is the main pathogen causing viral hepatitis in ducks, marked by high contagion and acute mortality. Live attenuated DHAV-1 vaccines are widely used to control the disease. This study aims to develop a mismatch amplification mutation assay (MAMA)-PCR for the rapid detection and differentiation of Korean DHAV-1 wild-type strains from vaccine strains. A MAMA primer was designed to target a single nucleotide polymorphism (SNPs) at position 2276 within the VP1 gene, allowing differentiation in a single PCR reaction. The MAMA-PCR accurately identified both strains, with detection limits of 100.5 ELD50/mL and 102.3 ELD50/mL, respectively. The MAMA-PCR demonstrated specificity, showing no cross-reactivity with 12 other viral and bacterial pathogens. The MAMA-PCR was applied to 89 farms, yielding results consistent with nested-PCR and sequence determination, identifying four positive farms for DHAV-1 vaccine strains. In conclusion, this study is the first to employ the MAMA-PCR method to distinguish between DHAV-1 wild-type and vaccine strains. The developed method is rapid, simple, specific, and sensitive, thereby serving as an effective tool for clinical diagnostics in identifying and differentiating between Korean DHAV-1 wild-type and vaccine strains.

Duck hepatitis A virus utilizes PCBP2 to facilitate viral translation and replication

Duck hepatitis A virus type 1 (DHAV-1) is an important member of the Picornaviridae family that causes highly fatal hepatitis in ducklings. Since picornaviruses have small genomes with limited coding capacity, they must utilize host proteins for viral cap-independent translation and RNA replication. Here, we report the role of duck poly(rC)-binding protein 2 (PCBP2) in regulating the replication and translation of DHAV-1. During DHAV-1 infection, PCBP2 expression was upregulated. A biotinylated RNA pull-down assay revealed that PCBP2 positively regulates DHAV-1 translation through specific interactions with structural domains II and III of the DHAV-1 internal ribosome entry site (IRES). Further studies revealed that PCBP2 promotes DHAV-1 replication via an interaction of its KH1 domain (aa 1–92) with DHAV-1 3Dpol. Thus, our studies demonstrated the specific role of PCBP2 in regulating DHAV-1 translation and replication, revealing a novel mechanism by which host‒virus interactions regulate viral translation and replication. These findings contribute to further understanding of the pathogenesis of picornavirus infections.

Detection of HBV DNA by direct PCR protocol and Nested PCR protocol and comparing them in chronic patients and healthy carriers of Hepatitis B virus.

Hepatitis B virus is a major public health problem, and the outcome of infection depends on the effectiveness of the virus's interaction with the host, and in particular on the strength of the natural and conditioned response of humoral and cellular immunity. This study was conducted to assess the clinical status, genetic immunity and viral (viral) traits of Iraqi patients with chronic hepatitis B virus and healthy carriers of hepatitis B surface antigen, as well as to show the relationship between the immune status and the chronic condition of the disease. The study included (60) patients with chronic hepatitis B virus type (B) and (60) healthy hepatitis B surface antigen carriers who attended the Teaching Hospital for Gastrointestinal and Liver Diseases in Nasiriya City Al-Hussein Teaching Hospital, Thalassemia Center and the Central Blood Bank in Nasiriya Citysouthern of Iraq. for the period from the first period. From February 2022 until the end of February 2022, the average age of patients infected with chronic hepatitis B virus was 64.5 years, and the average age of healthy carriers of hepatitis B surface antigen was 35. 1 year, and the ratio of males to females was (12.2:) for chronic patients and (13.6:) for carriers of the disease. As for the deoxyribonucleic acid, it was (100%) in chronic patients and healthy carriers using the Nested type polymerase chain reaction, and at a rate of (30.0%) and (46.7%) in chronic patients and healthy carriers, respectively using the polymerase chain reaction technique. direct with a significant difference between the two interactions. The current results confirm that a nested PCR protocol to detect HBV DNA is a more sensitive way of detecting HBV in Iraq CHB patients and carriers. Recent advanced techniques such as nucleic acid assays, quantitative assays for viral load and RT-PCR for Iraqi viral hepatitis laboratories are recommended.

TYPE PROFILE OF HIGH ONCOGENIC RISK HUMAN PAPILLOMAVIRUS IN CLINICAL FORMS OF CERVICAL INFECTION IN RUSSIAN FEDERATION

Abstract Aim: To establish a relationship between the clinical forms of cervical papillomavirus infection and the specific characteristics of high-risk human papillomavirus (HPV) types. The study included 1063 patients aged 16 to 71 years (Me = 33; IQR: 29–38) with active papillomavirus infection and its clinical forms. The patients were stratified into groups based on disease clinical forms during active HPV infection: carriers, mild cervical intraepithelial neoplasia, moderate cervical intraepithelial neoplasia, severe cervical intraepithelial neoplasia, carcinoma in situ, and invasive cervical cancer. Diagnostics was performed using real-time polymerase chain reaction (PCR) with HPV typing (types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68). The results demonstrated that viruses from the alpha-phylogenetic branch are responsible for developing clinical forms of HPV infection. It was found that severe forms of infection, including cervical cancer, was mainly linked to A9 family (HPV16, HPV31, HPV58) viruses, whereas initial disease stages – to A5 and A6 families (HPV51 and HPV66). A particularly significant observation is the transition from A5, A6, and A7 family HPV viruses with relation to HPV16, to the A9 family showing highly related to HPV16. This observation underscores the high significance of HPV16 monoinfection in cervical cancer within the context of the replication theory for HPV16-like viruses. Viral load exhibits a wave-like pattern depending on the clinical form and HPV family, indicating the dynamic nature of the infection process and the potential changes in viral load based on the disease stage and virus type. The study highlights the importance of identifying a specific HPV type in mono- or polyinfection to assess disease clinical form. This can provide significant aid to clinicians for assessing severity of the infection and devising the appropriate management strategy for patients. In conclusion, our findings emphasize a need to take into consideration a HPV type in diagnostics and treatment of cervical papillomavirus infection. This approach will enhance prognostic accuracy and effectiveness of therapeutic interventions aimed at preventing disease progression and cervical cancer development.

Surface Display of Duck Hepatitis A Virus Type 1 VP1 Protein on Bacillus subtilis Spores Elicits Specific Systemic and Mucosal Immune Responses on Mice.

Duck viral hepatitis, primarily caused by duck hepatitis A virus type 1 (DHAV-1), poses a significant threat to the global duck industry. Bacillus subtilis is commonly utilized as a safe probiotic in the development of mucosal vaccines. In this study, a recombinant strain of B. subtilis, designated as B. subtilis RV, was constructed to display the DHAV-1 capsid protein VP1 on its spore surface using the outer coat protein B as an anchoring agent. The immunogenicity of this recombinant strain was evaluated in a mouse model through mixed feeding immunization. The results indicated that B. subtilis RV could elicit specific systemic and mucosal immune responses in mice, as evidenced by the high levels of serum IgG, intestinal secretory IgA, and potent virus-neutralizing antibodies produced. Furthermore, the recombinant strain significantly upregulated the expression levels of IL-2, IL-6, IL-10, TNF-α, and IFN-γ in the intestinal mucosa. Thus, the recombinant strain maintained the balance of the Th1/Th2 immune response and demonstrated an excellent mucosal immune adjuvant function. In summary, this study suggests that B. subtilis RV can be a novel alternative for effectively controlling DHAV-1 infection as a vaccine-based feed additive.

Mechanisms of action of microbicides commonly used in infection prevention and control.

SUMMARYUnderstanding how commonly used chemical microbicides affect pathogenic microorganisms is important for formulation of microbicides. This review focuses on the mechanism(s) of action of chemical microbicides commonly used in infection prevention and control. Contrary to the typical site-specific mode of action of antibiotics, microbicides often act via multiple targets, causing rapid and irreversible damage to microbes. In the case of viruses, the envelope or protein capsid is usually the primary structural target, resulting in loss of envelope integrity or denaturation of proteins in the capsid, causing loss of the receptor-binding domain for host cell receptors, and/or breakdown of other viral proteins or nucleic acids. However, for certain virucidal microbicides, the nucleic acid may be a significant site of action. The region of primary damage to the protein or nucleic acid is site-specific and may vary with the virus type. Due to their greater complexity and metabolism, bacteria and fungi offer more targets. The rapid and irreversible damage to microbes may result from solubilization of lipid components and denaturation of enzymes involved in the transport of nutrients. Formulation of microbicidal actives that attack multiple sites on microbes, or control of the pH, addition of preservatives or potentiators, and so on, can increase the spectrum of action against pathogens and reduce both the concentrations and times needed to achieve microbicidal activity against the target pathogens.

Review of factors affecting virus inactivation in aerosols and droplets.

The inactivation of viruses in aerosol particles (aerosols) and droplets depends on many factors, but the precise mechanisms of inactivation are not known. The system involves complex physical and biochemical interactions. We reviewed the literature to establish current knowledge about these mechanisms and identify knowledge gaps. We identified 168 relevant papers and grouped results by the following factors: virus type and structure, aerosol or droplet size, temperature, relative humidity (RH) and evaporation, chemical composition of the aerosol or droplet, pH and atmospheric composition. These factors influence the dynamic microenvironment surrounding a virion and thus may affect its inactivation. Results indicate that viruses experience biphasic decay as the carrier aerosols or droplets undergo evaporation and equilibrate with the surrounding air, and their final physical state (liquid, semi-solid or solid) depends on RH. Virus stability, RH and temperature are interrelated, but the effects of RH are multifaceted and still not completely understood. Studies on the impact of pH and atmospheric composition on virus stability have raised new questions that require further exploration. The frequent practice of studying virus inactivation in large droplets and culture media may limit our understanding of inactivation mechanisms that are relevant for transmission, so we encourage the use of particles of physiologically relevant size and composition in future research.

HSP70 positively regulates translation by interacting with the IRES and stabilizes the viral structural proteins VP1 and VP3 to facilitate duck hepatitis A virus type 1 replication.

The maintenance of viral protein homeostasis depends on the interaction between host cell proteins and viral proteins. As a molecular chaperone, heat shock protein 70 (HSP70) has been shown to play an important role in viral infection. Our results showed that HSP70 can affect translation, replication, assembly, and release during the life cycle of duck hepatitis A virus type 1 (DHAV-1). We demonstrated that HSP70 can regulate viral translation by interacting with the DHAV-1 internal ribosome entry site (IRES). In addition, HSP70 interacts with the viral capsid proteins VP1 and VP3 and promotes their stability by inhibiting proteasomal degradation, thereby facilitating the assembly of DHAV-1 virions. This study demonstrates the specific role of HSP70 in regulating DHAV-1 replication, which are helpful for understanding the pathogenesis of DHAV-1 infection and provide additional information about the role of HSP70 in infection by different kinds of picornaviruses, as well as the interaction between picornaviruses and host cells.

MRNA and miRNA expression profiles reveal the potential roles of RLRs signaling pathway and mitophagy in duck hepatitis A virus type 1 infection

Duck hepatitis A virus 1 (DHAV-1) is the primary cause of duck viral hepatitis, leading to sudden mortality in ducklings and significant economic losses in the duck industry. However, little is known about how DHAV-1 affects duckling liver at the molecular level. We conducted an analysis comparing the expression patterns of mRNAs and miRNAs in DHAV-1-infected duckling livers to understand the underlying mechanisms and dynamic changes. We identified 6,818 differentially expressed mRNAs (DEGs) and 144 differentially expressed microRNAs (DEMs) during DHAV-1 infection. Functional enrichment analysis of DEGs and miRNA target genes using gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) revealed their potential involvement in innate antiviral immunity, mitophagy, and pyroptosis. We constructed coexpression networks of mRNA-miRNA interactions and confirmed key DEMs (novel-mir333, novel-mir288, novel-mir197, and novel-mir71) using RT-qPCR. Further investigation demonstrated that DHAV-1 activates the RLRs signaling pathway, disrupts mitophagy, and induces pyroptosis. In conclusion, DHAV-1-induced antiviral immunity is closely linked to mitophagy, suggesting it could be a promising therapeutic target.

Unravelling the acute respiratory infection landscape: virus type, viral load, health status and coinfection do matter.

Acute respiratory infections (ARI) are the most common infections in the general population and are mainly caused by respiratory viruses. Detecting several viruses in a respiratory sample is common. To better understand these viral codetections and potential interferences, we tested for the presence of viruses and developed quantitative PCR (Polymerase Chain Reaction) for the viruses most prevalent in coinfections: human rhinovirus (HRV) and respiratory syncytial virus (RSV), and quantified their viral loads according to coinfections and health status, age, cellular abundance and other variables. Samples from two different cohorts were analyzed: one included hospitalized infants under 12 months of age with acute bronchiolitis (n=719) and the other primary care patients of all ages with symptoms of ARI (n=685). We performed Multiplex PCR on nasopharyngeal swabs, and quantitative PCR on samples positive for HRV or/and RSV to determine viral loads (VL). Cellular abundance (CA) was also estimated by qPCR targeting the GAPDH gene. Genotyping was performed either directly from first-line molecular panel or by PCR and sequencing for HRV. The risks of viral codetection were 4.1 (IC95[1.8; 10.0]) and 93.9 1 (IC95[48.7; 190.7]) higher in infants hospitalized for bronchiolitis than in infants in primary care for RSV and HRV respectively (p<0.001). CA was higher in samples positive for multiple viruses than in mono-infected or negative samples (p<0.001), and higher in samples positive for RSV (p<0.001) and HRV (p<0.001) than in negative samples. We found a positive correlation between CA and VL for both RSV and HRV. HRV VL was higher in children than in the elderly (p<0.05), but not RSV VL. HRV VL was higher when detected alone than in samples coinfected with RSV-A and with RSV-B. There was a significant increase of RSV-A VL when codetecting with HRV (p=0.001) and when co-detecting with RSV-B+HRV versus RSV-A+ RSV-B (p=0.02). Many parameters influence the natural history of respiratory viral infections, and quantifying respiratory viral loads can help disentangle their contributions to viral outcome.