Rodent control strategies and Lassa virus: some unexpected effects in Guinea, West Africa.

The Natal multimammate mouse () is the host of Lassa mammarenavirus, causing Lassa haemorrhagic fever in West Africa. As there is currently no operational vaccine and therapeutic drugs are limited, we explored rodent control as an alternative to prevent Lassa virus spillover in Upper Guinea, where the disease is highly endemic in rural areas. In a seven-year experiment, we distributed rodenticides for 10-30 days once a year and, in the last year, added intensive snap trapping for three months in all the houses of one village.

Rodent control to fight Lassa fever: Evaluation and lessons learned from a 4-year study in Upper Guinea.

Lassa fever is a viral haemorrhagic fever caused by an arenavirus. The disease is endemic in West African countries, including Guinea. The rodents Mastomys natalensis and Mastomys erythroleucus have been identified as Lassa virus reservoirs in Guinea.

Negative impact of urban habitat on immunity in the great tit Parus major.

Urban habitats are described as having an overall negative influence on many fitness-related traits in several bird species, but a vital function such as immunity remains poorly studied. The immune response is strongly linked to individual condition, which partly depends on resource availability and the parasitic context that often differ between urban and natural habitats. A difference between the immunity of populations dwelling in urban areas and populations from more natural habitats can, therefore, be hypothesized.

Iophenoxic acid derivatives as markers of oral baits to wildlife. New tools for their detection in tissues of a game species and safety considerations for human exposure.

The bait-marker iophenoxic acid (IPA) and its derivatives are increasingly used for evaluating and optimizing the cost-effectiveness of baiting campaigns on wildlife, particularly on game species such as the wild boar. We aimed to determine whether concentrations of the three main IPA derivatives ethyl, methyl and propyl-IPA measured on thoracic liquid extracts (TLE) of hunted wild boars may be representative of two exposure doses, 40 and 200 mg, from 20 to 217 days after ingestion. Then we developed a method of detection of the three IPA derivatives by LC/ESI-MS-MS in muscle and liver to evaluate the suitability of these two other tissues for monitoring the marked bait consumption and for measuring available residues in the meat of marked animals.

Determination of bromadiolone residues in fox faeces by LC/ESI-MS in relationship with toxicological data and clinical signs after repeated exposure.

In many countries, the fox (Vulpes vulpes), predator of small mammals, is particularly affected by anticoagulant rodenticides such as bromadiolone due to secondary poisoning. Nevertheless, to date, no method of exposure monitoring is applicable in the field over large areas, and no toxicological data are available concerning sensitivity of foxes to bromadiolone. The aim of this work was to compare excretion kinetics of bromadiolone in fox faeces with clinical and haemostatic effects after repeated exposure to intoxicated voles.

Kinetics of bromadiolone in rodent populations and implications for predators after field control of the water vole, Arvicola terrestris.

We document the kinetics of bromadiolone in two rodent populations after a field control of water voles, and their implications for predator exposure. Water voles and common voles were trapped aboveground and underground from 1 to 135 days after bromadiolone treatment in the field. Livers, digestive tracts, and rests of the body were analyzed separately.

How environment and vole behaviour may impact rodenticide bromadiolone persistence in wheat baits after field controls of Arvicola terrestris?

We aimed to evaluate whether environmental factors affect the persistence of bromadiolone in baits in field treatment. Baits were distributed in three soils according to two types of distribution: (1) artificial galleries conform to agricultural practices; (2) storage cavities to mimic bait storage by voles. Persistence was evaluated for 30 days in galleries and 80 days in storage cavities in autumn and spring.