Swine Influenza Virus Antibodies in Humans, Western Europe, 2009

Serologic studies for swine influenza viruses (SIVs) in humans with occupational exposure to swine have been reported from the Americas but not from Europe. We compared levels of neutralizing antibodies against 3 influenza viruses—pandemic (H1N1) 2009, an avian-like enzootic subtype H1N1 SIV, and a 2007–08 seasonal subtype H1N1—in 211 persons with swine contact and 224 matched controls in Luxembourg. Persons whose profession involved contact with swine had more neutralizing antibodies against SIV and pandemic (H1N1) 2009 virus than did the controls. Controls also had antibodies against these viruses although exposure to them was unlikely. Antibodies against SIV and pandemic (H1N1) 2009 virus correlated with each other but not with seasonal subtype H1N1 virus. Sequential exposure to variants of seasonal influenza (H1N1) viruses may have increased chances for serologic cross-reactivity with antigenically distinct viruses. Further studies are needed to determine the extent to which serologic responses correlate with infection

Evolutionary and temporal dynamics of emerging influenza D virus in Europe (2009-22).

peer reviewedInfluenza D virus (IDV) is an emerging influenza virus that was isolated for the first time in 2011 in the USA from swine with respiratory illness. Since then, IDV has been detected worldwide in different animal species, and it was also reported in humans. Molecular epidemiological studies revealed the circulation of two major clades, named D/OK and D/660. Additional divergent clades have been described but have been limited to specific geographic areas (i.e. Japan and California). In Europe, IDV was detected for the first time in France in 2012 and subsequently also in Italy, Luxembourg, Ireland, the UK, Switzerland, and Denmark. To understand the time of introduction and the evolutionary dynamics of IDV on the continent, molecular screening of bovine and swine clinical samples was carried out in different European countries, and phylogenetic analyses were performed on all available and newly generated sequences. Until recently, D/OK was the only clade detected in this area. Starting from 2019, an increase in D/660 clade detections was observed, accompanied by an increase in the overall viral genetic diversity and genetic reassortments. The time to the most recent common ancestor (tMRCA) of all existing IDV sequences was estimated as 1995-16 years before its discovery, indicating that the virus could have started its global spread in this time frame. Despite the D/OK and D/660 clades having a similar mean tMRCA (2007), the mean tMRCA for European D/OK sequences was estimated as January 2013 compared to July 2014 for European D/660 sequences. This indicated that the two clades were likely introduced on the European continent at different time points, as confirmed by virological screening findings. The mean nucleotide substitution rate of the hemagglutinin-esterase-fusion (HEF) glycoprotein segment was estimated as 1.403 × 10-3 substitutions/site/year, which is significantly higher than the one of the HEF of human influenza C virus (P < 0.0001). IDV genetic drift, the introduction of new clades on the continent, and multiple reassortment patterns shape the increasing viral diversity observed in the last years. Its elevated substitution rate, diffusion in various animal species, and the growing evidence pointing towards zoonotic potential justify continuous surveillance of this emerging influenza virus

Neutralizing antibodies against influenza A in pigs before and after the 2009 pandemic, Luxembourg

Neutralizing antibodies against different swine influenza A viruses and pandemic H1N1 were analyzed in pigs before and after the pandemic. While in 2009 neutralization of the pandemic virus could be explained by cross-reaction with swine influenza viruses this was not the case in at least 2 farms in 2012

Diagnostic challenges and pockets of susceptibility identified during a measles outbreak, Luxembourg, 2019

Luxembourg was among the first countries in the World Health Organization (WHO) European Region documenting interruption of endemic measles transmission, but an increased incidence was registered in spring 2019. The outbreak started with an unvaccinated student who had been to a winter sports resort in a neighbouring country, where a measles outbreak was ongoing. Subsequently, 12 secondary and two tertiary cases were confirmed among students from the same school, relatives and healthcare workers, as well as six probably unrelated cases. Only 11 cases initially fulfilled the WHO definition for suspected measles cases. Fourteen of 20 cases with information on country of birth and the majority of unvaccinated cases (10/12) were born outside of Luxembourg. Measles IgM antibody results were available for 16 of the confirmed cases, and five of the eight IgM negative cases had been vaccinated at least once. All 21 cases were PCR positive, but for three previously vaccinated cases with multiple specimen types, at least one of these samples was negative. The outbreak highlighted diagnostic challenges from clinical and laboratory perspectives in a measles elimination setting and showed that people born abroad and commuters may represent important pockets of susceptible people in Luxembourg.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Human Seasonal Influenza Viruses in Swine Workers in Lagos, Nigeria: Consequences for Animal and Public Health

The influenza A virus has been scarcely investigated in pigs in Africa, with rare detection prior to 2009. The spread of A(H1N1)pdm09 changed the epidemiology due to frequent human-to-swine transmission and the emergence of various new reassortants. This study therefore aimed at estimating the level of circulation and characterizing influenza A viruses at the interface between swine workers, who are crucial players in the inter-species transmission of influenza A viruses, and their animals in several farms in Nigeria, a hub for pig production in Africa. This cross-sectional study showed that 24.6% (58/236) of the pig serum samples collected in 2013–2014 had anti-influenza A antibodies in the absence of vaccination programs, but none of the pig swabs (n = 1193) were positive according to RT-qPCR. Viral RNA was detected in 0.9% (2/229) of swine workers sampled at their place of work, and the strains were characterized as A(H1N1)pdm09 and seasonal A(H3N2). Our results highlight that more awareness of swine workers regarding the consequences of reverse zoonosis for animal and public health is warranted. Annual vaccination and the wearing of masks when experiencing influenza-like symptoms would help decrease influenza inter-species transmission, while surveillance should be adequately supported for early detection

Molecular epidemiology of Avian Rotaviruses Group A and D shed by different bird species in Nigeria

Abstract Background Avian rotaviruses (RVs) cause gastrointestinal diseases of birds worldwide. However, prevalence, diversity, epidemiology and phylogeny of RVs remain largely under-investigated in Africa. Methods Fecal samples from 349 birds (158 symptomatic, 107 asymptomatic and 84 birds without recorded health status) were screened by reverse transcription PCR to detect RV groups A and D (RVA and RVD). Partial gene sequences of VP4, VP6, VP7 and NSP4 for RVA, and of VP6 and VP7 for RVD were obtained and analyzed to infer phylogenetic relationship. Fisher’s exact test and logistic regression were applied to identify factors potentially influencing virus shedding in chickens. Results A high prevalence of RVA (36.1%; 126/349) and RVD (31.8%; 111/349) shedding was revealed in birds. In chickens, RV shedding was age-dependent and highest RVD shedding rates were found in commercial farms. No negative health effect could be shown, and RVA and RVD shedding was significantly more likely in asymptomatic chickens: RVA/RVD were detected in 51.9/48.1% of the asymptomatic chickens, compared to 18.9/29.7% of the symptomatic chickens (p < 0.001/p = 0.01). First RVA sequences were obtained from mallard ducks (Anas platyrhynchos) and guinea fowls (Numida meleagris). Phylogenetic analyses illustrated the high genetic diversity of RVA and RVD in Nigerian birds and suggested cross-species transmission of RVA, especially at live bird markets. Indeed, RVA strains highly similar to a recently published fox rotavirus (RVA/Fox-tc/ITA/288356/2011/G18P[17]) and distantly related to other avian RVs were detected in different bird species, including pigeons, ducks, guinea fowls, quails and chickens. Conclusion This study provides new insights into epidemiology, diversity and classification of avian RVA and RVD in Nigeria. We show that cross-species transmission of host permissive RV strains occurs when different bird species are mixed

Epidemiology of acute respiratory viral infections in children in Vientiane, Lao People's Democratic Republic

Respiratory infections are one of the most frequent reasons for medical consultations in children. In low resource settings such as in Lao People's Democratic Republic, knowledge gaps and the dearth of laboratory capacity to support differential diagnosis may contribute to antibiotic overuse. We studied the etiology, temporal trends, and genetic diversity of viral respiratory infections in children to provide evidence for prevention and treatment guidelines. From September 2014 to October 2015, throat swabs and nasopharyngeal aspirates from 445 children under 10 years old with symptoms of acute respiratory infection were collected at the Children Hospital in Vientiane. Rapid antigen tests were performed for influenza A and B and respiratory syncytial virus. Real-time reverse-transcription polymerase chain reactions (RT-PCRs) were performed to detect 16 viruses. Influenza infections were detected with a higher sensitivity using PCR than with the rapid antigen test. By RT-PCR screening, at least one pathogen could be identified for 71.7% of cases. Human rhinoviruses were most frequently detected (29.9%), followed by influenza A and B viruses combined (15.9%). We identify and discuss the seasonality of some of the infections. Altogether these data provide a detailed characterization of respiratory pathogens in Lao children and we provide recommendations for vaccination and further studies

Effect on different IAV and HPV life cycle steps.

<p>(<b>A–B</b>) Step of the IAV life cycle affected. A549 cells were infected with pandemic H1N1 (MOI 0.1), and treated with 50 µg/ml of bark extract (<b>A</b>) or 10 µg/ml of UF-concentrate (<b>B</b>) starting 2 h before infection or 0, 2, 4 or 6 h after infection. TCID50s were determined 24 h post infection. (<b>C</b>) Effect on HPV attachment. HaCaT cells preincubated for 1 h with the original (black bars) or tannin-free (grey bars) extracts or DMSO and infected for 15 min with 500 HPV pseudovirions per cell were washed five times and collected in SDS sample buffer for Western blotting. Cell-bound HPV16 particles were stained with anti-L1 antibody and relative band intensities to the β-actin band were quantified densitometrically. (<b>D</b>) Effect on HPV capsid disassembly. HaCaT cells were treated with 20 µg/ml of the extracts for 1 h before HPV 16 pseudovirion infection for 7 h followed by fixation and staining with mouse anti-L1-7 antibody. L1-7 recognizes an epitope located inside of the pseudovirion capsid accessible after uncoating. Fluorescence of L1-7-positive pixels was normalized to the cell nucleus signal (Hoechst staining) and expressed as % of untreated. n.d., not detectable or TCID50<1. * significant difference (p<0.05) as compared to “No treatment”.</p

Cross-species transmission of poultry pathogens in backyard farms: ducks as carriers of chicken viruses

In backyard farms of Lao People’s Democratic Republic, mixed-species rearing of poultry is a breeding-ground for cross-species transmission. Here, the epidemiology of viruses circulating among backyard poultry in Vientiane Province was assessed to guide future control strategies. Oral/tracheal and cloacal swabs, collected from 605 poultry (308 ducks, 297 chickens) between 2011 and 2015, were screened by PCR for Newcastle disease virus (NDV), coronavirus (CoV) and chicken anaemia virus (CAV). Chicken sera were screened for anti-NDV antibodies by ELISA. Statistical and phylogenetic analyses revealed transmission patterns and relationships. Closely related strains co-circulated in chickens and ducks. While CoV RNA was detected in oral/tracheal swabs of 9.3% of the chickens and 2.4% of the ducks, rates were higher in faecal swabs of both species (27.3% and 48.2%). RNA of infectious bronchitis virus (IBV) and duck CoV was found in faecal swabs of chickens (19.7% and 7.1%) and ducks (4.1% and 44.1%). Moreover, DNA of the generally chicken-specific CAV was detected in oral/tracheal swabs of chickens (18.1%) and, sporadically, of ducks (2.4%). Despite serological evidence of NDV circulation or vaccination (86.9%), NDV RNA was not detected. We found a high prevalence and indication for cross-species transmission of different CoV strains in backyard poultry. Interestingly, ducks served as biological, or at least mechanical, carriers of viral strains closely related not only to IBV, but also to CAV. Bird containment and poultry species separation could be first steps to avoid cross-species transmission and emergence of novel strains with broad host range and enhanced pathogenicity

Effect of virus or cell preincubation with Hamamelis extracts or individual compounds.

<p>(<b>A–B</b>) Preincubation of pandemic H1N1 A/Lux/46/2009 for 2 h with virus growth medium (“no treatment”) or bark extract/UF-fractions (<b>A</b>) or individual compounds (<b>B</b>) before infection of A549 cells (MOI 0.1) and titration 24 h post infection (p.i.). (<b>C–D</b>) Preincubation of A549 cells for 2 h with virus growth medium (“no treatment”) or bark extract/UF-fractions (<b>C</b>) or single compounds (<b>D</b>) before three washes with PBS, infection with pandemic H1N1 (MOI 0.1) and titration 24 h p.i. All experiments were done in at least triplicates. * significant difference (p<0.05) as compared to “No treatment”.</p