What is known about modified insects for disease prevention?: a systematic review

Nazareth, T.; Craveiro, I.; Moutinho, A.; Goncalves, C.; Goncalves, L.; Teodosio, R.; Sousa, C. A.

doi:10.1101/494849

Home/Archive/bioRxiv

bioRxiv · 10.1101/494849

What is known about modified insects for disease prevention?: a systematic review

Nazareth, T.·Craveiro, I.·Moutinho, A.·Goncalves, C.·Goncalves, L.·Teodosio, R.·Sousa, C. A.

View original source ↗Export metadata ↓

Abstract

The modification and release of insects to suppress or replace natural insect vectors constitutes a promising tool for vector control and disease prevention, facing the unprecedented global emergence of vector-borne diseases. Little is known regarding these innovative modification strategies and available evidence is not standardized turning it difficult to reflect on their actual efficacy and eventual effects.\n\nThis work conducted a systematic review, gathering and analyzing research articles from PubMed and Biblioteca Virtual em Saude databases whose results directly report efficacy and effects of the use of modified insects for disease prevention until 2016. Within more than 1500 publications that were screened a total of 349 where analyzed.\n\nA total of 12/3.4% reported field-based evidence, and 41/11.7% covered modification stretagies efficacy after insects release, their epidemiology impact or its long-term efficacy. Examples of successful results were the replacement of natural field populations by wolbachia-infected mosquitoes in 5 weeks, and the elimination of a population in laboratory cages after transgenic mosquitoes release over 10-20 weeks. Variability in the effective results were described (90/25.7%) questioning its reproducibility in different settings. We also found 38/10.9% publications reporting reversal outcomes, such as an increase of vector population after release. Ecological effects such as horizontal transfer events to non-target species (54/15.5%), and wolbachia-induced worsening pathogenesis on mammal filarial diseases (10/2.9%) were also reported.\n\nPresent work revealed promising outcomes of both suppressing and replacing approaches. However, it also revealed a need of field-based evidence mainly regarding epidemiologic and long-term impact of insect modification strategies. It pointed out some eventual irreversible and important effects that must not be ignored when considering open-field releases, and that may constitute constraints to generate the missing field evidence. Moreover, the level of variability of existing evidence suggests the need of local/specific evidence in each setting of an eventual release.\n\nAuthor summaryInnovative strategies are needed to arrest the unprecedented increase of vector-borne disease incidence, distribution and severity. Several modification techniques are being tried all over the world. However this is still an emergent topic with scarce available information and of complex understanding.\n\nPresent work is the unique structured review regarding the use of modified insects for vector-borne disease prevention, bringing neutral and robust evidence that will contribute with critical insights regarding these approaches.\n\nHere we explored more than 1200 publications and analyzed 349 publications on this subject, describing the actual efficacy and reported effects of several modification strategies. More than 30 categories were reported such as, the type of modification, the year of the publication, the species were results were tested, the type of study, and also type of Efficacy Outcome (from modification to long-term) and/or the type of Effects Outcome (from physiologic to ecologic effects). Analysis revealed promising outcomes regarding vector-control and disease prevention. However insects modification strategies still lack field-based evidence mainly regarding epidemiological and long-term efficacy. Eventual reversal outcomes on disease transmission, or irreversible biological effects (including horizontal transfer to non-target species or worsening pathogenesis in particular diseases in mammals), were also described. These effects need to be explored, dispelled or resolved before field trials occur in human residential areas. Some of these questions could only have a robust answer if these strategies would be implemented, needing to take the risk to observe reversal outcomes and/or irreversible effects. These findings reflect the big dilemma that is under the use of modified insects to prevent vector-borne diseases. Findings could support health authorities in decision-making and regulatory committees during advisory processes, by evaluating the pros/cons of each modifying technique for a particular setting. Moreover they could also summarize what is crucial to inform to communities if planning open field releases in residential areas.

Explore related subjects

ecology Preprint

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Nazareth, T., Craveiro, I., Moutinho, A., Goncalves, C., Goncalves, L., Teodosio, R., Sousa, C. A.. 2018-12-12. What is known about modified insects for disease prevention?: a systematic review. https://doi.org/10.1101/494849

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Beyond Single-Metric Assessments: Uncovering Masked Butterfly Declines via Multi-Scalar Analysis in Central Alberta

1. This study analyzed 21 years (2000-2025) of butterfly count data from Central Alberta, integrated with intensive 5-year (2021-2025) high-resolution intra-seasonal sampling. 2. Long-term macro-scale analysis revealed a significant decline in Shannon Diversity, a change that remained obscured when relying solely on traditional metrics of species richness and evenness. 3. This diversity decline was primarily driven by the severe, long-term collapse of the native Common Ringlet (Coenonympha tullia). 4. Four other dominant species--Cabbage White (Pieris rapae), Clouded Sulphur (Colias eriphyle), European Skipper (Thymelicus lineola), and Common Wood Nymph (Cercyonis pegala)--maintained long-term population stability, though their abundances were significantly constrained by extreme winter minimum temperatures and rapid spring warming. 5. High-resolution intra-seasonal analysis (2021-2025) demonstrated that community indices and species-specific abundances were strongly limited by daily weather, particularly wind velocity and temperature. 6. These findings illustrate that while traditional metrics like richness and evenness are fundamental to community ecology, they provide incomplete insights when applied in isolation; they are most effective when utilized as part of a complementary, multi-scalar framework. 7. This study highlights the necessity of coupling multi-decadal historical datasets with high-frequency, fine-scale sampling to accurately identify the mechanisms of community turnover that simpler metrics may overlook. 8. The results underscore the critical importance of standardized citizen science monitoring in quantifying environmental impacts and establishing conservation priorities for terrestrial insect groups.

ecology↗

bioRxiv2026

From concentration to export: resource contrasts and bee traits shape pollinator spillover to crops

Floral plantings can either concentrate bees or export them to adjacent crops, yet the ecological conditions influencing these outcomes remain unclear. Here, we develop a mathematical model as proof of concept for our previous integrative hypothesis: concentrator and exporter outcomes can arise as alternative, context-dependent outcomes of the same underlying resource-selection process. Using bees as a model and focusing specifically on spillover from floral plantings to crops, we identified resource-specific thresholds separating concentration- and export-favoring conditions. Our model translates differences in relative patch attractiveness into context-dependent concentration and export outcomes and generates resource-specific, testable predictions about the conditions favoring pollinator movement into crops. In our simulations, the concentrator-exporter transition occurred at a lower flowering-intensity contrast than at pollen or nectar contrasts, which suggests that flowering intensity may provide an initial cue for bee movement, whereas nectar and pollen rewards refine or sustain bee responses once crops are perceived as attractive. Spillover thresholds differed among resource contrasts, whereas response steepness varied across bee-trait and community scenarios. Under the model's trait-sensitivity formulation, predicted spillover probability responded more strongly to flowering contrast for specialists than for generalists; colony size amplified this response, whereas bee richness dampened it. Together, these patterns show how flowering and resource contrasts interact with bee traits and community context to shape predicted spillover. Our results confirm that the concentrator and exporter hypotheses can be understood as context-dependent outcomes of the same ecological process rather than as mutually exclusive alternatives. Experimental tests of the predicted thresholds conducted in the field could reveal when and where floral plantings are most likely to promote bee spillover to crops, potentially supporting crop pollination.

ecology↗

bioRxiv2026

A Computational Re-evaluation of Spatial Trials for Zoonotic Tuberculosis Control: Model Misspecification, Diagnostic Miss-classification, and the Illusion of Wildlife Culling Efficacy

1. Wildlife reservoir management frequently relies on the Randomised Badger Culling Trial's (RBCT) trade-off hypothesis, which posits that reductions in cattle herd infections are offset by a perturbation effect driven by disrupted host dispersal. This paper evaluates the computational and epidemiological robustness of this historical trial, which serves as the foundational empirical experiment guiding zoonotic tuberculosis (Mycobacterium bovis) control policies. 2. Using generalized linear mixed models with a generalized Poisson error distribution to explicitly address historical data overdispersion, this study contrasts traditional parametric inference against exact cluster-constrained permutation tests across distinct operational definitions of disease incidence. 3. Non-parametric diagnostics reveal that previously reported treatment and perturbation effects render as statistical artifacts under exact non-parametric permutation. Inside culling zones, parametric significance fails to withstand exact permutation verification due to extreme data leverage in localized cluster blocks. 4. Crucially, when diagnostic misclassification biases are eliminated by analysing total reactor datasets, all apparent culling effects disappear, and information criteria overwhelmingly favour nested null architectures. Unconfirmed reactors likely represent true biological infections missed by low-sensitivity post-mortem macro-necropsy, proving that host removal tracks observation noise rather than genuine zoonotic transmission pathways. 5. Finally, empirical scaling conducted in this study identifies a novel mathematical saturation effect, demonstrating that this sub-linear scaling is an operational artifact of unmodelled herd-level disease recurrence over time. 6. Policy implications. Because current zoonotic tuberculosis intervention frameworks are built upon a structurally misspecified statistical model, they have driven large-scale veterinary policies resulting in substantial, unevidenced ecological and economic interventions while failing to provide genuine public health, animal health, or disease control benefits.

ecology↗