Contact rates and exposure to inter-species disease transmission in mountain ungulates

Abstract

The risk for a pathogen to cross the species barrier depends on the rate of efficient contacts between the species. However, contact rates between species have rarely been estimated from observations. Here we estimate contact rates and exposure of chamois Rupicapra rupicapra and Alpine ibex Capra ibex exposed to domestic pasteurellosis and brucellosis carried by sheep or cattle herds summering in mountain pastures. We use field observation data on animal positions treated in a geographic information system (GIS). Comparing 10 pastures, we show that the management of domestic herds influences the risk of inter-species transmission. Exposure to direct transmission of pasteurellosis is high when herds are not guarded nor enclosed, whereas exposure to indirect transmission of brucellosis is increased on epidemiological dangerous points such as salt deposits. Our preliminary results need further investigation, but they underline the importance of both herd management and pathogen transmission mode when the aim is to reduce the risk of contamination of wild populations by a pathogen associated with domestic pathogens.

Effect of domestic sheep on chamois activity, distribution and abundance on sub-alpine pastures

“…The chamois used a saltlick in the southern part of the Fochsenflue throughout the day and this saltlick, although accessible, was not used by the sheep. Our findings contrast with other research 312 which found that saltlicks represented locations with high rates of interspecific encounters (Degiorgis et al 2002;Richomme et al 2006). The best method to avoid possible encounters at saltlicks would be to remove saltlicks from an area.…”

“…Flies may play a role in interspecific transmission of M. conjunctivae and they can also cause avoidance behaviour in ungulates (Degiorgis et al 1999;Fauchald et al 2007). Although chamois generally avoid sheep, the available evidence suggests that they often meet at places such as 75 saltlicks, and therefore these locations may provide conditions where disease transmission is more likely to occur (Degiorgis et al 2002;Pépin and N'Da 1991;Rebollo et al 1993;Richomme et al 2006). …”

Acute Die-off of Chamois (Rupicapra rupicapra) in the Eastern Austrian Alps due to Bacterial Bronchopneumonia withPasteurellaceae

“…As has been shown elsewhere (Richomme et al 2006), interspecific transmission of pathogens such as Pasteurella spp. is increased when mountain ungulates and domestic ungulates are allowed to move freely.…”

The diagnostic activity on wild animals through the description of a model case report (caseous lymphadenitis by <i>Corynebacterium pseudotuberculosis</i> associated with <i>Pasteurella</i> spp and parasites infection in an alpine ibex –<i>Capra ibex</i>)

“…As regards the antibiotic-resistance, the strain was sensitive to all classes of antimicrobials, in particular beta-lactam antibiotics which are the molecules of greater use for the treatment of pseudotuberculosis in domestic animals. In the lungs, two species of Pasteurellaceae were isolated; Pasteurella multocida and Mannheimia haemolytica, that reported by numerous authors and frequently found in wild ungulates (Richard et al, 1992;González-Candela et al, 2006;Richomme et al, 2006). Based on our experience (personal unpublished data), acquired mainly on the pneumonia of wild alpine ruminants (chamois and secondly roe deer, ibex and deer), Mannheimia haemolityca is more involved.…”