Biomedical subjects

Ian T Williams

Publications and source records attributed to Ian T Williams.

16 recordsLinked to original sources

PubMed2006

Locally acquired hepatitis E virus infection, El Paso, Texas.

Hepatitis E virus (HEV) is an enterically transmitted RNA virus that causes both epidemic and sporadic cases of acute hepatitis. Despite sero-surveys showing antibody to HEV in up to 36% of the US population, acute hepatitis E has been reported among individuals with no history of international travel only three times in the United States. We report a case of apparently locally-acquired hepatitis E that occurred in El Paso, Texas that was 98% similar to a previously isolated HEV found in swine in the United States. Like the three previous cases, a thorough investigation found no conclusive sources of infection. Active case surveillance found no additional cases.

Aged↗

PubMed2006

Changes in hepatitis C virus (HCV) viral load and interferon-alpha levels in HIV/HCV-coinfected patients treated with highly active antiretroviral therapy.

BACKGROUND: Reports are mixed as to whether highly active antiretroviral therapy (HAART) increases liver transaminase levels or hepatitis C virus (HCV) titers in HIV/HCV-coinfected individuals. It is hypothesized that increases in HCV RNA titers may result from changes in endogenous interferon-alpha (IFN-alpha) production. METHODS: HIV/HCV-coinfected patients receiving HAART were tested at baseline, 1, 2, 3, 6, and 9 months for liver transaminase levels, HIV and HCV viral loads, and IFN-alpha. Linear regression analysis was used to determine the effect of HAART on liver transaminase levels, HCV viral load, and IFN-alpha. RESULTS: Initiating HAART did not increase liver transaminase levels in majority of cases. In patients (n = 30) with baseline HIV titer >10,000 copies/mL, HCV titers increased 0.69 log10 and IFN-alpha decreased -0.96 log10 during HAART, in association with a > or =0.5 log10 decrease in HIV titer. As HIV titers reached their nadir approximately 4 months after initiation of HAART, HCV titers remained 0.54 log10 and IFN-alpha -0.71 log10 above and below baseline levels, respectively. HCV titers and IFN-alpha levels did not change from baseline in patients with baseline HIV titer < or =10,000 copies/mL. CONCLUSIONS: Coinfected patients did not have evidence of hepatoxicity HAART. In patients with baseline HIV titer >10,000 copies/mL, suppression of HIV replication by HAART was associated with an increase in HCV titer and a decrease in endogenous IFN-alpha levels.

Adult↗

PubMed2006

An outbreak of hepatitis B virus infection among methamphetamine injectors: the role of sharing injection drug equipment.

AIM: To identify risk factors for acute hepatitis B virus (HBV) infection among Wyoming methamphetamine injectors. DESIGN: A case-control study conducted in the setting of an outbreak. SETTING: A county in central Wyoming, United States. PARTICIPANTS: Cases were identified through surveillance and contact tracing and were defined as Natrona County, Wyoming, residents who were either symptomatic or confirmed serologically to be acutely infected with HBV during January-August, 2003. Controls were susceptible to HBV infection. All participants identified themselves as methamphetamine injectors. MEASUREMENTS: Participants were administered a survey that inquired about risk factors for HBV infection, including drug use practices and sexual behaviors. Controls were also tested serologically for acute HBV infection. FINDINGS: Among the 18 case-patients and 49 controls who participated in the study, sharing water used to prepare injections and/or rinse syringes was associated with HBV infection (94% of case-participants versus 44% of controls; OR = 21.9, 95% CI: 2.7, 177.8), as was sharing cotton filters (89% of case-participants versus 52% of controls; OR = 7.4, 95% CI: 1.5, 35.6); sharing syringes was not statistically associated. In logistic regression models adjusted for age, sex, and interview site, sharing rinse water and sharing cotton remained statistically associated. CONCLUSIONS: Methamphetamine use has become increasingly prevalent in the United States. Our findings highlight the need for awareness of risks associated with injection drug use and sharing behaviors. Enhanced hepatitis B vaccination programs and educational campaigns that target methamphetamine injectors specifically, including those living in rural areas, should be developed and implemented.

Adult↗

PubMed2006

Hepatitis C virus infection in Samoa and American Samoa.

Little is known about the prevalence of hepatitis C virus (HCV) in Pacific islands. In this study, serum specimens collected in 1985 and 2002 among the general populations of Samoa and American Samoa were tested for antibody to HCV by a third-generation enzyme immunoassay and a recombinant immunoblot assay. Of the 3,466 specimens tested, 8 (0.2%; 95% confidence interval = 0.07-0.4%) were positive for antibody to HCV. Prevalence did not vary by location or demographic characteristic. Thus, HCV is present in the Samoas but at a low prevalence.

American Samoa↗

PubMed2005

Transmission of hepatitis C virus to several organ and tissue recipients from an antibody-negative donor.

BACKGROUND: Although hepatitis C virus (HCV) transmission through tissue transplantation has been rarely reported, a donor with undetected viremia may infect several recipients. A patient developed acute hepatitis C shortly after tissue transplantation. Ninety-one tissues or organs had been recovered from the donor. OBJECTIVE: To determine whether the donor was the source of infection and the extent of transmission to other organ and tissue recipients. DESIGN: Descriptive epidemiologic study; serum testing for HCV infection. SETTING: Recipients were located in 16 states and 2 other countries. PARTICIPANTS: Donor and graft recipients. MEASUREMENTS: Hepatitis C virus infection was defined as the presence of anti-HCV or HCV RNA. The authors determined the genetic relatedness of viral isolates from the donor and recipients by genotype comparison and quasi-species analysis. RESULTS: The donor was anti-HCV-negative but was HCV RNA-positive (genotype 1a). Forty persons received transplants during 22 months. Five persons were HCV-infected before transplantation or had a genotype other than 1a, and 5 persons had no post-transplantation serum specimens available. Of the remaining 30 recipients, HCV infection occurred in 8 recipients: 3 of 3 organ recipients, 1 of 2 saphenous vein recipients, 1 of 3 tendon recipients, and 3 of 3 tendon with bone recipients. These 8 recipients had viral isolates genetically related to those of the donor. No cases occurred in recipients of skin (n = 2), cornea (n = 1), or irradiated bone (n = 16). LIMITATIONS: Post-transplantation serum specimens were unavailable for 5 recipients. CONCLUSIONS: An anti-HCV-negative donor was the source of HCV infection for 8 recipients of organs or tissues. Although HCV transmission from anti-HCV-negative donors is probably uncommon, changes in donor screening to include routine testing for HCV RNA merit further consideration to improve the safety of transplantation.

Female↗

PubMed2005

Molecular epidemiology of foodborne hepatitis a outbreaks in the United States, 2003.

BACKGROUND: Molecular epidemiologic investigations can link geographically separate foodborne hepatitis A outbreaks but have not been used while field investigations are in progress. In 2003, outbreaks of foodborne hepatitis A were reported in multiple states. METHODS: Case-control studies were conducted in 3 states. Hepatitis A virus was sequenced from serologic specimens from individuals associated with outbreaks and from individuals concurrently ill with hepatitis A in non-outbreak settings in the United States and Mexico. RESULTS: Case-control studies in Tennessee (TN), North Carolina (NC), and Georgia (GA) found green onions to be associated with illness among restaurant patrons (TN: odds ratio [OR], 65.5 [95% confidence interval {CI}, 8.9-482.5; NC: OR, 2.4 [95% CI, 0.3-21.9]; GA: OR, 20.9 [95% CI, 3.9-110.3]). Viral sequences from TN case patients differed by 2 nt, compared with those from case patients in NC and GA. A third sequence, differing from the TN and GA/NC sequences by 1 nt, was identified among case patients in a subsequent outbreak in Pennsylvania. Each outbreak sequence was identical to > or =1 sequence isolated from northern Mexican resident(s) with hepatitis A. The sources of green onions served in restaurants in TN and GA were 3 farms in northern Mexico. CONCLUSIONS: Ongoing viral strain surveillance facilitated the rapid implementation of control measures. Incorporation of molecular epidemiologic methods into routine hepatitis A surveillance would improve the detection of hepatitis A outbreaks and increase our understanding of hepatitis A epidemiology in the United States.

Case-Control Studies↗

PubMed2005

An outbreak of hepatitis A associated with green onions.

BACKGROUND: In November 2003, a large hepatitis A outbreak was identified among patrons of a single Pennsylvania restaurant. We investigated the cause of the outbreak and factors that contributed to its unprecedented size. METHODS: Demographic and clinical outcome data were collected from patients with laboratory confirmation of hepatitis A, and restaurant workers were tested for hepatitis A. A case-control study was conducted among patrons who dined at the restaurant between October 3 and October 6, 2003. Sequence analysis was performed on a 315-nucleotide region of viral RNA extracted from serum specimens. RESULTS: Of 601 patients identified, 3 died; at least 124 were hospitalized. Of 425 patients who recalled a single dining date at the restaurant, 356 (84 percent) had dined there between October 3 and October 6. Among 240 patients in the case-control study, 218 had eaten mild salsa (91 percent), as compared with 45 of 130 controls (35 percent) (odds ratio, 19.6; 95 percent confidence interval, 11.0 to 34.9) for whom data were available. A total of 98 percent of patients and 58 percent of controls reported having eaten a menu item containing green onions (odds ratio, 33.3; 95 percent confidence interval, 12.8 to 86.2). All restaurant workers were tested, but none were identified who could have been the source of the outbreak. Sequences of hepatitis A virus from all 170 patients who were tested were identical. Mild salsa, which contained green onions grown in Mexico, was prepared in large batches at the restaurant and provided to all patrons. CONCLUSIONS: Green onions that were apparently contaminated before arrival at the restaurant caused this unusually large foodborne outbreak of hepatitis A. The inclusion of contaminated green onions in large batches that were served to all customers contributed to the size of the outbreak.

Adolescent↗

PubMed2005

Risk factors for hepatitis B in an outbreak of hepatitis B and D among injection drug users.

During January-April, 2000, 12 cases of acute hepatitis B were reported in Pierce County, Washington, compared with seven in all of 1999. Seven (58.3%) case patients were injection drug users (IDUs), three of whom were coinfected with hepatitis D virus (HDV) and died of fulminant hepatitis. Vaccination clinics were implemented at the local health department and needle exchange program to control the outbreak. We investigated this outbreak to determine risk factors for hepatitis B virus (HBV) transmission among IDUs. Hepatitis B cases were ascertained through routine surveillance and prevaccination testing at vaccination clinics. We conducted a case-control study comparing IDU case patients with HBV-susceptible IDUs identified at the vaccination clinics. Fifty-eight case patients were identified during January-December, 2000, 20 (34.5%) of whom were coinfected with HDV. Thirty-eight case patients (65.5%) reported current IDU. In the case-control study, the 17 case patients were more likely than the 141 controls to report having more than one sex partner [odds ratio (OR) =4.8, 95% confidence interval (CI) =1.5-15.0], injecting more than four times a day (OR = 4.5, 95% CI =1.2-15.6) and sharing drug cookers with more than two people (58.8% vs. 14.0%, OR =14.0, 95% CI =2.4-81.5). Results were similar after controlling for syringe sharing in multivariable analysis. IDUs should be vaccinated against hepatitis B and should be advised against sharing drug injection equipment.

Acute Disease↗

PubMed2005

Prevalence and correlates of crack-cocaine injection among young injection drug users in the United States, 1997-1999.

OBJECTIVES: We estimated prevalence and identified correlates of crack-cocaine injection among young injection drug users in the United States. METHODS: We analyzed data from the second Collaborative Injection Drug Users Study (CIDUS II), a 1997-1999 cohort study of 18-30-year-old, street-recruited injection drug users from six US cities. RESULTS: Crack-cocaine injection was reported by 329 (15%) of 2198 participants. Prevalence varied considerably by site (range, 1.5-28.0%). No participants injected only crack-cocaine. At four sites where crack-cocaine injection prevalence was greater than 10%, recent (past 6 months) crack-cocaine injection was correlated with recent daily injection and sharing of syringes, equipment, and drug solution. Lifetime crack-cocaine injection was correlated with using shooting galleries, initiating others into drug injection, and having serologic evidence of hepatitis B virus and hepatitis C virus infection. CONCLUSIONS: Crack-cocaine injection may be a marker for high-risk behaviors that can be used to direct efforts to prevent HIV and other blood-borne viral infections.

Adolescent↗

PubMed2005

A large outbreak of hepatitis B virus infections associated with frequent injections at a physician's office.

OBJECTIVES: To determine whether hepatitis B virus (HBV) transmission occurred among patients visiting a physician's office and to evaluate potential transmission mechanisms. DESIGN: Serologic survey, retrospective cohort study, and observation of infection control practices. SETTING: Private medical office. PATIENTS: Those visiting the office between March 1 and December 26, 2001. RESULTS: We identified 38 patients with acute HBV infection occurring between February 2000 and February 2002. The cohort study, limited to the 10 months before outbreak detection, included 91 patients with serologic test results and available charts representing 18 case-patients and 73 susceptible patients. Overall, 67 patients (74%) received at least one injection during the observation period. Case-patients received a median of 14 injections (range, 2-25) versus 2 injections (range, 0-17) for susceptible patients (P < .001). Acute infections occurred among 18 (27%) of 67 who received at least one injection versus none of 24 who received no injections (RR, 13.6; CI95, 2.4-undefined). Risk of infection increased 5.2-fold (CI95, 0.6-47.3) for those with 3 to 6 injections and 20.0-fold (CI95, 2.8-143.5) for those with more than 6 injections. Typically, injections consisted of doses of atropine, dexamethasone, vitamin B12, or a combination of these mixed in one syringe. HBV DNA genetic sequences of 24 patients with acute infection and 4 patients with chronic infection were identical in the 1,500-bp region examined. Medical staff were seronegative for HBV infection markers. The same surface was used for storing multidose vials, preparing injections, and dismantling used injection equipment. CONCLUSION: Administration of unnecessary injections combined with failure to separate clean from contaminated areas and follow safe injection practices likely resulted in patient-to-patient HBV transmission in a private physician's office.

Aged↗

PubMed2003

Plasmodium falciparum apical membrane antigen 1 (PfAMA-1) is translocated within micronemes along subpellicular microtubules during merozoite development.

During the assembly of Plasmodium falciparum merozoites within the schizont stage, the parasite synthesizes and positions three sets of secretory vesicles (rhoptries, micronemes and dense granules) that are active during red cell invasion. There are up to 40 micronemes per merozoite, shaped like long-necked bottles, about 160 nm long and 65 nm at their widest diameter. On their external surfaces, they bear bristle-like filaments, each 3-4 nm thick and 25 nm long. Micronemes are translocated from a single Golgi-like cisterna near the nucleus along a band of two or three subpellicular microtubules to the merozoite apex, where they dock with the rhoptry tips. Dense granules are also formed around the periphery of the Golgi cisternae but their distribution is unrelated to microtubules. Three polyclonal antibodies raised against the recombinant PfAMA-1 ectodomain sequence recognizing both the 83 kDa and processed 66 kDa molecules label the peripheries of translocating and mature micronemes but do not label rhoptries significantly at any stage of merozoite development within schizonts. This result confirms that PfAMA-1 is a micronemal protein, and indicates that within the microneme it is located near or inserted into this organelle's boundary membrane.

Animals↗

PubMed2003

Transmission of HIV and hepatitis C virus from a nursing home patient to a health care worker.

BACKGROUND: We report a case of simultaneous HIV and hepatitis C virus (HCV) transmission from a nursing home patient to a health care worker (HCW) whose HIV and HCV infections were diagnosed during routine blood donor screening. METHODS: Detailed information about the HCW, possible occupational and nonoccupational blood and body fluid exposures, and possible source patient was collected. Blood samples were drawn from the HCW and patient, and HIV and HCV laboratory testing was performed at the Centers for Disease Control and Prevention. RESULTS: The HCW, who worked as a nursing home aide, had no nonoccupational risk factors for HIV or HCV infection but provided care for 1 HIV-infected patient with dementia and urinary and fecal incontinence. The HCW had numerous exposures to the patient's emesis, feces, and urine to unprotected chapped and abraded hands. HCW and patient blood samples were positive for anti-HCV by enzyme immunoassay and recombinant immunoblot assay testing. The HCW's and patient's HCV were genotyped as 1a, and their HIV-1 was genotyped as subtype B. HIV and HCV ribonucleic acid (RNA) sequence analysis showed that the HCW's and patient's viruses were very closely related. CONCLUSIONS: HIV and HCV transmission from the patient to the HCW appears to have occurred through nonintact skin exposure. Bloodborne pathogen transmission may have been prevented in this situation by consistent, unfailing use of barrier precautions.

Adult↗

PubMed2003

Long term antibody response to hepatitis B vaccination beginning at birth and to subsequent booster vaccination.

BACKGROUND: Few studies have examined the long term persistence of antibody after hepatitis B immunization beginning at birth and the response to a subsequent challenge with a booster dose of vaccine. METHODS: Two groups of children received hepatitis B vaccine on a schedule of birth and 1 and 6 months of age. Group 1 received recombinant vaccine and a booster dose at 5 years of age. Group 2 received plasma-derived vaccine and a booster dose at 9 years of age. Group 1 children were tested for antibody after the primary vaccine series. All children were tested for antibody before administration of the booster dose and at 2 and 4 weeks and 1 year after the booster. In addition all children were tested for markers of hepatitis B virus infection. RESULTS: Antibody testing conducted after the primary series for children in Group 1 (n = 70) showed that 90% had protective antibody concentrations at 13 months of age, and testing before the booster dose showed that 41% had protective antibody concentrations. All children with protective antibody concentrations after the primary series had an anamnestic antibody response to the booster dose. In Group 2 (n = 41) 39% of children had protective antibody concentrations before the booster dose, and 93% had an anamnestic antibody response to the booster dose. One year after the booster dose there were 26-fold and 11-fold declines in antibody concentration in Groups 1 and 2, respectively. CONCLUSIONS: A primary vaccination series with either plasma-derived or recombinant hepatitis B vaccine affords long term protection for children when vaccinated beginning soon after birth.

American Samoa↗

PubMed2002

Risk of hepatitis C virus infection among young adult injection drug users who share injection equipment.

Designing studies to examine hepatitis C virus (HCV) transmission via the shared use of drug injection paraphernalia other than syringes is difficult because of saturation levels of HCV infection in most samples of injection drug users (IDUs). The authors measured the incidence of HCV infection in a large cohort of young IDUs from Chicago, Illinois, and determined the risk of HCV seroconversion associated with specific forms of sharing injection paraphernalia. From 1997 to 1999, serum samples obtained from 702 IDUs aged 18-30 years were screened for HCV antibodies; prevalence was 27%. Seronegative participants were tested for HCV antibodies at baseline, at 6 months, and at 12 months. During 290 person-years of follow-up, 29 participants seroconverted (incidence: 10.0/100 person-years). The adjusted relative hazard of seroconversion, controlling for demographic and drug-use covariates, was highest for sharing "cookers" (relative hazard = 4.1, 95% confidence interval: 1.4, 11.8), followed by sharing cotton filters (relative hazard = 2.4, 95% confidence interval: 1.1, 5.0). Risks associated with syringe-sharing and sharing of rinse water were elevated but not significant. After adjustment for syringe-sharing, sharing cookers remained the strongest predictor of seroconversion (relative hazard = 3.5, 95% confidence interval: 1.3, 9.9). The authors conclude that sharing of injection equipment other than syringes may be an important cause of HCV transmission between IDUs.

Adult↗

PubMed2002

Incidence and risk factors for acute hepatitis B in the United States, 1982-1998: implications for vaccination programs.

From 1982-1998, enhanced sentinel surveillance for acute hepatitis B was conducted in 4 counties in the United States to determine trends in disease incidence and risk factors for infection. During this period, the reported incidence of acute hepatitis B declined by 76.1% from 13.8 cases per 100,000 in 1987 to 3.3 cases per 100,000 in 1998. Cases associated with injection drug use (IDU) decreased by 90.6%, men who have sex with men (MSM) by 63.5%, and heterosexual activity by 50.7%. During 1994-1998, the most commonly reported risk factor for infection was high-risk heterosexual activity (39.8%) followed by MSM activity (14.6%) and IDU (13.8%). Over half of all patients (55.5%) reported treatment for a sexually transmitted disease (STD) or incarceration in a prison or jail prior to their illness, suggesting that more than half of the acute hepatitis B cases might have been prevented through routine hepatitis B immunization in STD clinics and correctional health care programs.

Acute Disease↗

PubMed2002

Anthrax postexposure prophylaxis in postal workers, Connecticut, 2001.

After inhalational anthrax was diagnosed in a Connecticut woman on November 20, 2001, postexposure prophylaxis was recommended for postal workers at the regional mail facility serving the patient's area. Although environmental testing at the facility yielded negative results, subsequent testing confirmed the presence of Bacillus anthracis. We distributed questionnaires to 100 randomly selected postal workers within 20 days of initial prophylaxis. Ninety-four workers obtained antibiotics, 68 of whom started postexposure prophylaxis, and of these, 21 discontinued. Postal workers who never started or stopped taking prophylaxis cited as reasons disbelief regarding anthrax exposure, problems with adverse events, and initial reports of negative cultures. Postal workers with adverse events reported predominant symptoms of gastrointestinal distress and headache. The influence of these concerns on adherence suggests that communication about risks of acquiring anthrax, education about adverse events, and careful management of adverse events are essential elements in increasing adherence.

Adolescent↗