The National Animal Health Laboratory Network (NAHLN) reports 189 positive accessions out of 840 tested at seven veterinary diagnostic labs for the week ending 10 May, according to the American Association of Swine Veterinarians (AASV). In addition, they also adjusted last week's numbers from 191 positive accessions to 198.

The number of states reported to the NAHLN as having at least one confirmed case of PED remains at 29. AASV is aware, however, that case(s) have also been diagnosed in Virginia, which would bring the actual state count to 30.

US states with PEDv-positive swine accessions

Pig Farm Samples Testing Positive for PEDv: 6,617

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 6,617, which includes 264 for the month of May so far.

Since testing was fully reported in November 2013, 18,326 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, 198 farms have been tested, of which 79 samples or 40 per cent were positive for PEDv.

Since testing was fully reported in November 2013, 2,490 farm samples have been tested, of which 1,422 samples or 49 per cent tested positive for PEDv.

Nursery pigs

For the current month to date, 159 farms have been tested, of which 44 samples or 28 per cent were positive for PEDv.

Since testing was fully reported in November 2013, 2,930 farm samples have been tested, of which 1,213 samples or 37 per cent tested positive for PEDv.

Grower/finisher pigs

For the current month to date, 92 farms have been tested, of which 33 samples or 17 per cent were positive for PEDv.

Since testing was fully reported in November 2013, 3,264 farm samples have been tested, of which 1,222 samples or 28 per cent tested positive for PEDv.

Sows and boars

For the current month to date, 160 farms have been tested, of which 26 samples or 16 per cent tested positive for PEDv.

Since testing was fully reported in November 2013, 1,499 farm samples have been tested, of which 579 samples or 28 per cent tested positive for PEDv.

Unknown age class

For the current month to date, 522 farms have been tested, of which 100 samples or 19 per cent tested positive for PEDv.

Since testing was fully reported in November 2013, 8,794 farm samples have been tested, of which 2,351 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 4 May) is 6,617.

Those states with 100 or more positive tests are: Iowa, 1,971; Minnesota, 1,089; Illinois, 665; North Carolina, 650; Oklahoma, 380; Indiana, 357; Ohio, 308; Kansas, 256; Missouri, 169, Michigan, 156 and Nebraska, 115.

For the most recent week (week of 4 May), most of the new cases - 40 of the 189 new positive results - were in Iowa, followed by Minnesota (33) and Illinois (25).

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

Pig Samples Testing Positive for PEDv: 23,385

The total number of swine samples (termed 'biological samples' in the official report) since testing began in June 2013 now stands at 23,385.

For the current month to date, 7,806 samples have been tested, of which 1,241 or 16 per cent tested positive for PEDv.

Since testing was fully reported in November 2013, 86,590 samples have been tested, of which 23,385 or 24 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: 5,378

The total number of environmental samples testing positive since testing began in June 2013 now stands at 5,378.

For the current month to date, 1,221 samples have been tested, of which 276 or 23 per cent tested positive for PEDv.

Since testing was fully reported in November 2013, 19,079 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 15 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.