A non‐haemadsorbing (non‐HAD) ASF virus (ASFV) genotype II, namely Lv17/WB/Rie1, was isolated from a hunted wild boar in Latvia in 2017. Domestic pigs experimentally infected with the non‐HAD ASFV ...developed a nonspecific or subclinical form of the disease. Two months later, these animals were fully protected when exposed to other domestic pigs infected with a related virulent HAD genotype II ASFV.
This study aims at assessing the serological cross‐reactions existing between three mosquito‐borne flaviviruses with avian reservoirs co‐circulating in Europe: West Nile (WNV), Usutu (USUV) and ...Bagaza (BAGV). The study is useful for a better interpretation of serological results in diagnostics and surveillance. Serum samples obtained from a natural host, the red‐legged partridge (Alectoris rufa), experimentally infected with WNV, USUV or BAGV were analysed using two commercially available WNV competition ELISAs suitable for serological surveillance, and by the confirmatory virus neutralization test (VNT). The ELISAs examined showed different levels of specificity for WNV, as judged by cross‐reaction observed with the other flaviviruses. By VNT, virus‐specific antibodies were confirmed in 80%, 50% or 0% of sera from WNV‐, BAGV‐, or USUV‐inoculated birds, respectively. The results indicate how the co‐circulation of cross‐reacting flaviviruses may affect the outcomes of WNV serological surveillance when applying currently available serological tools. On the one hand, the choice of the ELISA test for antibody screening should consider the differences found in specificity, since one test is more specific for WNV while the other one is more suitable for detection of a broader range of flavivirus antibodies. On the other hand, besides corroborating that cross‐neutralization occurs between flaviviruses from different serocomplexes (WNV/USUV and BAGV), this study points out that cross‐neutralization between WNV and USUV is not symmetric, and reveals the difficulty to identify USUV infections serologically. This finding indicates that actual USUV infections might be underestimated in the current diagnostic schemes.
The African horse sickness virus (AHSV) belongs to the Genus Orbivirus, family Sedoreoviridae, and nine serotypes of the virus have been described to date. The AHSV genome is composed of ten linear ...segments of double-stranded (ds) RNA, numbered in decreasing size order (Seg-1 to Seg-10). Genome segment 2 (Seg-2) encodes outer-capsid protein VP2, the most variable AHSV protein and the primary target for neutralizing antibodies. Consequently, Seg-2 determines the identity of the virus serotype. An African horse sickness (AHS) outbreak in an AHS-free status country requires identifying the serotype as soon as possible to implement a serotype-specific vaccination program. Considering that nowadays 'polyvalent live attenuated' is the only commercially available vaccination strategy to control the disease, field and vaccine strains of different serotypes could co-circulate. Additionally, in AHS-endemic countries, more than one serotype is often circulating at the same time. Therefore, a strategy to rapidly determine the virus serotype in an AHS-positive sample is strongly recommended in both epidemiological situations. The main objective of this study is to describe the development and validation of three triplex real-time RT-PCR (rRT-PCR) methods for rapid AHSV serotype detection. Samples from recent AHS outbreaks in Kenia (2015-2017), Thailand (2020), and Nigeria (2023), and from the AHS outbreak in Spain (1987-1990), were included in the study for the validation of these methods.
Nanopore sequencing has emerged as a rapid and cost-efficient tool for diagnostic and epidemiological surveillance of SARS-CoV-2 during the COVID-19 pandemic. This study compared the results from ...sequencing the SARS-CoV-2 genome using R9 vs R10 flow cells and a Rapid Barcoding Kit (RBK) vs a Ligation Sequencing Kit (LSK). The R9 chemistry provided a lower error rate (3.5%) than R10 chemistry (7%). The SARS-CoV-2 genome includes few homopolymeric regions. Longest homopolymers were composed of 7 (TTTTTTT) and 6 (AAAAAA) nucleotides. The R10 chemistry resulted in a lower rate of deletions in thymine and adenine homopolymeric regions than the R9, at the expenses of a larger rate (~10%) of mismatches in these regions. The LSK had a larger yield than the RBK, and provided longer reads than the RBK. It also resulted in a larger percentage of aligned reads (99 vs 93%) and also in a complete consensus genome. The results from this study suggest that the LSK preparation library provided longer DNA fragments which contributed to a better assembly of the SARS-CoV-2, despite an impaired detection of variants in a R10 flow cell. Nanopore sequencing could be used in epidemiological surveillance of SARS-CoV-2.
Key points
• Sequencing SARS-CoV-2 genome is of great importance for the pandemic surveillance.
• Nanopore offers a low cost and accurate method to sequence SARS-CoV-2 genome.
• Ligation sequencing is preferred rather than the rapid kit using transposases.
HIV testing guidelines are poorly implemented in most clinical settings. The best screening strategy and healthcare scenario are still unknown. The aim of our study is to evaluate the impact of a ...structured HIV testing intervention (DRIVE), compared to HIV testing as routinely performed in clinical practice, in two different clinical settings: a primary care center and an emergency department.
Prospective evaluation of an HIV testing strategy in two clinical settings from the same healthcare area. The DRIVE program included trained nurse practitioners to perform the screening, a questionnaire to assess the risk of exposure and HIV indicator conditions (RE&IC), and rapid HIV tests. The main variables between the DRIVE program and clinical practice were the absolute number of newly diagnosed HIV infections and testing coverage.
The DRIVE program included 5,329 participants, of which 51.2% reported at least one positive answer in the questionnaire. The estimated HIV testing coverage was significantly higher in the DRIVE program than in the routine clinical practice (7.17% vs. 0.96%, p < 0.001), and was better in the primary care center than in the emergency department with the two strategies. Twenty-two HIV-positive people were identified, with a rate of 8.6‰ in the emergency department vs. 2.2‰ in the primary care center (p = 0.001). A higher rate of new HIV diagnoses was found in the DRIVE program compared to routine clinical practice (29.6 vs. 3.1 per 100,000 patients attended; p < 0.001).
An easy-to-implement, structured intervention increased the absolute number of new HIV diagnoses and HIV tests, compared to routine clinical practice.
Portal pneumatosis has been considered an ominous sign associated with intestinal ischemia, with a mortality rate of up to 90% as long as it is associated with sepsis. However, the prognosis of ...mesenteric ischemia depends on the etiology rather than the presence of portal pneumatosis. We present a patient with portal pneumatosis that disappeared 24 hours after the first surgery, but irreversible ischemic lesions were established in the terminal ileum. It should be noted that the excretion of the intravenous contrast is mainly through the kidneys, and it can be eliminated through alternative routes such as the bile duct or the mucosa of the small intestine (vicariant excretion), especially in patients with renal pathology.
This study aimed to compare the infection dynamics of three genotype II African swine fever viruses (ASFV) circulating in Europe. Eighteen domestic pigs divided into three groups were infected ...intramuscularly or by direct contact with two haemadsorbent ASFVs (HAD) from Poland (Pol16/DP/ OUT21) and Estonia (Est16/WB/Viru8), and with the Latvian non‐HAD ASFV (Lv17/WB/Rie1). Parameters, such as symptoms, pathogenicity, and distribution of the virus in tissues, humoral immune response, and dissemination of the virus by blood, oropharyngeal and rectal routes, were investigated. The Polish ASFV caused a case of rapidly developing fatal acute disease, while the Estonian ASFV caused acute to sub‐acute infections and two animals survived. In contrast, animals infected with the ASFV from Latvia developed a more subtle, mild, or even subclinical disease. Oral excretion was sporadic or even absent in the attenuated group, whereas in animals that developed an acute or sub‐acute form of ASF, oral excretion began at the same time the ASFV was detected in the blood, or even 3 days earlier, and persisted up to 22 days. Regardless of virulence, blood was the main route of transmission of ASFV and infectious virus was isolated from persistently infected animals for at least 19 days in the attenuated group and up to 44 days in the group of moderate virulence. Rectal excretion was limited to the acute phase of infection. In terms of diagnostics, the ASFV genome was detected in contact pigs from oropharyngeal samples earlier than in blood, independently of virulence. Together with blood, both samples could allow to detect ASFV infection for a longer period. The results presented here provide quantitative data on the spread and excretion of ASFV strains of different virulence among domestic pigs that can help to better focus surveillance activities and, thus, increase the ability to detect ASF introductions earlier.
Porcine teschoviruses (PTVs) constitute 1 of the 31 genera within the Picornaviridae family, comprising at least 13 genetic types (PTV-1 to PTV-13), of which only 11 (PTV-1 to PTV-11) have been ...recognized as serotypes to date. Specific for swine and wild boars, most PTVs are usually non-pathogenic, but some viral variants cause severe disorders in the central nervous system (Teschen disease) or milder signs (Talfan disease), as well as reproductive, digestive and respiratory disorders and skin lesions. Previous studies revealed a high diversity of teschoviruses circulating in Spanish pig populations. Phylogenetic analysis performed with these sequences and others available in GenBank disclosed 13 clusters, 11 of which corresponded to the known PTV serotypes, and 1 of 2 additional groups is represented by isolate CC25, whose full-length genomic sequence has been obtained. This group is new to science, and was putatively named PTV-12. Here, a complete characterization of this isolate is presented, including the experimental infection of minipigs to assess tissue tropism and possible pathogenicity in vivo in the host species. In addition, using this experimental animal model, we investigated whether a pre-existing infection with this PTV-12 isolate could confer cross-protection against infection with a heterotypic PTV-1 virulent strain. Based on phylogenetic analysis and serological data, we propose CC25 as the prototype strain of a new teschovirus serotype, PTV-12.
Teschovirus and Sapelovirus are two genera of the Picornaviridae family, comprising highly variable and heterogeneous enteric viruses, commonly found in faecal samples from domestic pigs. Although ...both of them are also known to infect wild boar, studies on their presence in these wild suids are scarce. The present study aimed at determining the presence of porcine teschovirus (PTV) and sapelovirus (PSV) in free-living wild boar populations, as well as to study their relationships with similar viruses present in pigs. Fresh faecal samples (n=63) from wild boar were collected in Doñana Biological Reserve (SW Spain) during 2007 and 2011, and analysed using multiplex RT-PCR for the simultaneous detection and differentiation of PTV and PSV. A total of 32 samples (50.8%) presented positive PTV bands, while PSV amplicons were detected in 4 samples (6.4%). All PSV-positive samples were also positive for PTV, which indicated co-infection with both viruses. Virus isolation was successful from 6 samples, 4 of which were identified as PTV by RT-PCR, and three of these were further characterized by sequencing of the VP1 capsid protein. The remaining two isolates were negative for PTV or PSV. Genetic characterization of PSV-positive faecal samples, using the VP4 protein coding gene, was successful in 4 stool samples. Close phylogenetic relationship was found among wild boar and domestic pig strains in both PTV and PSV. More studies are needed to ascertain the epizootiological significance of these findings.
In the course of an epidemiologic surveillance program for swine diseases carried out in Spain, 206 cytopathic viruses were isolated from 600 porcine fecal samples between 2004 and 2005. The virus ...isolates were examined using reverse transcription polymerase chain reaction (RT-PCR) methods specific for different types of porcine picornaviruses, including members of the Teschovirus, Enterovirus, and Sapelovirus genera, and PCR for porcine adenoviruses. Of the 206 isolates, 97 (47%) were identified as teschoviruses, 18 (9%) as sapeloviruses, and 7 (3%) as porcine adenoviruses. Neither Porcine enterovirus B nor Swine vesicular disease virus was found among the isolates. The present study confirms that teschoviruses are highly prevalent in porcine fecal samples, at least in Spain. It also reveals that these viruses commonly circulate among apparently healthy pigs.
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