Ziekten, plagen en zoönoseverwekkers in de insectenteelt

Samenvatting

Insect farming as new livestock sector has grown rapidly in recent years, both in terms of production volumes and the number of farms. Veterinary and public health risks have so far been understudied. The goal of this policy supporting (BO) research project commissioned by the Ministry of Agriculture, Nature and Food Quality (LNV) is to gain insight into the occurrence of diseases, pests and potential zoonotic pathogens in insect farming in the Netherlands. In addition, this project aims to gain insight into hygiene measures and possible prevention and treatment methods on insect farms, and associated risks. In this project, interviews were held with 11 insect farmers in the Netherlands (mealworm, BSF larvae) and 7 experts involved in insect farming, with questions about presence of, and (preventive) measures against, infectious diseases, fungal diseases, parasitic diseases, pests; internal and external hygiene measures; use and effectiveness of veterinary treatments. In addition, samples of larvae and frass were collected (2 to 7 samplings) at 10 insect farms. Each sample was analyzed by culturing for the presence of Salmonella enterica, Listeria monocytogenes, Campylobacter spp. In addition, 1 or 2 larvae and frass samples per farm were analyzed by nanopore sequencing (Pathosense) for semi-quantitative analysis of the presence of bacteria and viruses. Following the results from the interviews and sampling, additional literature review and risk assessment was conducted. The interviews revealed that farmers have little to no experience with infectious and parasitic diseases, although abnormalities or mortality are seen in practice. Farmers have varying degrees of experience with fungi and pests. Diagnostic tests are barely done. The use of hygiene measures and personal protective equipment varies widely, as does the source of information on which these measures are based. The measures applied are mainly general (preventive) measures. Almost no chemical treatments are used in the insect sector. In the 141 samples (larvae and frass) from 10 farms (min 8 - max 25 per farm) no Salmonella enterica, Campylobacter spp. or Listeria monocytogenes were detected. A semi-quantitative analysis based on nanopore sequencing was done in 23 samples (larvae and frass), in which no viruses with possible zoonotic potential were identified. The bacteria with possible zoonotic potential are mostly present in low amounts, and include bacteria known as environmental bacteria or bacteria that can cause food infection, for which processing in the chain is relevant for exposure of the consumer. A number of recommendations are included in this report. Further (field) research is needed on the occurrence, transmission and risks of the pathogens with possible zoonotic potential or impact on insect health. It is recommended to build and share more knowledge on insect health, treatment options and meaningful preventive measures for healthy and safe (food) production. In addition, research on the occurrence of health problems among insect farmers is desired.