LitCovid-sentences  

PMC:7281378 / 83938-103564 JSONTXT 11 Projects

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Id Subject Object Predicate Lexical cue
T636 0-2 Sentence denotes 4.
T637 3-13 Sentence denotes Discussion
T638 14-144 Sentence denotes As of February 2020, influenza viruses have been identified and reported in swine from 53 countries worldwide (Table 1; Figure 3).
T639 145-340 Sentence denotes The influenza viruses have been detected in different sample types including swine sera, nasal, tracheal, oropharyngeal, nasopharyngeal swabs as well as oral fluids collected from the live swine.
T640 341-421 Sentence denotes Nasal and snout wipes, lung homogenates and fecal slurry samples were also used.
T641 422-660 Sentence denotes Additionally, the lung as well as other internal organ tissues (Table 2) obtained from either dead or sacrificed swine have also been used for the detection of IAV symptoms i.e., lesions in lungs, pneumonia, bronchitis, bronchiolitis etc.
T642 661-820 Sentence denotes Various methods have been used for the detection of influenza viruses in swine samples depending on the sample type, sample numbers and objective of the study.
T643 821-1147 Sentence denotes Virus isolation methods, using either MDCK, Caco-2, HRT18, or swine testicle cells or the pathogen free embryonated chicken eggs, although considered the gold standard [335,336,337] have largely been taken over lately by the sequencing approaches which tend to provide a considerably faster identification of the IAV subtypes.
T644 1148-1396 Sentence denotes The additional benefit of sequencing over virus isolation is that the sequences would be useful for analyzing the influenza virus outbreak clusters [338], virus evolution or reassortment [339] using phylogenetic analyses in different gene segments.
T645 1397-1584 Sentence denotes A recent study reported that next-generation sequencing can be useful in the influenza virus diagnosis and for the identification of the novel virulence markers and drug resistance [340].
T646 1585-1731 Sentence denotes Most of the studies have used real-time RT-PCR with matrix-gene specific oligonucleotide primers and TaqMan probe for IAV detection [308,341,342].
T647 1732-1846 Sentence denotes The conserved sequences of the matrix-gene specific primers can detect any IAV subtype in the swine samples [343].
T648 1847-2169 Sentence denotes Most of the studies used subtype-specific real-time RT-PCR for the IAV subtyping, however, few studies opted for the conventional approach of reverse-transcription PCR followed by Sanger sequencing for amplification of the HA and/or NA genes for retrieving the sequences for phylogenetic analyses to identify the subtypes.
T649 2170-2315 Sentence denotes Although the real-time RT-PCR is a powerful and rapid tool for the subtyping of IAV strains, it is more expensive than reverse-transcription PCR.
T650 2316-2610 Sentence denotes A few studies have reported reverse-transcription PCR based amplification of all the eight gene segments of IAV to generate the whole genome sequences [33,91,128,231] but in most cases, the whole genome sequences were generated using MiSeq next-generation sequencing approach [150,214,325,329].
T651 2611-2738 Sentence denotes A great advantage of this sequencing approach is that it can identify novel influenza viruses in the swine samples [80,90,301].
T652 2739-2906 Sentence denotes Most of the serological investigations used one or more methods for influenza virus detection and subtyping in the swine samples e.g., ELISA, HI, NI, MN, or VN assays.
T653 2907-3027 Sentence denotes The serological methods are useful in large-scale surveillances for screening large number of samples in a limited time.
T654 3028-3254 Sentence denotes However, the molecular detection assays are more reliable than the serological methods given the higher sensitivity, but the serological assays are rapid and affordable hence are preferred for large-scale surveillance studies.
T655 3255-3406 Sentence denotes The molecular and serological investigations report either active infections (viral RNA) or past exposures (antibodies) in swine samples, respectively.
T656 3407-3573 Sentence denotes The molecular detection approaches followed by sequencing are largely used for the research focusing on the influenza virus epidemiology [73,78,82,87,94,128,146,150].
T657 3574-3822 Sentence denotes Several studies used histological examinations e.g., immunohistochemistry or immunofluorescence to identify the IAV symptoms in lung or other internal organs of either dead or severely sick swine sacrificed for the investigations [130,189,315,318].
T658 3823-3950 Sentence denotes Immunohistochemistry provides a rapid and affordable diagnosis of the influenza virus disease using swine tissue samples [344].
T659 3951-4083 Sentence denotes One major benefit of immunohistochemistry is that it can be used in the retrospective analysis of the archived tissue samples [245].
T660 4084-4404 Sentence denotes A large number of investigations have reported sub-clinical influenza virus infections in asymptomatic (apparently healthy) swine [78,103,150,161,171,278,300], indicating that influenza infections can go undetected while the swine may be shedding virus and hence may infect other swine and farm workers in contact [183].
T661 4405-4626 Sentence denotes Intriguingly, most of the swine samples processed in Australia, Europe, and North America were obtained from the symptomatic swine while most of the Chinese swine samples were collected from asymptomatic swine (Figure 5).
T662 4627-4966 Sentence denotes Symptomatic swine may exhibit mild or severe influenza like symptoms [59,202,252], including fever, coughing, sneezing, pneumonia, bronchitis, reduced appetite, diarrhea, nasal and/or ocular discharge, conjunctivitis, weakness, anorexia, prostration, weight loss, abortion in sows, and mortality in some cases [89,224,231,239,248,282,318].
T663 4967-5079 Sentence denotes Most studies where the swine were severely infected reported reduced appetite and weight loss [129,246,247,292].
T664 5080-5226 Sentence denotes Due to IAV infection, the swine takes longer to weigh 100 kg body mass [226], hence the IAV disease burden affects the swine farmers economically.
T665 5227-5380 Sentence denotes Varying rates of mortality of swine due to IAV infections were reported from around the world ranging from 0.5% to 30% [138,206,213,218,221,273,296,327].
T666 5381-5639 Sentence denotes This wide difference in mortality rate could be due to novel virus strains emerged through reassortments within the swine [273,315,327] or inter-species transmission, e.g., avian to swine transmission, resulting into severe disease outbreaks [27,80,119,133].
T667 5640-5857 Sentence denotes One example of the emergence of a novel influenza virus strain is the emergence of A(H1N1)pdm09 strain due to reassortment between avian and swine IAV strains in swine which resulted into 2009 influenza pandemic [33].
T668 5858-6087 Sentence denotes Additionally, the emergence of IAV subtype H1N2 is another classic example of influenza virus reassortment which resulted into severe disease outbreaks in Japanese and Korean swine populations during 1990s and 2000s [27,121,140].
T669 6088-6210 Sentence denotes Strains of IAV can infect the swine of any age group; piglets as young as one week may become infected with IAV naturally.
T670 6211-6476 Sentence denotes Interestingly, a study in Denmark observed a piglet as young as just three days was infected with IAV despite having maternally derived IAV antibodies [183], suggesting that the infection might have occurred from the infected sow which was shedding the virus [183].
T671 6477-6678 Sentence denotes However, the symptoms of the influenza-like illness in swine may last only for one week but the virus shedding may still persist until 41 days after appearance of the influenza-like symptoms [183,296].
T672 6679-6852 Sentence denotes This phenomenon may have serious implications in influenza virus spill over to the non-infected swine as well as to the exposed farm workers due to prolonged virus shedding.
T673 6853-7055 Sentence denotes Three other studies observed virus shedding in swine and reported that the virus shedding may persist until the 11 day [256], 20 day [255], or 29 day [296] after onset of the clinical symptoms in swine.
T674 7056-7175 Sentence denotes This variation in the duration of the virus shedding might be strain dependent, which needs to be further investigated.
T675 7176-7427 Sentence denotes A higher rate of virus shedding and IAV prevalence was reported during the fall and early winter months than summer season because the high relative humidity present in the environment during summer decreases the transmission of influenza virus [267].
T676 7428-7655 Sentence denotes The high relative humidity in summer facilitates the generation of larger droplets which are less likely to be aerosol transmitted to a longer distance as they tend to fall on the ground quickly after their formation [240,258].
T677 7656-7804 Sentence denotes Several cases of inter-species transmission were identified which documented transmission of IAV between human and swine or between birds and swine.
T678 7805-8146 Sentence denotes The occurrence of the avian influenza virus strains in swine in China (H5N1, H9N2, H4N1, H4N6, H5N3, H10N5, H4N8, H6N6, H7N9), United States (H4N6, H6N2, H7N2), Canada (H4N6, H3N3), South Korea (H7N2, H5N2), Nigeria (H5N1), and Egypt (H5N1, H5N2, H9N2 ) serve as the evidence of interspecies transmission of avian influenza viruses to swine.
T679 8147-8286 Sentence denotes The first evidence of avian influenza virus active infection in swine appeared in 1999 in Canada when H4N6 virus was isolated from a swine.
T680 8287-8414 Sentence denotes Later several other avian-origin IAV strains were detected and sequenced in swine in China, Canada, and South Korea (Figure 6).
T681 8415-8672 Sentence denotes Various studies have spotted wild birds visiting the swine farms or in the vicinity which suggested that wild birds may have served as the carriers for the introduction of the different avian-origin IAV subtypes to the swine populations [59,80,100,246,332].
T682 8673-8889 Sentence denotes The highest number of avian-origin IAV strains were reported in Chinese swine which shows frequent avian-swine interaction in China, a country that has historically been an epicenter for influenza virus disease [69].
T683 8890-9002 Sentence denotes Egypt is recognized as a “hot spot” for the influenza virus reassortment due to its geographical location [345].
T684 9003-9233 Sentence denotes The role of migratory wild birds in the introduction of avian influenza in Egypt has been already established [346,347], and the highly pathogenic strains of the IAV have previously been detected in migratory birds in Egypt [348].
T685 9234-9531 Sentence denotes Since migratory wild birds were reported to harbor in the vicinity of Cairo [60] therefore, the probability of the migratory bird–swine interaction in the regions remain high which very well explains the occurrence of highly and low pathogenic strains of avian-origin IAV in swine in Cairo, Egypt.
T686 9532-9775 Sentence denotes Given the “mixing vessel” nature of the swine, the occurrence of avian-origin IAV strains in swine is alarming in terms of IAV reassortment and evolution which may trigger the emergence of novel IAV strains of pandemic potential in the future.
T687 9776-10087 Sentence denotes Further, the multiple reports of double or triple reassortant IAV strains in swine are evidence that IAV co-infections may facilitate the antigenic diversity of the influenza viruses; and as a result, new HA and NA subtypes of IAV may be continually added to the existing 18 HA and 11 NA subtypes in the future.
T688 10088-10267 Sentence denotes Intriguingly, the frequency of the occurrence of double or triple-reassortant IAV strains in swine has dramatically increased in the recent decades [76,81,87,109,161,250,268,278].
T689 10268-10498 Sentence denotes One unique example of the reassortment and evolution of the pandemic strain of IAV in swine was the emergence of A(H1N1)pdm09 virus in swine in Mexico which evolved due to the reassortment between avian and swine IAV strains [33].
T690 10499-10838 Sentence denotes While an overwhelming majority of investigations reported IAV in the swine across the world (Figure 7A), there were only a few reports which documented either active infections or past exposures of the swine to the influenza virus types IBV [37,171,186,277] (Figure 7B), ICV [38,117,186] (Figure 7C) or IDV [5,43,44,45,46,217] (Figure 7D).
T691 10839-11057 Sentence denotes A low prevalence of IBV was observed in swine given that only one study reported the IBV antibodies in swine samples in England during 1991–1992 [186] with no evidence of further spill over to other European countries.
T692 11058-11161 Sentence denotes The active infection of IBV was later reported in US swine when two IBV isolates were obtained in 2009.
T693 11162-11365 Sentence denotes A recent study from Taiwan reported three strains of the Victoria/B lineage of IBV in naturally infected swine in 2014 [171], again there was no further report of dissemination to nearby Asian countries.
T694 11366-11448 Sentence denotes The IBV infected swine were apparently healthy with no signs of influenza disease.
T695 11449-11631 Sentence denotes The first report of ICV appeared in Chinese swine after the virus was isolated from apparently healthy swine in 1981 in a routine diagnostic procedure at an abattoir in Beijing [38].
T696 11632-11788 Sentence denotes Later ICV seroprevalence was reported in English and Japanese swine during 1980s–1990s [117,186] with no further evidence of circulation anymore thereafter.
T697 11789-11958 Sentence denotes The IDV was first detected and characterized in 2011 in Oklahoma based swine in the United States which appeared to have made a species jump from cattle to swine [5,43].
T698 11959-12142 Sentence denotes Interestingly, a complete IDV genome was retrieved from a symptomatic sow in Italy in 2015 which was found closely related to the IDV genome reported in 2011 from Oklahoma, USA [217].
T699 12143-12244 Sentence denotes This might have happened due to the trade of the cattle or swine between Italy and the United States.
T700 12245-12475 Sentence denotes A recent study from China identified IDV sequences which shared a high similarity (99%–100%) with the IDV sequences reported earlier from the cattle in China [102] which was another evidence of bovine to swine transmission of IDV.
T701 12476-12622 Sentence denotes The IDV has been in circulation in swine in the current decade with reports emerging from swine in Italy, Luxembourg, China and the United States.
T702 12623-12819 Sentence denotes In summary, IAV was first isolated from a swine in USA in 1930 [34,349] and later antibodies for the human influenza viruses were reported in swine at the State Prison of New Jersey in 1937 [259].
T703 12820-12984 Sentence denotes More IAV outbreaks and cases in swine in North America were reported during 1981–2000; the frequency has now dramatically fallen in the last two decades (Figure 8).
T704 12985-13095 Sentence denotes This might be due to improved swine influenza surveillance and vaccination in North America in recent decades.
T705 13096-13248 Sentence denotes The H1N1, H1N2, H3N2, and A(H1N1)pdm09 viruses were reported from the commercial, backyard, exhibition, feral swine and wild boars in the United States.
T706 13249-13445 Sentence denotes As of February 2020, the highest number of reports of influenza virus infections in swine in a country were documented in the United States (n = 40) followed by China (n = 39) and Canada (n = 24).
T707 13446-13576 Sentence denotes The highest number of IAV positive swine samples were reported in the United States (36128/200384) followed by China (5031/90760).
T708 13577-13723 Sentence denotes One of the factors behind the higher number of IAV cases in swine in the United States compared to China would be related to the disease symptoms.
T709 13724-13967 Sentence denotes A majority of the North American swine samples that were screened for the IAV infections had either mild or severe symptoms of influenza-like illness which would have made it visually easier to identify IAV infected swine in the United States.
T710 13968-14176 Sentence denotes On the contrary, a smaller number of Chinese swine exhibited influenza-like disease symptoms while a large proportion of the Chinese swine population appeared to have sub-clinical infections with no symptoms.
T711 14177-14292 Sentence denotes This would have made it difficult for identifying the influenza virus infected swine during surveillances in China.
T712 14293-14428 Sentence denotes The first report of IDV in 2011 in Oklahoma swine reflected the antigenic diversity and evolution of influenza viruses in the US swine.
T713 14429-14686 Sentence denotes However, the recent influenza virus disease prevalence in North American swine appeared to have declined, nevertheless, given the large swine population of the continent, the surveillance should continue to track the influenza virus diversity and evolution.
T714 14687-14959 Sentence denotes The first serological evidence of IAV in European swine was documented from the Czechoslovakia during 1969–1972, but the first H1N1 virus in European swine was isolated in Belgium in 1979 which was apparently transmitted from wild ducks in Germany to the swine in Belgium.
T715 14960-15113 Sentence denotes Since then several H1N1, H1N2, H3N2, and A(H1N1)pdm09 viruses have been detected in commercial and backyard swine as well as in wild boars within Europe.
T716 15114-15279 Sentence denotes The incidence of IAV in European swine has increased several folds in the past two decades with a relatively high number of IAV positive swine samples (19644/49814).
T717 15280-15389 Sentence denotes Most of the IAV positive European swine were reported having influenza-like symptoms at the time of sampling.
T718 15390-15557 Sentence denotes Germany reported the highest number of IAV positive swine in Europe where the pork industry is considered the third largest globally after China and the United States.
T719 15558-15859 Sentence denotes Importantly, the IDV was more recently identified in the European swine, first in Italy in 2015, and later a retrospective study identified IDV infection in swine samples collected in Luxembourg during 2014–2015 which indicated that the circulation of IDV in European swine took place only after 2014.
T720 15860-15927 Sentence denotes The evidence has suggested the bovine to swine transmission of IDV.
T721 15928-16145 Sentence denotes This observation is interesting because until recently more emphasis has been given to the avian-swine interaction and the bovine–swine interactions have been neglected from the influenza virus spill over perspective.
T722 16146-16291 Sentence denotes The first occurrence of IAV in Asian swine can be traced back to 1969, but the IAV prevalence has increased multi-fold in the recent two decades.
T723 16292-16400 Sentence denotes The IAV subtypes H1N1, H1N2, H3N2, and A(H1N1)pdm09 have become endemic in swine in several Asian countries.
T724 16401-16569 Sentence denotes The highly pathogenic avian-origin IAV strains of H5N1 and H7N9 have been reported from Chinese swine while H5N1 has been documented in swine in Viet Nam and Indonesia.
T725 16570-16649 Sentence denotes The highly pathogenic strains of H5N2 have been reported in South Korean swine.
T726 16650-16765 Sentence denotes Several LPAIV strains including H4N1, H4N6, H4N8, H6N6, H9N2, and H10N5 have also been documented in Chinese swine.
T727 16766-16930 Sentence denotes The studies suggested a frequent interaction between wild birds and swine in China which appeared to have transmitted avian-origin IAV strains in the Chinese swine.
T728 16931-17056 Sentence denotes Occurrence of equine influenza virus H3N8 in Chinese swine further expanded the genetic diversity of swine influenza viruses.
T729 17057-17267 Sentence denotes Despite an avian to human transmission of certain avian influenza virus strains including H5N1 virus, only a limited human to human transmission of avian influenza viruses was established in the past [350,351].
T730 17268-17555 Sentence denotes With the passage of these avian-origin IAV strains in a mammalian host like swine, a high probability remains of these avian influenza virus strains to adapt and gain the ability of the human to human transmission, if happens, the consequences would be devastating for the public health.
T731 17556-17707 Sentence denotes Australian swine were free from influenza virus until the year 2009 when a New South Wales swine farm reported an influenza-like outbreak in the swine.
T732 17708-17812 Sentence denotes The zoonotic transmission of the A(H1N1)pdm09 virus was reported to the farm workers and the farm owner.
T733 17813-17941 Sentence denotes Until now, there have only been four IAV reports in Australian swine which reflects a low prevalence of IAV in Australian swine.
T734 17942-18056 Sentence denotes New Zealand is yet to officially report the influenza virus prevalence in swine and remains free from the disease.
T735 18057-18231 Sentence denotes A retrospective study identified that the A(H1N1)pdm09 virus was present in Mexican swine as early as 2000, well before the influenza pandemic occurred during March–May 2009.
T736 18232-18450 Sentence denotes A high genetic diversity of IAV in Mexican swine due to live swine imports from North America and Europe during 1980s laid the foundation of the emergence of zoonotic strain of A(H1N1)pdm09 virus in Mexican swine [33].
T737 18451-18559 Sentence denotes The highest number of IAV positive swine in Central America were reported from Mexico followed by Guatemala.
T738 18560-18725 Sentence denotes Interestingly, a report of the highly pathogenic H5N2 virus in Mexican swine in 2018 further triggers the alarm in the context of a potential novel IAV reassortment.
T739 18726-18881 Sentence denotes Outbreaks of IAV in the South American swine populations occurred during the last two decades, with the highest prevalence reported in the Brazilian swine.
T740 18882-19034 Sentence denotes A considerable proportion of cases showed sub-clinical infections with no symptoms which might have made it more difficult to detect the infected swine.
T741 19035-19153 Sentence denotes The reports of IAV active infections or the seroprevalence appeared in the African swine only during last two decades.
T742 19154-19283 Sentence denotes Until February 2020, IAV have been detected in swine in Cameroon, Nigeria, Egypt, Kenya, Reunion Island, Uganda, Togo, and Ghana.
T743 19284-19487 Sentence denotes However, South Africa has a considerable swine population [352], but currently there is no published report on the prevalence of active IAV or other influenza virus infections in the South African swine.
T744 19488-19626 Sentence denotes This might be because of the lack of an active surveillance for the detection of the influenza virus disease in the swine in South Africa.