Seasonality and zoonotic foodborne pathogens in Canada: relationships between climate and Campylobacter, E. coli and Salmonella in meat products.

Infections due to Campylobacter, Escherichia coli and Salmonella pose a significant health burden in Canada, resulting in major costs to the health care system and economic impacts due to lost productivity resulting from illness. Recent literature suggests that climate may play a role in the prevalence of these pathogens along the food chain. This study used integrated surveillance data to examine associations between weather variables, serving as a proxy for climate, in agricultural areas and Campylobacter, generic E. coli and Salmonella contamination on samples of beef, poultry and swine meat products in Canada. Various temperature metrics (average, maximum and variability) were correlated with Campylobacter prevalence along the food chain. The prevalence of E. coli and Salmonella was correlated with both precipitation and temperatures metrics; however, analysis for E. coli was limited to beef and swine meats at retail settings, because prevalence in other combinations approached 100%, which obviated further analysis. Campylobacter contamination in poultry and swine at abattoir and retail settings demonstrated a seasonal trend, with increased prevalence generally from June or July through November, compared to the baseline month of December. Based on these analyses, Campylobacter is the most likely foodborne bacteria studied whose occurrence in meat products is affected by climatic changes in Canada. An exploratory analysis of data at the provincial scale, using Ontario as an example, revealed similar directional relationships between climate and bacterial prevalence.

How will climate change impact microbial foodborne disease in Canada?

Foodborne disease is a major concern in Canada and represents a significant climate change-related threat to public health. Climate variables, including temperature and precipitation patterns, extreme weather events and ocean warming and acidification, are known to exert significant, complicated and interrelated effects along the entire length of the food chain. Foodborne diseases are caused by a range of bacteria, fungi, parasites and viruses, and the prevalence of these diseases is modified by climate change through alterations in the abundance, growth, range and survival of many pathogens, as well as through alterations in human behaviours and in transmission factors such as wildlife vectors. As climate change continues and/or intensifies, it will increase the risk of an adverse effect on food safety in Canada ranging from increased public health burden to the emergence of risks not currently seen in our food chain. Clinical and public health practitioners need to be aware of the existing and emerging risks to respond accordingly.

Near-real-time tracking of gaps in prevention of mother-to-child transmission of HIV in three districts of KwaZulu-Natal Province, South Africa.

BACKGROUND: Identifying and addressing gaps in the prevention of mother-to-child transmission of HIV (PMTCT) is required if South Africa (SA) is to achieve targets for eliminating MTCT (eMTCT). Potential PMTCT gaps that increase MTCT risk include late maternal HIV diagnosis, lack of or delayed antiretroviral therapy (ART) during pregnancy and breastfeeding, and lack of effective prophylaxis for HIV-exposed infants. OBJECTIVES: To investigate, in near real time, PMTCT gaps among HIV-infected infants in three districts of KwaZulu-Natal Province, SA. METHODS: Between May and September 2016, PMTCT co-ordinators from eThekwini, uMgungundlovu and uMkhanyakude districts received daily email notification of all HIV polymerase chain reaction (PCR)-positive results. Co-ordinators reviewed facility records for each infant to identify gaps in PMTCT care, including maternal age, timing of maternal HIV diagnosis, maternal treatment history and maternal viral load (VL) monitoring. Data were submitted via the mobile phone SMS (text message) service using Rapid Pro technology and analysed in Stata 14. RESULTS: Data on PMTCT gaps were received for 367 (91.8%) of 400 infants with HIV PCR-positive results, within a median time of 12.5 days (interquartile range (IQR) 6 - 23). The median maternal age was 25 years (IQR 22 - 30), with 48 teenage mothers (15 - 19 years). The sample size was too small to determine whether there were significant differences in PMTCT gaps between the 48 teenage mothers and 293 older (20 - 34 years) mothers. Of the mothers, 220 (60.0%) were first diagnosed prior to conception or at their first antenatal care (ANC) visit, and 127 (34.6%) at or after delivery; 137 (37.3%) transmitted HIV to their infants despite receiving >12 weeks of ART. VL results were unavailable for 70.0% of women. Only 41 (17.5%) of women known to be HIV-positive during ANC had confirmed virological suppression. No statistically significant differences in PMTCT gaps were observed between districts, owing to small sample sizes in uMgungundlovu and uMkhanyakude. CONCLUSIONS: The findings highlight the need to improve services during ANC, in particular prioritising maternal VL monitoring. We intend to use improved technology to streamline data collection and reporting towards eMTCT.

Multi-Exposure Pathway Model to Compare Escherichia coli O157 Risks and Interventions.

The relative contributions of exposure pathways associated with cattle-manure-borne Escherichia coli O157:H7 on public health have yet to be fully characterized. A stochastic, quantitative microbial risk assessment (QMRA) model was developed to describe a hypothetical cattle farm in order to compare the relative importance of five routes of exposure, including aquatic recreation downstream of the farm, consumption of contaminated ground beef processed with limited interventions, consumption of leafy greens, direct animal contact, and the recreational use of a cattle pasture. To accommodate diverse environmental and hydrological pathways, existing QMRAs were integrated with novel and simplistic climate and field-level submodels. The model indicated that direct animal contact presents the greatest risk of illness per exposure event during the high pathogen shedding period. However, when accounting for the frequency of exposure, using a high-risk exposure-receptor profile, consumption of ground beef was associated with the greatest risk of illness. Additionally, the model was used to evaluate the efficacy of hypothetical interventions affecting one or more exposure routes; concurrent evaluation of multiple routes allowed for the assessment of the combined effect of preharvest interventions across exposure pathways-which may have been previously underestimated-as well as the assessment of the effect of additional downstream interventions. This analysis represents a step towards a full evaluation of the risks associated with multiple exposure pathways; future incorporation of variability associated with environmental parameters and human behaviors would allow for a comprehensive assessment of the relative contribution of exposure pathways at the population level.

Near-real-time tracking of gaps in prevention of mother-to-child transmission of HIV in three districts of KwaZulu-Natal Province, South Africa

Background. Identifying and addressing gaps in the prevention of mother-to-child transmission of HIV (PMTCT) is required if South Africa (SA) is to achieve targets for eliminating MTCT (eMTCT). Potential PMTCT gaps that increase MTCT risk include late maternal HIV diagnosis, lack of or delayed antiretroviral therapy (ART) during pregnancy and breastfeeding, and lack of effective prophylaxis for HIV-exposed infants.Objectives. To investigate, in near real time, PMTCT gaps among HIV-infected infants in three districts of KwaZulu-Natal Province, SA.Methods. Between May and September 2016, PMTCT co-ordinators from eThekwini, uMgungundlovu and uMkhanyakude districts received daily email notification of all HIV polymerase chain reaction (PCR)-positive results. Co-ordinators reviewed facility records for each infant to identify gaps in PMTCT care, including maternal age, timing of maternal HIV diagnosis, maternal treatment history and maternal viral load (VL) monitoring. Data were submitted via the mobile phone SMS (text message) service using Rapid Pro technology and analysed in Stata 14.Results. Data on PMTCT gaps were received for 367 (91.8%) of 400 infants with HIV PCR-positive results, within a median time of 12.5 days (interquartile range (IQR) 6 - 23). The median maternal age was 25 years (IQR 22 - 30), with 48 teenage mothers (15 - 19 years). The sample size was too small to determine whether there were significant differences in PMTCT gaps between the 48 teenage mothers and 293 older (20 - 34 years) mothers. Of the mothers, 220 (60.0%) were first diagnosed prior to conception or at their first antenatal care (ANC) visit, and 127 (34.6%) at or after delivery; 137 (37.3%) transmitted HIV to their infants despite receiving >12 weeks of ART. VL results were unavailable for 70.0% of women. Only 41 (17.5%) of women known to be HIV-positive during ANC had confirmed virological suppression. No statistically significant differences in PMTCT gaps were observed between districts, owing to small sample sizes in uMgungundlovu and uMkhanyakude.Conclusions. The findings highlight the need to improve services during ANC, in particular prioritising maternal VL monitoring. We intend to use improved technology to streamline data collection and reporting towards eMTCT

Description of a multi-university education and collaborative care child psychiatry access program: New York State's CAP PC.

OBJECTIVE: Although, child mental health problems are widespread, few get adequate treatment, and there is a severe shortage of child psychiatrists. To address this public health need many states have adopted collaborative care programs to assist primary care to better assess and manage pediatric mental health concerns. This report adds to the small literature on collaborative care programs and describes one large program that covers most of New York state. PROGRAM DESCRIPTION: CAP PC, a component program of New York State's Office of Mental Health (OMH) Project TEACH, has provided education and consultation support to primary care providers covering most of New York state since 2010. The program is uniquely a five medical school collaboration with hubs at each that share one toll free number and work together to provide education and consultation support services to PCPs. METHODS: The program developed a clinical communications record to track information about all consultations which forms the basis of much of this report. 2-week surveys following consultations, annual surveys, and pre- and post-educational program evaluations have also been used to measure the success of the program. RESULTS: CAP PC has grown over the 6years of the program and has provided 8013 phone consultations to over 1500 PCPs. The program synergistically provided 17,523 CME credits of educational programming to 1200 PCPs. PCP users of the program report very high levels of satisfaction and self reported growth in confidence. CONCLUSIONS: CAP PC demonstrates that large-scale collaborative consultation models for primary care are feasible to implement, popular with PCPs, and can be sustained. The program supports increased access to child mental health services in primary care and provides child psychiatric expertise for patients who would otherwise have none.

Comparing listeriosis risks in at-risk populations using a user-friendly quantitative microbial risk assessment tool and epidemiological data.

Although infection by the pathogenic bacterium Listeria monocytogenes is relatively rare, consequences can be severe, with a high case-fatality rate in vulnerable populations. A quantitative, probabilistic risk assessment tool was developed to compare estimates of the number of invasive listeriosis cases in vulnerable Canadian subpopulations given consumption of contaminated ready-to-eat delicatessen meats and hot dogs, under various user-defined scenarios. The model incorporates variability and uncertainty through Monte Carlo simulation. Processes considered within the model include cross-contamination, growth, risk factor prevalence, subpopulation susceptibilities, and thermal inactivation. Hypothetical contamination events were simulated. Results demonstrated varying risk depending on the consumer risk factors and implicated product (turkey delicatessen meat without growth inhibitors ranked highest for this scenario). The majority (80%) of listeriosis cases were predicted in at-risk subpopulations comprising only 20% of the total Canadian population, with the greatest number of predicted cases in the subpopulation with dialysis and/or liver disease. This tool can be used to simulate conditions and outcomes under different scenarios, such as a contamination event and/or outbreak, to inform public health interventions.

Cystic Fibrosis Foundation and European Cystic Fibrosis Society Survey of cystic fibrosis mental health care delivery.

BACKGROUND: Psychological morbidity in individuals with cystic fibrosis (CF) and their caregivers is common. The Cystic Fibrosis Foundation (CFF) and European Cystic Fibrosis Society (ECFS) Guidelines Committee on Mental Health sought the views of CF health care professionals concerning mental health care delivery. METHODS: An online survey which focused on the current provision and barriers to mental health care was distributed to CF health care professionals. RESULTS: Of the 1454 respondents, many did not have a colleague trained in mental health issues and 20% had no one on their team whose primary role was focused on assessing or treating these issues. Insufficient resources and a lack of competency were reported in relation to mental health referrals. Seventy-three percent of respondents had no experience with mental health screening. Of those who did, they utilized 48 different, validated scales. CONCLUSIONS: These data have informed the decision-making, dissemination and implementation strategies of the Mental Health Guidelines Committee sponsored by the CFF and ECFS.

The relationship between feed efficiency and the circadian profile of blood plasma analytes measured in beef heifers at different physiological stages.

The characterization of blood metabolite concentrations over the circadian period and across physiological stages is important for understanding the biological basis of feed efficiency, and may culminate in indirect methods for assessing feed efficiency. Hematological analyses for albumin, urea, creatine kinase, glutamate dehydrogenase, aspartate aminotransferase, carbon dioxide, and acetate were carried out in growing and gestating heifers. These measures were carried out in a sample of 36 Bos taurus crossed beef heifers held under the same husbandry conditions. Hourly blood samples were collected over a 24-h period on three separate sampling occasions, corresponding approximately to the yearling (and open), early-gestation and late-gestation stages. This design was used to determine variation throughout the day, effects due to physiological status and any associations with feed efficiency, as measured by residual feed intake. Blood analyte levels varied with time of day, with the most variation occurring between 0800 and 1600 h. There were also considerable differences in analyte levels across the three physiological stages; for example, creatine kinase was higher (P<0.05) in open heifers, followed by early- and late-gestation heifers. Feed efficiency was also associated with analyte abundance. In more feed-efficient open heifers, there were higher activities of creatine kinase (P<0.05) and aspartate aminotransferase (P<0.05), and lower concentrations of carbon dioxide (P<0.05). Furthermore, in late gestation, more efficient heifers had lower urea concentrations (P<0.05) and lower creatine kinase levels (P<0.05). Over the whole experimental period, carbon dioxide concentrations were numerically lower in more feed efficient heifers (P=0.079). Differences were also observed across physiological stages. For instance, open heifers had increased levels (P<0.05) of creatine kinase, aspartate aminotransferase, carbon dioxide than early and late pregnancy heifers. In essence, this study revealed relevant information about the metabolic profile in the context of feed efficiency and physiological stages. Further optimization of our approach, along with the evaluation of complementary analytes, will aid in the development of robust, indirect assessments of feed efficiency.

Investigating groundwater flow between Edwards and Trinity aquifers in central Texas.

Understanding the nature of communication between aquifers can be challenging when using traditional physical and geochemical groundwater sampling approaches. This study uses two multiport wells completed within Edwards and Trinity aquifers in central Texas to determine the degree of groundwater inter-flow between adjacent aquifers. Potentiometric surfaces, hydraulic conductivities, and groundwater major ion concentrations and Sr isotope values were measured from multiple zones within three hydrostratigraphic units (Edwards and Upper and Middle Trinity aquifers). Physical and geochemical data from the multiport wells were combined with historical measurements of groundwater levels and geochemical compositions from the region to characterize groundwater flow and identify controls on the geochemical compositions of the Edwards and Trinity aquifers. Our results suggest that vertical groundwater flow between Edwards and Middle Trinity aquifers is likely limited by low permeability, evaporite-rich units within the Upper and Middle Trinity. Potentiometric surface levels in both aquifers vary with changes in wet vs. dry conditions, indicating that recharge to both aquifers occurs through distinct recharge areas. Geochemical compositions in the Edwards, Upper, and Middle Trinity aquifers are distinct and likely reflect groundwater interaction with different lithologies (e.g., carbonates, evaporites, and siliceous sediments) as opposed to mixing of groundwater between the aquifers. These results have implications for the management of these aquifers as they indicate that, under current conditions, pumping of either aquifer will likely not induce vertical cross-formational flow between the aquifers. Inter-flow between the Trinity and the Edwards aquifers, however, should be reevaluated as pumping patterns and hydrogeologic conditions change.

Modification of the cranial closing wedge ostectomy technique for the treatment of canine cruciate disease. Description and comparison with standard technique.

OBJECTIVE: To describe a modification of the cranial closing wedge ostectomy (CCWO) technique and to compare its efficacy to the standard technique on cadaveric specimens. METHODS: The standard and modified CCWO technique were applied to eight pairs of cadaveric tibiae. The following parameters were compared following the ostectomy: degrees of plateau levelling achieved (degrees), tibial long axis shift (degrees), reduction in tibial length (mm), area of bone wedge removed (cm²), and the area of proximal fragment (cm²). RESULTS: The size of the removed wedge of bone and the reduction in tibial length were significantly less with the modified CCWO technique. CLINICAL SIGNIFICANCE: The modified CCWO has two main advantages. Firstly a smaller wedge is removed, allowing a greater preservation of bone stock in the proximal tibia, which is advantageous for implant placement. Secondly, the tibia is shortened to a lesser degree, which might reduce the risk of recurvatum, fibular fracture and patella desmitis. These factors are particularly propitious for the application of this technique to Terrier breeds with excessive tibial plateau angle, where large angular corrections are required. The modified CCWO is equally effective for plateau levelling and results in an equivalent tibial long-axis shift. A disadvantage with the modified technique is that not all of the cross sectional area of the distal fragment contributes to load sharing at the osteotomy.

Elasticity, strength, and water permeability of bilayers that contain raft microdomain-forming lipids.

Bilayers composed of phosphatidylcholine (PC), sphingomyelin (SM), and cholesterol (CHOL) are commonly used as systems to model the raft-lipid domain structure believed to compartmentalize particular cell membrane proteins. In this work, micropipette aspiration of giant unilamellar vesicles was used to test the elasticities, water permeabilities, and rupture tensions of single-component PC, binary 1:1 PC/CHOL, and 1:1 SM/CHOL, and ternary 1:1:1 PC/SM/CHOL bilayers, one set of measurements with dioleoyl PC (DOPC; C18:1/C18:1 PC) and the other with stearoyloleoyl PC (SOPC; C18:0/C18:1 PC). Defining the elastic moduli (K(A)), the initial slopes of the increase in tension (sigma) versus stretch in lipid surface area (alpha(e)) were determined for all systems at low (15 degrees C) and high (32-33 degrees C) temperatures. The moduli for the single-component PC and binary phospholipid/CHOL bilayers followed a descending hierarchy of stretch resistance with SM/CHOL > SOPC/CHOL > DOPC/CHOL > PC. Although much more resistant to stretch than the single-component PC bilayers, the elastic response of vesicle bilayers made from the ternary phospholipid/CHOL mixtures showed an abrupt softening (discontinuity in slope), when immediately subjected to a steady ramp of tension at the low temperature (15 degrees C). However, the discontinuities in elastic stretch resistance at low temperature vanished when the bilayers were held at approximately 1 mN/m prestress for long times before a tension ramp and when tested at the higher temperature 32-33 degrees C. The elastic moduli of single-component PC and DOPC/CHOL bilayers changed very little with temperature, whereas the moduli of the binary SOPC/CHOL and SM/CHOL bilayers diminished markedly with increase in temperature, as did the ternary SOPC/SM/CHOL system. For all systems, increasing temperature increased the water permeability but decreased rupture tension. Concomitantly, the measurements of permeability exhibited a prominent correlation with the rupture tension across all the systems. Together, these micromechanical tests of binary and ternary phospholipid/CHOL bilayers demonstrate that PC hydrocarbon chain unsaturation and temperature are major determinants of the mechanical and permeation properties of membranes composed of raft microdomain-forming lipids.

Geometric implications of the tibial wedge osteotomy for the treatment of cranial cruciate ligament disease in dogs.

The tibial wedge osteotomy (TWO), a procedure that reduces the tibial plateau slope, has become an established surgical technique for the treatment of cranial cruciate ligament injuries in dogs, yet variation from the desired postoperative tibial plateau slope of 6 degrees has been noted. The objectives of this study were to investigate the geometric implications of this procedure and to identify factors that affect the postoperative angles. The records of 35 consecutive cases that had a TWO performed were reviewed and comparisons were made between the alignment of the cortices and level of the osteotomy using duplicated tracings of a preoperative radiograph. The existing method for calculating the size of wedge to be removed was found to result in a postoperative slope greater than the expected 6 degrees. Our results indicate that the desired postoperative angle is more likely to be achieved if the cranial cortices are aligned and the osteotomy is performed proximally.

Determinants of passive hip range of motion in adult Greyhounds.

OBJECTIVE: To determine the ranges of normal pelvic limb range of motion in adult Greyhound dogs, and to explore which factors influence hip range of motion in a population bred to meet the specific demands of racing. Design A cross-sectional study design. METHOD: Thirty-two dogs (17 male and 15 female) 13 to 81 months old were randomly selected from a local pool of 160 Greyhounds. Goniometric measurements of hip, stifle and hock range of motion were recorded in triplicate. Signalment information collected included sex, weight and age of each Greyhound. The outcome factors for the study were range of hip flexion and hip extension. The theorised exposures, age, sex, weight, racing history and hock and stifle range of motion, were modelled against the outcome variables by linear regression analysis. RESULTS: Male dogs were significantly heavier (P < 0.001) and older (P < 0.002) than female dogs. Mean hip flexion was 71.75 degrees and mean hip extension 128.10 degrees. The determinants of hip flexion were sex (P = 0.008) and range of stifle flexion (P = 0.002). Race training did not influence the range of hip flexion in the sample. Determinants of hip extension included range of stifle extension (P = 0.015), history of race training (P = 0.004) and hock flexion. The mean hip extension of raced Greyhounds was 134.95 degrees compared with 121.25 degrees for unraced Greyhounds (mean difference -13.70, 95% confidence interval -18.12, -9.29; P < 0.001). CONCLUSIONS: This study has reported isolated pelvic limb joint range of motion in the racing Greyhound. Hip range of motion was affected by stifle range of motion, sex and race training. Dogs that had received race training had greater flexibility, possibly due to training having an active stretching role on muscles, tendons and other structures limiting the hip range of motion.

Reduced aerobic capacity and physical functioning in older HIV-infected men.

Aerobic capacity and physical functioning decline with age and chronic illness. The extent of physical disability is unknown in older HIV-infected adults, who represent a rapidly growing proportion of HIV/AIDS patients in the United States. We performed functional performance testing including treadmill testing in 32 HIV-infected male veterans aged 40-69 years. Controls were 47 healthy male subjects tested previously in the same exercise laboratory. HIV-infected subjects were classified as younger (40-49 years, n = 12) or older age (50+ years, n = 20). Peak aerobic capacity (VO2peak) was significantly reduced in the older vs. younger HIV subjects [19.1 mL/kg/min +/- 5.7 (mean, SD) vs. 25.2 +/- 4.2, p = 0.01]. VO2peak was reduced 41% +/- 15% (mean, SD) in HIV-infected subjects compared to expected values from age-matched healthy controls. Regression analyses show a similar decline in VO2peak with age in HIV-infected and healthy controls. Mean 6-min walk distance was not significantly different between the HIV-infected age groups, and was reduced only 8% compared to expected values for healthy adults. Current CD4 count and HAART exposure were similar in the two age groups and were not significantly associated with VO2peak. Anemia (HCT <35%) was significantly associated with reduced VO2peak (p = 0.02), but this association was not independent of the effect of age (p = 0.1). We conclude that older HIV-infected adults have markedly impaired aerobic capacity but maintain the capacity to undertake day-to-day activities. Additional physiologic and metabolic testing is needed to measure the effect of HAART toxicity and primary aging on aerobic capacity, and to determine if older HIV-infected adults are at greater risk.

Self-expanding metal stents in the palliation of malignant dysphagia: outcome analysis in 100 consecutive patients.

SUMMARY. Patients with inoperable esophageal malignancy often undergo palliative self-expanding metal stent insertion. This analysis of cases shows that although such stents provide good palliation of dysphagia, complications frequently occur. Complications reported were pain after insertion, bleeding, food bolus impaction, stent migration and increased gastroesophageal reflux. Furthermore, in patients with esophageal adenocarcinoma, survival was less if the distal end of the stent entered the stomach, rather than lying entirely within the esophagus. Reduced survival, in this group with gastroesophageal junction tumors, may be a result of increased gastroesophageal reflux leading to pulmonary aspiration. Stents incorporating an antireflux valve have been shown to reduce symptomatic gastroesophageal reflux. It may be that such valves offer a survival advantage where stent insertion ablates the function of the lower esophageal sphincter. Further studies are needed to assess the role of antireflux stents on survival in patients with gastroesophageal junction tumors.

Comparison of methods to estimate physical activity and energy expenditure in African American children.

Low levels of physical activity and high levels of obesity among children in the US is a public health concern. Accurate methods to estimate physical activity are needed to determine the efficacy of intervention programs and to explore relationships between daily physical activity and health status in children. The purpose of this study was to compare the simultaneous use of the Tritrac-R3D accelerometer (Tritrac), Yamax SW-200 Digiwalker step-counter (Digiwalker) and the Self Administered Physical Activity Checklist (SAPAC) to assess physical activity (PA) and energy expenditure (EE) in African-American children aged 7 to 10 years, using the doubly-labeled water (DLW) as the criterion method. Physical activity and energy expenditure were measured over seven consecutive days under free-living conditions. Resting metabolic rate and peak VO(2) were measured before the experimental period. There was no difference in physical activity energy expenditure (PAEE) measured by Tritrac or DLW (p > 0.05). Tritrac activity counts were highly correlated with DLW-PAEE (r = 0.81). High correlations between Digiwalker and DLW were observed when body weight was considered. A low correlation (r = 0.49) was observed between the physical activity energy expenditure by SAPAC and DLW. In conclusion, with some limitations the Tritrac and Digiwalker can provide useful and accurate information about PA and EE in 7- to 10-year-old children.

Role of dietary copper in enhancing resistance to Escherichia coli mastitis.

The role of dietary copper in enhancing resistance to Escherichia coli mastitis was investigated in first-lactation heifers. Twenty-three primigravid Holstein heifers were maintained on a basal (6.5 ppm copper; -Cu) diet or a diet supplemented (20 ppm) with copper sulfate (+Cu) beginning 60 d prepartum through 42 d of lactation. Liver biopsies and blood samples were taken for liver and blood minerals and plasma ceruloplasmin. Milk samples were taken weekly postpartum for bacteriology. The overall mean liver Cu concentration was about threefold higher, and the overall mean plasma Cu concentration was greater in the +Cu group than the -Cu group. At 34 d of lactation, one pathogen-free quarter per animal was infused with 22 cfu of Escherichia coli strain 727. Plasma Cu was greater at -24, 0, 18, 24, 36, 96, 192, and 240 h relative to infusion for +Cu animals. Plasma Zn concentration was higher at 24 h for the +Cu group. Milk bacterial count (log10 cfu/ml) was lower at 12, 18, and 48 h for the +Cu group. Somatic cell count (log10/ml) was lower at 18 h in +Cu animals. Clinical score at 24 h was lower for +Cu cows, while at 144 h, clinical score was lower for -Cu cows. Rectal temperature was lower at 18 h for the +Cu group. Plasma ceruloplasmin and Fe, dry matter intake and milk production did not differ. Copper supplementation reduced the clinical response during experimental E. coli mastitis, but duration was unchanged.