Optimizing the early detection of low pathogenic avian influenza H7N9 virus in live bird markets

Abstract

In Southeast Asia, surveillance at live bird markets (LBMs) has been identified as crucial for detecting avian influenza viruses (AIV) and reducing the risk of human infections. However, the design of effective surveillance systems in LBMs remains complex given the rapid turn-over of poultry. We developed a deterministic transmission model to provide guidance for optimizing AIV surveillance efforts. The model was calibrated to fit one of the largest LBMs in northern Vietnam at high risk of low pathogenic H7N9 virus introduction from China to identify the surveillance strategy that optimizes H7N9 detection. Results show that (i) using a portable diagnostic device would slightly reduce the number of infected birds leaving the LBM before the first detection, as compared to a laboratory-based diagnostic strategy, (ii) H7N9 detection could become more timely by sampling birds staying overnight, just before new susceptible birds are introduced at the beginning of a working day, and (iii) banning birds staying overnight would represent an effective intervention to reduce the risk of H7N9 spread but would decrease the likelihood of virus detection if introduced. These strategies should receive high priority in Vietnam and other Asian countries at risk of H7N9 introduction.

Assessing the effectiveness of environmental sampling for surveillance of foot-and-mouth disease virus in a cattle herd

“…Such effective strategies include 5 samples every 2 days, 10 samples every 5 days or 20 samples every 8 days. Which choice of strategy in the event of an outbreak will depend on multiple factors including the aims of the surveillance (early detection or proving absence) ( 22 , 23 ), the cost and availability of sampling and laboratory testing ( 24 , 25 ), the attitudes of farmers ( 26 ) and the wishes of the competent authority, and as such we do not suggest a single ‘best’ strategy.…”

Research and Innovation Opportunities to Improve Epidemiological Knowledge and Control of Environmentally Driven Zoonoses

“…For instance, surveillance that prioritises market operations (e.g., wholesale, retail, both wholesale and retail), animal species, or seasons and time periods presenting higher risks of contamination can be a way to limit costs [ 61 ]. Previous studies have shown it is possible to optimize early detection of avian influenza in live bird markets by minimising trade-offs between surveillance costs and the number of infected birds in live markets at time of detection [ 62 ]. However, more research is needed to assess the capacity of predictive models to anticipate outbreaks based on environmental factors and decision support tools that can consider multiple criteria to identify risks and minimise trade-offs, e.g., the article by M.C.…”

Modern technologies and solutions to enhance surveillance and response systems for emerging zoonotic diseases

“…For example, during the COVID-19 pandemic, early detection aided health authorities in identifying infected individuals, thereby slowing the spread of the disease [ 16 , 17 ]. Similarly, for diseases transmitted between animals and humans, early detection and timely implementation of control measures can prevent large-scale transmission within populations [ [18] , [19] , [20] ]. Therefore, it is crucial to establish robust surveillance and response systems that enable early detection and rapid response to emerging zoonotic disease outbreaks before they escalate into epidemics or pandemics [ 5 ].…”