Rodent control to fight plague: field assessment of methods based on rat density reduction

Abstract

Rodents represent a serious threat to food security and public health. The extent to which rodent control can mitigate the risk from rodent-borne disease depends on both the effectiveness of control in reducing rodent abundance and the impact on disease epidemiology. Focusing on a plague-endemic region of Madagascar, this study compared the effectiveness of 3 methods: live-traps, snap-traps, and rodenticides. Control interventions were implemented inside houses between May and October 2019. Tracking tiles monitored rodent abundance. Rodent fleas, the vector involved in plague transmission, were collected. Rodent populations consisted of Rattus rattus and Mus musculus. In terms of trap success, we found that our live-trap regime was more effective than snap-traps. While all 3 control strategies appeared to reduce in-house rodent activity in the short term, we found no evidence of a longer-term effect, with in-house rodent abundance in treated sites comparable to non-treatment sites by the following month. Endemic flea, Synopsyllus fonquerniei, is a key plague vector usually found on rats living outdoors. Although we found no evidence that its abundance inside houses increased following control, this may have been due to a lack of power caused by significant variation in S. fonquerniei abundance. The presence of S. fonquerniei in houses was more likely when S. fonquerniei abundance on outdoor rats was higher, which in turn correlated with high rat abundance. Our results emphasize that control strategies need to consider this connectivity between in-house rat-flea populations and the outdoor populations, and any potential consequences for plague transmission.

Synergistic effects of EP‐1 and ivermectin mixture (iEP‐1) to control rodents and their ectoparasites

“…2 There is an urgent need to control rodent populations in order to reduce the risk of plague occurrence as well as other rodentborne diseases. 3 Traditional culling of rodents with rodenticides has been widely used to reduce their number, but it often suffers from various setbacks such as rapid population recovery after poisoning, high risk to non-target animals and are against some people's beliefs. 4 In addition to causing high mortality in rodents, it increases the loads of flea or tick on the surviving population of rodents.…”

“…In recent years, the risk of plague outbreaks has been increasing due to climate change and human activities 2 . There is an urgent need to control rodent populations in order to reduce the risk of plague occurrence as well as other rodent‐borne diseases 3 …”

Influence of grazing on the activity pattern and temporal niche of two dominant rodent species in Alxa desert

“…Animal behaviour underlies many critical ecological functions, including nutrient cycling, primary productivity, pathogen transmission and habitat provision (Gribben et al, 2009;Barber and Dingemanse, 2010;Palkovacs and Dalton, 2015;Fernandes et al, 2020;Rahelinirina et al, 2021). While every species is inherently linked to ecosystem function, keystone species or ecosystem engineers are far more critical for overall ecosystem function than other species (Wilson et al, 2020).…”

It’s a trap: effective methods for monitoring house mouse populations in grain-growing regions of south-eastern Australia

“…Many studies use trapping or other indexes to monitor rodent populations, with some data being used to assess potential damage to crops or to assess disease risk (e.g. Stenseth et al 2003;Whisson et al 2005;Singleton et al 2010;Jones et al 2017;Swanepoel et al 2017;Rahelinirina et al 2021;Wang et al 2021). Good estimates of pest rodent population size relative to damage thresholds are necessary to guide management decisions, and determine the success of control or management operations Kaboodvandpour and Leung 2012).…”