Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA.
Mahaliana Labs SARL, Antananarivo, Madagascar.
Nat Commun. 2024 Jan 19;15(1):605. doi: 10.1038/s41467-024-44777-3.
Theoretical models have successfully predicted the evolution of poultry pathogen virulence in industrialized farm contexts of broiler chicken populations. Whether there are ecological factors specific to more traditional rural farming that affect virulence is an open question. Within non-industrialized farming networks, live bird markets are known to be hotspots of transmission, but whether they could shift selection pressures on the evolution of poultry pathogen virulence has not been addressed. Here, we revisit predictions for the evolution of virulence for viral poultry pathogens, such as Newcastle's disease virus, Marek's disease virus, and influenza virus, H5N1, using a compartmental model that represents transmission in rural markets. We show that both the higher turnover rate and higher environmental persistence in markets relative to farms could select for higher optimal virulence strategies. In contrast to theoretical results modeling industrialized poultry farms, we find that cleaning could also select for decreased virulence in the live poultry market setting. Additionally, we predict that more virulent strategies selected in markets could circulate solely within poultry located in markets. Thus, we recommend the close monitoring of markets not only as hotspots of transmission, but as potential sources of more virulent strains of poultry pathogens.
理论模型成功预测了家禽病原体在肉鸡种群的工业化农场环境中的毒力进化。是否存在特定于更传统的农村养殖的生态因素会影响毒力，这是一个悬而未决的问题。在非工业化养殖网络中，活禽市场已知是传播的热点，但它们是否会改变家禽病原体毒力进化的选择压力尚待解决。在这里，我们重新使用代表农村市场传播的隔室模型，预测病毒家禽病原体（如新城疫病毒、马立克氏病病毒和 H5N1 流感病毒）毒力的进化。我们表明，相对于农场，市场中的更高周转率和更高环境持久性都可能选择更高的最佳毒力策略。与模拟工业化家禽养殖场的理论结果相反，我们发现市场中的清洁也可能选择降低活禽市场中的毒力。此外，我们预测市场中选择的更具毒性的策略可能仅在市场中的家禽中循环。因此，我们建议不仅密切监测作为传播热点的市场，还要监测市场作为更具毒性的家禽病原体菌株的潜在来源。
