ABSTRACT
Superspreading, the phenomenon where a small proportion of individuals contribute disproportionately to new infections, has profound effects on disease dynamics. Superspreading can arise through variation in contacts, infectiousness or infectious periods. The latter has received little attention, yet it drives the dynamics of many diseases of critical public health, livestock health and conservation concern. Here, we present rare evidence of variation in infectious periods underlying a superspreading phenomenon in a free-ranging wildlife system. We detected persistent infections of Mycoplasma ovipneumoniae, the primary causative agent of pneumonia in bighorn sheep (Ovis canadensis), in a small number of older individuals that were homozygous at an immunologically relevant genetic locus. Interactions among age-structure, genetic composition and infectious periods may drive feedbacks in disease dynamics that determine the magnitude of population response to infection. Accordingly, variation in initial conditions may explain divergent population responses to infection that range from recovery to catastrophic decline and extirpation.
Subject(s)
Pneumonia, Mycoplasma/veterinary , Sheep Diseases/epidemiology , Sheep, Bighorn , Animals , Animals, Wild , Mycoplasma ovipneumoniae , Pneumonia , SheepABSTRACT
The effectiveness of previously untested disaster plans was demonstrated during the aftermath of the crash of Delta Airlines Flight 191 at D/FW International Airport on Friday, August 2, 1985. These plans, in effect for years and subjected to periodic review, were as yet untried before this first disaster at D/FW International since tsl opening. This paper outlines the disaster plans, the actual problems encountered, the logistics of a disaster of this kind, and insights gained from the experience
