The National Animal Health Laboratory Network (NAHLN) reports 221 positive accessions out of 822 tested at eight veterinary diagnostic labs for the week ending 19 April 2014, reports the American Association of Swine Veterinarians (AASV). In addition, it says, the Network adjusted a couple of earlier week’s numbers.

The number of states reported to the NAHLN as having at least one confirmed case of PED now stands at 29. AASV reports, however, that cases have also been diagnosed in Virginia, which would bring the actual state count to 30.

US states with PEDv-positive swine accessions

Pig Farms Testing Positive for PEDv: 6,019

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 6,019, which includes 721 for the month of April so far.

Since testing was fully reported in November 2013, 15,863 farm samples have been tested, of which 32 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, 360 farms have been tested, of which 162 or 45 per cent were positive for PEDv.

Since testing was fully reported in November 2013, 2,119 farms have been tested, of which 1,277 or 50 per cent tested positive for PEDv.

Nursery pigs

For the current month to date, 333 farms have been tested, of which 112 or 34 per cent were positive for PEDv.

Since testing was fully reported in November 2013, 2,591 farms have been tested, of which 1,104 or 37 per cent tested positive for PEDv.

Grower/finisher pigs

For the current month to date, 364 farms have been tested, of which 72 or 20 per cent were positive for PEDv.

Since testing was fully reported in November 2013, 2,8,46 farms have been tested, of which 1,140 or 29 per cent tested positive for PEDv.

Sows and boars

For the current month to date, 247 farms have been tested, of which 46 or 19 per cent tested positive for PEDv.

Since testing was fully reported in November 2013, 1,222 farms have been tested, of which 538 or 31 per cent tested positive for PEDv.

Unknown age class

For the current month to date, 1,279 farms have been tested, of which 337 or 26 per cent tested positive for PEDv.

Since testing was fully reported in November 2013, 7,622 farms have been tested, of which 2,099 or 26 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 13 April) is 6,019.

Those states with 100 or more positive tests are: Iowa, 1,834; Minnesota, 980; North Carolina, 605; Illinois, 578; Oklahoma, 355; Indiana, 324; Ohio, 283; Kansas, 240; Missouri, 138 and Michigan, 130.

For the most recent week (week of 13 April), 46 of the 221 new positive results were in Minnesota, followed by Illinois (43) and Iowa (41).

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

Individual Pigs Testing Positive for PEDv: 20,603

The total number of individual swine samples (termed 'biological samples' in the official report) since testing began in June 2013 now stands at 20,603.

For the current month to date, 14,131 samples have been tested, of which 3,183 or 23 per cent tested positive for PEDv.

Since testing was fully reported in November 2013, 70,507 samples have been tested, of which 20,603 or 25 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: 4,638

The total number of environmental samples testing positive since testing began in June 2013 now stands at 4,638.

For the current month to date, 3,142 samples have been tested, of which 915 or 29 per cent tested positive for PEDv.

Since testing was fully reported in November 2013, 16,073 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) and cited by the American Association of Swine Veterinarians (AASV) in a report dated 16 April 2014.

Veterinary diagnostic laboratories that have voluntarily reported PEDv and SDCv testing data to NAHLN include: University of Georgia–Athens, University of Illinois, Iowa State University, University of Illinois, Kansas State University, University of Minnesota, Nebraska Veterinary Diagnostic Center, Ohio Department of Agriculture, Purdue University, Michigan State University-Diagnostic Center for Population and Animal Health, South Dakota State University and North Dakota State University. 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.