BackgroundPoultry farmers are at high risk of H7N9 avian influenza infection. H7N9 influenza-related knowledge is the precondition motivating poultry farmers to adopt preventive behaviours against H7N9 infection. This study aimed to examine what elements of the knowledge were associated with poultry farmers' protection intention using the protection motivation theory (PMT). MethodsIn this cross-sectional study, using stratified random sampling method, we recruited poultry farmers from 36 villages of three cities (Suqian, Nantong, and Zhenjiang city) representing the northern, central, and southern Jiangsu Province, one of the major provinces affected by H7N9 outbreaks. We assessed H7N9 influenza-related knowledge with 25 dichotomous questions (ask for ‘know/don't know’ responses). Each element of PMT (perceived severity and vulnerability of H7N9 infection, perceived self-efficacy and response efficacy of adopting preventive behaviours) was measured using four items on a seven-point Likert scale ranging from “very strongly disagree” to “very strongly agree”. Exploratory Factor Analysis (EFA) was done to explore the types or elements of protective knowledge. We used structural equation modelling (SEM) to examine the associations between different types of knowledge and PMT constructs and protection intention. Ethical approval was given by local veterinary authorities and verbal consent was obtained from each participant before completing the survey. FindingsBetween Nov 5, 2013 and Jan 20, 2014, we recruited 297 poultry farmers (226 [76%] of whom were male; 112 farmers from Suqian, 96 from Nantong, and 89 from Zhenjiang). The EFA revealed four main knowledge types: symptoms, self-protection measures at work, basic preventive measures, and routine hygiene. The SEM showed that knowledge of symptoms (β=0·135, p=0·018) and self-protection measures at work (β=0·141, p=0·004) were positively associated with self-efficacy. Knowledge of symptoms (β=0·211, p<0·0001) and self-protection measures at work (β=0·343, p<0·0001) were also positively associated with response efficacy. Knowledge of basic preventive measures was negatively associated with perceived vulnerability (β=–0·165, p<0·001), while positively associated with self-efficacy (β=0·309, p<0·0001) and response efficacy (β=0·276, p<0·0001). Routine hygiene knowledge was positively associated with perceived vulnerability (β=0·120, p=0·013) and response efficacy (β=0·225, p<0·0001). Perceived vulnerability (β=0·312, p<0·0001), self-efficacy (β=0·129, p=0·034), and response efficacy (β=0·642, p<0·0001) were positively associated with protection intention. InterpretationDespite the limitation of small sample size from only one province, potentially under-representing the true knowledge level of poultry farmers in China, these findings reveal that different types of knowledge have various mechanisms influencing poultry farmers' intention to adopt preventive behaviours against H7N9 infection. These findings highlight the directions for intervention design for future avian influenza prevention. FundingNational Natural Science Foundation of China (71573221).