African Swine Fever Surveillance: Why What Happens to the Sample Matters

There has never been an outbreak of African swine fever (ASF) in the UK, but maintaining that disease-free status depends on preparedness, vigilance and effective surveillance. In May 2026, the UK Government published an updated disease control strategy for Great Britain, outlining the measures that would be used to detect and respond to an outbreak should ASF enter the country. In Great Britain, suspected ASF is managed through official disease surveillance and control arrangements, so sample collection, transport and testing need to sit within those established pathways.

Surveillance is an important part of that preparedness. Whether samples are collected from domestic pigs, wild boar or during investigations of suspected disease, reliable laboratory testing depends on more than simply collecting the right sample.

What happens to the sample afterwards matters, too. A sample collected in the field may need to travel considerable distances before reaching a diagnostic laboratory. It could spend hours or days in transit, particularly when surveillance involves remote locations, large numbers of samples or alternative sampling methods. During that time, preserving the material needed for molecular detection becomes an important part of the overall workflow.

Research into ASF detection has demonstrated that sample type and collection method can influence the material available for testing. More recent work has also investigated how samples can be safely transported while maintaining the nucleic acid needed for molecular detection. (1,2)

So, when thinking about ASF surveillance, it is worth looking beyond the point of collection: what happens to the sample between the field and the laboratory can be just as important. This is where molecular transport media such as PrimeStore® MTM can play a role.

Learn why sample transport and preservation are critical considerations when developing an effective ASF surveillance workflow:

Choosing the right sample for ASFV detection

There is no single sample type that will suit every ASF surveillance situation. EDTA blood, serum and tissues such as spleen can all be used for ASFV detection, while alternative approaches including blood swabs, ear biopsies and oral samples have also been investigated. (1,3,4)

The suitability of a sample can depend on factors such as the stage of infection, whether animals are showing clinical signs and the purpose of the surveillance programme.

For example, research by Pikalo et al. found that EDTA blood was significantly better suited to early ASFV detection than serum. Spleen samples also produced strong results, while several alternative matrices were investigated for situations where conventional sampling may be less practical. (1)

This highlights an important point: collecting a sample is only the first step. Once it has been collected, it needs to remain suitable for testing.

What happens to a sample after collection?

For a sample collected close to a diagnostic laboratory, transport may be relatively straightforward. That is not necessarily the case for veterinary surveillance. Samples may be collected on farms, during field investigations or from wild animals, and then transported to a laboratory for molecular testing. There may be a delay before processing, particularly when large numbers of samples are involved or when sampling takes place in remote locations.

During this time, the conditions in which a sample is stored can affect the material available for downstream testing.

For ASFV molecular diagnostics, the objective is to preserve the viral nucleic acid so that it can still be detected when the sample reaches the laboratory. This is where molecular transport media such as PrimeStore® MTM can play a role.

PrimeStore® MTM and ASFV sample transport

PrimeStore® Molecular Transport Medium (MTM) is designed to inactivate pathogens while stabilising microbial nucleic acids during transport and storage. There is direct evidence supporting its use in ASFV sample workflows:

In a 2021 study, Pikalo et al. compared several methods for collecting blood swabs from experimentally infected domestic pigs and wild boar. The researchers assessed plain cotton swabs, GenoTube Livestock Swabs, PrimeSwabs and PrimeStore® MTM, using EDTA blood as the reference sample matrix. (1) The results showed clear differences between the swab methods. Plain cotton swabs and GenoTubes produced the weakest results, with several samples containing only trace amounts or fewer than 10² genome copies per run. Both PrimeSwabs and PrimeStore® MTM performed significantly better. When the two were compared directly, the PrimeStore® MTM buffer produced the best results and performed significantly better than all the other swab options tested, including PrimeSwab alone. (1)

The study also provides a useful example of why the transport stage deserves attention. The blood swabs were placed into their respective collection systems and stored at room temperature for five days before processing. This was intended to replicate the transfer of samples from the field to the laboratory. The PrimeStore® MTM buffer was subsequently used for nucleic acid extraction and ASFV-specific qPCR. (1) In other words, the researchers were not simply looking at whether ASFV could be detected immediately after collection. They were considering what happened to the sample during the period between collection and laboratory analysis.

Preserving nucleic acid during the journey

The role of transport media becomes particularly relevant when samples cannot be processed immediately. PrimeStore® MTM uses a guanidine thiocyanate-based formulation designed to provide pathogen inactivation and nucleic acid stabilisation during transport and storage. (1)

More recent research has investigated this approach specifically with ASFV. A 2020 study evaluated the transportation of ASFV clinical samples using PrimeStore® MTM, including whole blood, spleen swabs and oral fluid. The researchers reported complete ASFV inactivation in the tested sample types while maintaining the viral genomic material required for real-time PCR detection. They also investigated stability at ambient temperature, finding that PrimeStore® MTM helped maintain ASFV genomic material under the conditions tested. (2) This is particularly relevant to surveillance workflows where maintaining samples during transport is a practical challenge. Rather than treating transport as a gap between field sampling and laboratory testing, it can be built into the diagnostic workflow from the outset.

Could alternative samples support ASF surveillance?

Blood remains an important sample for ASFV detection, but alternative sampling approaches may have practical advantages in some surveillance settings.

Studies have demonstrated that ASFV can be detected in oral, nasal and rectal swabs, as well as other alternative matrices. (3)

Research has also explored oral swabs as a sample type for ASFV detection. Goodell et al. investigated PCR detection of ASFV nucleic acid in oral swabs collected from clinical and nonclinical sows across three swine farms in Vietnam, using a molecular transport medium to assess their potential for diagnostic laboratory testing. (4) However, the performance of alternative sample types can vary, with studies reporting lower ASFV genome concentrations in some matrices. (1,3,4) This highlights the importance of considering sample collection, preservation and downstream testing as part of the same workflow. Preserving the material collected during sampling and transport can therefore be an important consideration when working with specimens that may contain low levels of viral nucleic acid.

From field sampling to laboratory testing

An ASF surveillance programme might therefore look something like this:

Sample collection → Preservation → Transport → Nucleic acid extraction → PCR detection

PrimeStore® MTM fits into the middle of that workflow, providing a means of preserving nucleic acid and inactivating pathogens during transport and storage. That can be particularly useful when samples are collected away from the laboratory or when immediate processing is not possible.

The 2021 ASFV study provides evidence that this approach can work with blood swabs, while the more recent 2025 research extends the evidence to additional clinical sample types, including oral fluid. (1,2)

The choice of sample and transport method will ultimately depend on the surveillance objective and the laboratory’s validated workflow. But considering these factors together can help avoid treating sample transport as an afterthought.

Why what happens to the sample matters

ASF surveillance depends on reliable laboratory detection, and the conditions required to achieve a useful molecular result begin before the sample reaches the laboratory. Choosing an appropriate sample and preserving it effectively during transport should therefore be considered as part of the overall molecular workflow, rather than as separate steps.

Supporting ASFV surveillance with PrimeStore® MTM

PrimeStore® Molecular Transport Medium is designed to inactivate pathogens and preserve microbial nucleic acids during sample transport and storage, supporting downstream molecular testing.

With evidence supporting its use in ASFV sample workflows, PrimeStore® MTM can help bridge the gap between field collection and laboratory detection.

VH Bio supplies PrimeStore® MTM to the UK and Republic of Ireland. Contact our team by filling in the form below to discuss PrimeStore® MTM for veterinary molecular sample collection, transport and surveillance applications.

References

1. Pikalo J., Deutschmann P., Fischer M., Roszyk H., Beer M., Blome S. African swine fever laboratory diagnosis—Lessons learned from recent animal trials. Pathogens. 2021;10(2):177. doi:10.3390/pathogens10020177.
2. Rempel J, Onyilagha C, Goonewardene K, Ambagala A. Safe and efficient transportation of clinical samples for molecular detection of African swine fever virus. Front Cell Infect Microbiol. 2025;15:1630865. doi:10.3389/fcimb.2025.1630865.
3. Elnagar A., Pikalo J., Beer M., Blome S., Hoffmann B. Swift and reliable “easy lab” methods for the sensitive molecular detection of African swine fever virus. International Journal of Molecular Sciences. 2021;22(5):2307. doi:10.3390/ijms22052307.
4. Goodell C., Torrison J., Tran V., Nguyen H., Tran Q., Maala C., Helm C., Lai D., Nguyen T., Le H., Nguyen N., Do D.T., Nguyen T., Nguyen N., Zimmerman J., Gomez-Duran O. PCR detection of ASFV nucleic acid in oral swabs from clinical and nonclinical sows of three swine farms in Vietnam. Proceedings of the 54th Annual Meeting of the American Association of Swine Veterinarians. 2023:151. doi:10.54846/am2023/55.