Search Results (61)

Poliovirus wastewater surveillance (WWS) is an important complementary system to acute flaccid paralysis surveillance and a substitute surveillance for enteroviruses in stool samples of children, within global poliovirus eradication efforts. However, current guidelines provide limited data on sampling schemes for polio-free countries. This study aims to provide a summary of sampling schemes used for poliovirus WWS in studies done in countries of European Union (EU), together with an analysis of their objectives and a comparison with studies done in other countries. The study selection for this literature review was based on three sources: a World Health Organisation literature review, the PubMed database, and a systematic literature review of WWS of communicable disease agents. From 1446 studies, 72 studies published between 1 January 1995 and 5 September 2024 were included in the qualitative analysis. These studies were analysed by country of origin, objective, sampling site, catchment population size, sampling frequency, sampling method and sample volume. The results indicate that most studies from EU countries had conducted poliovirus WWS directly in line with World Health Organisation recommendations, despite these being primarily designed for developing countries. Our review may encourage countries to optimise their poliovirus WWS systems based on their own risks for poliovirus introduction and circulation. Full article

Enteroviruses (EVs) are small, non-enveloped RNA viruses that can cause diverse clinical outcomes, particularly severe in patients with primary immunodeficiency (PID) due to their impaired ability to clear infections. This study aimed to characterize EV excretion among 138 Tunisian PID patients over a five-year period, to identify circulating EV serotypes and assess their genetic diversity. A total of 558 stool samples were collected and analyzed by virus isolation and intratypic differentiation using RT-qPCR. Molecular typing was performed through Sanger sequencing of the VP1 region and whole genome sequencing using Next-Generation Sequencing (NGS) technologies. Phylogenetic analysis was conducted using the Maximum Likelihood (ML) method. EVs were detected in 55 stool samples from 23 patients. The excretion kinetics of EVs ranged between 30 and 946 days. Thirteen serotypes were identified, including one Poliovirus (PV) and twelve Non-Polio Enteroviruses (NPEVs), predominantly belonging to species B. Two previously unreported serotypes in Tunisia were detected: Coxsackievirus A5 (CVA5) and Echovirus type 19 (E19). In addition, five patients presented enhanced susceptibility to the excretion of successive EV serotypes, and one patient exhibited a co-infection. A possible recombination event was identified in one patient involving Coxsackievirus B5 (CVB5), Coxsackievirus A9 (CVA9) and Coxsackievirus B1 (CVB1) sequences. Phylogenetic analysis showed close genetic relationships with European, American and Asian strains. These findings underscore the dynamic nature of EV circulation and the importance of ongoing molecular surveillance to detect emerging serotypes and guide public health strategies. Full article

Human non-polio enteroviruses (NPEVs) cause a plethora of infections in humans, ranging from mild to severe neurological diseases including aseptic meningitis. NPEVs are the leading cause of aseptic meningitis in both children and adults worldwide. In Russia, reports of NPEV infections have surged, especially in the post-COVID era starting in 2022, with elevated infection rates into 2023. A comprehensive examination of the whole genome is crucial for understanding the evolution of NPEV genes and for predicting potential outbreaks. This study focused on identifying the circulating NPEV strains in the Ural Federal District and Western Siberia, using Sanger sequencing and next-generation sequencing (NGS) methodologies. Biological samples were collected from (n = 225) patients diagnosed with aseptic meningitis. Bioinformatics analysis targeted the nucleotide sequences of the major capsid protein (partial VP1) gene fragment, and the assembly of whole NPEV genomes. A total of 159 NPEVs were characterized, representing 70.7% of the collected samples. The main capsid variants forming the predominant genotypic profile included E30 (n = 39, 24.3%), E6 (n = 31, 19.3%), and CVA9 (n = 25, 15.6%). Using NGS, we successfully assembled 13 whole genomes for E6, E30, EV-B80, CVA9, CVB5, E11, and EV-A71 and 3 partial genomes for E6 and EV-B87. This molecular-genetic analysis provides contemporary insights into the genotypic composition, circulation patterns, and evolutionary dynamics of the dominant NPEV associated with aseptic meningitis in the Ural Federal District and Western Siberia. The laboratory-based monitoring and epidemiological surveillance for genetic changes and evolutionary studies are important for improving prevention and healthcare. Full article

Background/Objectives: Despite large-scale measles and rubella (MR) vaccination campaigns in West Africa, measles outbreaks persist, raising concerns about campaign effectiveness, coverage, and underlying determinants. This study assesses the impact of MR follow-up campaigns in 12 of 17 West African countries (2024–2025) and examines the factors contributing to post-campaign outbreaks. The main objective of this study is to evaluate the impact of MR campaigns on measles transmission, identify the characteristics of post-campaign outbreaks, and propose strategies to improve campaign effectiveness and accelerate progress toward measles elimination in West Africa. Methods: We conducted a cross-sectional and ecological analytical study to examine spatial and temporal variations based on measles surveillance data from 2024 to 2025, post-campaign coverage surveys (PCCS), district-level outbreak reports, and administrative coverage reports. Trends in measles cases before and after the MMR campaigns were assessed, along with demographic characteristics and spatial analyses of confirmed cases. Results: In 2024, 70.5% (12/17) of countries conducted measles vaccination campaigns, but measles outbreaks increased in 2025 (64 districts in 2024 versus 383 in 2025). Children under five remained the most affected (54%), with 85% of cases being either unvaccinated (57%) or of unknown status (28%). Administrative coverage exceeded 95% in most countries, but measles PCCS revealed gaps, with only Senegal (93%) and Guinea-Bissau (94%) achieving high verified coverage. No country achieved 95% national MPCC. Conclusions: Suboptimal campaign quality, gaps in immunity beyond target age groups, and unreliable administrative data contributed to the persistence of outbreaks. Recommendations include extending Measles vaccination campaigns to older children (5–14 years), improving preparedness by drawing on experiences from other programs such as polio, standardizing PCCS data survey and analysis methodologies across all countries, and integrating Measles vaccination campaigns with other services such as nutrition. Full article

Oncogenic viruses are well-established contributors to cancer development in both humans and animals. While many animal oncogenic viruses exhibit strong host specificity, concerns remain about their potential to cross species barriers and impact human health. This article examines the classification and molecular mechanisms of oncogenic viruses, including retroviruses, papillomaviruses, herpesviruses, and hepadnaviruses, in animals. It explores historical cases of cross-species transmission, such as the contamination of early polio vaccines with simian virus 40 (SV40), which resulted from the use of rhesus monkey kidney cells and insufficient screening for latent simian viruses, and the hypothesised association between bovine leukaemia virus (BLV) and human breast cancer. To provide a broader comparative perspective, the discussion also includes examples of viruses with a lower economic impact, illustrating that zoonotic and oncogenic potential is not limited to commercially significant species. Biological barriers—including receptor specificity and immune defences—generally limit transmission; however, frequent human–animal interactions, consumption of contaminated food, and viral mutations may increase zoonotic risk. Advances in molecular diagnostics, such as polymerase chain reaction (PCR), next-generation sequencing (NGS), and serological testing, play a critical role in identifying emerging threats. Prevention strategies, including veterinary vaccination programs, biosafety protocols, and the One Health approach integrating human and veterinary medicine, are essential for mitigating risks. While current evidence indicates that oncogenic animal viruses do not significantly contribute to human cancers, ongoing surveillance and research remain crucial to detect emerging threats. Understanding viral oncogenesis in animals continues to provide valuable insights into cancer prevention and therapy in humans. Full article

Background: This study aimed to analyze the patterns and underlying reasons associated with population movement across Sindh, Pakistan. Methods: Cross-sectional surveys were conducted in response to the detection of WPV1 in various districts in Sindh province, where genetic linkages with poliovirus isolates in Karachi had been identified. The surveys targeted union councils (UCs) contributing sewage to the environmental sample collection sites where WPV1 was detected. Results: In the Karachi division a total of 1392 participants were interviewed, and outside Karachi 1471 participants were included. A significantly higher proportion of female participants were interviewed in Karachi (n = 72, 55.0%) compared to other divisions of Sindh (n = 794, 45.0%) (p < 0.001). Linguistic distribution varied significantly between regions, with Pashto speakers predominating in Karachi (n = 336, 86.4%), and Sindhi in other divisions (n = 501, 79.4%) (p < 0.001). OPV coverage exceeded 90% across all districts, and over 85% of children received RI vaccines. Travel patterns also differed significantly; participants from Karachi (n = 686, 44.2%) were less likely to report travel compared to other divisions (n = 865, 55.8%), who frequently traveled for family events, business, or employment (p < 0.001). Conclusions: It is critical to redefine high-risk populations annually based on updated mobility data, social survey analyses, and virus detection via surveillance to better identify and reach unvaccinated children in the Pakistan polio program. In addition, strategically placed PTPs along both formal and informal travel corridors based on an updated risk framework will enhance vaccination, thereby reducing the risk of virus spread. Full article

As part of the WHO’s Global Polio Eradication Initiative, acute flaccid paralysis (AFP) surveillance in children under 15 years old is crucial for monitoring the emergence of polioviruses and tracking Non-Polio Enteroviruses (NPEVs). This study outlines the past 17 years of AFP surveillance in Greece from 2008 to 2024, during which a total of 256 AFP cases were recorded. Stool samples from these cases were analyzed using virus isolation in cell cultures (RD/L20B) and sequencing of NPEV-positive samples. The Attica region reported the highest number of cases with 81 (31%), followed by Central Macedonia and Crete, each with 29 cases (11%). The overall analysis of fecal specimens identified the etiological agent in 18 (7%) specimens, with 13 (4.7%) classified as NPEVs, 4 (1.5%) as adenoviruses, and 1 (0.4%) as a parechovirus. Coxsackievirus A, Coxsackievirus B, and various Echoviruses were the most frequently detected NPEV types. Notably, more than half of these positive specimens (10/18) were from the Attica region, which has the highest population density. These findings highlight the ongoing relevance of AFP surveillance in polio-free settings for broader pathogen monitoring and public health preparedness. Continued vigilance and investment in AFP surveillance are critical to sustaining Greece’s polio-free status and detecting emerging viral threats. Full article

Background: Pakistan reported its first case of COVID-19 in February 2020 and joined other countries in activating a national emergency response following the declaration of the COVID-19 pandemic by the World Health Organization (WHO). Playing a vital role in the early phase of the country’s response was the National Stop Transmission of Polio (NSTOP) program, a highly trained cadre of polio workers who ordinarily support polio eradication efforts in the country. Methods: We developed a reporting tool using Microsoft Excel that tracked the activities of NSTOP officers to support the COVID-19 response. All NSTOP officers submitted their activity reports fortnightly using this reporting tool. Each provincial NSTOP officer reviewed and compiled their respective officers’ reports and sent them to the federal NSTOP Team. We present a summary of the reports for the period from 1 March 2020 to 31 July 2020. Results: A total of 71 officers of the NSTOP program supported various aspects of Pakistan’s COVID-19 response, including coordination, detection and response activities, surveillance, quarantine/isolation management, training and orientation sessions for healthcare personnel, data analysis, community engagement, and risk communication. They successfully investigated 32,729 suspected COVID-19 cases, of which about one-third were confirmed cases, and facilitated the collection and dispatch of >57,000 samples from these cases. Conclusions: This report details NSTOP contributions to the early phase of the COVID-19 response in Pakistan, demonstrating the value of polio investments beyond eradicating the disease to encompass having a workforce that is ready to respond to emergent disease threats and outbreaks. Such a workforce could also play a role in strengthening the capacity of existing immunization systems to help improve routine vaccination coverage in resource-limited settings. Full article

Non-polio enteroviruses continue to cause numerous epidemics world-wide that range from mild to severe disease, including acute flaccid paralysis, meningitis, severe respiratory infections and encephalitis. Using publicly available data we present a comprehensive global and regional temporal distribution of non-polio enteroviruses, with a focus on highly prevalent genotypes. We found that regional distribution did vary compared to global prevalence where the top prevalent genotypes included CVA6 and EV-A71 in Asia, EV-D68 in North America and CVA13 in Africa, while E-30 was prevalent in Europe, South America and Oceania. In 2020, the COVID-19 pandemic did interrupt non-polio enterovirus detections globally, and cases rebounded in subsequent years, albeit at lower prevalence and with decreased genotype diversity. Environmental surveillance for non-polio enteroviruses does occur and has been used in some regions as an early-warning system; however, further development is needed to effectively supplement potential gaps in clinical surveillance data. Overall, monitoring for non-polio enteroviruses is critical to identify true incidence, improve understanding of genotype circulation, provide an early warning system for emerging/re-emerging genotypes and allow for better outbreak control. Full article

Since its discovery via metagenomics in 2008, human cosavirus (HCoSV) has been detected in the cerebrospinal fluid (CSF) and feces of humans with meningitis, acute flaccid paralysis (AFP), and acute gastroenteritis. To date, 34 HCoSV genotypes have been documented by the Picornaviridae study group. However, the documented genetic diversity of HCoSV in Nigeria is limited. Here we describe the genetic diversity of HCoSV in Nigeria using a metagenomics approach. Archived and anonymized fecal specimens from children (under 15 years old) diagnosed with non-polio AFP from five states in Nigeria were analyzed. Virus-like particles were purified from 55 pools (made from 254 samples) using the NetoVIR protocol. Pools were subjected to nucleic acid extraction and metagenomic sequencing. Reads were trimmed and assembled, and contigs classified as HCoSV were subjected to phylogenetic, pairwise identity, recombination analysis, and, when necessary, immuno-informatics and capsid structure prediction. Fifteen pools yielded 23 genomes of HCoSV. Phylogenetic and pairwise identity analysis showed that all belonged to four species (eleven, three, three, and six members of Cosavirus asiani, Cosavirus bepakis, Cosavirus depakis, and Cosavirus eaustrali, respectively) and seventeen genotypes. Ten genomes belong to seven (HCoSV-A3/A10, A15, A17, A19, A24, D3, and E1) previously assigned genotypes, while the remaining thirteen genomes belonged to ten newly proposed genotypes across the four HCoSV species, based on the near-complete VP1 region (VP1*) of the cosavirus genome. Our analysis suggests the existence of at least seven and eight Cosavirus bepakis and Cosavirus eaustrali genotypes, respectively (including those described here). We report the first near-complete genomes of Cosavirus bepakis and Cosavirus depakis from Nigeria, which contributes to the increasing knowledge of the diversity of HCoSV, raising the number of tentative genotypes from 34 to over 40. Our findings suggest that the genetic diversity of HCoSV might be broader than is currently documented, highlighting the need for enhanced surveillance. Full article

The detection of “silent” poliovirus (PV) circulation among clinically healthy populations is an important component of supplementary surveillance for poliomyelitis. Migrants from countries or regions where polio is endemic, affected by outbreaks, or at risk may contribute to the introduction of PVs of epidemic significance: wild poliovirus type 1, vaccine-derived polioviruses (VDPVs), or poliovirus type 2 into polio-free countries. Migrant children, refugees under 5 years of age, are considered a “risk group” in Russia and are subject to testing for PVs. During 2014–2023, guided by the algorithm of virological and molecular investigation of acute flaccid paralysis cases recommended by the WHO, 51,548 migrant children, arriving from 40 countries, were examined. Among 4% of children excreting various cytopathogenic viruses, polio excretors accounted for 20.8%. Among the PVs, PV3 was predominant (41.7%), and PV types 2, 1, and a mixture of PVs accounted for, respectively, 28.2%, 18.8%, and 11.3%. All isolates of PVs 1 and 3 were identified as Sabin-like. The detection of five children excreting epidemically significant PV2 (four VDPV2 and one Sabin-like) required an assessment of the risk of dissemination and additional immunization activities. Among 580 identified isolates of NPEV, the most abundant was the E. betacoxsakie species at 73.8% (CVB1–6, E11, E6, E13, E7). Information on NPEVs expands our knowledge of the spectrum of NPEVs circulating among healthy children worldwide, but its prognostic significance is still unclear. The detection of PVs in children from the “risk group” allows targeted anti-epidemic measures and is a significant advantage of this type of supplementary surveillance for polio. Full article

Background: Polio is an infectious viral disease that can cause paralytic complications and death. Despite global efforts to eradicate wild poliovirus, there are ongoing outbreaks globally and the mutated form of paralytic polio, i.e., circulating vaccine-derived poliovirus, is present in Nigeria. Low vaccination uptake and poor sanitation are responsible for outbreaks in countries where polio had previously been eliminated. This review identifies policies, strategies and interventions for polio eradication and assesses their impact on polio vaccine uptake and eradication efforts in Nigeria. Methods: A systematic literature review was conducted and guided by the Population, Intervention, Comparator and Outcome (PICO) framework and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flowchart, with identified articles appraised using the Critical Appraisal Skills Program appraisal tool. Results: A total of 393 articles were identified, of which 26 articles were included. Key findings indicate polio intervention services, policies and mass campaigns have had a significant impact on eradicating WPV in Nigeria. However, there are gaps in variant polio eradication efforts, with low vaccination uptake, poor surveillance, vaccine hesitancy, lack of community engagement, weaknesses in the healthcare system and other challenges in Nigeria regionally and nationally, posing a risk to public health that threatens the eradication of all forms of polio in Nigeria. Conclusions: Recommendations are suggested for changes to practice and policy to improve polio vaccination uptake in Nigeria and globally in the short-term (1–2 years), mid-term (3–4 years) and long-term (5+ years). Collaborative targeted polio vaccination programs and funding of public health infrastructure are imperative globally alongside national strategic policy intervention frameworks to strengthen the World Health Organization Global Polio Eradication Initiative and improve vaccine uptake and monitoring of vaccine hesitancy. Simultaneous health-literate community engagement is needed to achieve and maintain polio eradication efforts, which must be integrated into national health frameworks and coordinated across the African continent. Full article

Wastewater surveillance is a promising tool to monitor potential outbreaks and determine the disease burden within a community. This system has been extensively used to monitor polio and COVID-19 infection levels, yet few attempts have been made to apply it to monitoring pathogenic yeast. This study aimed to investigate the application of wastewater surveillance for potentially pathogenic yeast in wastewater treatment plant influent. This was done by comparing culture-dependent data with culture-independent data and investigating the fluconazole concentration in wastewater. Additional studies on the growth of isolated strains were conducted. We found that a multiplex PCR system to detect multiple yeasts holds promise as a molecular detection tool for wastewater surveillance. Culture-dependent results indicated that Candida spp. specifically C. krusei and C. glabrata, were most prominent. Growth studies supported that these species grow well in this environment while the less frequently isolated yeasts grew poorly. The data from culture-dependent and independent techniques showed some correlation, with similar species being identified with both, further promoting the use of molecular tools for surveillance. This study highlights the presence of potentially pathogenic yeasts in wastewater, which may indicate the prevalence of these yeasts in the environment or community. This wastewater may also be a potential source of infection for persons encountering it due to poor wastewater management. Full article

Individuals with certain primary immunodeficiency disorders (PID) may be unable to clear poliovirus infection after exposure to oral poliovirus vaccine (OPV). Over time, vaccine-related strains can revert to immunodeficiency-associated vaccine-derived poliovirus (iVDPVs) that can cause paralysis in the patient and potentially spread in communities with low immunity. We reviewed the efforts for detection and management of PID patients with iVDPV infections and the epidemiology through an analysis of 184 cases reported to the World Health Organization (WHO) during 1962–2024 and a review of polio program and literature reports. Most iVDPV patients (79%) reported in the WHO Registry were residents in middle-income countries and almost half (48%) in the Eastern Mediterranean Region. Type 2 iVDPV was most frequently isolated (53%), but a sharp decline was observed after the switch to bivalent OPV in 2016, with only six cases reported during 2017–2024 compared to 63 during 2009–2016. Patients with common variable immunodeficiency have longer excretion of iVDPV than with other PID types. Implementation of sensitive sentinel surveillance to detect cases of iVDPV infection in high-risk countries and offer antiviral treatment to patients is challenged by competition with other health priorities and regulatory hurdles to the compassionate use of investigational antiviral drugs. Full article

In the context of the near-global eradication of wild poliovirus, the significance of non-polio enteroviruses (NPEVs) in causing acute flaccid paralysis (AFP) and their impact on public health has gained increased attention. This research, conducted from 2001 to 2021, examined stool samples from 1597 children under 15 years in São Paulo, Brazil, through the AFP/Poliomyelitis Surveillance Program, detecting NPEVs in 6.9% of cases. Among the 100 NPEV-positive strains analyzed, 90 were genotyped through genomic sequencing of the partial VP1 region, revealing a predominance of EV-B species (58.9%), followed by EV-A (27.8%) and EV-C (13.3%). This study identified 31 unique NPEV types, including EV-A71, CVB2, and E11, as the most prevalent, along with the first documented occurrence of CVA19 in Brazil. These findings emphasize the importance of NPEV genotyping in distinguishing AFP from poliomyelitis, enhancing understanding of these viruses’ epidemiology. Moreover, it ensures that AFP cases are correctly classified, contributing to the effective surveillance and eradication efforts for poliomyelitis. Full article