Effects of morphine dependence on the pathogenesis of swine herpesvirus infection.
To further understand the effects of opiates on the pathogenesis of infectious disease, naturally occurring pathogens were studied in a swine model. Swine were given morphine for 21-42 days to establish a tolerant, dependent state. On day 7 after morphine initiation, pigs were challenged with swine herpesvirus-1 (SHV-1); on day 14, selected animals were superinfected with Pasteurella multocida. Evaluations were made of the clinical disease, protective effect of SHV-1 vaccination, and pathology. Morphine-dependent animals developed significantly greater virus-induced and secondary bacterial pneumonia. Prior vaccination with SHV-1 was not protective against pneumonia in morphine-dependent pigs. Unexpectedly, clinical signs associated with neurologic disease were less pronounced, and mortality from viral encephalitis was decreased in morphine-treated animals. Collectively, the findings demonstrate that morphine dependence is associated with a marked alteration of the pathogenesis of SHV-1 and that the effects of this opiate on pathogenesis are determined by the specific site of infection.
Risdahl
J M
JM
Department of Clinical and Population Sciences, University of Minnesota, St. Paul 55108.
Peterson
P K
PK
Chao
C C
CC
Pijoan
C
C
Molitor
T W
TW
D000818:Animals; D006566:Herpesviridae Infections / Q000150:complications* / Q000382:microbiology / Q000401:mortality; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D010326:Pasteurella Infections / Q000150:complications; D016979:Pasteurella multocida; D019966:Substance-Related Disorders / Q000150:complications*; D013552:Swine
D009020:Morphine