Outbreak of salmonellosis linked to live poultry from a mail-order hatchery.

BACKGROUND: Outbreaks of human salmonella infections are increasingly associated with contact with live poultry, but effective control measures are elusive. In 2005, a cluster of human salmonella Montevideo infections with a rare pattern on pulsed-field gel electrophoresis (the outbreak strain) was identified by PulseNet, a national subtyping network. METHODS: In cooperation with public health and animal health agencies, we conducted multistate investigations involving patient interviews, trace-back investigations, and environmental testing at a mail-order hatchery linked to the outbreak in order to identify the source of infections and prevent additional illnesses. A case was defined as an infection with the outbreak strain between 2004 and 2011. RESULTS: From 2004 through 2011, we identified 316 cases in 43 states. The median age of the patient was 4 years. Interviews were completed with 156 patients (or their caretakers) (49%), and 36 of these patients (23%) were hospitalized. Among the 145 patients for whom information was available, 80 (55%) had bloody diarrhea. Information on contact with live young poultry was available for 159 patients, and 122 of these patients (77%) reported having such contact. A mail-order hatchery in the western United States was identified in 81% of the trace-back investigations, and the outbreak strain was isolated from samples collected at the hatchery. After interventions at the hatchery, the number of human infections declined, but transmission continued. CONCLUSIONS: We identified a prolonged multistate outbreak of salmonellosis, predominantly affecting young children and associated with contact with live young poultry from a mail-order hatchery. Interventions performed at the hatchery reduced, but did not eliminate, associated human infections, demonstrating the difficulty of eliminating salmonella transmission from live poultry.

Francisella tularensis infection in dogs: 88 cases (2014-2016).

OBJECTIVE: To characterize the epidemiology, clinical signs, and treatment of dogs with Francisella tularensis infection in New Mexico. ANIMALS: 87 dogs in which 88 cases of tularemia (1 dog had 2 distinct cases) were confirmed by the New Mexico Department of Health Scientific Laboratory Division from 2014 through 2016 and for which medical records were available. PROCEDURES: Dogs were confirmed to have tularemia if they had a 4-fold or greater increase in anti-F tularensis antibody titer between acute and convalescent serum samples or F tularensis had been isolated from a clinical or necropsy specimen. Epidemiological, clinical, and treatment information were collected from the dogs' medical records and summarized. RESULTS: All 88 cases of tularemia were confirmed by paired serologic titers; the first (acute) serologic test result was negative for 84 (95%) cases. The most common reported exposure to F tularensis was wild rodent or rabbit contact (53/88 [60%]). Dogs had a median number of 3 clinical signs at initial evaluation; lethargy (81/88 [92%]), pyrexia (80/88 [91%]), anorexia (67/88 [76%]), and lymphadenopathy (18/88 [20%]) were most common. For 32 (36%) cases, the dog was hospitalized; all hospitalized dogs survived. CONCLUSIONS AND CLINICAL RELEVANCE: Dogs with F tularensis infection often had nonspecific clinical signs and developed moderate to severe illness, sometimes requiring hospitalization. Veterinarians examining dogs from tularemia-enzootic areas should be aware of the epidemiology and clinical signs of tularemia, inquire about potential exposures, and discuss prevention methods with owners, including reducing exposure to reservoir hosts and promptly seeking care for ill animals.

Multistate outbreak of human Salmonella Typhimurium infections linked to live poultry from agricultural feed stores and mail-order hatcheries, United States 2013.

Live poultry-associated salmonellosis is an emerging public health issue in the United States. Public and animal health officials collaborated to investigate one of the largest (356 cases, 39 states) of these outbreaks reported to date. A case was defined as illness in a person infected with the outbreak strain of Salmonella Typhimurium with illness onset between 1 March and 22 October 2013. The median patient age was seven years (range: < 1-87 years); 58% of ill persons were children ≤ 10 years, 51% were female, 25% were hospitalized; 189 (76%) of 250 patients reported live poultry exposure in the week before illness; and 149 (95%) of 157 reported purchasing live poultry from agricultural feed stores. Traceback investigations identified 18 live poultry sources, including 16 mail-order hatcheries. Environmental sampling was conducted at two mail-order hatcheries. One (2.5%) of 40 duplicate samples collected at one hatchery yielded the outbreak strain. Live poultry are an important source of human salmonellosis, particularly among children, highlighting the need for educational campaigns and comprehensive interventions at the mail-order hatchery and agricultural feed store levels. Prevention and control efforts depend on a One Health approach, involving cooperation between public and animal health officials, industry, health professionals, and consumers.

Modeling relationships between climate and the frequency of human plague cases in the southwestern United States, 1960-1997.

The relationships between climatic variables and the frequency of human plague cases (1960-1997) were modeled by Poisson regression for two adjoining regions in northeastern Arizona and northwestern New Mexico. Model outputs closely agreed with the numbers of cases actually observed, suggesting that temporal variations in plague risk can be estimated by monitoring key climatic variables, most notably maximum daily summer temperature values and time-lagged (1 and 2 year) amounts of late winter (February-March) precipitation. Significant effects also were observed for time-lagged (1 year) summer precipitation in the Arizona model. Increased precipitation during specific periods resulted in increased numbers of expected cases in both regions, as did the number of days above certain lower thresholds for maximum daily summer temperatures (80 degrees F in New Mexico and 85 degrees F in Arizona). The number of days above certain high-threshold temperatures exerted a strongly negative influence on the numbers of expected cases in both the Arizona and New Mexico models (95 degrees F and 90 degrees F, respectively). The climatic variables found to be important in our models are those that would be expected to influence strongly the population dynamics of the rodent hosts and flea vectors of plague.

Experimental evaluation of rodent exclusion methods to reduce hantavirus transmission to residents in a Native American community in New Mexico.

We conducted a pilot study to evaluate the efficacy of rodent proofing continuously occupied homes as a method for lowering the risk for hantavirus pulmonary syndrome (HPS) among residents of a Native American community in northwestern New Mexico. Rodent proofing of dwellings was paired with culturally appropriate health education. Seventy homes were randomly assigned to treatment or control categories. Treatment homes were rodent-proofed by sealing openings around foundations, doors, roofs, and pipes and repairing screens and windows. Repairs to each dwelling were limited to $500 US. After repairs were completed, 15-20 snap traps were placed in each treatment and control home and checked approximately every 2 days for an average of 3-4 weeks. During 23,373 trap nights, one house mouse (Mus musculus) was captured in one treatment home, and 20 mice (16 deer mice, Peromyscus maniculatus, two Pinyon mice, Peromyscus truei, and two unidentified mice) were captured in five control homes (one house had 14 captures, two had two captures, and two had one capture). Trap success was 0.01% in treatment homes and 0.15% in controls. Intensity of infestation (mean number of mice captured per infested home) was 1 in treatment homes and 4 in controls. Observations of evidence of infestation (feces, nesting material, gnaw marks, or reports of infestation by occupant) per 100 days of observation were 1.2 in treatment homes and 3.1 in controls. Statistical power of the experiment was limited because it coincided with a period of low rodent abundance (August-November 2000). Nevertheless, these results suggest that inexpensive rodent proofing of occupied rural homes can decrease the frequency and intensity of rodent intrusion, thereby reducing the risk of HPS among rural residents in the southwestern United States.

Yersinia pestis infection in dogs: 62 cases (2003-2011).

OBJECTIVE: To describe the epidemiology, clinical signs, and treatment practices in dogs with Yersinia pestis infection in New Mexico. DESIGN: Retrospective case series. ANIMALS: 62 dogs with plague in New Mexico. PROCEDURES: Confirmed case animals had isolation of Yersinia pestis from a clinical specimen, a positive direct fluorescent antibody test result, or a minimum 4-fold change between acute and convalescent serum antibody titers with clinically compatible illness. Retrospective review of cases of laboratory-confirmed plague from 2003 to 2011 was performed with a standardized chart abstraction form. Epidemiologic, clinical, and treatment data were evaluated. RESULTS: 62 confirmed cases of canine plague were identified from 2003 to 2011. Most cases (85%) were confirmed by serologic titers alone or in conjunction with other testing methods. Clinical signs included fever (100%), lethargy (97%), anorexia (77%), lymphadenopathy (23%), vomiting (13%), diarrhea (8%), and abscesses (2%). Most case animals (73%) were treated with multiple antimicrobials. Sixty (97%) case animals survived; of the 2 nonsurvivors, one was euthanized and another died. Potential sources of exposure to Y pestis included hunting, rodent or rabbit exposure, and residence in rural areas. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that dogs with exposure to Y pestis can develop moderate to severe illness or die as a result of infection. Veterinarians practicing in and examining animals from the western United States need to be familiar with the epidemiology of plague and query owners about potential plague exposures when consistent clinical signs are present. Veterinarians are often the first to recognize signs of plague among sentinel populations and have the opportunity to intervene and prevent zoonotic disease transmission.