Prevalence Of Virus Research Articles

Determinants of worse liver-related outcome according to HDV infection among HBsAg positive persons living with HIV: Data from the ICONA cohort.

We aimed to study hepatitis D virus (HDV) prevalence and risk of progression to severe liver-related events (SLRE) in HBsAg positive people living with HIV (PLWH) in Italy; role of HDV-RNA copy levels, HCV coinfection and nadir CD4 counts were also investigated. People living with HIV (PLWH) from Italian Foundation cohort Naïve antiretrovirals (ICONA) with available HBsAg and HDV Ab were enrolled. HBsAg, HDV Ab, HDV-RNA and HDV genotypes were tested. time from first HDV screening to Severe Liver Related Events (SLRE: decompensated cirrhosis, liver transplantation, HCC). Fine-grey regression models were used to evaluate the association of HDV Ab, HDV-RNA, HDV/HCV coinfection, CD4 nadir and outcome. Secondary end-points: time to SLRE or death;HDV Ab and HDV-RNA prevalence. A total of 152/809 (18.8%) HBsAg positive PLWH showed HDV Ab reactivity; 63/93 (67.7%) were HDV-RNA positive. Being male, persons who inject drugs (PWID), HCV Ab positive, with FIB-4 > 3.25 were independent factors of HDV Ab positivity. In a median follow-up of 5 years, 37 PLWH (4.1% at 5-year) developed SLRE and 97 (12.0%) reached the SLRE or death end-point. HDV-RNA positive (independently from HDV-RNA copy level) PLWH had a 4.6-fold (95%CI 2.0-10.5) higher risk of SLRE than HDV negatives. PLWH positive for both HCV Ab and HDV Ab showed the highest independent risk of SLRE (ASHR: 11.9, 95%CI: 4.6-30.9 vs. HCV neg/HDV neg). Nadir CD4 < 200/mL was associated with SLRE (ASHR: 3.9, 95% 1.0-14.5). One-fifth of the HBsAg positive PLWH harbour HDV infection, and are at high risk of progression to advanced liver disease. HCV contributes to worse outcomes. This population needs urgently effective treatments.

Nucleic acid amplification testing (NAT) impact on blood safety compared to Immunoassays in blood banks: A Review

Blood transfusions are fundamental to clinical procedures; however, many people worldwide cannot access safe blood. Blood product safety must be essential in each country’s national health policies. Several aspects of the blood donation process are carefully performed, including laboratory testing comprising blood type determination, antigen-antibody analyses, and nucleic acid amplification testing (NAT); however, NAT is not mandatory in all countries. The traditional screening method is based on antigen-antibody binding techniques, such as ELISA (enzyme-linked immunosorbent assay), with high sensitivity and specificity. Nevertheless, these methods have a seroconversion window period (WP), in which antigen-antibody testing cannot detect the pathogen and has not caused any symptoms yet. NAT is a sensitive molecular method based on viral nucleic acid amplification and detection. Moreover, its use in blood banks is increasing worldwide because it narrows the window period. For example, Huang et al. in 2017 reported the detection of 22 samples reactive only by nucleic acid testing for either HIV, HBV, or HCV compared with ELISA. The present article shows how blood safety has improved by implementing NAT as a routine method for viral nucleic acid detection, highlighting the importance of this technique as evidenced by the findings presented herein. Moreover, these results are highly significant, demonstrating the relevance of NAT and advocating for its application on a global scale in blood management protocols. This development could be particularly beneficial for regions with a high viral infection prevalence, including many countries. Keywords: Nucleic acid amplification, Immunoassay, viral infection, blood bank.

Hepatitis B immunization status and risk factors of people aged 1 to 69 in Huangpu District, Shanghai, China.

China has long been with high Hepatitis B Virus(HBV) prevalence in the world. The HBV prevalence of people aged 1-59 decreased to less than 8% in 2006, and by 2020, HBsAg positive rate of children aged <5 decreased to less than <1% which was due to the free three-dose hepatitis B(HepB) immunization for newborns nationwide since 2002. Huangpu district was selected as one of the pilot areas for free Hep B vaccination in newborns since 1986, which formed an early protection in the population from mother-to-child transmission. However, the existed HBV infected people were still needed to be discovered, evaluated whether to receive antiviral therapies and intervened with health education in order to reduce the incidence of viral hepatitis related hepatocellular carcinoma (HCC) and also reach the goal to eliminate public health hazards of viral hepatitis by 2030. To know HepB immunization status among people aged 1 to 69 in Huangpu district of Shanghai, and find out risk factors changes of HBV infection. Cross-sectional study was applied to analyze the HepB immunization status and related risk factors by carrying out survey among 706 participants aged 1 to 69 years old. Blood samples were collected for detection of serological HBV markers including hepatitis B surface antigen(HBsAg), hepatitis B surface antibody(HBsAb) and hepatitis B core antibody(HBcAb). Participants with HBsAg positive were required to complete additional examinations such as alanine aminotransferase(ALT), aspartate aminotransferase(AST), total bilirubin, albumin, globulin, liver fibroscan and liver ultrasound. For participants aged 1 to 14, the positive rate of HBsAg, HBsAb and HBcAb was 0.00, 50.00 and 30.46%, respectively. The HBsAb positive rate reached a peak of 90.91% at 2 years old, and then showed a significant downward trend (χ2 = 55.612, p < 0.001). All the participants have completed three-dose Hep B vaccination, however for the second dose, those who vaccinated 30 days later than the appointed time(aged one month) got higher HBcAb prevalence than those who vaccinated on time(χ2 = 5.87, p = 0.015). Two mothers were found HBsAg positive, but there was no significant difference in children's HBcAb positive rates regardless of the mothers' HBsAg results. For participants aged 15 to 69, the positive rate of HBsAg, HBsAb and HBcAb was 4.21, 44.25 and 49.23%, respectively. Multivariate analysis for HBcAb positive among people aged 15 to 69 showed that age(50-69) and HBsAb positive were the risk factors for HBcAb positive(p < 0.05). Higher education was the protective factor for HBcAb positive(p < 0.05). After the screening for HBsAg, 22 participants were tested HBsAg positive and required additional examinations, and a total of 12 completed all the examinations. One participant was recognized as active HBV infection without antivirus treatment. Among the 12 participants, 2 have received antiviral treatment before and 4 had a history of HBV infection in family members. In this study, HBsAg positive rate of those who aged 1 to 14 was 0.00%, which indicated that the HepB immunization has achieved a lot in protecting children from being infected. However, failing to get timely Hep B vaccination could be an influencing factor for HBcAb positive in children. As a result, additional tests for HBV DNA could be done to specify an HBV infection and more attention should be paid to the timeliness of Hep B vaccination in the next step. The HBcAb positive rate of people aged 1 to 69 was relatively higher than that of other provinces. Despite of the limited participants with full examinations, we should still put emphasis on HBV treatment and the possibility of transmission within families.

Epidemiological surveillance of respiratory viral infections in SARS-CoV-2-negative samples during COVID-19 pandemic in Iran

BackgroundTo improve the patient care, public health surveillance, and infection control, it is crucial to identify the presence and frequency of the common respiratory infections in individuals with COVID-19 symptoms but tested negative for SARS-CoV-2. This study aimed to shed light on this during the COVID-19 pandemic in Iran.MethodsIn this cross-sectional study, a total of 1,002 patients with acute respiratory infection who had negative SARS-CoV-2 test results and referred to Valfajr Health Center, the National Collaborating Laboratory of Influenza and COVID-19 National Reference Laboratory at Pasteur Institute of Iran were recruited between January 2020 and January 2022. Nasopharyngeal and oropharyngeal swab samples were collected to detect 17 common respiratory viruses via TaqMan one-step real-time multiplex PCR. Demographic and clinical data of the participants were obtained from their electronic medical records.ResultsIn total, 218 samples (21.8%) were tested positive for at least one respiratory virus infection. Most of the common investigated respiratory viruses belonged to the years 2020 and 2022. The number of investigated patients in 2021 was few, which highlights the impact of health measures following the COVID-19 pandemic in Iran. Influenza A was the most common virus (5.8%), while adenovirus had the lowest prevalence (0.1%). Although the rate of respiratory virus infection was higher in men (24%) compared to women (19.3%), this difference was not statistically significant (P = 0.069). The prevalence of respiratory viruses had an inverse association with increasing age, with the highest rate (55.6%) observed in the age group below 2 years and the lowest rate (12.7%) in those above 65 years.ConclusionOur findings underscore the significance of adopting a comprehensive approach to respiratory infections detection and management. These results can be employed for the development of syndromic surveillance systems and implementation of the effective infection control measures. Furthermore, the results contribute to better understanding of the dynamics of respiratory viruses, both during pandemic periods and in non-pandemic contexts.

Prevention, testing, and treatment interventions for hepatitis B and C in refugee populations: results of a scoping review

Background and aimsRefugees are at higher risk for hepatitis B (HBV) and hepatitis C (HCV), but often face unique healthcare barriers to vaccination, testing, and treatment. This scoping review aimed to identify and characterize HBV and HCV prevention and care services serving refugee populations globally.MethodsA literature search was conducted on Embase, Cochrane, and PubMed databases. Research studies published in English between January 2010 to July 2022 describing an HBV or HCV prevention, testing, or treatment intervention for refugees were included.ResultsThere were a total of 69 articles reporting viral hepatitis prevalence, implementation of services, or economic modelling. Of the 38 implementation studies, 14 were stand-alone HBV and/or HCV interventions, while 24 studies included HBV and/or HCV in an intervention targeting multiple infectious diseases and/or parasitic infections. Interventions commonly included a testing (n = 30) or referral (n = 24) component. Frequently reported features to promote program accessibility included bilingual services (n = 25), community partnerships (n = 21), and multidisciplinary staff members (n = 18), such as cultural and/or linguistic mediators, community health workers, community health leaders, lay health workers, local health staff, members of the refugee community, and social workers. The most commonly reported challenge was the transience of refugees (n = 5). Twenty studies noted funding sources, of which twelve reported governmental funding (not including national health insurance) and eight reported that refugees received national health insurance.ConclusionsThis is the first scoping review to characterize the types of hepatitis prevention, screening, and treatment interventions serving refugee populations globally. Published experiences of HBV and HCV services for refugee populations remain limited. Additional efforts are needed to disseminate models of hepatitis interventions for refugees to ensure access to care for this key population. To achieve hepatitis elimination globally, best practices must be identified and shared to expand access to hepatitis services for refugee populations.

SEROPREVALENCE OF TRANSFUSION-TRANSMITTED INFECTIONS AMONG VOLUNTARY BLOOD DONORS AT A TERTIARY CARE HOSPITAL

Objectives: Blood transfusion is an effective treatment for saving millions of lives. However, transfusion-transmitted infections (TTIs) hamper blood safety. To prevent transmission of these diseases, screening for infections is an essential step for blood safety. Aim: The aim of this study was to assess the seroprevalence of TTI among healthy voluntary blood donors. Methods: This was a retrospective cross-sectional study at the Department of Immunohematology and Blood Transfusion, Tirunelveli Medical College and Hospital, Tirunelveli, for a period of 6 years from January 2017 to December 2022. Data of the blood donors screened were retrieved and analyzed with the aid of screening register and seropositive donor register over 2 months (December 2022 and January 2023). Results: Among 53522 donors, 0.44% were seropositive for TTI (0.44%, n=233/53522) in which 99.57% (n=232/233) were male donors. Prevalence was more in 18–25 age group (39.91%, n=93/233). Hepatitis B virus (HBV) was the most prevalent microbe (n=144/53522) (0.27%). The prevalence of HBV showed a decreasing trend, while the prevalence of syphilis showed an increasing trend. The prevalence of human immunodeficiency virus, hepatitis C virus and malaria was unchanged. Conclusion: Seroprevalence and changing trends of TTI among blood donors reveal the prevalence of infections in the general population which gives an idea of disease burden on society. Education about confidential unit exclusion and implementation can help reduce transmission risk and wastage.

The consensus guideline of perioperative antiviral therapy for AIDS patients in China based on clinical practice.

The prevalence of human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS) has emerged as a major public health concern in China. When patients with HIV infection undergo surgical treatment, there are two main challenges. Firstly, medical staff face a high risk of HIV infection due to occupational exposure. Secondly, the patient's immune function is impaired, increasing the risk of opportunistic infections and postoperative complications. The surgical treatment of such patients is unique, and the risk of occupational exposure during the operation primarily depends upon the viral load of HIV/AIDS patients. Therefore, perioperative antiretroviral therapy is of paramount importance in order to standardize the perioperative antiretroviral therapy (ART) for HIV/AIDS patients. The Surgery Group of the Chinese Association of STD and AIDS Prevention and Control, in collaboration with the Treatment Association, and Surgery Group of the Chinese Medical Association of Tropical Diseases and Parasitology, has developed an expert consensus on perioperative antiretroviral therapy for HIV/AIDS patients. This consensus encompasses various aspects, including surgical risk assessment, selection of perioperative antiretroviral therapy regimens, prevention of opportunistic infections, and the crucial focus on rapid preoperative viral load reduction and immune function reconstruction for HIV/AIDS patients.

Viruses in chronic rhinosinusitis: a systematic review.

Unlike acute rhinosinusitis (ARS) which is mostly viral in etiology, the role of viruses in chronic rhinosinusitis (CRS) remains unclear. Viruses may play a role in initiation, exacerbations or perpetuate chronic inflammatory responses in the sinonasal mucosa. Research needs to characterize whether viruses are part of the normal sinonasal microbiome, colonizers or pathogenic. Systematic review of the English literature was conducted. Following databases were searched with an initial search conducted in November 2021 and then updated through June 2023: Ovid Medline (1946 to present), Ovid Embase (1988 to present), Scopus (2004 to present) and Web of Science (1975 to present). MeSH (Medical Subject Headings) terms included: viruses, virus diseases, sinusitis, and rhinovirus. Keywords: virus, viral infection*, sinusitis, rhinovirus, chronic rhinosinusitis, CRS, respiratory virus, respiratory infection*, and exacerbat*. A supplementary search was conducted through September 2023: Ovid Medline (1946 to present), Epub Ahead of Print, In-Process & Other Non-Indexed Citations and Ovid MEDLINE(R) Daily. Keywords used were: virus, viral infection*, sinusitis, chronic rhinosinusitis, CRS, respiratory virus, respiratory infection*, and exacerbat*. Thirty studies on viruses in CRS met inclusion criteria for full review. These included 17 studies on prevalence of virus in CRS, 5 examining probable causes of host susceptibility to viral infections in CRS, and 8 studies examining pathological pathways in viral association of CRS. The prevalence of viruses in nasal specimens of CRS subjects was higher as compared to controls in most studies, though a few studies showed otherwise. Rhinovirus was the most common virus detected. Studies showed that viruses may be associated with persistent hyper-responsiveness in the sinonasal mucosa, susceptibility to bacterial infections, upregulation of genes involved in the immune response and airway remodeling as well as CRS exacerbations. Presence of viruses was also associated with worse symptom severity scores in CRS subjects. Most data show higher presence of viruses in nasal and serum samples of CRS subjects as compared to controls but their exact role in CRS pathophysiology in unclear. Large studies with longitudinal sampling at all disease phases (i.e., prior to disease initiation, during disease initiation, during disease persistence, and during exacerbations) using standardized sampling techniques are needed to definitively elucidate the role of virus in CRS.

A metatranscriptomic evaluation of viruses in field-collected bed bugs.

Cimex lectularius, known as the common bed bug, is a widespread hematophagous human ectoparasite and urban pest that is not known to be a vector of any human infectious disease agents. However, few studies in the era of molecular biology have profiled the microorganisms harbored by field populations of bed bugs. The objective of this study was to examine the viruses present in a large sampling of common bed bugs and related bat bugs (Cimex pipistrelle). RNA sequencing was undertaken on an international sampling of > 500 field-collected bugs, and multiple workflows were used to assemble contigs and query these against reference nucleotide databases to identify viral genomes. Shuangao bed bug virus 2, an uncharacterized rhabdovirus previously discovered in Cimex hemipterus from China, was found in several bed bug pools from the USA and Europe, as well as in C. pipistrelle, suggesting that this virus is common among bed bug populations. In addition, Shuangao bed bug virus 1 was detected in a bed bug pool from China, and sequences matching Enterobacteria phage P7 were found in all bed bug pools, indicating the ubiquitous presence of phage-derived elements in the genome of the bed bug or its enterobacterial symbiont. However, viral diversity was low in bed bugs in our study, as no other viral genomes were detected with significant coverage. These results provide evidence against frequent virus infection in bed bugs. Nonetheless, our investigation had several important limitations, and additional studies should be conducted to better understand the prevalence and composition of viruses in bed bugs. Most notably, our study largely focused on insects from urban areas in industrialized nations, thus likely missing infrequent virus infections and those that could occur in rural or tropical environments or developing nations.

Immunogenicity and protective efficacy of recombinant adenovirus expressing a novel genotype G2b PEDV spike protein in protecting newborn piglets against PEDV.

Porcine epidemic diarrhea (PED) is a highly infectious and economically significant gastrointestinal disorder that affects pigs of all ages. Preventing and controlling PED is achieved by immunizing sows with vaccines, enabling passive piglet immunization via colostrum. The prevalence of G2b porcine epidemic diarrhea virus (PEDV) continues in China despite the use of commercial vaccines, raising questions regarding current vaccine efficacy and the need for novel vaccine development. Adenovirus serotype 5 (Ad5) has several advantages, including high transduction efficiency, a wide range of host cells, and the ability to infect cells at various stages. In this study, we expressed the immunogenic proteins of spike (S) using an Ad5 vector and generated a PED vaccine candidate by inducing significant humoral immunity. The rAd5-PEDV-S prevented PED-induced weight loss, diarrhea, and intestinal damage in piglets. This novel vaccine candidate strain possesses the potential for use in the pig breeding industry.

Prevalence of Human Papilloma Virus in the Patients with Oral Cancer Referred to Shiraz Teaching Hospital during 2016–2017

Prevalence of Human Papilloma Virus in the Patients with Oral Cancer Referred to Shiraz Teaching Hospital during 2016–2017

The Prevalence of Epstein-Barr Virus and Multiple Sclerosis in Mena Region: A Systematic Review

The Prevalence of Epstein-Barr Virus and Multiple Sclerosis in Mena Region: A Systematic Review

Prevalence of Bovine leukemia virus in Egyptian women’s breast cancer tissues

ABSTRACT Bovine leukemia virus (BLV) infects cattle around the world and presents in commercial bovine products. Several studies have suggested that BLV may play a role in breast oncogenesis. This study aimed to determine the risk factors for BLV infection and the presence of the BLV gene in breast tissue. A total of 100 formalin-fixed and paraffin-embedded breast tissue specimens were collected (50 confirmed cancer samples and 50 negative samples). DNA was extracted from breast tissues, and nested PCR was done to detect the tax gene of BLV. Immunohistochemical staining for ER, PR, Her2/neu, and Ki-67 was applied. Bovine leukemia virus DNA was detected in 16% of breast cancer tissue samples and in only 4% of tissue samples without cancer. No statistically significant association was reported between the presence of BLV and tumor grade, stage, or LN metastasis. A high percentage of positivity (100%, 88%, and 75%) was reported for ER, PR, and Ki-67 in BLV-positive cancer samples, respectively. There was a significant association between the BLV tax gene and breast cancer in Egyptian women. Thus, there is a need to control BLV transmission to humans from cattle, and further investigations about its risk related to public health are highly required.

Engineered Antiviral Sensor Targets Infected Mosquitoes.

Escalating vector disease burdens pose significant global health risks, as such innovative tools for targeting mosquitoes are critical. CRISPR-Cas technologies have played a crucial role in developing powerful tools for genome manipulation in various eukaryotic organisms. Although considerable efforts have focused on utilizing class II type II CRISPR-Cas9 systems for DNA targeting, these modalities are unable to target RNA molecules, limiting their utility against RNA viruses. Recently, the Cas13 family has emerged as an efficient tool for RNA targeting; however, the application of this technique in mosquitoes, particularly Aedes aegypti, has yet to be fully realized. In this study, we engineered an antiviral strategy termed REAPER (vRNA Expression Activates Poisonous Effector Ribonuclease) that leverages the programmable RNA-targeting capabilities of CRISPR-Cas13 and its potent collateral activity. REAPER remains concealed within the mosquito until an infectious blood meal is uptaken. Upon target viral RNA infection, REAPER activates, triggering programmed destruction of its target arbovirus such as chikungunya. Consequently, Cas13-mediated RNA targeting significantly reduces viral replication and viral prevalence of infection, and its promiscuous collateral activity can even kill infected mosquitoes within a few days. This innovative REAPER technology adds to an arsenal of effective molecular genetic tools to combat mosquito virus transmission.

Simian immunodeficiency virus and storage buffer: Field-friendly preservation methods for RNA viral detection in primate feces.

Simian immunodeficiency virus (SIV), which originated in African monkeys, crossed the species barrier into humans and ultimately gave rise to HIV and the global HIV/AIDS epidemic. While SIV infects over 40 primate species in sub-Saharan Africa, testing for RNA viruses in wild primate populations can be challenging. Optimizing field-friendly methods for assessing viral presence/abundance in non-invasively collected biological samples facilitates the study of viruses, including potentially zoonotic viruses, in wild primate populations. This study compares SIV RNA preservation and recovery from non-human primate feces stored in four different buffers. Our results will inform future fieldwork and facilitate improved approaches to characterizing prevalence, shedding, and transmission of RNA viruses like SIV in natural hosts including wild-living non-human primates.

Incidence and causative agent distribution of viral-induced paediatric asthma exacerbations under strict infection control measures: a single-centre retrospective study in Japan

BackgroundThe prevalence of respiratory viruses in children changed under strict infection control measures during the coronavirus disease 2019 (COVID-19) outbreak. In this study, we investigated the frequency of viral detection in the nasopharynx of paediatric patients with asthma exacerbations requiring hospitalization during the COVID-19 pandemic, as well as the distribution of causative viruses.MethodsWe included paediatric patients admitted for asthma exacerbations between November 2020 and December 2022 at a single centre in Kobe, Japan. Demographic, clinical, and laboratory data were collected from their medical records and using additional questionnaires. All patients enrolled in this study met the diagnostic criteria for asthma exacerbations outlined in the Japanese Pediatric Guideline for the Treatment and Management of Bronchial Asthma 2020. Statistical differences were calculated using univariate analyses (chi-square or Mann‒Whitney U test).ResultsWe enrolled 203 children hospitalized for asthma attacks and collected nasopharyngeal samples from 189 patients. The median patient age was 3.0 years. Asthma severity was classified as mild (4.0%), moderate (82.3%), or severe (13.8%). The proportion of viral respiratory infections was 95.2% (180/189). The rate of patients with multiple viral infections was 20.6% (39/189). The most frequently detected pathogens were rhinovirus and enterovirus (RV/EV) at 69.3% (131/189), allowing for duplicate detection, followed by respiratory syncytial virus (RSV) at 28.6% (54/189). We also detected RV/EV almost every month compared to RSV and other viruses. In addition, RV/EV-positive patients were significantly older (p = 0.033), exhibited higher WBC counts (p < 0.001) and higher Eos counts (p < 0.001), had elevated total IgE levels (p < 0.001) and house dust mite-specific IgE levels (p = 0.019), had a shorter duration of hospitalization (p < 0.001), and had a shorter duration of oxygen therapy (p < 0.001). In patients positive for RV/EV, the use of ICSs significantly reduced the severity of the condition (p < 0.001).ConclusionEven under strict infection control measures, respiratory viruses were detected in the nasopharynx of almost all paediatric patients who had asthma exacerbations requiring hospitalization.

Transmission mode predicts coinfection patterns of insect-specific viruses in field populations of the Queensland fruit fly.

Insect-specific viruses (ISVs) can affect insect health and fitness, but can also interact with other insect-associated microorganisms. Despite this, ISVs are often studied in isolation from each other, in laboratory populations. Consequently, their diversity, prevalence and associations with other viruses in field populations are less known, yet these parameters are important to understanding virus epidemiology. To help address this knowledge gap, we assessed the diversity, prevalence and coinfections of three ISVs (horizontally transmitted cripavirus, biparentally transmitted sigmavirus and maternally transmitted iflavirus) in 29 field populations of Queensland fruit fly, Australia's most significant horticultural pest, in the context of their different transmission modes. We detected new virus variant diversity. In contrast to the very high virus prevalence in laboratory populations, 46.8% of 293 field flies carried one virus and 4.8% had two viruses. Cripavirus and sigmavirus occurred in all regions, while iflavirus was restricted to subtropical and tropical regions. Cripavirus was most prevalent (37.5%), followed by sigmavirus (13.7%) and iflavirus (4.4%). Cripavirus coinfected some flies with either one of the two vertically transmitted viruses. However, sigmavirus did not coinfect individuals with iflavirus. Three different modelling approaches detected negative association patterns between sigmavirus and iflavirus, consistent with the absence of such coinfections in laboratory populations. This may be linked with their maternal transmission and the ineffective paternal transmission of sigmavirus. Furthermore, we found that, unlike sigmavirus and iflavirus, cripavirus load was higher in laboratory than field flies. Laboratory and mass-rearing conditions may increase ISV prevalence and load due to increased transmission opportunities. We conclude that a combination of field and laboratory studies is needed to uncover ISV interactions and further our understanding of ISV epidemiology.

Phaeoviruses Present in Cultured and Natural Kelp Species, Saccharina latissima and Laminaria hyperborea (Phaeophyceae, Laminariales), in Norway.

Phaeoviruses (Phycodnaviridae) are large icosahedral viruses in the phylum Nucleocytoviricota with dsDNA genomes ranging from 160 to 560 kb, infecting multicellular brown algae (Phaeophyceae). The phaeoviral host range is broader than expected, not only infecting algae from the Ectocarpales but also from the Laminariales order. However, despite phaeoviral infections being reported globally, Norwegian kelp species have not been screened. A molecular analysis of cultured and wild samples of two economically important kelp species in Norway (Saccharina latissima and Laminaria hyperborea) revealed that phaeoviruses are recurrently present along the Norwegian coast. We found the viral prevalence in S. latissima to be significantly higher at the present time compared to four years ago. We also observed regional differences within older samples, in which infections were significantly lower in northern areas than in the south or the fjords. Moreover, up to three different viral sequences were found in the same algal individual, one of which does not belong to the Phaeovirus genus and has never been reported before. This master variant therefore represents a putative new member of an unclassified phycodnavirus genus.

Serological evidence of virus infection in Eidolon helvum fruit bats: implications for bushmeat consumption in Nigeria.

The Eidolon helvum fruit bat is one of the most widely distributed fruit bats in Africa and known to be a reservoir for several pathogenic viruses that can cause disease in animals and humans. To assess the risk of zoonotic spillover, we conducted a serological survey of 304 serum samples from E. helvum bats that were captured for human consumption in Makurdi, Nigeria. Using pseudotyped viruses, we screened 304 serum samples for neutralizing antibodies against viruses from the Coronaviridae, Filoviridae, Orthomyxoviridae and Paramyxoviridae families. We report the presence of neutralizing antibodies against henipavirus lineage GH-M74a virus (odds ratio 6.23; p < 0.001), Nipah virus (odds ratio 4.04; p = 0.00031), bat influenza H17N10 virus (odds ratio 7.25; p < 0.001) and no significant association with Ebola virus (odds ratio 0.56; p = 0.375) in this bat cohort. The data suggest a potential risk of zoonotic spillover including the possible circulation of highly pathogenic viruses in E. helvum populations. These findings highlight the importance of maintaining sero-surveillance of E. helvum, and the necessity for further, more comprehensive investigations to monitor changes in virus prevalence, distribution over time, and across different geographic locations.

Adjusted estimate of the prevalence of hepatitis delta virus in 25 countries and territories

Hepatitis delta virus (HDV) is a satellite RNA virus that requires the hepatitis B virus (HBV) for assembly and propagation. Individuals infected with HDV progress to advanced liver disease faster than HBV-monoinfected individuals. Recent studies have estimated the global prevalence of anti-HDV antibodies among the HBV-infected population to be 5-15%. This study aimed to better understand HDV prevalence at the population level in 25 countries/territories. We conducted a literature review to determine the prevalence of anti-HDV and HDV RNA in hepatitis B surface antigen (HBsAg)-positive individuals in 25 countries/territories. Virtual meetings were held with experts from each setting to discuss the findings and collect unpublished data. Data were weighted for patient segments and regional heterogeneity to estimate the prevalence in the HBV-infected population. The findings were then combined with The Polaris Observatory HBV data to estimate the anti-HDV and HDV RNA prevalence in each country/territory at the population level. After adjusting for geographical distribution, disease stage and special populations, the anti-HDV prevalence among the HBsAg+ population changed from the literature estimate in 19 countries. The highest anti-HDV prevalence was 60.1% in Mongolia. Once adjusted for the size of the HBsAg+ population and HDV RNA positivity rate, China had the highest absolute number of HDV RNA+ cases. We found substantially lower HDV prevalence than previously reported, as prior meta-analyses primarily focused on studies conducted in groups/regions that have a higher probability of HBV infection: tertiary care centers, specific risk groups or geographical regions. There is large uncertainty in HDV prevalence estimates. The implementation of reflex testing would improve estimates, while also allowing earlier linkage to care for HDV RNA+ individuals. The logistical and economic burden of reflex testing on the health system would be limited, as only HBsAg+ cases would be screened. There is a great deal of uncertainty surrounding the prevalence of hepatitis delta virus among people living with hepatitis B virus at the population level. In this study, we aimed to better understand the burden in 25 countries and territories, to refine techniques that can be used in future analyses. We found a lower prevalence in the majority of places studied than had been previously reported. These data can help inform policy makers on the need to screen people living with hepatitis B virus to find those coinfected with hepatitis delta virus and at high risk of progression, while also highlighting the pitfalls that other researchers have often fallen into.