Over the last few decades, various methods have been continuously developed to provide evidence of the presence or absence of diseases, such as the risk-based surveillance. At the same time, digital technologies are transforming veterinary practice, offering new possibilities for improving diagnoses and communication between professionals and farmers. The use of smartphones and social media during visits to farms has shown good potential as a tool for improving the animal health services provided by veterinarians. However, the potential of smartphone messaging apps as a tool to help aquatic animal disease surveillance programs is still little explored. The objectives of the study were to evaluate the functionality and effectiveness of a monitoring and communication system (MCS) for smartphones as an auxiliary component in surveillance programs aimed at estimating the frequency of notifiable diseases in tilapia and to compare the results with traditional passive surveillance methods.
All commercial tilapia farms registered with the OVS/DF (n=112) took part in this study, divided into three different commercial groups: i) breeding, larviculture or alevin sales farms (n=8); ii) closed and semi-closed fattening farms (n=77); and iii) recreational fishing farms (pay-to-fish) (n=27). Participants were previously sensitized to instantly report any atypical health events involving tilapia, such as high mortality, or just the observation of moribund tilapias. The messaging and social media application WhatsApp® (Meta Platforms, Inc., USA) was used. For all farmers, automatic messages were sent every two weeks reminding them to participate in the study. Among the options requested by the message, the farmer could type "1" in the event of an atypical health event or "2" in the absence of health events. Each time a positive report was made, the farm was visited immediately to collect of samples and diagnosis of the afection.
Twenty-seven communications/samples were taken from a total of 25 different production units (22.32%) that presented some atypical event in tilapia production. It was observed that the proportion of reports of atypical health events was higher at hatcheries and alevin sales farms (75.0%; 6/8), followed by pay-to-fish farms (22.2%; 6/27) and commercial fattening farms (19.5%; 15/77). With regard to communications/collections, 20 (74.1%; 20/27) were carried out in the autumn and winter months. The cause of mortality was confirmed in most cases (22/27; 81.48%), based on clinical, anatomopathological, parasitological, molecular, environmental and physico-chemical analyses of the pond water. The information and photos sent by the producers via the app in each case helped to direct clinical suspicions, as well as facilitating quick technical visits. As for the number of positive farms, the results were as follows: ISKNV=1 and Francisella orientalis=2. The results of the study revealed that the MCS method, although simple, was easy to execute, extremely practical and allowed for rapid decision-making by the technicians involved in diagnosing diseases. This method was considered an effective component for disease surveillance, with advantages over traditional passive and active surveillance components.