The NAHLN reports 262 positive accessions out of 819 tested at six veterinary diagnostic labs for the week ending 12 April 2014. In addition, they also adjusted a couple of earlier week’s numbers and added Vermont to the list of states reporting at least one confirmed case.

The number of states reported to the NAHLN as having at least one confirmed case of PED now stands at 29. The American Association of Swine Veterinarians (AASV) adds 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: 5,790

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 5,790, which is 491 for the month of April so far.

Since testing was fully reported in November 2013, 14,797 farm samples have been tested, of which 33 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, 241 farms have been tested, of which 110 or 46 per cent were positive for PEDv.

Since testing was fully reported in November 2013, 1,991 farms have been tested, of which 1,225 or 51 per cent tested positive for PEDv.

Nursery pigs

For the current month to date, 211 farms have been tested, of which 86 or 41 per cent were positive for PEDv.

Since testing was fully reported in November 2013, 2,454 farms have been tested, of which 1,078 or 38 per cent tested positive for PEDv.

Grower/finisher pigs

For the current month to date, 281 farms have been tested, of which 51 or 23 per cent were positive for PEDv.

Since testing was fully reported in November 2013, 2,646 farms have been tested, of which 1,119 or 30 per cent tested positive for PEDv.

Sows and boars

For the current month to date, 147 farms have been tested, of which 32 or 22 per cent tested positive for PEDv.

Since testing was fully reported in November 2013, 1,094 farms have been tested, of which 524 or 33 per cent tested positive for PEDv.

Unknown age class

For the current month to date, 797 farms have been tested, of which 217 or 27 per cent tested positive for PEDv.

Since testing was fully reported in November 2013, 7,094 farms have been tested, of which 1,980 or 26 per cent tested positive for PEDv.

Results by state

Reports of PED outbreaks have been received from Vermont and Virginia, bringing the total number of states affected to 30.

The total number of positive accessions on this report (up to the week of 6 April) is 5,524.

Those states with 100 or more positive tests are: Iowa, 1,793; Minnesota, 936; North Carolina, 585; Illinois, 535; Oklahoma, 351; Indiana, 306; Ohio, 263; Kansas, 235; Missouri, 131 and Michigan, 121.

For the most recent week (week of 6 April), 51 of the 262 new positive results were in Minnesota, followed by Iowa (48) and Illinois (43).

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

Individual Pigs Testing Positive for PEDv: 19,623

The total number of individual swine samples (termed 'biological samples' in the official report) since testing began in June 2013 now stands at 19,623.

For the current month to date, 8,181 samples have been tested, of which 2,202 or 27 per cent tested positive for PEDv.

Since testing was fully reported in November 2013, 61,571 samples have been tested, of which 19,623 or 27 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: 4,444

The total number of environmental samples testing positive since testing began in June 2013 now stands at 4,444.

For the current month to date, 2,043 samples have been tested, of which 721 or 35 per cent tested positive for PEDv.

Since testing was fully reported in November 2013, 14,973 samples have been tested, of which 26 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.