Giardia duodenalis in feedlot cattle from the central and western United States

<p>Abstract</p> <p>Background</p> <p><it>Giardia duodenalis </it>is a ubiquitous protozoan parasite that has emerged as a significant opportunistic human pathogen. <it>G. duodenalis </it>may have a deleterious effect on animal growth and performance, therefore its potential as a production limiting organism should not be discounted. We therefore undertook this study to determine management and environmental factors in feedlots that influence the prevalence and environmental load of <it>G. duodenalis </it>cysts in fecal material deposited by feedlot cattle in the central and western United States.</p> <p>Results</p> <p>Twenty two feedlots from 7 states were included in the study, and up to 240 fecal samples were collected from pen floors of up to 6 pens per feedlot. <it>Giardia duodenalis </it>cysts were identified and counted using direct immunofluorescent microscopy. The estimated overall point prevalence of <it>G. duodenalis </it>was 19.1%, representing feedlots from a wide range of climates and management systems. Pen-level prevalence varied from 0 to 63.3%, with pen-level shedding estimates ranging from 0 to 261,000 cysts/g feces. Higher environmental temperatures, increased animal density, and increased time in the feedlot were associated with a lower prevalence of <it>G. duodenalis</it>. Removing manure before placing a new group of cattle in a pen was associated with a decreased prevalence of <it>G. duodenalis </it>in fecal pats. Using coccidiostats as a feed additive was associated with a higher prevalence of <it>Giardia</it>.</p> <p>Conclusion</p> <p>Management practices could be employed that would limit the probability that feedlot cattle shed <it>G. duodenalis </it>in their feces and therefore potentially limit contamination of their environment.</p

Risk for Avian Influenza Virus Exposure at Human–Wildlife Interface

To assess risk for human exposure to avian influenza viruses (AIV), we sampled California wild birds and marine mammals during October 2005–August 2007and estimated human–wildlife contact. Waterfowl hunters were 8 times more likely to have contact with AIV-infected wildlife than were persons with casual or occupational exposures (p<0.0001)

Risk for avian influenza virus exposure at human-wildlife interface.

To assess risk for human exposure to avian influenza viruses (AIV), we sampled California wild birds and marine mammals during October 2005-August 2007 and estimated human-wildlife contact. Waterfowl hunters were 8 times more likely to have contact with AIV-infected wildlife than were persons with casual or occupational exposures (p&lt;0.0001)

AS-627-04 Resolution on Establishment of an Institute for Policy Research

Endorses the proposal to establish the Institute for Policy Research

Influenza A Viruses in Wild Birds of the Pacific Flyway, 2005–2008

Avian influenza viruses (AIVs) pose a significant threat to public health, and viral subtypes circulating in natural avian reservoirs can contribute to the emergence of pathogenic influenza viruses in humans. We investigated the prevalence and distribution of AIVs in 8826 migratory and resident wild birds in North America along the Pacific flyway, which is a major north–south migration pathway that overlaps with four other flyways in Alaska providing opportunities for mixing of Eurasian and American origin influenza viruses. Overall, the prevalence of AIVs was low (1%) among the wide range of avian species tested, but we detected AIVs in 69 hunter-harvested waterfowl (Anseriformes) sampled at a national wildlife refuge in California from October 2007 to January 2008. A wide range of subtypes were detected in waterfowl with H6N1, H10N7, H7N3, and H3N5 being the most common. We suspect H6N1 was introduced or remerged in 2007 at this key wintering site for waterfowl along the Pacific Flyway. Over a 3-week period, 13 H6N1 AIVs were isolated from two northern pintails (Anas acuta), three northern shovelers (Anas clypeata), three ring-necked ducks (Aythya collaris), four American widgeon (Anas americana), and one gadwall (Anas strepera). We conclude that a diverse array of AIVs was present and that cross-species transmission was occurring among waterfowl in the central valley wetlands of California

Epidemiology of a Phocine Distemper Virus Outbreak Along the North Atlantic Coast of the United States

Due to an increase in pinniped strandings with consistent pathological findings throughout the North Atlantic coast of the United States during the summer and fall of 2006, an unusual mortal- ity event (UME) was declared by the National Oceanic and Atmospheric Administration's (NOAA) National Marine Fisheries Service (NMFS) on 20 October 2006. The goals of this investigation were to describe the magnitude and duration of the peak in mortalities involved in the UME and to evaluate associations with potential causative agents. Seal strandings during the UME were compared to historical strandings in the area to characterize the epidemiologic pat- terns of the UME. Temporal increases in phocine distemper virus (PDV) prevalence as detected by serology and polymerase chain reaction (PCR) were significantly correlated with increased seal stranding frequency. During July to October 2006, there was a significant spatial and tempo- ral cluster of PDV positive seals centered near Cape Ann, Massachusetts. Our findings provide evidence that PDV infections increased in harbor seals along the North Atlantic coast of the U.S. in 2006, and PDV likely played a role in a UME that involved harbor seals (Phoca vitulina), harp seals Phoca groenlandica), hooded seals (Cystophora cristata), and gray seals (Halichoerus grypus)