Ian T Williams

Centers for Disease Control and Prevention, Атланта, Michigan, United States

Are you Ian T Williams?

Claim your profile

Publications (70)469.53 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: In August 2014, PulseNet, the national molecular subtyping network for foodborne disease surveillance, detected a multistate cluster of Salmonella enterica serotype Newport infections with an indistinguishable pulse-field gel electrophoresis (PFGE) pattern (XbaI PFGE pattern JJPX01.0061). Outbreaks of illnesses associated with this PFGE pattern have previously been linked to consumption of tomatoes harvested from Virginia's Eastern Shore in the Delmarva region and have not been linked to cucumbers or other produce items. To identify the contaminated food and find the source of the contamination, CDC, state and local health and agriculture departments and laboratories, and the Food and Drug Administration (FDA) conducted epidemiologic, traceback, and laboratory investigations. A total of 275 patients in 29 states and the District of Columbia were identified, with illness onsets occurring during May 20-September 30, 2014. Whole genome sequencing (WGS), a highly discriminating subtyping method, was used to further characterize PFGE pattern JJPX01.0061 isolates. Epidemiologic, microbiologic, and product traceback evidence suggests that cucumbers were a source of Salmonella Newport infections in this outbreak. The epidemiologic link to a novel outbreak vehicle suggests an environmental reservoir for Salmonella in the Delmarva region that should be identified and mitigated to prevent future outbreaks.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: Cyclospora cayetanensis is a parasite that can cause a prolonged or remitting/relapsing diarrheal illness. U.S. outbreaks of cyclosporiasis, since the mid-1990s, have been linked to various types of imported fresh produce. In late June 2013, public health officials in Iowa and Nebraska began receiving reports of laboratory-confirmed cases of cyclosporiasis not associated with international travel. A total of 631 such cases, with onset dates during JuneAugust, were reported by 25 states; 497 (79%) of the cases were from Iowa, Nebraska, and Texas. Methods: FDA, State and Local officials reviewed distribution records for pertinent food items identified in epidemiologic investigations. An environmental investigation was conducted at the processing facility and farms. Results: In Iowa and Nebraska, restaurant-associated cases were linked to a bagged salad mix (iceberg and romaine lettuces, carrots, and red cabbage) from Taylor Farms, Guanajuato, Mexico. The environmental investigation conducted by FDA, in conjunction with CDC, industry and Mexican officials, at the processing facility and selected growing areas in Guanajuato found no clear sources of Cyclospora or routes of contamination at the locations that were visited; environmental samples collected by FDA, CDC and Taylor Farms tested negative for Cyclospora. Epidemiologic and traceback investigations for several case clusters in Texas pointed to cilantro harvested from Puebla, Mexico, although a single processor or farm could not be identified. Conclusion: In 2013, at least two unrelated outbreaks of cyclosporiasis occurred, which were linked to different types of produce from different regions of Mexico. As with previous outbreaks, the sources and routes of contamination of these food items were not identified. To reduce the risk for future outbreaks of cyclosporiasis, investigations to determine what leads to contamination of produce and novel molecular methods to detect and link cases to each other and to food vehicles/sources are needed. Mexico is working with the firms to identify any areas for concern and take necessary corrective actions.
    IDWeek 2014 Meeting of the Infectious Diseases Society of America; 10/2014
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: Salmo­nella causes approximately 1.2 million infections and 400 deaths annually in the United States. On June 13, 2013, PulseNet, a national molecular subtyping network for foodborne disease surveillance, identified a cluster of human infections of Salmonella Heidelberg with indistinguishable genetic fingerprints. States and CDC initiated an investigation to identify the source and prevent additional illnesses. METHODS: We defined a case as illness with an outbreak strain with onset March 1, 2013–present. Our investigation included collection of patient exposures and comparison to a population survey, isolate testing for antimicrobial resistance, and traceback and culture of retail chicken. United States Department of Agriculture’s (USDA) Food Safety and Inspection Service (FSIS) conducted intensified Salmonella testing at four production facilities. RESULTS: We identified 403 case-patients in 23 states and Puerto Rico; 40% (128/318) were hospitalized. A higher percentage (82% [51/61]) consumed chicken prepared at home than reported in the 2006-2007 FoodNet Population Survey, (65%, p-value <0.002); 80% (16/20) reported eating Foster Farms brand chicken. One sub-cluster was linked to Foster Farms-sourced rotisserie chicken from a single store location which subsequently recalled more than 23,000 units of rotisserie chicken products. Chicken products collected from Foster Farms facilities, Foster Farms retail chicken samples, and leftover case-patient food yielded the outbreak strains. Case-patient and poultry isolates were resistant to combinations of seven different antimicrobials, with 50 exhibiting multidrug resistance. On October 17, 2013, USDA-FSIS issued an alert about chicken from three Foster Farms facilities, reminding consumers to properly handle raw poultry. On October 11, 2013, Foster Farms began implementing process enhancements. CONCLUSIONS: This multidrug resistant Salmonella outbreak, in which epidemiologic, traceback, and laboratory evidence identified Foster Farms chicken as the source, highlights the need for more rigorous Salmonella control in raw chicken products. In response, Foster Farms implemented measures to decrease Salmonella burden in chicken parts, which may stimulate nationwide adoption of more stringent standards by other producers.
    2014 Council of State and Territorial Epidemiologists Annual Conference; 06/2014
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: During June—August 2013, a multistate outbreak including 631 cyclosporiasis cases was reported to CDC. Most cases occurred in Iowa (140), Nebraska (87), and Texas (270). In Iowa and Nebraska, most illness onsets occurred during June, and were associated with consumption of pre-packaged salad mix containing lettuce, cabbage, and carrots. Most Texas patients had illness onsets during July. These temporal differences suggested that a different food vehicle might be causing illnesses in Texas. State health department-administered questionnaires identified multiple Texas clusters: of the two largest, Cluster 1 comprised patients from a small town (Town X), and Cluster 2 included patients who ate at a single restaurant (Restaurant A) in a different town during the incubation period. We investigated these clusters to identify possible additional contaminated food vehicles. METHODS: Cases were defined as gastrointestinal illness in persons between June 1-August 31, 2013 with Cyclospora in stool and without international travel ≤2 weeks before illness onset. We interviewed Cluster 1 case-patients about foods eaten ≤14 days before illness onset and compared results with 2006–2007 New Mexico Foodborne Diseases Active Surveillance Network (FoodNet) Population Survey data. We conducted a case-control study with Cluster 2, including case-patients who ate at Restaurant A during July 6–16, 2013, and Restaurant A meal date-matched controls reporting no diarrhea ≤14 days afterwards. Menu-specific questionnaires were administered to gather meal consumption data and ingredient-level analyses were performed. RESULTS: The seven Cluster 1 patients were significantly more likely to have consumed fresh cilantro (odds ratio [OR]:18.7; 95% confidence interval [CI]:2.2-863.4) and lemon (OR:11.2; 95% CI: 1.4-516.9) than FoodNet respondents. We interviewed 21 Cluster 2 case-patients and 65 controls. Eating fresh cilantro (matched OR [mOR]:19.8; CI:4.0–>999), onions (mOR:15.3; CI:2.1-697.7), and tomatoes (mOR:5.5; CI:1.1-54.1) from Restaurant A was significantly associated with illness. Of these, only cilantro was consumed by all Cluster 2 case-patients. Additionally, of the four salsas prepared at Restaurant A, three containing uncooked cilantro were significantly associated with illness (hot salsa mOR:8.0; CI:2.3-31.4; side salsa mOR:5.7; CI:1.6-23.7; fire salsa mOR:3.5; CI:1.1-12.7), while salsa containing cooked cilantro was not (salsa ranchera mOR:6.0; CI:0.7-75.2). CONCLUSIONS: Cilantro was the likely source of illnesses among patients in Texas Cluster 2. Although these illnesses occurred soon after identification of a multistate outbreak linked to pre-packaged salad mix, these investigations indicate that the large increase in cyclosporiasis illnesses during summer 2013 were caused by at least two different food vehicles.
    2014 Council of State and Territorial Epidemiologists Annual Conference; 06/2014
  • [Show abstract] [Hide abstract]
    ABSTRACT: SUMMARY We investigated an outbreak of 396 Salmonella enterica serotype I 4,5,12:i:- infections to determine the source. After 7 weeks of extensive hypothesis-generation interviews, no refined hypothesis was formed. Nevertheless, a case-control study was initiated. Subsequently, an iterative hypothesis-generation approach used by a single interviewing team identified brand A not-ready-to-eat frozen pot pies as a likely vehicle. The case-control study, modified to assess this new hypothesis, along with product testing indicated that the turkey variety of pot pies was responsible. Review of product labels identified inconsistent language regarding preparation, and the cooking instructions included undefined microwave wattage categories. Surveys found that most patients did not follow the product's cooking instructions and did not know their oven's wattage. The manufacturer voluntarily recalled pot pies and improved the product's cooking instructions. This investigation highlights the value of careful hypothesis-generation and the risks posed by frozen not-ready-to-eat microwavable foods.
    Epidemiology and Infection 08/2013; 142(5):1-11. DOI:10.1017/S0950268813001787 · 2.49 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: In September 2012, the Centers for Disease Control and Prevention (CDC), the Food and Drug Administration (FDA), and the New Mexico Environmental Department investigated an outbreak of illnesses caused by Salmonella Bredeney associated with consumption of Trader Joe’s Valencia Creamy Salted Peanut Butter (PB) manufactured by Sunland, Inc. of Portales, New Mexico. METHODS: Epidemiology: A total of 42 persons infected with the outbreak strain were reported from 20 states; 61% of cases were children <10 years old. Of 33 case-patients who completed the food exposure questionnaire, 78% reported shopping at different locations of Trader Joe’s, a major grocery chain; 100% of the cases purchased PB produced by a single manufacturer, Sunland, Inc. Laboratory: FDA and state partners collected product samples at the manufacturer, retail locations, and case patient’s homes; additionally, FDA collected environmental samples at the manufacturer. S. Bredeney with a PFGE pattern matching the outbreak strain was isolated from opened jars of PB from case-patients’ homes, as well as from retained products and the environment at the firm. In addition, Salmonella Cerro, Meleagridis, Anatum, Mbandaka, and Kiambu were isolated from the manufacturer’s environment. RESULTS: Investigation: Sunland, Inc. was identified as the sole contract manufacturer of the implicated PB. CDC, FDA, and the states collaborated with both Trader Joe’s and Sunland, Inc. to promptly recall implicated products. The FDA investigated Sunland, Inc., collecting samples, records, and production information from the firm. Investigators found multiple GMP deficiencies and determined that the firm’s internal controls were insufficient to prevent shipment of contaminated product. As a result of FDA’s investigational findings, the initial recall was later expanded to include multiple other products. CONCLUSIONS: Conclusion: The combination of laboratory, investigational, and epidemiologic findings led to the rapid recall of the implicated PB and subsequent expansion to additional Sunland, Inc. products. Based on the firm’s history of violations, FDA took the additional step of suspending Sunland, Inc.’s registration to prevent additional contaminated product from reaching consumers. The collaboration between CDC, FDA, state and local public health officials, and industry partners led to prompt removal of the product and prevention of additional illnesses.
    2013 Council of State and Territorial Epidemiologists Annual Conference; 06/2013
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Shiga toxin-producing Escherichia coli (STEC) O157:H7 is the causal agent for more than 96,000 cases of diarrheal illness and 3,200 infection-attributable hospitalizations annually in the United States. We defined a confirmed case as a compatible illness in a person with the outbreak strain during 10/07/2011-11/30/2011. Investigation included hypothesis generation, a case-control study utilizing geographically-matched controls, and a case series investigation. Environmental inspections and tracebacks were conducted. We identified 58 cases in 10 states; 67% were hospitalized and 6.4% developed hemolytic uremic syndrome. Any romaine consumption was significantly associated with illness (matched Odds Ratio (mOR) = 10.0, 95% Confidence Interval (CI) = 2.1-97.0). Grocery Store Chain A salad bar was significantly associated with illness (mOR = 18.9, 95% CI = 4.5-176.8). Two separate traceback investigations for romaine lettuce converged on Farm A. Case series results indicate that cases (64.9%) were more likely than the FoodNet population (47%) to eat romaine lettuce (p-value = 0.013); 61.3% of cases reported consuming romaine lettuce from the Grocery Store Chain A salad bar. This multistate outbreak of STEC O157:H7 infections was associated with consumption of romaine lettuce. Traceback analysis determined that a single common lot of romaine lettuce harvested from Farm A was used to supply Grocery Store Chain A and a university campus linked to a case with the outbreak strain. An investigation at Farm A did not identify the source of contamination. Improved ability to trace produce from the growing fields to the point of consumption will allow more timely prevention and control measures to be implemented.
    PLoS ONE 02/2013; 8(2):e55300. DOI:10.1371/journal.pone.0055300 · 3.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: SUMMARY In 2008, nationwide investigations of a Salmonella serotype Saintpaul outbreak led first to consumer warnings for Roma and red round tomatoes, then later for jalapeño and serrano peppers. In New Mexico, where there were a large number of cases but no restaurant-based clusters, the NM Department of Health and the Indian Health Service participated with CDC in individual-level and household-level case-control studies of infections in New Mexico and the Navajo Nation. No food item was associated in the individual-level study. In the household-level study, households with an ill member were more likely to have had jalapeño peppers present during the exposure period and to have reported ever having serrano peppers in the household. This report illustrates the complexity of this investigation, the limitations of traditional individual-level case-control studies when vehicles of infection are ingredients or commonly eaten with other foods, and the added value of a household-level study.
    Epidemiology and Infection 12/2012; 141(10):1-6. DOI:10.1017/S0950268812002877 · 2.49 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background. On July 7 and 11, 2007, respectively, health officials in Texas and Indiana reported 4 possible cases of type A foodborne botulism to the US Centers for Disease Control and Prevention. Foodborne botulism is a rare and sometimes fatal illness caused by consuming foods containing botulinum neurotoxin.Methods. Investigators reviewed patients' medical charts and food histories. Clinical specimens and food samples were tested for botulinum toxin and neurotoxin-producing Clostridium spp. Investigators conducted inspections of the cannery that produced the implicated product.Results. Eight confirmed outbreak associated cases were identified from Indiana (2), Texas (3), and Ohio (3). Botulinum toxin type A was identified in leftover chili sauce consumed by the Indiana patients and one of the Ohio patients. Cannery inspectors found violations of federal canned-food regulations that could have led to survival of C. botulinum spores during sterilization. The company recalled 39 million cans of chili. Following the outbreak, the US Food and Drug Administration inspected other canneries with similar canning systems and issued warnings to the industry about the danger of C. botulinum and the importance of compliance with canned food manufacturing regulations.Conclusion. Commercially produced hot dog chili sauce caused these cases of type A botulism. This is the first US foodborne botulism outbreak involving a commercial cannery in more than 30 years. Sharing of epidemiologic and laboratory findings allowed for the rapid identification of implicated food items and swift removal of potentially deadly products from the market by US food regulatory authorities.
    Clinical Infectious Diseases 10/2012; 56(3). DOI:10.1093/cid/cis901 · 9.42 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In 2010, 41 patients ill with Escherichia coli O157:H7 isolates determined to be indistinguishable by pulsed-field gel electrophoresis were identified among residents of five Southwestern U.S. states. A majority of patients reported consuming complimentary samples of aged raw-milk Gouda cheese at national warehouse chain store locations; sampling Gouda cheese was significantly associated with illness (odds ratio, 9.0; 95 % confidence interval, 1.7 to 47). Several Gouda samples yielded the O157:H7 outbreak strain, confirming the food vehicle and source of infections. Implicated retail food-sampling operations were inconsistently regulated among affected states, and sanitation deficiencies were common among sampling venues. Inspection of the cheese manufacturer indicated deficient sanitation practices and insufficient cheese curing times. Policymakers should continue to reexamine the adequacy and enforcement of existing rules intended to ensure the safety of raw-milk cheeses and retail food sampling. Additional research is necessary to clarify the food safety hazards posed to patrons who consume free food samples while shopping.
    Journal of food protection 10/2012; 75(10):1759-65. DOI:10.4315/0362-028X.JFP-12-136 · 1.80 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Contaminated food ingredients can affect multiple products, each distributed through various channels and consumed in multiple settings. Beginning in November 2008, we investigated a nationwide outbreak of salmonella infections. A case was defined as laboratory-confirmed infection with the outbreak strain of Salmonella Typhimurium occurring between September 1, 2008, and April 20, 2009. We conducted two case-control studies, product "trace-back," and environmental investigations. Among 714 case patients identified in 46 states, 166 (23%) were hospitalized and 9 (1%) died. In study 1, illness was associated with eating any peanut butter (matched odds ratio, 2.5; 95% confidence interval [CI], 1.3 to 5.3), peanut butter-containing products (matched odds ratio, 2.2; 95% CI, 1.1 to 4.7), and frozen chicken products (matched odds ratio, 4.6; 95% CI, 1.7 to 14.7). Investigations of focal clusters and single cases associated with nine institutions identified a single institutional brand of peanut butter (here called brand X) distributed to all facilities. In study 2, illness was associated with eating peanut butter outside the home (matched odds ratio, 3.9; 95% CI, 1.6 to 10.0) and two brands of peanut butter crackers (brand A: matched odds ratio, 17.2; 95% CI, 6.9 to 51.5; brand B: matched odds ratio, 3.6; 95% CI, 1.3 to 9.8). Both cracker brands were made from brand X peanut paste. The outbreak strain was isolated from brand X peanut butter, brand A crackers, and 15 other products. A total of 3918 peanut butter-containing products were recalled between January 10 and April 29, 2009. Contaminated peanut butter and peanut products caused a nationwide salmonellosis outbreak. Ingredient-driven outbreaks are challenging to detect and may lead to widespread contamination of numerous food products.
    New England Journal of Medicine 08/2011; 365(7):601-10. DOI:10.1056/NEJMoa1011208 · 54.42 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In May 2008, PulseNet detected a multistate outbreak of Salmonella enterica serotype Saintpaul infections. Initial investigations identified an epidemiologic association between illness and consumption of raw tomatoes, yet cases continued. In mid-June, we investigated two clusters of outbreak strain infections in Texas among patrons of Restaurant A and two establishments of Restaurant Chain B to determine the outbreak's source. We conducted independent case-control studies of Restaurant A and B patrons. Patients were matched to well controls by meal date. We conducted restaurant environmental investigations and traced the origin of implicated products. Forty-seven case-patients and 40 controls were enrolled in the Restaurant A study. Thirty case-patients and 31 controls were enrolled in the Restaurant Chain B study. In both studies, illness was independently associated with only one menu item, fresh salsa (Restaurant A: matched odds ratio [mOR], 37; 95% confidence interval [CI], 7.2-386; Restaurant B: mOR, 13; 95% CI 1.3-infinity). The only ingredient in common between the two salsas was raw jalapeño peppers. Cultures of jalapeño peppers collected from an importer that supplied Restaurant Chain B and serrano peppers and irrigation water from a Mexican farm that supplied that importer with jalapeño and serrano peppers grew the outbreak strain. Jalapeño peppers, contaminated before arrival at the restaurants and served in uncooked fresh salsas, were the source of these infections. Our investigations, critical in understanding the broader multistate outbreak, exemplify an effective approach to investigating large foodborne outbreaks. Additional measures are needed to reduce produce contamination.
    PLoS ONE 02/2011; 6(2):e16579. DOI:10.1371/journal.pone.0016579 · 3.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Raw produce is an increasingly recognized vehicle for salmonellosis. We investigated a nationwide outbreak that occurred in the United States in 2008. We defined a case as diarrhea in a person with laboratory-confirmed infection with the outbreak strain of Salmonella enterica serotype Saintpaul. Epidemiologic, traceback, and environmental studies were conducted. Among the 1500 case subjects, 21% were hospitalized, and 2 died. In three case-control studies of cases not linked to restaurant clusters, illness was significantly associated with eating raw tomatoes (matched odds ratio, 5.6; 95% confidence interval [CI], 1.6 to 30.3); eating at a Mexican-style restaurant (matched odds ratio, 4.6; 95% CI, 2.1 to ∞) and eating pico de gallo salsa (matched odds ratio, 4.0; 95% CI, 1.5 to 17.8), corn tortillas (matched odds ratio, 2.3; 95% CI, 1.2 to 5.0), or salsa (matched odds ratio, 2.1; 95% CI, 1.1 to 3.9); and having a raw jalapeño pepper in the household (matched odds ratio, 2.9; 95% CI, 1.2 to 7.6). In nine analyses of clusters associated with restaurants or events, jalapeño peppers were implicated in all three clusters with implicated ingredients, and jalapeño or serrano peppers were an ingredient in an implicated item in the other three clusters. Raw tomatoes were an ingredient in an implicated item in three clusters. The outbreak strain was identified in jalapeño peppers collected in Texas and in agricultural water and serrano peppers on a Mexican farm. Tomato tracebacks did not converge on a source. Although an epidemiologic association with raw tomatoes was identified early in this investigation, subsequent epidemiologic and microbiologic evidence implicated jalapeño and serrano peppers. This outbreak highlights the importance of preventing raw-produce contamination.
    New England Journal of Medicine 02/2011; 364(10):918-27. DOI:10.1056/NEJMoa1005741 · 54.42 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Monitoring disease incidence and transmission patterns is important to characterize groups at risk for hepatitis C virus (HCV) infection. Clinical cases generally represent about 20% to 30% of all newly acquired infections. We used sentinel surveillance to determine incidence and transmission patterns for acute hepatitis C in the United States using data from 25 years of population-based surveillance in the general community. Acute cases of hepatitis C were identified from 1982 through 2006 by a stimulated passive surveillance system in 4 to 6 US counties. Cases were defined by a discrete onset of symptoms, alanine aminotransferase (ALT) levels greater than 2.5 times the upper limit of normal (×ULN), negative findings for serologic markers for acute hepatitis A and B, and positive findings for antibody to HCV or HCV RNA. Incidence and frequency of reported risk factors were the main outcome measures. Of 2075 patients identified, the median age was 31 years, 91.5% had ALT values greater than 7×ULN, 77.3% were jaundiced, 22.5% were hospitalized, and 1.2% died. Incidence averaged 7.4 per 100,000 individuals (95% confidence interval [CI], 6.4-8.5 per 100,000) during 1982 to 1989 then declined averaging 0.7 per 100,000 (95% CI, 0.5-1.0 per 100,000) during 1994 to 2006. Among 1748 patients interviewed (84.2%), injection drug use (IDU) was the most commonly reported risk factor. The average number of IDU-related cases declined paralleling the decline in incidence, but the proportion of IDU-related cases rose from 31.8% (402 of 1266) during 1982 to 1989 to 45.6% (103 of 226) during 1994 to 2006. Among IDU-related cases reported during 1994 to 2006, 56 of 61 individuals (91.8%) had been in a drug treatment program and/or incarcerated. The incidence of acute HCV declined substantially over the 25 years of population-based surveillance. Despite declines, IDU is the most common risk factor for new HCV infection.
    Archives of internal medicine 02/2011; 171(3):242-8. DOI:10.1001/archinternmed.2010.511 · 13.25 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Human Salmonella infections associated with dry pet food have not been previously reported. We investigated such an outbreak of Salmonella Schwarzengrund and primarily affecting young children. Two multistate case-control studies were conducted to determine the source and mode of infections among case-patients with the outbreak strain. Study 1 evaluated household exposures to animals and pet foods, and study 2 examined risk factors for transmission among infant case-patients. Environmental investigations were conducted. Seventy-nine case-patients in 21 states were identified; 48% were children aged 2 years or younger. Case-households were significantly more likely than control households to report dog contact (matched odds ratio [mOR]: 3.6) and to have recently purchased manufacturer X brands of dry pet food (mOR: 6.9). Illness among infant case-patients was significantly associated with feeding pets in the kitchen (OR: 4.4). The outbreak strain was isolated from opened bags of dry dog food produced at plant X, fecal specimens from dogs that ate manufacturer X dry dog food, and an environmental sample and unopened bags of dog and cat foods from plant X. More than 23 000 tons of pet foods were recalled. After additional outbreak-linked illnesses were identified during 2008, the company recalled 105 brands of dry pet food and permanently closed plant X. Dry dog and cat foods manufactured at plant X were linked to human illness for a 3-year period. This outbreak highlights the importance of proper handling and storage of pet foods in the home to prevent human illness, especially among young children.
    PEDIATRICS 09/2010; 126(3):477-83. DOI:10.1542/peds.2009-3273 · 5.30 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Ribavirin, with interferons or pegylated interferons, is used to treat chronic hepatitis C. Ribavirin is contraindicated in pregnancy (FDA Pregnancy Category X) and in men whose partners may become pregnant. In 2003, the Ribavirin Pregnancy Registry was established to monitor pregnancy exposures to ribavirin and to evaluate the potential human teratogenicity of prenatal exposure. This voluntary registry enrolls pregnant women who have been exposed to ribavirin during pregnancy or during the six months prior to conception either directly, by taking ribavirin, or indirectly through sexual contact with a man taking ribavirin. Women are followed until delivery; live born infants are followed for one year. The Registry aims to enroll 131 live births following direct (maternal) exposure to ribavirin and 131 live births following indirect (male) exposures. After more than five years of operation, the Registry has enrolled 49 live births with direct exposure and 69 live births following indirect exposure. Six outcomes with birth defects have been reported. All were among live born infants: torticollis (2), hypospadias (1), polydactyly and a neonatal tooth (1), glucose-6-phosphate dehydrogenase deficiency (1), ventricular septal defect and cyst of 4th ventricle of the brain (1). Three received direct exposures ([6.1% (95% CI: 1.2, 16.9)], three were exposed indirectly [4.3% (95% CI: 0.9, 12.2)]. Although current enrollment is far short of the required sample size, preliminary findings have not detected a signal indicating human teratogenicity for ribavirin. However, findings must be interpreted with caution concerning direct or indirect prenatal ribavirin exposures.
    Birth Defects Research Part A Clinical and Molecular Teratology 07/2010; 88(7):551-9. DOI:10.1002/bdra.20682 · 2.21 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND. In studies of hepatitis C virus (HCV) seroconversion in injection drug users (IDUs), some have questioned whether underreporting of syringe sharing, a stigmatized behavior, has led to misattribution of HCV risk to other injection-related behaviors. METHODS. IDUs aged 15-30 years who were seronegative for human immunodeficiency virus and HCV antibodies were recruited into a prospective study in 5 US cities. Behavioral data were collected via computer-assisted self-interviewing to reduce socially desirable reporting. Hazard ratios (HRs) were estimated to assess associations between behavior and HCV seroconversion. Because the shared use of cookers, cottons, and rinse water was highly correlated, a summary variable was created to represent drug preparation equipment sharing. RESULTS. Among 483 IDUs who injected during the period covered by the follow-up assessments, the incidence of HCV infection was 17.2 cases per 100 person years; no HIV seroconversions occurred. Adjusting for confounders, the shared use of drug preparation equipment was significantly associated with HCV seroconversion (adjusted HR, 2.66; 95% confidence interval, 1.03-23.92), but syringe sharing was not (adjusted HR, 0.91). We estimated that 37% of HCV seroconversions in IDUs were due to the sharing of drug preparation equipment. CONCLUSIONS. Associations between sharing drug preparation equipment and HCV seroconversion are not attributable to underascertainment of syringe sharing. Avoiding HCV infection will require substantial reductions in exposure to all sources of contaminated blood.
    The Journal of Infectious Diseases 02/2010; 201(3):378-85. DOI:10.1086/649783 · 5.78 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We investigated 4 hepatitis C virus (HCV) infection outbreaks at hemodialysis units to identify practices associated with transmission. Apparent failures to follow recommended infection control precautions resulted in patient-to-patient HCV transmission, through cross-contamination of the environment or intravenous medication vials. Fastidious attention to aseptic technique and infection control precautions are essential to prevent HCV transmission. Infect Control Hosp Epidemiol 2009; 30: 900-903
    Infection Control and Hospital Epidemiology 10/2009; 30(9):900-3. DOI:10.1086/605472 · 3.94 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To evaluate the impact of routine hepatitis B (HB) vaccination on the prevalence of chronic hepatitis B virus (HBV) infection among children in Pacific Island countries where HBV infection was highly endemic, we conducted HB serosurveys during 2000 to 2007 among women of childbearing age born before implementation of HB vaccination and among children born after its implementation. Serum specimens were collected from children aged 2 to 6 years and their mothers in Chuuk, Federated States of Micronesia in 2000, children aged 2 to 9 years and their mothers in Pohnpei, Federated States of Micronesia in 2005, and 5- to 9-year-old children and prenatal clinic patients in 2007 in Republic of the Marshall Islands (RMI). Specimens were tested for HB surface antigen (HBsAg) and antibodies to HB core antigen (total anti-HBc). HB vaccination coverage was determined from health department vaccination registries. We defined chronic HBV infection as the presence of HBsAg. Birthdose and 3 dose HB vaccination coverage was 48% and 87%, respectively, in Chuuk, 87% and 90% in Pohnpei, and 49% and 93% in RMI. Chronic HBV infection prevalence among children was 2.5% (9/362) in Chuuk, 1.5% (7/478) in Pohnpei and 1.8% (6/331) in RMI. Chronic HBV infection prevalence among women was 9.2% (21/229) in Chuuk, 4.4% (10/229) in Pohnpei, and 9.5% (11/116) in RMI. Hepatitis B vaccination has resulted in a substantial decline in chronic infection in children in the Pacific Islands. HB vaccine effectiveness is high in this region, despite challenges in providing HB vaccine at birth and completing vaccination series on schedule.
    The Pediatric Infectious Disease Journal 10/2009; 29(1):18-22. DOI:10.1097/INF.0b013e3181b20e93 · 3.14 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Historically, hepatitis A virus (HAV) has been highly prevalent in developing countries, with most infections occurring during childhood, when they are likely to be asymptomatic. Shifts in the acquisition of infection from childhood to adulthood, when clinical hepatitis is more likely, may leave populations vulnerable to large outbreaks. We conducted cross-sectional serosurveys from 1995 to 2008 in four Pacific Island nations to determine the proportion of people previously infected with HAV by measuring antibodies to HAV (anti-HAV). In American Samoa, 0.0% of 4- to 6-year-olds (95% CI 0.0-3.7) were anti-HAV positive. In Chuuk, FSM, 8.6% of 2- to 6-year-olds (95% CI 5.7-11.5) were anti-HAV positive compared with 98.3% of individuals > or =16 years old (95% CI 96.6-100). In Pohnpei, FSM, 0.8% of 2- to 9-year-olds (95% CI 0.0-1.6) were anti-HAV positive compared with 95.1% of > or =16 year-olds (95% CI 92.2-98.0). In RMI, 85.7% (95% CI 81.9-89.5) of 4- to 9-year-olds were anti-HAV positive. In Palau, 0.7% of 7- to 8-year-olds were anti-HAV positive (95% CI 0.0-1.8). The low HAV seroprevalence among children in American Samoa, FSM and Palau may indicate a vulnerability to hepatitis A morbidity among these populations. These data will be useful for evaluating the need for hepatitis A surveillance and vaccination programs.
    Transactions of the Royal Society of Tropical Medicine and Hygiene 06/2009; 103(9):906-10. DOI:10.1016/j.trstmh.2009.05.001 · 1.93 Impact Factor

Publication Stats

2k Citations
469.53 Total Impact Points

Institutions

  • 1998–2014
    • Centers for Disease Control and Prevention
      • • National Center for Emerging and Zoonotic Infectious Diseases
      • • Division of Viral Hepatitis
      Атланта, Michigan, United States
  • 2010
    • Malawi Centers of Disease Control and Prevention
      Lilongwe, Central Region, Malawi
  • 2006
    • San Francisco Department of Public Health
      San Francisco, California, United States
  • 2005
    • National Institute of Allergy and Infectious Diseases
      베서스다, Maryland, United States
  • 2002
    • University of Illinois at Chicago
      • Division of Epidemiology and Biostatistics
      Chicago, IL, United States
    • New York Academy of Medicine
      New York City, New York, United States