Do animal exhibitors support and follow recommendations to prevent transmission of variant influenza at agricultural fairs? A survey of animal exhibitor households after a variant influenza virus outbreak in Michigan.

Influenza A viruses circulate in swine and can spread rapidly among swine when housed in close proximity, such as at agricultural fairs. Youth who have close and prolonged contact with influenza-infected swine at agricultural fairs may be at increased risk of acquiring influenza virus infection from swine. Animal and human health officials have issued written measures to minimize influenza transmission at agricultural exhibitions; however, there is little information on the knowledge, attitudes, and practice (KAP) of these measures among animal exhibitors. After an August 2016 outbreak of influenza A(H3N2) variant ("H3N2v") virus infections (i.e., humans infected with swine influenza viruses) in Michigan, we surveyed households of animal exhibitors at eight fairs (including one with known H3N2v infections) to assess their KAP related to variant virus infections and their support for prevention measures. Among 170 households interviewed, most (90%, 151/167) perceived their risk of acquiring influenza from swine to be low or very low. Animal exhibitor households reported high levels of behaviours that put them at increased risk of variant influenza virus infections, including eating or drinking in swine barns (43%, 66/154) and hugging, kissing or snuggling with swine at agricultural fairs (31%, 48/157). Among several recommendations, including limiting the duration of swine exhibits and restricting eating and drinking in the animal barns, the only recommendation supported by a majority of households was the presence of prominent hand-washing stations with a person to monitor hand-washing behaviour (76%, 129/170). This is a unique study of KAP among animal exhibitors and highlights that animal exhibitor households engage in behaviours that could increase their risk of variant virus infections and have low support for currently recommended measures to minimize infection transmission. Further efforts are needed to understand the lack of support for recommended measures and to encourage healthy behaviours at fairs.

Epidemiologic and surveillance studies on avian influenza in live-bird markets in New York and New Jersey, 2001.

In 2001, all 109 retail live-bird markets (LBMs) in New York and New Jersey were surveyed for the presence of avian influenza virus (AIV) by a real time reverse transcriptase/polymer chain reaction assay (RRT/PCR) and results compared to virus isolation (VI) in embryonating chicken eggs. The RRT/PCR had a 91.9% sensitivity and 97.9% specificity in detecting presence of AIV at the market level. However, the sensitivity at the sample level is 65.87%. The RRT/PCR is a reliable method to identify AIV at the market level. In addition, a cross-sectional epidemiologic study of the LBMs showed that, during the past 12 months, markets that were open 7 days per week and those that also sold rabbits had the highest risk for being positive for AIV. Markets that were closed one or more days per week and those that performed daily cleaning and disinfecting had the lowest risk for being AIV positive.

Development of multiplex real-time RT-PCR as a diagnostic tool for avian influenza.

A multiplex real-time reverse transcriptase-polymerase chain reaction (RRT-PCR) assay for the simultaneous detection of the H5 and H7 avian influenza hemagglutinin (HA) subtypes was developed with hydrolysis type probes labeled with the FAM (H5 probe) and ROX (H7 probe) reporter dyes. The sensitivity of the H5-H7 subtyping assay was determined, using in vitro transcribed RNA templates, to have a reproducible detection limit for H7 of approximately 10(4) HA gene copies and approximately 10(4)-10(5) HA gene copies of H5. A direct comparison of H5-H7 multiplex RRT-PCR with hemagglutination inhibition (HI) was performed with 83 AI RRT-PCR and virus isolation positive tracheal and cloacal swab samples obtained from various avian species and environmental swabs from live-bird markets in New York and New Jersey. Both multiplex RRT-PCR and HI agreed on the subtype determination of 79 (95.2%) of the 83 samples, of which 77 were positive for H7 and two were determined to be non-H5/non-H7 subtypes. No samples were determined to be the H5 subtype by either assay.

Low-pathogenicity avian influenza virus in live bird markets--what about the livestock area?

Low-pathogenic avian influenza virus (AV) continues to be isolated from the live bird markets (LBMs) in the Northeasten United States. Recent years have seen increasing numbers of these markets opening and an expansion of the type of animals they sell in conjunction with traditional live poultry. Specific-pathogen-free chickens were released into the livestock area of 13 New York City LBMs and then tested for evidence of AIV. We were able to recover virus or demonstrate seroconversion among the chickens introduced to four of the markets.

Isolation of Salem virus, a novel equine paramyxovirus, and assessment of its etiologic role in a disease outbreak.

Salem virus (SalV) is a recently identified equine virus belonging to the family Paramyxoviridae. The only known isolate was obtained from a horse that was involved in a disease outbreak of undetermined nature and the circumstances of its isolation suggested an etiologic role. However, the experimental infection of a colostrum-deprived foal failed to reproduce the disease; only mild neutropenia and temperature elevation were recorded. An additional attempt to establish an etiological relationship with the disease was made by conducting a retrospective evaluation of the serological profiles of animals involved in the outbreak. Animals reported as being affected by the disease according to a comprehensive United States Department of Agriculture (USDA) database were found to be 48% (n=27) positive for antibodies to SalV, but the percent positive for all horses, affected and unaffected, was actually higher at 56% (n=62). For 15 affected horses for which paired acute and convalescent serum specimens were available, no unequivocal seroconversions to SalV were identified. Furthermore, the horse from which SalV was isolated was not listed as one of the animals affected by the disease. In total, the evidence suggests that SalV was not the etiological agent of the disease and that its isolation was fortuitous.

West Nile virus outbreak among horses in New York State, 1999 and 2000.

West Nile (WN) virus was identified in the Western Hemisphere in 1999. Along with human encephalitis cases, 20 equine cases of WN virus were detected in 1999 and 23 equine cases in 2000 in New York. During both years, the equine cases occurred after human cases in New York had been identified.

West Nile virus infection in mosquitoes, birds, horses, and humans, Staten Island, New York, 2000.

West Nile (WN) virus transmission in the United States during 2000 was most intense on Staten Island, New York, where 10 neurologic illnesses among humans and 2 among horses occurred. WN virus was isolated from Aedes vexans, Culex pipiens, Cx. salinarius, Ochlerotatus triseriatus, and Psorophora ferox, and WN viral RNA was detected in Anopheles punctipennis. An elevated weekly minimum infection rate (MIR) for Cx. pipiens and increased dead bird density were present for 2 weeks before the first human illness occurred. Increasing mosquito MIRs and dead bird densities in an area may be indicators of an increasing risk for human infections. A transmission model is proposed involving Cx. pipiens and Cx. restuans as the primary enzootic and epizootic vectors among birds, Cx. salinarius as the primary bridge vector for humans, and Aedes/Ochlerotatus spp. as bridge vectors for equine infection.

Interpretations of antibody responses to Salmonella enterica serotype enteritidis gm flagellin in poultry flocks are enhanced by a kinetics-based enzyme-linked immunosorbent assay.

Many regulatory and diagnostic programs for the detection of Salmonella enterica serotype Enteritidis infection in commercial poultry flocks have relied on rapid Pullorum agglutination tests to screen birds because of the shared antigens of S. enterica Enteritidis and S. enterica Pullorum and Gallinarum; however, the use of the enzyme-linked immunosorbent assay (ELISA) format affords better analytical sensitivity than crude agglutination tests. In this study, we adapted our earlier conventional indirect ELISA, using gm flagellin as the antigen, to a kinetics-based, computer-controlled ELISA (KELA). The KELA was used to screen for flagellin antibody from three commercial flocks: (i) a large flock involved in a U.S. Department of Agriculture trace back from a human S. enterica Enteritidis foodborne outbreak (n = 3,209), (ii) a flock infected with the endemic S. enterica Enteritidis serotype but which also had multiple other Salmonella serotypes (n = 65), and (iii) an S. enterica Pullorum-infected flock (n = 12). The first flock (S. enterica Enteritidis prevalence of 2.45% based on culture) provided a field test of the KELA and allowed the calculation of diagnostic sensitivity (D-Sn) and diagnostic specificity (D-Sp). With a cutoff of 10 (used for screening flocks [i.e., high sensitivity]), the KELA has a D-Sn of 95.2% and a D-Sp of 18.5%; with a cutoff of 140 (used in confirmatory flock testing [i.e., high specificity]), the KELA has a D-Sn of 28.0% and a D-Sp of 99.1%. We found that with a cutoff of 60 (D-Sn = 63.1%; D-Sp = 91.6%), we could eliminate reactions in the KELA caused by other non-S. enterica Enteritidis salmonellae. The KELA was also compared to two commercial rapid Pullorum tests, the Solvay (D-Sn = 94.9%; D-Sp = 55.5%) and the Vineland (D-Sn = 62.0%; D-Sp = 75.3%).

Outbreak of vesicular dermatitis among horses at a midwestern horse show.

Dermatitis consisting of blisters on the nose and other parts of the body was reported among horses at a Midwestern horse show. Some horses also had jaundice, hematuria and anorexia. An outbreak investigation was initiated, and of 239 horses for which information could be obtained, 58 (24%) were found to have been affected. Median duration of illness was 5 days, and all horses recovered. Age, sex, water source, grain source, and stabling location were not associated with illness. The use of wood shavings bedding obtained at the show grounds was the factor most strongly associated with the development of vesicular lesions. Horses that became ill were 43 times more likely to have been bedded on wood shavings obtained from the show grounds than were horses that did not become ill. Among horses bedded on shavings from the show grounds, the risk was further increased by a factor of 5 if the shavings had been wetted. Neither organic nor heavy metal toxicants were identified in the samples of the wood shavings. However, samples did contain plant tissues originating from a tree belonging to the family Simaroubaceae, some species of which are known to cause vesicular eruptions in people.

Salmonella enteritidis infection in two species of psittaciformes.

In 1990, Salmonella enteritidis phage type 4 was recovered from two young (less than 20-week-old) lilac-crowned Amazon parrots (Amazona finschi Schlater), one in Tennessee and one in Kansas. The parrot from Tennessee was treated for a plugged naris and anorexia before the S. enteritidis infection was discovered. The parrot from Kansas exhibited signs of septicemia and died within 24 hours of examination. An apparently healthy green-cheeked conure (Pyrrhura molinae) on the same premises as the parrot from Tennessee was positive for S. enteritidis phage type 4 on a cloacal swab. These are the first reported cases of avian infection with S. enteritidis phage type 4 in the United States. Because several infectious agents were present simultaneously in the Amazon parrots, it was difficult to determine the precise role of S. enteritidis phage type 4 in the clinical presentations.

Chronic diarrhea associated with drinking untreated water.

PURPOSE: To determine the cause of an outbreak of chronic diarrhea and to define the clinical profile of the illness. DESIGN: A case series of patients with chronic diarrhea and case-control and cohort studies to determine the vehicle and cause of the illness. SETTING: Rural Henderson County, Illinois. PATIENTS: Seventy-two patients who had onset of chronic diarrheal illness between May and August 1987. Controls were local residents and eating companions who did not have diarrheal illness. A cohort study included 80 truck drivers from a local firm. METHODS AND MEASUREMENTS: Nonbloody diarrhea was characterized by extreme frequency (median, 12 stools/d), marked urgency, fecal incontinence, and weight loss (mean, 4.5 kg). The median incubation period was 10 days. Nine patients were hospitalized; none died. Diarrhea persisted in 87% of patients after 6 months. Antimicrobial therapy produced no clinical improvement. No bacterial, mycobacterial, viral, or parasitic agents known to be enteropathogenic were detected in stools or implicated water. Three of five small-bowel biopsies showed mild inflammatory changes. Mild inflammation was also seen in two of nine colonic biopsies. Case-control studies implicated a local restaurant (P = 0.0001, odds ratio = 19) and subsequently the untreated well water served in the restaurant (P = 0.04, odds ratio = 9.3) as the vehicle of transmission. CONCLUSIONS: This is the first outbreak of chronic diarrhea linked to drinking untreated water. The causative agent and pathophysiologic mechanism of the illness remain elusive.