AN INTERMEDIATE HOST FOR THE SWINE INFLUENZA VIRUS

Science ◽  
1939 ◽  
Vol 89 (2315) ◽  
pp. 441-442 ◽  
Author(s):  
R. E. Shope
Keyword(s):  
Influenza Virus ◽  
Intermediate Host ◽  
Swine Influenza Virus ◽  
Swine Influenza

scholarly journals TRANSMISSION OF SWINE INFLUENZA VIRUS BY LUNGWORM MIGRATION

1961 ◽  
Vol 113 (3) ◽  
pp. 517-520 ◽  
Author(s):  
H. G. Sen ◽  
G. W. Kelley ◽  
N. R. Underdahl ◽  
G. A. Young
Keyword(s):  
Influenza Virus ◽  
Experimental Evidence ◽  
Intermediate Host ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
Multiple Injections

Experimental evidence is presented which confirms the reports by Shope (1, 2) that swine lungworms can serve as an intermediate host in transmitting swine influenza virus to pigs. The virus is present in a masked non-infective form as he showed and a provocative stimulus is necessary to initiate infection. Multiple injections of Ascaris extract or the migration of Ascaris larvae furnished the needed provocation. The virus could be elicited in the spring and summer as well as fall and winter, from the pathogen-free, colostrum-deprived pigs.

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

1941 ◽  
Vol 74 (1) ◽  
pp. 49-68 ◽  
Author(s):  
Richard E. Shope
Keyword(s):  
Influenza Virus ◽  
Respiratory Tract ◽  
Intermediate Host ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
Preceding Paper ◽  
Virus Infections ◽  
Single Experiment ◽  
Hog Cholera ◽  
Hog Cholera Virus

1. The swine lungworm can serve as intermediate host in transmitting swine influenza virus to swine. The virus is present in a masked non-infective form in the lungworm, however, and, to induce infection, must be rendered active by the application of a provocative stimulus to the swine it infests. Multiple intramuscular injections of H. influenzae suis furnish a means of provoking infection. Swine influenza infections can be provoked in properly prepared swine during the autumn, winter, and spring, but not during the summer. The phenomenon, while not regularly reproducible, occurs in well over half the experiments conducted outside the refractory period of summer. No explanation for the failures is apparent. 2. The virus can persist in its lungworm intermediate host for at least 2 years. 3. Swine infected with swine influenza virus by way of the lungworm intermediate host exhibit a more pronounced pneumonia of the posterior lobes of the lung than do animals infected intranasally with virus. The situation of the worms providing the virus will account for this. 4. Occasional swine infested with lungworms carrying influenza virus fail to become clinically ill after provocation but instead become immune. In these it is believed that lungworms containing the virus are localized outside the respiratory tract at the time of provocation. 5. It is believed that the experiments described furnish an explanation for the findings recorded in the preceding paper, in which swine influenza virus infections were induced in apparently normal swine by multiple injections of H. influenzae suis. 6. In a single experiment swine lungworms failed to transmit hog cholera virus.

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

1943 ◽  
Vol 77 (2) ◽  
pp. 127-138 ◽  
Author(s):  
Richard E. Shope
Keyword(s):  
Influenza Virus ◽  
Intermediate Host ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
Virus Infections

1. The presence of masked swine influenza virus has been demonstrated in lungworm larvae from earthworms dug on Midwestern farms. 2. Swine influenza virus infections were provoked in 2 of 3 swine obtained from an Iowa farm during an interepizootic period. 3. The evidence presented has been interpreted as indicating that the swine lungworm is the reservoir and intermediate host for swine influenza virus in the field. 4. A concept of the epidemiology of swine influenza in which the causative virus is represented as being maintained and disseminated in a masked form by its lungworm intermediate host has been presented.

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

1943 ◽  
Vol 77 (2) ◽  
pp. 111-126 ◽  
Author(s):  
Richard E. Shope
Keyword(s):  
Influenza Virus ◽  
Intermediate Host ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
Single Species ◽  
Virus Infections ◽  
Intermediate Hosts ◽  
Single Experiment ◽  
Negative Results ◽  
June July

1. During a 3 year study of the lungworm as intermediate host for the swine influenza virus 98 transmission experiments, using 216 swine, have been conducted. Of these, 50 gave negative results. In the remaining 48, transmission of swine influenza virus by way of the lungworm was demonstrated in one or more animals of each experiment. Irregularities in the results would appear to be due not so much to lack of transmission of masked virus by the lungworms as to failure to evoke its pathogenic capabilities. 2. The stimulus of choice that was most successful in the provocation of swine influenza consisted of multiple intramuscular injections of H. influenzae suis. In several experiments pigs developed swine influenza virus infections 9 to 17 days after infestation with infected lungworms in the absence of any known provocative stress. In these instances an immune response of the swine to the lungworms themselves is suspected of having furnished the provocation. 3. During May, June, July, and August, swine prepared by the ingestion of lungworms carrying virus were absolutely refractory to the provocation of influenza, and they were relatively refractory in September and October. The masked virus was activated most readily during the first 4 months of the year. 4. In a single experiment we succeeded in demonstrating by direct means the presence of swine influenza virus in the neighborhood of lungworms at the base of the lung at a time when the virus was not demonstrable anywhere else in the respiratory tract. 5. Masked swine influenza virus was found to be present in lungworm ova obtained either from the respiratory tracts or the feces of infected swine. 6. In a number of instances, masked swine influenza virus has been found to persist for over a year in lungworm larvae within the earthworm intermediate hosts, and in one case its presence was demonstrated after 32 months. 7. Two varieties of a single species of earthworm, namely, Allolobophora caliginosa f. typica (Savigny) and A. caliginosa f. trapezoides (Dugès), have been found separately capable of serving as intermediate hosts for virus-infected lungworms. 8. Lungworm ova, obtained from convalescent swine which are no longer carrying swine influenza virus in infectious form in their respiratory tracts, contain masked virus.

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

1941 ◽  
Vol 74 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Richard E. Shope
Keyword(s):  
Influenza Virus ◽  
Intermediate Host ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
Virus Infections ◽  
Intramuscular Injections

Multiple intramuscular injections of H. influenzae suis were found to precipitate swine influenza virus infections in a group of apparently normal swine. The most likely explanation of the phenomenon seemed to be that the animals, though healthy and susceptible, harbored the virus in some unknown manner. The factors possibly determining the phenomenon were explored experimentally but without success.

scholarly journals Epidemic Status of Swine Influenza Virus in China

2013 ◽  
Vol 54 (1) ◽  
pp. 3-11 ◽  
Author(s):  
Weili Kong ◽  
Jiahui Ye ◽  
Shangsong Guan ◽  
Jinhua Liu ◽  
Juan Pu
Keyword(s):  
Influenza Virus ◽  
Swine Influenza Virus ◽  
Swine Influenza

scholarly journals Isolation of a Novel Swine Influenza Virus from Oklahoma in 2011 Which Is Distantly Related to Human Influenza C Viruses

2013 ◽  
Vol 9 (2) ◽  
pp. e1003176 ◽  
Author(s):  
Ben M. Hause ◽  
Mariette Ducatez ◽  
Emily A. Collin ◽  
Zhiguang Ran ◽  
Runxia Liu ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
Human Influenza
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