Pathogenic micro-organisms are a continuous threat as they can cause illness, immunosuppression and poor performance. A good start of a broiler flock begins with healthy chicks in a clean house. We developed a tool to check if broiler houses start the new cycle with a low viral load. The number of cleaning and disinfection protocols is endless, the same for the used chemicals.
A check of the efficacy is often missing, mainly because tools are lacking. Visual inspection doesn’t give information on the success of the disinfection. Bacterial sampling and ATP-testing provides more information about the results disinfection regarding bacteria, but representativeness is questionable as only very small parts of the broiler house are sampled.
With a test where the broilers act as incubator, a better indication is generated on what was still infectious in the house at the time the chickens arrive. Micro-organisms quite resistant to disinfectants would fit best to test. When these resistant micro-organisms are not prevalent anymore, other less resistant pathogens will be inactivated as well.
Figure 1: Relative susceptibility of groups of micro-organisms to disinfectants. Adapted from: Gerald McDonnell and A. Denver Russell Clin. Microbiol. Rev. 1999
GD developed VIR-check. It uses the results of a multiplex PCR on five non-enveloped viruses: rotavirus A, rotavirus D, reovirus, Avian Nephritis Virus-3 and Chicken Astrovirus to measure the success.
of the C&D. Experimental infection on day one with four of these viruses showed a peak in shedding at day 6-7 of age. A field study in Dutch poultry showed that approximately 100 percent of the flocks tested positive on these viruses at the end of the cycle, except for rotavirus D: only 50 percent of the flocks were positive.
How does it work?
The test is easy to perform. Six cloacal swabs taken at age day 6-7 are tested on presence of these non-enveloped viruses by PCR. It provides a good indication of the viral load in the house at the arrival of chicks. The results are transformed by a formula into the so called VIR-check score. Due to the way the formula is developed, vertical transmission of a virus does not influence the main score. A low VIR- check score represents a low exposure to the viruses tested, which is suggestive to a successful C&D procedure, including for the enveloped viruses, gram-positive and gram-negative bacteria as they are more sensitive to disinfection than the tested viruses. The correlation to performance parameters and VIR-check scores is currently under investigation.
Per house both tests cost 89 euro excluding VAT.
- Clients from inside the EU can send the swabs or FTA cards directly to GD. Product code: 11935, VIR-check (swabs) pooled 1-10
- Clients from outside the EU can streak the six swabs on one spot of an FTA-card and send this to GD. Product code: 11936, VIR-check (FTA card) pooled 1-4
Samples can be send to:
7418 EW Deventer
Read more about submitting samples.
Are you interested in the VIR-check? Please contact GD support for more information.