PMID- 9442243
OWN - NLM
STAT- MEDLINE
DCOM- 19980302
LR  - 20081121
IS  - 0002-9645 (Print)
IS  - 0002-9645 (Linking)
VI  - 59
IP  - 1
DP  - 1998 Jan
TI  - Clinical effects of porcine reproductive and respiratory syndrome virus on pigs 
      during the early postnatal interval.
PG  - 52-5
AB  - OBJECTIVE: To determine the effect of congenital and early postnatal infection of 
      pigs with porcine reproductive and respiratory syndrome virus (PRRSV) on 
      postnatal survival and growth. ANIMALS: 20 pregnant gilts and their pigs and 
      fetuses. PROCEDURE: 16 pregnant gilts (principals) comprising 4 groups (4 
      gilts/group) were exposed oronasally to 4 strains of PRRSV (a vaccine strain, and 
      3 field strains) at or about day 90 of gestation. Four pregnant gilts (controls) 
      were kept under similar conditions, except for exposure to PRRSV. Samples 
      collected from pigs before ingestion of colostrum and samples and specimens 
      collected from pigs at selected times thereafter were tested for PRRSV and 
      homologous antibody. Pigs were observed for clinical signs and were weighed at 
      birth and at weekly intervals until they were euthanatized and necropsied at 
      about 3 weeks of age. RESULTS: At least some members of all litters of principal 
      gilts were infected congenitally. Most noninfected, liveborn littermates became 
      infected within the first week of life. Infection of pigs with field strains did, 
      and infection of pigs with the vaccine strain did not, adversely affect postnatal 
      survival and growth rate. All infected pigs had generalized lymph node 
      enlargement. CONCLUSION: Exposure of pregnant gilts to either attenuated 
      (vaccine) or virulent (field) strains of PRRSV can result in congenital 
      infection. Vaccine as well as field strains can be transmitted postnatally from 
      infected to noninfected littermates. Pigs infected with field strains have a 
      poorer rate of survival and growth than do noninfected pigs. CLINICAL RELEVANCE: 
      Because attenuated (vaccine) PRRSV can cause congenital infection and be 
      transmitted postnatally from congenitally infected to immune-naive pigs, the use 
      of attenuated virus during gestation is, at best, questionable.
FAU - Mengeling, W L
AU  - Mengeling WL
AD  - Virology Swine Research Unit, National Animal Disease Center, USDA-Agricultural 
      Research Service, Ames, IA 50010, USA.
FAU - Lager, K M
AU  - Lager KM
FAU - Vorwald, A C
AU  - Vorwald AC
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Am J Vet Res
JT  - American journal of veterinary research
JID - 0375011
RN  - 0 (Antibodies, Viral)
SB  - IM
MH  - Animals
MH  - Animals, Newborn
MH  - Antibodies, Viral/blood
MH  - Colostrum/*virology
MH  - Female
MH  - Infectious Disease Transmission, Vertical/*veterinary
MH  - Lymph Nodes/pathology
MH  - Macrophages, Alveolar/*virology
MH  - Porcine Reproductive and Respiratory 
      Syndrome/pathology/physiopathology/*transmission
MH  - Porcine respiratory and reproductive syndrome virus/*isolation & purification
MH  - Pregnancy
MH  - Pregnancy Complications, Infectious/*veterinary
MH  - Swine
EDAT- 1998/01/27 00:00
MHDA- 1998/01/27 00:01
CRDT- 1998/01/27 00:00
PHST- 1998/01/27 00:00 [pubmed]
PHST- 1998/01/27 00:01 [medline]
PHST- 1998/01/27 00:00 [entrez]
PST - ppublish
SO  - Am J Vet Res. 1998 Jan;59(1):52-5.