# REV and LPDV in wild turkeys in Texas

Dustin Edwards's current research follows two retroviruses of birds, reticuloendotheliosis virus (REV) and lymphoproliferative disease virus (LPDV), in wild turkeys in Texas, Oklahoma and Nebraska. This page explains what the viruses are, why they matter for wild turkeys and for the endangered Attwater's prairie chicken, how the work is done, and what each published study found. It is written for hunters, landowners, students and anyone curious about wildlife health. The full list of papers is on the [publications page](/research/publications).

## What are REV and LPDV?

Both are retroviruses of birds. A retrovirus copies its RNA genome into DNA and inserts that DNA, called the provirus, into the chromosomes of the cells it infects. An infected bird carries the provirus for life. That lifelong integration is part of why some retroviruses can cause cancer, and it is also what makes them detectable: a small blood sample holds enough infected cells to find the viral DNA.

**Reticuloendotheliosis virus (REV)** infects a wide range of birds, including chickens, turkeys, ducks and prairie chickens. It can weaken the immune system and sometimes causes tumors. REV can also insert itself into the genome of fowlpox virus, a common poxvirus of birds, so a fowlpox infection can carry REV along with it.

**Lymphoproliferative disease virus (LPDV)** is a retrovirus of turkeys. It has been reported in wild turkeys across the eastern United States and in states bordering Texas.

Both viruses are associated with immunosuppression and with lymphoid tumors, cancers of lymphocytes, a type of white blood cell. They may also affect how long birds survive and how well they reproduce, though how much they do so in wild populations is still an open question. Because the two viruses cause disease that looks alike, telling them apart takes a molecular test, which is why the work screens for both.

## Why they matter for wild turkeys and prairie chickens

The Attwater's prairie chicken is a highly endangered bird whose survival depends on captive breeding. An REV outbreak in a captive breeding flock in Texas killed many adult prairie chickens. In wild birds, REV infection is usually uncommon and disease is rarely seen, so the outbreak raised a practical question: could wild birds living near captive flocks be a reservoir for the virus?

Wild turkeys were the natural group to check. Like prairie chickens, they are galliform birds (the order that includes quail, grouse and chickens), and they range widely across Texas. Texas has native Rio Grande wild turkeys, and it has also received Eastern wild turkeys imported from other states for restoration. Moving birds is an important conservation tool, but imported birds can bring viruses, including LPDV, from regions where those viruses are established.

For people who manage, hunt or study wild turkeys, knowing where these viruses occur is a first step toward understanding whether they play a part in population health, and toward making informed choices when birds are moved between regions.

## How the research is done

The work combines field sampling with molecular diagnostics:

- **Field sampling.** Blood is collected from wild turkeys, often as small dried blood spots that are easy to store and ship.
- **PCR detection.** DNA is extracted from the blood and tested by PCR for REV and LPDV proviral DNA. REV is detected by amplifying parts of the viral long terminal repeat (LTR) and the viral *pol* gene. A control PCR for a bird gene confirms that each sample holds DNA that will amplify, so a negative result can be trusted.
- **Sequencing and genome analysis.** Viral DNA from positive samples is sequenced so strains can be compared with each other and with strains from other regions. Some viruses are sequenced as whole or nearly whole genomes.

Through this approach, the group has confirmed REV and LPDV in wild turkeys across Texas, Oklahoma and Nebraska, often in regions undergoing habitat management or restoration. Comparisons of LPDV sequences point to broad circulation of the virus across the central and southern United States. Genome analysis has also found REV integrated into fowlpox virus strains circulating in the field. With collaborators in Brazil, the group confirmed REV in the Amazon biome for the first time, with strains similar to North American ones but not integrated into poxvirus genomes.

The primer sequences and cycling conditions are published on the [REV primers](/research/protocols/rev-lpdv-primers) and [pan-avian GAPDH](/research/protocols/pan-avian-gapdh) protocol pages.

## What the studies found

### REV in wild turkeys in Texas

The first survey tested wild turkeys in Texas for REV after the prairie chicken outbreak. REV was detected in native Rio Grande wild turkeys and in an Eastern wild turkey that had been imported during restoration efforts. The study concluded that continued surveillance, including genetic analysis of the viruses found, is needed to identify where outbreaks in captive prairie chicken flocks come from ([Survey of Reticuloendotheliosis Virus in Wild Turkeys in Texas, USA](/research/publications/10-7589-2018-08-187/), 2019; [doi.org/10.7589/2018-08-187](https://doi.org/10.7589/2018-08-187)).

### LPDV and REV in Rio Grande wild turkeys in Texas

Because LPDV had been found in states bordering Texas, and because REV had turned up in a turkey imported from a region where LPDV is established, the next study tested Rio Grande wild turkeys in Texas for both viruses. It provided the first molecular evidence of LPDV in Texas, continued to detect REV, and found a bird infected with both viruses at once. The Texas LPDV sequences were closely related to LPDV from other southern and central states. More work is needed to learn how the virus affects reproduction, coinfection and the overall health of wild turkey populations ([Molecular Surveillance for Lymphoproliferative Disease Virus and Reticuloendotheliosis Virus in Rio Grande Wild Turkeys in Texas, USA](/research/publications/10-7589-jwd-d-22-00023/), 2022; [doi.org/10.7589/JWD-D-22-00023](https://doi.org/10.7589/JWD-D-22-00023)).

### REV in Brazil

Working with collaborators in Brazil, the group tested birds from a state in northern Brazil for REV. The virus was found in Muscovy ducks, wild turkeys and chickens. This was the first evidence of REV in the Amazon biome, and the Brazilian strains were closely related to strains from the United States. The study gives a baseline for future monitoring in the region ([Detection of Reticuloendotheliosis Virus in Muscovy Ducks, Wild Turkeys, and Chickens in Brazil](/research/publications/10-7589-2019-04-088/), 2020; [doi.org/10.7589/2019-04-088](https://doi.org/10.7589/2019-04-088)).

### REV genomes from a wild turkey and a prairie chicken

Two short genome reports describe complete or nearly complete REV genomes, which give a reference point for tracing where the virus comes from:

- A nearly intact REV provirus sitting inside the genome of a field strain of fowlpox virus, from a Rio Grande wild turkey in Texas. It shows that fowlpox virus circulating in wild turkeys can carry REV with it ([Genome Sequence of Fowlpox Virus-Integrated Reticuloendotheliosis Virus from a Rio Grande Wild Turkey](/research/publications/10-1128-mra-00174-22/), 2022; [doi.org/10.1128/mra.00174-22](https://doi.org/10.1128/mra.00174-22)).
- A near-complete REV provirus from an endangered Attwater's prairie chicken, isolated during the outbreak in a captive breeding flock ([Near-Complete Proviral Genome Sequence of Reticuloendotheliosis Virus Isolated from an Attwater's Prairie Chicken](/research/publications/10-1128-mra-00173-22/), 2022; [doi.org/10.1128/mra.00173-22](https://doi.org/10.1128/mra.00173-22)).

## What comes next

Finding a virus in a population is not the same as knowing what it does there. The open questions are how REV and LPDV affect the survival and reproduction of wild turkeys, how the viruses move between wild birds, restored populations and captive flocks, and how fowlpox virus helps spread REV. Continued sampling and sequencing are aimed at those questions.

## Related pages

- [Retrovirus research](/research/retroviruses)
- [HTLV-1 research](/research/retroviruses/human)
- [Research](/research)
- [Publications](/research/publications)
- [Protocols](/research/protocols)