PMID- 34271476
OWN - NLM
STAT- MEDLINE
DCOM- 20211104
LR  - 20211104
IS  - 1873-1716 (Electronic)
IS  - 0167-5877 (Linking)
VI  - 194
DP  - 2021 Sep
TI  - A comparison of three sampling approaches for detecting PRRSV in suckling 
      piglets.
PG  - 105427
LID - S0167-5877(21)00171-9 [pii]
LID - 10.1016/j.prevetmed.2021.105427 [doi]
AB  - Determining whether porcine reproductive and respiratory syndrome virus (PRRSV) 
      is circulating within a breeding herd is a longstanding surveillance challenge. 
      Most commonly, piglets in farrowing rooms are sampled to infer the PRRSV status 
      of the sow herd, with sample size based on the expectation of hypergeometric 
      distribution and piglet selection based on simple random sampling (SRS), i.e., 
      randomly selecting individuals from a population in a manner that all individuals 
      have equal chance of being selected. Conceptually straightforward, the 
      assumptions upon which it is based (homogeneous population and independence of 
      individuals) rarely hold in modern swine facilities. Alternative approaches for 
      sample selection include two-stage stratified sampling (2SS), i.e., randomly 
      selecting litters (first stratum) and randomly selecting piglets (second stratum) 
      within selected litters, and risk-based sampling (RBS), i.e., selecting litters 
      with a higher risk of having viremic piglets, and randomly selecting pigs within 
      those litters. The objectives of this study were to 1) characterize the pattern 
      of distribution of PRRSV-viremic piglets in farrowing rooms and 2) compare the 
      efficiency of SRS, 2SS, and RBS for the detection of PRRSV-viremic piglets. In 12 
      sow farms, serum samples were collected from all 4510 piglets in 422 litters 
      housed in 23 farrowing rooms and tested for PRRSV RNA. At the population level, 
      the distribution of PRRSV-viremic pigs was analyzed for population homogeneity 
      and spatial clustering. At the litter level, litter size and sow parity were 
      evaluated as risk factors. A non-homogeneous distribution of PRRSV-viremic 
      piglets was observed in nearly all farrowing rooms (15/16), and spatial 
      clustering detected on 11 occasions (11/16). Simulated sampling based on 
      farrowing room data determined that 2SS required 1-to-25 fewer samples than SRS 
      to detect >/= 1 viremic piglet in 13 of 16 rooms and the same number of samples in 
      3 rooms. RBS required 1-to-7 fewer samples than 2SS to detect >/= 1 viremic piglet 
      in 7 of 16 rooms, the same number of samples in 6 rooms, and 1 more sample in 3 
      rooms. Notably, SRS was less efficient than either 2SS or RBS in detecting 
      PRRSV-viremic piglets in farrowing rooms, regardless of the confidence level. It 
      may be concluded that the core assumptions upon which most current surveillance 
      methods are based do not hold in modern farrowing room facilities. 
      Simulation-based sample size tables for SRS and 2SS are provided.
CI  - Copyright (c) 2021 Elsevier B.V. All rights reserved.
FAU - Almeida, M N
AU  - Almeida MN
AD  - Department of Veterinary Diagnostic and Production Animal Medicine, College of 
      Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA. Electronic 
      address: malmeida@iastate.edu.
FAU - Zhang, M
AU  - Zhang M
AD  - Department of Statistics, College of Liberal Arts and Sciences, Iowa State 
      University, Ames, IA, USA.
FAU - Lopez, W A L
AU  - Lopez WAL
AD  - PIC, Hendersonville, TN, USA.
FAU - Vilalta, C
AU  - Vilalta C
AD  - Upnorth Analytics, Barcelona, Spain.
FAU - Sanhueza, J
AU  - Sanhueza J
AD  - Departamento de Ciencias Veterinarias y Salud Publica, Facultad de Recursos 
      Naturales, Universidad Catolica de Temuco, Temuco, Chile.
FAU - Corzo, C A
AU  - Corzo CA
AD  - Veterinary Population Medicine Department, College of Veterinary Medicine, 
      University of Minnesota, St. Paul, MN, USA.
FAU - Zimmerman, J J
AU  - Zimmerman JJ
AD  - Department of Veterinary Diagnostic and Production Animal Medicine, College of 
      Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA.
FAU - Linhares, D C L
AU  - Linhares DCL
AD  - Department of Veterinary Diagnostic and Production Animal Medicine, College of 
      Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA.
LA  - eng
PT  - Comparative Study
PT  - Journal Article
DEP - 20210708
PL  - Netherlands
TA  - Prev Vet Med
JT  - Preventive veterinary medicine
JID - 8217463
SB  - IM
MH  - Animals
MH  - Female
MH  - Litter Size
MH  - Porcine Reproductive and Respiratory Syndrome/*diagnosis
MH  - *Porcine respiratory and reproductive syndrome virus/isolation & purification
MH  - Pregnancy
MH  - Swine
MH  - *Viremia/veterinary
OTO - NOTNLM
OT  - PCR
OT  - PRRSV
OT  - Sample size
OT  - Surveillance
OT  - Swine
EDAT- 2021/07/17 06:00
MHDA- 2021/11/05 06:00
CRDT- 2021/07/16 20:31
PHST- 2020/12/11 00:00 [received]
PHST- 2021/06/28 00:00 [revised]
PHST- 2021/07/05 00:00 [accepted]
PHST- 2021/07/17 06:00 [pubmed]
PHST- 2021/11/05 06:00 [medline]
PHST- 2021/07/16 20:31 [entrez]
AID - S0167-5877(21)00171-9 [pii]
AID - 10.1016/j.prevetmed.2021.105427 [doi]
PST - ppublish
SO  - Prev Vet Med. 2021 Sep;194:105427. doi: 10.1016/j.prevetmed.2021.105427. Epub 
      2021 Jul 8.