scholarly journals THE SWINE LUNGWORM AS A RESERVOIR AND INTERMEDIATE HOST FOR SWINE INFLUENZA VIRUS

1955 ◽  
Vol 102 (5) ◽  
pp. 567-572 ◽  
Author(s):  
Richard E. Shope
Keyword(s):  
Influenza Virus ◽  
Swine Influenza Virus ◽  
Influenza Virus Infection ◽  
Swine Influenza ◽  
Weather Conditions ◽  
Virus Infections ◽  
Serological Evidence ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
Show Evidence

Twenty-five swine, infested with lungworms infected with masked swine influenza virus, were exposed to adverse weather conditions on one or more occasions. Of these, 4 came down with apparent swine influenza, while 6 others developed serological evidence of infection with swine influenza virus. The remaining 15 prepared swine, as well as 8 lungworm-free control swine, failed to show evidence of swine influenza virus infection, despite repeated exposures to adverse weather. The data presented indicate that, in the 10 swine in which swine influenza virus infections were elicited, some feature of the weather to which the animals were exposed was responsible for provoking masked influenza virus to infectivity. The exact constituent of the meteorological complex comprising "weather", responsible for the provocation, cannot be determined from the data obtained.

scholarly journals Sporadic occurrence of zoonotic swine influenza virus infections.

1984 ◽  
Vol 20 (4) ◽  
pp. 833-835 ◽  
Author(s):  
C C Dacso ◽  
R B Couch ◽  
H R Six ◽  
J F Young ◽  
J M Quarles ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
Virus Infections

scholarly journals THE INFECTION OF MICE WITH SWINE INFLUENZA VIRUS

1935 ◽  
Vol 62 (4) ◽  
pp. 561-572 ◽  
Author(s):  
Richard E. Shope
Keyword(s):  
Influenza Virus ◽  
Virus Disease ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
Serial Passage ◽  
Virus Infections ◽  
Human Influenza ◽  
Human Influenza Virus ◽  
The Stability ◽  
At Will

The experiments confirm the earlier observation of Andrewes, Laidlaw and Smith that the swine influenza virus is pathogenic for white mice when administered intranasally. Two field strains of the swine influenza virus were found to differ in their initial pathogenicity for mice. One strain was apparently fully pathogenic even in its 1st mouse passage while the other required 2 or 3 mouse passages to acquire full virulence for this species. Both strains, however, were initially infectious for mice, without the necessity of intervening ferret passages. There is no evidence that bacteria play any significant rôle in the mouse disease though essential in that of swine, and fatal pneumonias can be produced in mice by pure virus infections. Mice surviving the virus disease are immune to reinfection for at least a month. In mice the disease is not contagious though it is notably so in swine. The virus, while regularly producing fatal pneumonias when administered intranasally to mice, appears to be completely innocuous when given subcutaneously or intraperitoneally. Prolonged serial passage of the virus in mice does not influence its infectivity or virulence for swine or ferrets. It is a stable virus so far as its infectivity is concerned, and can be transferred at will from any one of its three known susceptible hosts to any other. In discussing these facts the stability of the swine influenza virus has been contrasted with the apparent instability of freshly isolated strains of the human influenza virus. Though the mouse is an un-natural host for the virus it is, nevertheless, useful for the study of those aspects of swine influenza which have to do with the virus only.

scholarly journals High Risk of Influenza Virus Infection Among Swine Workers: Examining a Dynamic Cohort in China

2019 ◽  
Vol 71 (3) ◽  
pp. 622-629 ◽  
Author(s):  
Laura K Borkenhagen ◽  
Guo-Lin Wang ◽  
Ryan A Simmons ◽  
Zhen-Qiang Bi ◽  
Bing Lu ◽  
...  
Keyword(s):  
Influenza Virus ◽  
High Risk ◽  
Virus Infection ◽  
Influenza A ◽  
Swine Influenza Virus ◽  
Influenza Virus Infection ◽  
Swine Influenza ◽  
Influenza A Viruses ◽  
Increased Risk ◽  
Swine Workers

Abstract Background China is thought to be a hotspot for zoonotic influenza virus emergence, yet there have been few prospective studies examining the occupational risks of such infections. Methods We present the first 2 years of data collected from a 5-year, prospective, cohort study of swine-exposed and -unexposed participants at 6 swine farms in China. We conducted serological and virological surveillance to examine evidence for swine influenza A virus infection in humans. Results Of the 658 participants (521 swine-exposed and 137 swine-unexposed), 207 (31.5%) seroconverted against at least 1 swine influenza virus subtype (swine H1N1 or H3N2). Swine-exposed participants’ microneutralization titers, especially those enrolled at confined animal feeding operations (CAFOs), were higher against the swine H1N1 virus than were other participants at 12 and 24 months. Despite elevated titers, among the 187 study subjects for whom we had complete follow-up, participants working at swine CAFOs had significantly greater odds of seroconverting against both the swine H1N1 (odds ratio [OR] 19.16, 95% confidence interval [CI] 3.55–358.65) and swine H3N2 (OR 2.97, 95% CI 1.16–8.01) viruses, compared to unexposed and non-CAFO swine workers with less intense swine exposure. Conclusions While some of the observed increased risk against swine viruses may have been explained by exposure to human influenza strains, study data suggest that even with elevated preexisting antibodies, swine-exposed workers were at high risk of infection with enzootic swine influenza A viruses.

Role of IFN-α during the acute stage of a swine influenza virus infection

2010 ◽  
Vol 88 (1) ◽  
pp. 172-178 ◽  
Author(s):  
Filip Barbé ◽  
Xavier Saelens ◽  
Debby Braeckmans ◽  
François Lefèvre ◽  
Kristien Van Reeth
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Swine Influenza Virus ◽  
Influenza Virus Infection ◽  
Swine Influenza ◽  
Acute Stage

scholarly journals A Pre-Pandemic Outbreak of Triple-Reassortant Swine Influenza Virus Infection Among University Students, South Dakota, 2008

2011 ◽  
Vol 204 (8) ◽  
pp. 1165-1171 ◽  
Author(s):  
Fatimah S. Dawood ◽  
Libo Dong ◽  
Feng Liu ◽  
Dianna M. Blau ◽  
Patrick J. Peebles ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
University Students ◽  
South Dakota ◽  
Swine Influenza Virus ◽  
Influenza Virus Infection ◽  
Swine Influenza

scholarly journals AN ANTIVIRAL SUBSTANCE FROM PENICILLIUM FUNICULOSUM

1953 ◽  
Vol 97 (5) ◽  
pp. 601-625 ◽  
Author(s):  
Richard E. Shope
Keyword(s):  
Influenza Virus ◽  
Therapeutic Effect ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
Maximum Effect ◽  
Virus Infections ◽  
Whole Process ◽  
The Central Nervous System ◽  
Antiviral Substance ◽  
Cellular Components

A culture of P. funiculosum isolated on Guam proved capable of elaborating a substance which exerted a favorable therapeutic effect against swine influenza virus infections in white mice. The culture was extremely variable and irregular in its production of the antiviral substance, and during maintenance in the laboratory for several years gradually lost this property. Efforts to restore it were unsuccessful. Subsequently it was found that the mold elaborated a substance, now designated helenine, which is therapeutically effective against Columbia SK encephalomyelitis virus infections in mice. Helenine appears to differ from the substance earlier procured from the mold, which was active against swine influenza virus infections in mice. It is frequently present in greater or lesser amount in the fluid portions of stationary cultures of P. funiculosum but is more regularly obtained and in larger amount, from the cellular components of the pellicles. When liberated from these latter by mechanical bruising and fracturing, it goes into solution in the culture fluids. It is precipitable from aqueous solution by 50 per cent acetone. Infected mice injected with helenine in amounts less than the amount which produces a maximal therapeutic effect exhibit a dosage response. Increasing the dose above the optimum fails to increase the therapeutic effect. Helenine exerts its maximum effect when given within the first 10 hours after viral infection but its influence is apparent even when treatment is delayed for up to 24 hours. It is not effective against massive amounts of virus and gives the best therapeutic results when used in the treatment of animals infected with from 10 to 1000 fatal doses of virus. Treatment of infected mice with helenine delays the entrance of virus into their brains for from 24 to 48 hours. The mechanism by which helenine exerts its therapeutic effect against SK virus is not known but the findings presented suggest either that it causes an inhibition or interruption of multiplication of the virus, slowing down the whole process of infection and spread to the central nervous system, or that in some way it interferes temporarily with the neuroinvasiveness of the virus.

scholarly journals Porcine Fetuses with Pulmonary Hypoplasia Resulting from Experimental Swine Influenza Virus Infection

1980 ◽  
Vol 17 (4) ◽  
pp. 455-468 ◽  
Author(s):  
T. T. Brown ◽  
W. L. Mengeling ◽  
P. S. Paul ◽  
E. C. Pirtle
Keyword(s):  
Influenza Virus ◽  
Viral Antigen ◽  
Pulmonary Hypoplasia ◽  
Fluorescent Antibody ◽  
Swine Influenza Virus ◽  
Influenza Virus Infection ◽  
Swine Influenza ◽  
Epithelial Injury ◽  
Antibody Staining ◽  
Direct Fluorescent Antibody

Porcine fetuses between 51 and 57 days of gestation were inoculated intraallantoically with swine influenza virus and examined 3, 7, 13, 28 and 58 days after inoculation. At 3 and 7 days, severe epithelial necrosis was seen in most bronchial buds and there was moderate epithelial necrosis in more fully differentiated major bronchi. As a result of the epithelial injury, bronchial buds did not develop further and the surrounding mesoderm failed to differentiate. By 28 days, the lungs of inoculated fetuses were about one-half the size of the normal control lungs. Microscopically, the lungs of the inoculated fetuses were composed of major bronchi surrounded by multiple islands of cartilage, medium to large arteries and a few small, incompletely developed lobules. Influenza virus was isolated most consistently and in greatest quantity from the lung, trachea and chorion of inoculated fetuses. Influenza viral antigen was shown in the epithelium of bronchial buds, bronchi and the trachea by direct fluorescent antibody staining. Hemagglutination inhibiting antibodies to influenza virus were first found in the serum of an inoculated fetus at 13 days and in the sera of all inoculated fetuses at 28 and 58 days.

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