(-)-2''-deoxy-3''-thiacytidine is a potent, highly selective inhibitor of human immunodeficiency virus type 1 and type 2 replication in vitro.

The (-)-enantiomer of 2'-deoxy-3'-thiacytidine (3TC) was found to be a potent and selective inhibitor of human immunodeficiency virus types 1 (HIV-1) and 2 (HIV-2) in vitro. We determined its antiviral activity against a number of laboratory strains of HIV-1 and HIV-2 in a range of CD4-bearing lymphocyte cell lines (mean 50% inhibitory concentration [IC50] range, 4 nM to 0.67 microM). 3TC was also active against a range of HIV-1 strains in peripheral blood lymphocytes (mean IC50 range, 2.5 to 90 nM). The IC50 for cytotoxicity in seven lymphocyte cell cultures, including human peripheral blood lymphocytes, ranged from 0.5 to 6 mM. 3TC had no detectable antiviral activity against a range of other viruses or in cells chronically infected with HIV-1 or HIV-2. The effects of time of addition of the compound and varying the multiplicity of infection on the antiviral activity of 3TC were determined. The results showed that 3TC is a potent and selective inhibitor of HIV-1 and HIV-2 replication in vitro.     

Comparing Active and Passive Varicella Surveillance in Philadelphia, 2005–2010: Recommendations for the Transition to Nationwide Passive Varicella Disease Surveillance

Objective

The Philadelphia Department of Public Health (PDPH) conducts active surveillance for varicella in West Philadelphia. For its approximately 300 active surveillance sites, PDPH mandates biweekly reports of varicella (including zero cases) and performs intensive case investigations. Elsewhere in Philadelphia, surveillance sites passively report varicella cases, and abbreviated investigations are conducted. We used active varicella surveillance program data to inform the transition to nationwide passive varicella surveillance.

Methods

We compared classification of reported cases, varicella disease incidence, and reporting completeness for active and passive surveillance areas for 2005–2010. We assessed reporting completeness using capture-recapture analysis of 2- to 18-year-old cases reported by schools/daycare centers and health-care providers.

Results

From 2005 to 2010, PDPH received 3,280 passive and 969 active surveillance varicella case reports. Most passive surveillance reports were classified as probable cases (18% confirmed, 56% probable, and 26% excluded), whereas nearly all of the active surveillance reports were either confirmed or excluded (36% confirmed, 11% probable, and 53% excluded). Overall incidence rates calculated using confirmed/probable cases were similar in the active and passive surveillance areas. Detection of laboratory-confirmed, breakthrough, and moderate-to-severe cases was equivalent for both surveillance areas.

Conclusions

Although active surveillance for varicella results in better classified cases, passive surveillance provides comparable data for monitoring disease trends in breakthrough and moderate-to-severe varicella. To further improve passive surveillance in the two-dose-varicella vaccine era, jurisdictions should consider conducting periodic enhanced surveillance, encouraging laboratory testing, and collecting additional varicella-specific variables for passive surveillance.To monitor the impact of the varicella vaccination program, the Centers for Disease Control and Prevention, in collaboration with the Philadelphia Department of Public Health (PDPH) and Los Angeles County Department of Health Services, conducted varicella surveillance through the Varicella Active Surveillance Project (VASP) from 1996–2011.¹ This new program was essential, because when varicella vaccine was recommended for use in the United States in 1996, varicella was not nationally notifiable; varicella had been removed from the list of notifiable conditions in 1981 because reporting the then-common disease was not feasible in many states.² VASP has supplied vital information for programmatic decision-making, including the 2007 recommendation for a second dose of varicella vaccine.³With the success of the varicella vaccination program in reducing the incidence of disease, relatively small active surveillance areas cannot accurately monitor further declines in varicella incidence, changes in age distribution, and disease severity. Therefore, more widespread passive surveillance is required. In 2003, varicella was again added to the national notifiable diseases list, and the Council of State and Territorial Epidemiologists (CSTE) recommended that all states implement case-based surveillance by 2005.^4–6 To mitigate the burden of varicella surveillance, CSTE recommended that states begin by focusing on the collection of three varicella-specific variables: age at disease onset, number of lesions (as a proxy for disease severity), and vaccination status, adding variables, including rash characteristics, varicella-related complications, and diagnostic laboratory data, when feasible.² As of 2010, 38 states were conducting case-based passive surveillance, but the completeness of information collected is unknown.⁷In this article, we briefly summarize the characteristics of active and passive surveillance in Philadelphia, Pennsylvania, and compare active and passive varicella surveillance data for 2005–2010 as the basis for recommendations to optimize the quality of national passive surveillance. Specifically, we compared (1) the proportions of confirmed, probable, and excluded cases among overall reports; (2) the proportions of cases reported by type of reporting site; (3) the overall reported incidence of varicella; (4) the completeness of reporting assessed by capture-recapture methodology; and (5) the extent of laboratory testing and findings from testing. Our results suggest that optimizing passive surveillance in the U.S. will require efforts to improve the identification and exclusion of non-varicella cases through periodic enhanced surveillance, laboratory testing, or more thorough investigation of rash characteristics.     

Early Sexual Risk Among Black and Minority Ethnicity Teenagers: A Mixed Methods Study

PurposeTo determine how ethnic background influences early sexual activity among young adults.MethodsQuantitative data were collected during the Research with East London Adolescents Community Health Survey study, a population-based survey of young adults belonging to white and black and minority ethnic groups and residing in east London in 2001 (n = 2,689) and 2003 (n = 2,675). Qualitative data were obtained from 146 young adults between January and September 2003.ResultsBlack Caribbean, black African, white other, and mixed ethnicity young men were most likely to report high-risk sexual behaviors, that is, sexual debut at the age of ≤13 years, having unprotected sex, and having multiple sexual partners. There were marked variations within groups commonly collapsed as “black” or as “Muslim.” Black Caribbean and black African young adults reported high rates of protective behaviors in addition to risk behaviors. Qualitative data confirmed variations in sexual behavior within ethnic groups. Longitudinally, risk of engaging in two or more high-risk sexual behaviors was predicted by low family support (OR: 2.8, 95% CI: 1.6–4.9), regular smoking (OR: 4.5, 95% CI: 1.7–12.0), and usage of illicit drugs (OR: 2.9, 95% CI: 1.5–5.8), with lower risk predicted by low peer support (OR: .3, 95% CI: .2–.6).ConclusionsYoung adults belonging to black and minority ethnic groups reported a wide variation in sexual risk behaviors. High levels of high-risk behaviors were reported in ethnic groups known to have high rates of sexually transmitted infections. Effective sexual health interventions should be started early and they must focus on sexual debut and partner choices as well as messages regarding safe sex.     

A Canadian Working Group report on fecal microbial therapy: microbial ecosystems therapeutics

A working group from across Canada comprised of clinician and basic scientists, epidemiologists, ethicists, Health Canada regulatory authorities and representatives of major funding agencies (Canadian Institutes of Health Research and the Crohn's and Colitis Foundation of Canada) met to review the current experience with fecal microbial therapy and to identify the key areas of study required to move this field forward. The report highlights the promise of fecal microbial therapy and related synthetic stool therapy (together called 'microbial ecosystems therapeutics') for the treatment of Clostridium difficile colitis and, possibly, other disorders. It identifies pressing clinical issues that need to be addressed as well as social, ethical and regulatory barriers to the use of these important therapies.