Historical Background

PCV2-associated PMWS was first identified in Canadian high health herds in 1991 (Harding, 1996; Harding and Clark, 1997). Affected herds were free of major enteric and respiratory pathogens including Mycoplasma hyopneumoniae, Actinobacillus pleuropneumoniae (APP), salmonellosis, swine dysentery, transmissible gastroenteritis virus (TGEV), pseudorabies virus, and PRRSV. The herd sizes varied from small (50 sows) to large (1,200 sows) and genetics also varied widely. In 1996, interstitial pneumonia and lymphadenopathy was observed in a 6-week-old pig in California (Daft et al., 1996). Also in 1996, workers in France observed a piglet wasting disease (LeCann et al., 1997). Subsequently, PCV2 was isolated from material of affected French and U.S. pigs (Allan et al., 1998b).

 

References:

Allan GM, McNeilly F, Kennedy S, Daft B, Clarke EG, Ellis JA, Haines DM, Meehan BM, Adair BM: Isolation of porcine circovirus-like viruses from pigs with a wasting disease in the USA and Europe. J Vet Diagn Invest. 10:3-10, 1998

Daft B, Nordhausen RW, Latimer KS, Niagro FD: Interstitial pneumonia and lymphadenopathy associated with circoviral infection in a six-week-old pig. Proc Am Assoc Vet Lab Diagn 39:32, 1996

Harding JC: Postweaning multisystemic wasting syndrome (PMWS): preliminary epidemiology and clinical presentation. In: Proc Western Canadian Assoc Swine Pract. 21, 1996

Harding JCS, Clark EG: Recognizing and diagnosing postweaning multisystemic wasting syndrome (PMWS). Swine Health Prod. 5:201-203, 1997

LeCann P, Albina E, Madec F, Cariolet R, Jestin A: Piglet wasting disease. Vet Rec. 141:660, 1997