
Highly pathogenic avian influenza (HPAI) is a major threat to domestic poultry, causing considerable economic losses and requiring rapid intervention to limit its spread. Traditionally, the tracing of contacts on a farm where the virus has been detected is based on fixed time windows, often ill-suited to the transmission dynamics of the virus, which are specific to each farm.
A Franco-Dutch research team has proposed the use of mathematical modeling to optimize the identification of epidemiological links between infected farms. By modeling the increase in daily mortalities observed in infected farms, the scientists have developed a method capable of estimating the probable dates of the first infections in these farms. This method, integrated into an online application, will enable veterinary services to better target the critical periods for monitoring contacts, thus saving the resources needed for this monitoring while increasing the effectiveness of the control measures implemented in infected farms.
"Our approach offers a tailor-made solution for each farm, enabling veterinary services to react more quickly and effectively," explains Sébastien Lambert, a researcher from Toulouse in the IHAP research unit.
The application, accessible via an online website, was tested on 63 infected farms in France and the Netherlands. The results show a wide variability in the dates of first infection, ranging from 3 to 20 days before official detection, underlining the importance of a personalized approach to each farm whenever possible.
This discovery will improve the management of HPAI epidemics, as well as other emerging infectious animal diseases. The researchers are already planning to extend their model to other poultry species, and to adapt it for use on farms vaccinated against HPAI.