Ian T Williams

Centers for Disease Control and Prevention, Atlanta, MI, United States

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Publications (64)444.07 Total impact

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    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; · 2.87 Impact Factor
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    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 01/2013; 8(2):e55300. · 3.53 Impact Factor
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    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; · 2.87 Impact Factor
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    ABSTRACT: SUMMARY In November 2009, we initiated a multistate investigation of Salmonella Montevideo infections with pulsed-field gel electrophoresis pattern JIXX01.0011. We identified 272 cases in 44 states with illness onset dates ranging from 1 July 2009 to 14 April 2010. To help generate hypotheses, warehouse store membership card information was collected to identify products consumed by cases. These records identified 19 ill persons who purchased company A salami products before onset of illness. A case-control study was conducted. Ready-to-eat salami consumption was significantly associated with illness (matched odds ratio 8·5, 95% confidence interval 2·1-75·9). The outbreak strain was isolated from company A salami products from an environmental sample from one manufacturing plant, and sealed containers of black and red pepper at the facility. This outbreak illustrates the importance of using membership card information to assist in identifying suspect vehicles, the potential for spices to contaminate ready-to-eat products, and preventing raw ingredient contamination of these products.
    Epidemiology and Infection 08/2012; · 2.87 Impact Factor
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    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. · 54.42 Impact Factor
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    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. · 11.46 Impact Factor
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    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. · 54.42 Impact Factor
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    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 01/2011; 6(2):e16579. · 3.53 Impact Factor
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    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. · 4.47 Impact Factor
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    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. · 2.27 Impact Factor
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    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. · 5.85 Impact Factor
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    ABSTRACT: Background: About 40,000 laboratory-confirmed Salmonella infections are reported annually in the U.S.; serotype Typhimurium causes ~19%. Outbreak investigations involving contaminated food ingredients are complex as products may be distributed through multiple channels and consumed in various settings over an extended period of time. We investigated a large multistate outbreak of Salmonella Typhimurium infections identified in November 2008. Methods: A case was defined as infection in a person with outbreak strain of S. Typhimurium with illness onset on or after 9/1/2008. Two case-control studies (CC1 and CC2) were performed. Controls were well persons from the community matched by age and location. Traceback and environmental investigations were conducted. Results: Among 714 cases identified in 46 states, 23% were hospitalized and nine died. In CC1, illness was associated with eating any peanut butter (PB) (matched odds ratio [mOR]=2.53, 95% confidence interval [CI]=1.26-5.31). The outbreak strain was isolated from Brand A institutional PB produced by Manufacturer A. Continuing interviews of patients not associated with institutions indicated that many patients had eaten PB-containing products. In CC2, illness was associated with eating PB crackers (mOR=9.08, CI=4.86-18.05), specifically Brand B (mOR=18.65, CI=7.59-55.07) and Brand C (mOR=4.13, CI=1.65-10.68). Major national brands of jarred PB found in grocery stores were not associated with illness. The outbreak strain was isolated from Brand B PB crackers containing peanut paste from Manufacturer A, PB flavored pet treats, and other PB-containing products linked to Manufacturer A. Traceback investigations resulted in the recall of >3,900 PB and PB-containing products. Conclusion: A large multistate outbreak caused by contaminated PB and PB-containing products from Manufacturer A used as ingredients in many widely distributed foods, resulted in one of the largest U.S. food recalls in recent history.
    Infectious Diseases Society of America 2009 Annual Meeting; 10/2009
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    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. · 3.57 Impact Factor
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    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.
    Infection Control and Hospital Epidemiology 10/2009; 30(9):900-3. · 4.02 Impact Factor
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    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. · 1.82 Impact Factor
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    ABSTRACT: There was an increase in perinatal hepatitis B virus (HBV) infections in one Arkansas county that disproportionately affected Marshallese infants. An estimated 6000 to 10,000 Marshallese, from the Pacific island nation of the Marshall Islands where HBV is highly endemic, live in one Arkansas county. We conducted a retrospective review of hospital and health department records from 2003 to 2005 in that county. We compared maternal screening for hepatitis B surface antigen (HBsAg) between Marshallese and non-Marshallese. We also reviewed birth and immunization records for infants born to HBsAg-positive mothers to evaluate postexposure prophylaxis (PEP). Ten percent (n = 41) of Marshallese births and 0.1% (n = 15) of non-Marshallese births were to HBsAg-positive women. Among those born to HBsAg-positive women, Marshallese and non-Marshallese infants were equally likely to receive PEP with hepatitis B vaccine (98% vs. 100%; P[r] = 0.98) and hepatitis B immune globulin (HBIG) <or=12 hours after birth (88% vs. 87%; P = 0.91). Approximately 57% (n = 32) of all infants born to HBsAg-positive women were tested for perinatal HBV infection. The proportion of Marshallese (17%) and non-Marshallese (13%) infants who tested positive for HBsAg at ages 9 to 25 months was similar (P = 0.78). Receiving HBIG >12 hours after birth was the only factor significantly associated with infection. Although HBV infection was more prevalent among Marshallese compared with non-Marshallese women, there were no differences in infant receipt of PEP and perinatal HBV infection. Delivery hospitals in this county had standing orders to administer hepatitis B vaccine to all newborns, which likely provided a safety net to prevent perinatal HBV transmission in this high-risk population.
    The Pediatric Infectious Disease Journal 06/2009; 28(7):593-7. · 3.57 Impact Factor
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    ABSTRACT: De novo hepatitis C virus (HCV) infection among transplant patients is rarely recognized but can have severe consequences. We investigated the scope, source, and mode of HCV transmission within a transplant center after incident HCV infection was identified in 2 patients who had liver transplantation in late 2006. Patients were interviewed, and transplant logs, medical records, and staff practices were reviewed to identify opportunities for HCV transmission. Infection via receipt of blood or organs was evaluated. Molecular epidemiology was used to determine the relatedness between persons with incident and chronic HCV infection. HCV from infected blood or organ donors was ruled out. Among the 308 patients who underwent transplant in 2006, no additional incident HCV infections were identified. Eighty-five (28%) had pre-transplant chronic HCV infection; 13 were considered possible HCV source patients based upon shared days on the inpatient unit, nursing assignment, or invasive procedures in common with incident HCV case-patients. Viral isolates from 1 HCV source patient and 1 incident case-patient were found to be highly related by quasispecies analysis, confirming patient-to-patient HCV transmission. Possible modes of transmission identified were the improper use of multidose vials, sharing of blood-contaminated glucometers, and touch contamination. Sporadic transmission or endemic levels of HCV transmission might be overlooked in a setting with high HCV prevalence, such as liver transplant units, where multiple, repeated opportunities for patient-to-patient HCV transmission can occur. Surveillance through pre- and post-transplant screening is necessary to identify incident HCV infection in this setting. Constant, meticulous attention must be paid to maintaining aseptic technique and good infection control practices to eliminate HCV transmission opportunities.
    Transplant Infectious Disease 06/2009; 11(4):324-9. · 1.98 Impact Factor
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    ABSTRACT: Long-term follow-up studies of populations that received recombinant hepatitis B (HB) vaccination beginning at birth are limited. Micronesian adolescents who had received 3 doses of recombinant HB vaccine (Recombivax 5 microg at birth, 2.5 microg at 2 months, 2.5 microg ug at 6 months) and tested negative for antibody to HB core antigen (anti-HBc) 2 years after primary vaccination (baseline testing) were followed up 15 years after primary vaccination. After testing for anti-HBc, HB surface antigen (HBsAg), and antibody to HBsAg (anti-HBs), participants received a booster dose of HB vaccine. An anamnestic response was defined as an increase in anti-HBs concentrations to a level > or = 10 mIU/mL 14 days postbooster. Of the 105 participants, 42 (40.0%) had anti-HBs concentrations > or = 10 mIU/mL on baseline testing. At 15 years, 8 (7.6%) were anti-HBc positive; none were HBsAg positive. Of the remaining 97, 7 (7.3%) had anti-HBs concentrations > or = 10 mIU/mL. Of the 96 who received a booster dose, 46 (47.9%) had an anamnestic response; final antibody concentrations were 10-99 mIU/mL for 17 (17.7%) and > 100 mIU/mL for 29 (30.2%). Participants with anti-HBs concentrations > or = 10 mIU/mL on baseline testing were more likely to have an anamnestic response at 15 years [26/39 (66.7%) versus 20/57 (35.1%); P = 0.003]. Fifteen years after primary vaccination starting at birth, 8% of participants had evidence of past HB virus infection, but none had chronic infection. Absence of an anamnestic response to an additional vaccine dose, seen in half of participants, might indicate waning immunity.
    The Pediatric Infectious Disease Journal 09/2008; 27(10):881-5. · 3.57 Impact Factor
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    ABSTRACT: To examine hepatitis C virus (HCV) seroprevalence among injection drug users in 4 US cities from 1994 through 2004. Demographic characteristics, behaviors, and prevalence of HCV antibody among 5088 injection drug users aged 18-40 years from Baltimore, Maryland; Chicago, Illinois; Los Angeles, California; and New York, New York, enrolled in 3 related studies--Collaborative Injection Drug User Study (CIDUS) I (1994-1996), CIDUS II (1997-1999), and CIDUS III/Drug User Intervention Trial (2002-2004)--were compared using the chi(2) and Mantel-Haenszel tests of significance. Trends over time were assessed by logistic regression. Prevalence of HCV infection was 65%, 35%, and 35% in CIDUS I, CIDUS II, and CIDUS III, respectively. The adjusted prevalence odds ratio (OR) of being HCV antibody positive increased with the number of years of injection drug use (OR, 1.93 [95% confidence interval {CI}, 1.68-2.21] for each year of injecting within the first 2 years; OR, 1.09 [95% CI, 1.07-1.11] for each year of injecting beyond the first 2 years). Significant decreases were observed in the prevalence of HCV antibody between CIDUS I and CIDUS III in Baltimore (OR, 0.30; 95% CI, 0.20-0.43) and Los Angeles (OR, 0.17; 95% CI, 0.09-0.31) and among people of races other than black in Chicago (OR, 0.12; 95% CI, 0.08-0.17). No decrease in prevalence was seen in New York (OR, 1.04; 95% CI, 0.69-1.58) or among blacks in Chicago (OR, 0.55; 95% CI, 0.16-1.90). Although regional differences exist, our data suggest that the incidence of HCV infection among injection drug users in the United States decreased from 1994 through 2004.
    Clinical Infectious Diseases 07/2008; 46(12):1852-8. · 9.37 Impact Factor
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    ABSTRACT: New injection drug users (IDUs) are at high risk for blood-borne viral infections. Given U.S. policy to only fund proven-effective HIV prevention interventions, insights into conducting intervention trials among young IDUs are provided here by describing methods and participants' characteristics in the CIDUS III/DUIT study. In 2002-2004, 15-30-year-old IDUs in Baltimore, Chicago, Los Angeles, New York, and Seattle were recruited through community outreach, advertising and coupon-based participant referrals. Baseline interviews assessed sociodemographics, injection, and sexual behaviors. Antibody tests for HIV and hepatitis A, B, and C viruses (HAV, HBV, and HCV) were conducted. IDUs who were HIV and HCV antibody negative at baseline were eligible to participate in a randomized controlled HIV/HCV prevention trial. Follow-up assessments were conducted 3 and 6 months post-intervention. Data were analyzed to identify participant differences at baseline by city, trial enrollment, and trial retention. Baseline assessments were completed by 3285 IDUs. Participants were mean age 23.8 years, 69% male, 64% White, 17% Hispanic, and 8% Black. Seroprevalence of HIV, HCV, HBV, and HAV antibodies were 2.9, 34.4, 22.4, and 19.3%, respectively. Of the 2062 (62.7%) baseline participants who were HIV and HCV antibody negative, 859 (41.7%) were randomized. At least one follow-up assessment was completed by 712 (83%) randomized participants. Contextual factors, primarily homelessness, were associated with lower enrollment and retention. Recruitment and retention of young-adult IDUs for complex intervention trials is complicated, yet feasible. Risk behaviors among participants enrolling in and completing the trial reflected those eligible to enroll.
    Drug and Alcohol Dependence 12/2007; 91 Suppl 1:S4-17. · 3.14 Impact Factor

Publication Stats

2k Citations
444.07 Total Impact Points

Institutions

  • 2004–2013
    • Centers for Disease Control and Prevention
      • • Scientific Education and Professional Development Program Office
      • • Division of Viral Hepatitis
      Atlanta, MI, United States
  • 2010
    • Malawi Centers of Disease Control and Prevention
      Lilongwe, Central Region, Malawi
  • 2003
    • Beth Israel Medical Center
      New York City, New York, 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