The majority of healthcare-associated diarrhea is not attributable to CDAD, and the prevalence of asymptomatic C. difficile colonization exceeds CDAD rates in healthcare facilities. PCR detection of asymptomatic C. difficile colonization among patients with non-CDAD diarrhea may be contributing to rising CDAD rates and a significant number of CDAD false positives. PCR may be useful for CDAD screening, but further study is needed to guide interpretation of PCR detection of C. difficile and the value of confirmatory tests. A gold standard CDAD diagnostic assay is needed.

Key Points Question Does COVID-19 convalescent plasma (CCP), compared with placebo, improve the clinical status of hospitalized patients with COVID-19 requiring noninvasive supplemental oxygen? Findings In this randomized clinical trial including 941 patients, based on the World Health Organization 11-point Ordinal Scale for Clinical Improvement, CCP did not benefit 468 participants randomized to CCP compared with 473 randomized to placebo from April 2020 to March 2021. However, in exploratory analyses, CCP appeared to benefit those enrolled from April to June 2020, the period when most participants received high-titer CCP and were not receiving remdesivir and corticosteroids at randomization. Meaning In this trial, CCP did not meet prespecified outcomes for efficacy, but high-titer CCP may have benefited hospitalized patients with COVID-19 early in the pandemic when other treatments were not in use, suggesting a heterogenous treatment effect over time.

We conducted an anonymous cross-sectional seroprevalence study of a population with a low frequency of injection drug use to determine whether persons with a history of cosmetic procedures, such as tattooing and body piercing, or intranasal drug use were at increased risk for hepatitis C virus (HCV) or hepatitis B virus (HBV) infection. Students 18 years and older from eight college campuses in Houston, Texas, were invited to participate in the study. Of the 7,960 who completed a self-administered questionnaire and provided a blood sample, 5,282 U.S.-or Canadian-born participants were analyzed. Their median age was 21, 62% were female, 42% were white, 26% black, 22% Hispanic, and 10% Asian or other. Two percent reported injection drug use, 13.7% intranasal drug use, 21.2% body piercings, and 25.2% tattoos. The overall prevalence of HCV infection was 0.9% and of HBV infection was 5.2%. Higher HCV prevalence was independently associated with increasing age (odds ratio [OR] per year ‫؍‬ 1.11; 95% confidence interval [CI] ‫؍‬ 1.08-1.14), history of injection drug use (OR ‫؍‬ 18.24; 95% CI ‫؍‬ 7.74-42.92), blood transfusion before 1991 (OR ‫؍‬ 3.21; 95% CI ‫؍‬ 1.02-10.12), and incarceration (OR ‫؍‬ 3.48; 95% CI ‫؍‬ 1.45-8.37). Among 5,066 students who denied injecting drugs, HCV prevalence was 0.8% in those who reported intranasal drug use and 0.6% each in those who reported tattoos and those who reported body piercing. Increased HBV prevalence was associated with high-risk sexual behaviors and black or Asian race. In conclusion, there was no increased risk for HCV or HBV infection in low-risk adults based solely on history of cosmetic procedures or snorting drugs. However, proper infection control practices for cosmetic procedures should be followed, illegal drug use discouraged, and hepatitis B vaccination provided to adolescents and sexually active adults. (HEPATOLOGY 2006;44:341-351.)

Background Hepatitis B vaccine provides a model for improving uptake and completion of multi-dose vaccinations in the drug-using community. Methods DASH project conducted randomized controlled trial among not-in-treatment current drug users in two urban neighborhoods. Neighborhoods were cluster-randomized to receive a standard (HIV information) or enhanced (HBV vaccine acceptance/adherence) behavioral intervention; participants within clusters were randomized to a standard (0, 1, 6 mo) or accelerated (0, 1, 2 mo) vaccination schedule. Outcomes were completion of three-dose vaccine and HBV seroprotection. Results Of those screening negative for HIV/HBV, 77% accepted HB vaccination and 75% of those received all 3 doses. Injecting drug users (IDUs) on the accelerated schedule were significantly more likely to receive 3 doses (76%) than those on the standard schedule (66%, p=.04), although for drug users as a whole the adherence was 77% and 73%. No difference in adherence was observed between behavioral intervention groups. Predictors of adherence were older age, African American race, stable housing, and alcohol use. Cumulative HBV seroprotection (≥10 mIU/mL) was gained by 12 months by 65% of those completing. Seroprotection at 6 months was greater for the accelerated schedule group. Conclusions The accelerated vaccine schedule improves hepatitis B vaccination adherence among IDU.

Hepatitis C virus (HCV), an emerging bloodborne pathogen, causes chronic liver disease frequently except in about 10-20% of infections which undergo spontaneous resolution. Investigating factors that influence viral clearance is essential to understand the natural history of this infection and establishing novel strategies for prevention and treatment. HCV clearance was estimated in a unique cohort of 1260 HIV and HBV negative current drug users enrolled for a hepatitis B vaccination study. It was defined as the inability to detect viral RNA using a PCR method in presence of serum anti-HCV antibody EIA. Associated demographic and socio-behavioral factors including drug use patterns were identified from the enrolled subjects using multivariate regression analysis. 33.3 % (420/1260) of drug users were found positive for anti-HCV antibodies and 14.8% (62/420) of these individuals achieved viral clearance (negative PCR test). Race or ethnicity of the participants was the only significant factor associated with HCV clearance. Hispanics (OR = 3.4, 95% CI: 1.3-8.5, p = 0.01) and Caucasians (OR = 3.1, 95% CI: 1.5-6.6, p = 0.003) had significantly higher odds of clearing the virus compared to African Americans when adjusted for age and gender. None of the socio-behavioral factors including alcohol intake and drug use patterns were significant determinants of HCV clearance. Racial or ethnic differences in HCV clearance were observed in this study suggesting an important role of host genetic susceptibility factors in determining the clinical course of this disease. Further research is needed to examine these genetic associations of host-virus relationships.

Despite the high immunogenicity of the hepatitis B vaccine, evidence suggests that immunological response in drug users is impaired compared to the general population. A sample of not-in-treatment adult drug users from two communities in Houston, Texas, USA, susceptible to hepatitis B virus (HBV), was sampled via outreach workers and referral methodology. Participants were randomized to either the standard multi-dose hepatitis B vaccine schedule (0, 1, 6 month) or to an accelerated (0, 1, 2 month) schedule. The participants were followed for one year. Antibody levels were measured at 2, 6 and 12 months after enrollment in order to determine the immune responses. At 12 months, cumulative adequate protective response was achieved in 65% of the HBV susceptible subgroup using both the standard and accelerated schedules. The standard group had a higher mean antibody titer (184.6 vs 57.6 mIU/mL). But at six months, seroconversion at the adequate protective response was reached by a higher proportion of participants and the mean antibody titer was also higher in the accelerated schedule group (104.8 vs. 64.3 mIU/mL). Multivariate analyses indicated a 63% increased risk of non-response for participants 40 years or older (p=0.046). Injecting drugs more than once a day was also highly associated with the risk of non-response (p=0.016). Conclusions from this research will guide the development of future vaccination programs that anticipate other prevalent chronic conditions, susceptibilities, and risk-taking behaviors of hard-to-reach populations.

Objectives. We demonstrated the effectiveness of an accelerated hepatitis B vaccination schedule in drug users. Methods. We compared the long-term effectiveness of accelerated (0–1–2 months) and standard (0–1–6 months) hepatitis B vaccination schedules in preventing hepatitis B virus (HBV) infections and anti-hepatitis B (anti-HBs) antibody loss during 2-year follow-up in 707 drug users (HIV and HBV negative at enrollment and completed 3 vaccine doses) from February 2004 to October 2009. Results. Drug users in the accelerated schedule group had significantly lower HBV infection rates, but had a similar rate of anti-HBs antibody loss compared with the standard schedule group over 2 years of follow-up. No chronic HBV infections were observed. Hepatitis C positivity at enrollment and age younger than 40 years were independent risk factors for HBV infection and antibody loss, respectively. Conclusions. An accelerated vaccination schedule was more preferable than a standard vaccination schedule in preventing HBV infections in drug users. To overcome the disadvantages of a standard vaccination schedule, an accelerated vaccination schedule should be considered in drug users with low adherence. Our study should be repeated in different cohorts to validate our findings and establish the role of an accelerated schedule in hepatitis B vaccination guidelines for drug users.

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