Multi-Species Patterns of Avian Cholera Mortality in Nebraska's Rainwater Basin

Abstract

ABSTRACT:Nebraska's Rainwater Basin (RWB) is a key spring migration area for millions of waterfowl and other avian species. Avian cholera has been endemic in the RWB since the 1970s and in some years tens of thousands of waterfowl have died from the disease. We evaluated patterns of avian cholera mortality in waterfowl species using the RWB during the last quarter of the 20th century. Mortality patterns changed between the years before (1976)(1977)(1978)(1979)(1980)(1981)(1982)(1983)(1984)(1985)(1986)(1987)(1988) and coincident with (1989)(1990)(1991)(1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)) the dramatic increases in lesser snow goose abundance and mortality. Lesser snow geese (Chen caerulescens caerulescens) have commonly been associated with mortality events in the RWB and are known to carry virulent strains of Pasteurella multocida, the agent causing avian cholera. Lesser snow geese appeared to be the species most affected by avian cholera during 1989-1999; however, mortality in several other waterfowl species was positively correlated with lesser snow goose mortality. Coincident with increased lesser snow goose mortality, spring avian cholera outbreaks were detected earlier and ended earlier compared to [1976][1977][1978][1979][1980][1981][1982][1983][1984][1985][1986][1987][1988]. Dense concentrations of lesser snow geese may facilitate intraspecific disease transmission through bird-to-bird contact and wetland contamination. Rates of interspecific avian cholera transmission within the waterfowl community, however, are difficult to determine.

Characterisation and comparison of avian Pasteurella multocida strains by conventional and ERIC-PCR assays

“…2). The simultaneous presence of certain clones in a wide variety of avian species verifies the possibility of cross-infection between different host species (Blanchong et al, 2006).…”

Pasteurella multocida: from Zoonosis to Cellular Microbiology

“…P. multocida is a common commensal or opportunistic pathogen found in the upper respiratory tracts of most livestock, domestic, and wild animals (34), including chickens (126)(127)(128)(129)(130)(131), turkeys (132,133), and other wild birds (123,(134)(135)(136)(137)(138)(139)(140)(141)(142)(143)(144), cattle and bison (121,(145)(146)(147), swine (34, 148-151), rabbits (152)(153)(154), dogs (41, [155][156][157], cats (domestic house cats as well as large wild cats, such as tigers, leopards, cougars, and lions) (39, 42-46, 49, 157-166), goats (125,139,167,168), chimpanzees (169), marine mammals (seals, sea lions, and walruses) (170), and even komodo dragons (171,172). The manifestation and pathological symptoms associated with Pasteurella infection, or "pasteurellosis," range from asymptomatic or mild chronic upper respiratory inflammation to acute, often fatal, pneumonic and/or disseminated disease.…”

Using Amplified Fragment Length Polymorphism Analysis to Differentiate Isolates of Pasteurella Multocida Serotype 1

“…Analyses to determine whether the observed genetic changes among the P. multocida isolates examined affected functional properties (e.g., virulence) of the bacteria were beyond the scope of this project. However, genome plasticity may enhance a bacterium's ability to adapt to diverse natural environments (Earl et al, 2007), and genetic change leading to fluctuations in P. multocida virulence levels provides a possible mechanism to explain observed temporal variations in North American P. multocida restriction enzyme fingerprints (Wilson et al, 1995b;Samuel et al, 2003b) and avian cholera mortality patterns Blanchong et al, 2006). Unlike previously employed techniques for differentiating P. multocida serotype 1 isolates, including restriction enzyme (Wilson et al, 1995a, b;Samuel et al, 2003b) and serotyping (Rhoades and Rimler, 1991) analyses, AFLP analysis does not currently allow the ready assignment of isolates to predefined groupings.…”

“…Most pathogenic P. multocida isolates cultured from wild waterfowl in the Pacific, Central, and Mississippi flyways of North America are serotype 1 (Botzler, 1991). There have been significant annual and geographic fluctuations in the patterns of avian cholera mortality among wild bird species, and factors influencing the initiation and the course of an avian cholera outbreak are not well understood (Rosen, 1969;Wobeser, 1992;Blanchong et al, 2006;Samuel et al, 2007).…”