The National Animal Health Laboratory Network (NAHLN) reports 187 positive accessions out of 825 tested at eight veterinary diagnostic labs for the week ending 17 May, according to the American Association of Swine Veterinarians (AASV).

NAHLN finally received confirmation of the positive case in Virginia. Thus the number of states reported to the NAHLN as having at least one confirmed case of PED is now 30.

US states with PEDv-positive swine accessions

Pig Farm Samples Testing Positive for PEDv: 6,804

The total number of pig farm samples (termed 'laboratory biological accessions' in the official report) that have tested positive for the PED virus (PEDv) since April 2013 now stands at 6,804, which includes 450 for the month of May so far.

Since testing was fully reported in November 2013, 19,137 farm samples have been tested, of which 31 per cent have tested positive for the virus.

Figure 1. Number of pig farm samples positive for PEDv
(since April 2013; data from NAHLN)

Results by age class

Suckling pigs

For the current month to date, 319 farms have been tested, of which 125 samples or 39 per cent were positive for PEDv.

Since testing was fully reported in November 2013, 2,612 farm samples have been tested, of which 1,469 samples or 48 per cent tested positive for PEDv.

Nursery pigs

For the current month to date, 281 farms have been tested, of which 73 samples or 26 per cent were positive for PEDv.

Since testing was fully reported in November 2013, 3,052 farm samples have been tested, of which 1,242 samples or 36 per cent tested positive for PEDv.

Grower/finisher pigs

For the current month to date, 347 farms have been tested, of which 66 samples or 19 per cent were positive for PEDv.

Since testing was fully reported in November 2013, 3,419 farm samples have been tested, of which 1,255 samples or 28 per cent tested positive for PEDv.

Sows and boars

For the current month to date, 280 farms have been tested, of which 46 samples or 16 per cent tested positive for PEDv.

Since testing was fully reported in November 2013, 1,619 farm samples have been tested, of which 599 samples or 27 per cent tested positive for PEDv.

Unknown age class

For the current month to date, 849 farms have been tested, of which 164 samples or 19 per cent tested positive for PEDv.

Since testing was fully reported in November 2013, 9,121 farm samples have been tested, of which 2,415 samples or 25 per cent tested positive for PEDv.

Results by state

According to AASV, the total number of states affected remains at 30.

The total number of positive accessions on this report (up to the week of 11 May) is 6,804.

Those states with 100 or more positive tests are: Iowa, 2,002; Minnesota, 1,123; Illinois, 696; North Carolina, 668; Oklahoma, 388; Indiana, 367; Ohio, 313; Kansas, 260; Missouri, 183, Michigan, 165 and Nebraska, 119.

For the most recent week (week of 11 May), most of the new cases - 35 of the 187 new positive results - were in Minnesota, followed by Iowa and and Illinois, each with 31.

Also reporting one or more positive results were Colorado, Indiana, Kansas, Kentucky, Michigan, Missouri, North Carolina, Nebraska, Ohio, Oklahoma, Pennsylvania, South Dakota, Texas and Wisconsin.

Pig Samples Testing Positive for PEDv: 24,341

The total number of swine samples (termed 'biological samples' in the official report) since testing began in June 2013 now stands at 24,341.

For the current month to date, 13,837 samples have been tested, of which 2,169 or 16 per cent tested positive for PEDv.

Since testing was fully reported in November 2013, 92,684 samples have been tested, of which 23 per cent tested positive for PEDv.

Figure 2. Number of pig samples positive for PEDv
(since June 2013; data from NAHLN)

Environmental Samples Testing Positive for PEDv: 5,565

The total number of environmental samples testing positive since testing began in June 2013 now stands at 5,565.

For the current month to date, 2,302 samples have been tested, of which 460 or 20 per cent tested positive for PEDv.

Since testing was fully reported in November 2013, 20,163 samples have been tested, of which 25 per cent tested positive.

Figure 3. Number of environmental samples positive for PEDv
(since June 2013; data from NAHLN)

Notes on the report

These data are collated by USDA APHIS VS NVSL National Animal Health Laboratory Network (NAHLN) in a report dated 21 May 2014 made available by the Veterinary diagnostic laboratories that have voluntarily reported PEDV testing data to NAHLN include: University of Georgia – Athens, University of Illinois, Iowa State University, Kansas State University, Michigan State University - Diagnostic Center for Population and Animal Health, University of Minnesota, Nebraska Veterinary Diagnostic Center, North Dakota State University, Ohio Department of Agriculture, Oregon State University, Purdue University, South Dakota State University and Texas Veterinary Medical Diagnostic Laboratory. This data does not include testing conducted at private diagnostic laboratories, at the NVSL, or for research purposes.

Data summaries provided in this report reflect the most current and complete data available at the time of report preparation; summaries in this report may differ from those provided in past reports.

PEDv data were collated and summarized by Iowa State University Diagnostic Laboratory from mid-April through mid-June, 2013; only summary data on positive samples are available for that time period. Totals for April 2013 only include testing after 4/16/2013.

NAHLN Laboratories began providing more granular information about PEDv testing starting the week of 6/16/2013, and USDA NAHLN began collating the testing data at that time. During the 2013 federal government shutdown, the University of Minnesota Diagnostic Laboratory collected and reported PEDv testing data (weeks of 9/22/13 through 10/6/13).

Data on PEDv-negative accessions and samples became available from all laboratories starting November 2013. Therefore, summaries “total number tested” and “percent positive” are only calculated for samples tested after November 1, 2013.

In general, a laboratory accession is a set of samples received at the laboratory in which the samples were collected at a single premises on a single day. Therefore, each laboratory accession represents a swine herd and each sample represents an individual animal tested for PEDv on a given date. Because multiple swine within a herd are often simultaneously infected, analyses often use the laboratory accession as the epidemiological unit of interest.

Age classes are defined as suckling (up to one month old or still on sow), nursery (one to three months), grower/finisher (three to eight months) and sow/boar (older than eight months).

A single accession can include samples from multiple age classes or samples tested in different weeks. Therefore, the same accession can be counted in more than one age class category or more than one testing week summary.

This report does not currently include results of testing on feed samples.

This report only includes PCR testing data for PEDv at this time, with additional testing types to be added to the report as information on the performance of new assays becomes available.

Further Reading

Find out more information on PED by clicking here.