Mette Frimodt Hansen

With the rollback of insecticides, novel tools for pest control are urgently needed. Aphids are particularly a major concern with few sustainable control alternatives. Ecological intensification has been promoted as a way of “inviting" back nature’s self-regulating abilities into agricultural production systems. Although such measures enhance the presence of natural enemies in agroecosystems, we demonstrate that in an ecologically intensified apple orchard, biocontrol of rosy apple aphid was minimal. We verified why the biodiverse settings did not result in enhanced ecosystem services, i.e., biological control of the rosy apple aphid. Close monitoring of food–web interactions in thousands of aphid colonies showed that tending ants dominated responses, while those of natural enemies were weak or absent. However, application of artificial aphid honeydew diverted ants from tending aphids and flipped the myrmecophily-dominated state into favoring numerical responses of a guild of natural enemies. Responses were swift and controlled both Aphis pomi and Dysaphis plantaginea, provided intervention was synced with aphid and predator phenology. Although myrmecophily in aphids is well-known on its own accord, it has been completely overlooked in ecological intensification. To unlock the aphid-biocontrol potential provided through ecological intensification, myrmecophily needs to be disrupted. Although particularly true for perennial systems, generally practices that reduce soil disturbance favor ants and may amplify aphid pests, thereby reducing biocontrol impacts in ecological intensification efforts. Harnessing ecosystem services requires careful analysis and good understanding of agroecosystem intricacies.

Background: Cases of reported tick-borne diseases in humans have increased over the past decades. Strategies informing the public about ticks, their associated diseases, and preventive measures are often highlighted as important in limiting pathogen transfer and disease. However, knowledge about the motivation for people to apply preventative measures is sparse. Methods: The aim was to examine if Protection Motivation Theory, a model of disease prevention and health promotion, can predict the use of protective measures against ticks. Ordinal logistic regression and Chi-square tests were used on data from a cross-sectional survey with respondents from Denmark, Norway, and Sweden (n = 2658). We examined the effect of (1) the perceived seriousness of tick bites, Lyme borreliosis (LB), and tick-borne encephalitis (TBE), and (2) the perceived probability of getting a tick bite, Lyme borreliosis, and tick-borne encephalitis on protection against ticks. Finally, we examined if there was an association between the use of a protective measure and the perceived efficacy of that measure. Results: The perceived seriousness of a tick bite and LB significantly predict who is more likely to apply protective measures for all three countries combined. The perceived seriousness of TBE did not significantly predict the level of adoption of protective measures applied by respondents. The perceived likelihood of getting a tick bite within the next 12 months and the perceived likelihood of getting LB if bitten by a tick significantly predicted the application of protective measures. However, the increases in the likelihood of protection were very small. The application of a certain type of protection was always correlated with the perceived efficacy of the same protective measure. Conclusion: Some variables of PMT may be used to predict the level of adoption of protection applied against ticks and tick-borne diseases. We found that the perceived seriousness of a tick bite and LB significantly predict the level of adoption protection. The perceived likelihood of getting a tick bite or LB also significantly predicted the level of adoption of protection, although the change was very small. The results regarding TBE were less clear. Lastly, there was an association between applying a protective measure and the perceived efficacy of the same measure.

Background: The tick-borne bacterium, Neoehrlichia mikurensis (N. mikurensis) can cause severe febrile illness and thromboembolic complications in immunocompromised individuals. We investigated the presence of N. mikurensis DNA in retrospectively collected plasma from a well-characterized cohort of Danish immunocompromised patients. Methods: Plasma samples from 239 patients with immune dysfunction related to hematological or rheumatological disease or due to immunosuppressive therapy, were retrieved from a transdisciplinary biobank (PERSIMUNE) at Rigshospitalet, Copenhagen, Denmark. Serving as immunocompetent controls, plasma samples from 192 blood donors were included. All samples were collected between 2015 and 2019. Real-time PCR targeting the groEL gene was used to detect N. mikurensis DNA. Sequencing was used for confirmation. Borrelia burgdorferi sensu lato IgG antibodies were detected by ELISA as a proxy of tick exposure. Prevalence was compared using Fisher’s exact test. Results: Neoehrlichia mikurensis DNA was detected in 3/239 (1.3%, 95% confidence interval (CI): 0.3 – 3.6%) patients, all of whom primarily had a hematological disease. Follow-up samples of these patients were negative. N. mikurensis DNA was not detected in any of the blood donor samples. IgG antibodies against B. burgdorferi s.l. were detected with similar prevalence in immunocompromised patients and blood donors, i.e., 18/239 (7.5%, 95% CI: 4.8–11.5%) and 11/192 (5.7%, 95%: CI 3.2–10.0%). Conclusion: In this study, patients with N. mikurensis were not identified by clinical indication and N. mikurensis may therefore be underdiagnosed in Danish patients. Further investigations are needed to explore the clinical significance and implications of this infection.