Browsing by Subject "infectious diseases"
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Item Open Access Feasibility and Acceptability of Door-to-Door Rapid HIV Testing Among Latino Immigrants and Their HIV Risk Factors in North Carolina(2010) Seña, Arlene C; Hammer, Juliana P; Wilson, Kate; Zeveloff, Abigail; Gamble, JuliaLatino immigrants in the United States are disproportionally impacted by the HIV epidemic but face barriers to clinic-based testing. We assessed a community-based strategy for rapid HIV testing by conducting "door-to-door'' outreaches in apartments with predominately Latino immigrants in Durham, North Carolina, that has experienced an exponential growth in its Latino population. Eligible persons were 18 years or older, not pregnant, and reported no HIV test in the previous month. Participants were asked to complete a survey and offered rapid HIV testing. Of the 228 Latino participants, 75.4% consented to HIV testing. There was a high prevalence of sexual risk behaviors among participants, with 42.5% acknowledging ever having sex with a commercial sex worker (CSW). Most (66.5%) had no history of prior HIV testing. In bivariate analysis, perceived HIV risk, no history of HIV testing, sex with a CSW, sex in exchange for drugs or money, living with a partner, and alcohol use were significantly associated with test acceptance. In the multivariate analysis, participants who had never been tested for HIV were more likely to consent to rapid HIV testing than those who had tested in the past (adjusted odds ratio 2.5; 95% confidence interval [CI], 1.1, 5.6). Most participants supported rapid HIV testing in the community (97%). Door-to-door rapid HIV testing is a feasible and acceptable strategy for screening high-risk Latino immigrants in the community. Factors associated with HIV risk among Latino migrants and immigrants in the United States should be considered along with novel testing strategies in HIV prevention programs.Item Open Access Frequency of Occult High-Grade Squamous Intraepithelial Neoplasia and Invasive Cancer within Anal Condylomata in Men Who Have Sex with Men(2010) Schlecht, Hans P; Fugelso, Dana K; Murphy, Ryan K; Wagner, Katiri T; Doweiko, John P; Proper, JoAnn; Dezube, Bruce J; Panther, Lori AHuman papillomavirus causes anal condylomata, high-grade anal intraepithelial neoplasia, and anal squamous cell cancer. We found high-grade intraepithelial neoplasia or squamous cell cancer in 75 (47%) of 159 HIV-seropositive men who have sex with men (MSM) and in 42 (26%) of 160 HIV-seronegative MSM with anal condylomata meriting surgery (P < .001, determined by use of the X-2 test). Anal condylomata in MSM often harbor high-grade intraepithelial neoplasia and squamous cell cancer.Item Open Access Genotyping of Human Lice Suggests Multiple Emergences of Body Lice from Local Head Louse Populations(2010) Li, Wenjun; Ortiz, Gabriel; Fournier, Pierre-Edouard; Gimenez, Gregory; Reed, David L; Pittendrigh, Barry; Raoult, DidierBackground: Genetic analyses of human lice have shown that the current taxonomic classification of head lice ( Pediculus humanus capitis) and body lice ( Pediculus humanus humanus) does not reflect their phylogenetic organization. Three phylotypes of head lice A, B and C exist but body lice have been observed only in phylotype A. Head and body lice have different behaviours and only the latter have been involved in outbreaks of infectious diseases including epidemic typhus, trench fever and louse borne recurrent fever. Recent studies suggest that body lice arose several times from head louse populations. Methods and Findings: By introducing a new genotyping technique, sequencing variable intergenic spacers which were selected from louse genomic sequence, we were able to evaluate the genotypic distribution of 207 human lice. Sequence variation of two intergenic spacers, S2 and S5, discriminated the 207 lice into 148 genotypes and sequence variation of another two intergenic spacers, PM1 and PM2, discriminated 174 lice into 77 genotypes. Concatenation of the four intergenic spacers discriminated a panel of 97 lice into 96 genotypes. These intergenic spacer sequence types were relatively specific geographically, and enabled us to identify two clusters in France, one cluster in Central Africa ( where a large body louse outbreak has been observed) and one cluster in Russia. Interestingly, head and body lice were not genetically differentiated. Conclusions: We propose a hypothesis for the emergence of body lice, and suggest that humans with both low hygiene and head louse infestations provide an opportunity for head louse variants, able to ingest a larger blood meal ( a required characteristic of body lice), to colonize clothing. If this hypothesis is ultimately supported, it would help to explain why poor human hygiene often coincides with outbreaks of body lice. Additionally, if head lice act as a reservoir for body lice, and that any social degradation in human populations may allow the formation of new populations of body lice, then head louse populations are potentially a greater threat to humans than previously assumed.Item Open Access Global Trends in Typhoid and Paratyphoid Fever(2010) Crump, John A; Mintz, Eric DTyphoid and paratyphoid fever continue to be important causes of illness and death, particularly among children and adolescents in south-central and Southeast Asia, where enteric fever is associated with poor sanitation and unsafe food and water. High-quality incidence data from Asia are underpinning efforts to expand access to typhoid vaccines. Efforts are underway to develop vaccines that are immunogenic in infants after a single dose and that can be produced locally in countries of endemicity. The growing importance of Salmonella enterica serotype Paratyphi A in Asia is concerning. Antimicrobial resistance has sequentially emerged to traditional first-line drugs, fluoroquinolones, and third-generation cephalosporins, posing patient treatment challenges. Azithromycin has proven to be an effective alternative for treatment of uncomplicated typhoid fever. The availability of full genome sequences for S. enterica serotype Typhi and S. enterica serotype Paratyphi A confirms their place as monomorphic, human-adapted pathogens vulnerable to control measures if international efforts can be redoubled.Item Open Access Lessons from the pandemic: Responding to emerging zoonotic viral diseases-a Keystone Symposia report.(Annals of the New York Academy of Sciences, 2022-10) Cable, Jennifer; Fauci, Anthony; Dowling, William E; Günther, Stephan; Bente, Dennis A; Yadav, Pragya Dhruv; Madoff, Lawrence C; Wang, Lin-Fa; Arora, Rahul K; Van Kerkhove, Maria; Chu, May C; Jaenisch, Thomas; Epstein, Jonathan H; Frost, Simon David William; Bausch, Daniel G; Hensley, Lisa E; Bergeron, Éric; Sitaras, Ioannis; Gunn, Michael D; Geisbert, Thomas W; Muñoz-Fontela, César; Krammer, Florian; de Wit, Emmie; Nordenfelt, Pontus; Saphire, Erica Ollmann; Gilbert, Sarah C; Corbett, Kizzmekia S; Branco, Luis M; Baize, Sylvain; van Doremalen, Neeltje; Krieger, Marco A; Clemens, Sue Ann Costa; Hesselink, Renske; Hartman, DanThe COVID-19 pandemic caught the world largely unprepared, including scientific and policy communities. On April 10-13, 2022, researchers across academia, industry, government, and nonprofit organizations met at the Keystone symposium "Lessons from the Pandemic: Responding to Emerging Zoonotic Viral Diseases" to discuss the successes and challenges of the COVID-19 pandemic and what lessons can be applied moving forward. Speakers focused on experiences not only from the COVID-19 pandemic but also from outbreaks of other pathogens, including the Ebola virus, Lassa virus, and Nipah virus. A general consensus was that investments made during the COVID-19 pandemic in infrastructure, collaborations, laboratory and manufacturing capacity, diagnostics, clinical trial networks, and regulatory enhancements-notably, in low-to-middle income countries-must be maintained and strengthened to enable quick, concerted responses to future threats, especially to zoonotic pathogens.Item Open Access Lessons Learned from the Anaerobe Survey: Historical Perspective and Review of the Most Recent Data (2005-2007)(2010) Snydman, David R; Jacobus, Nilda V; McDermott, Laura A; Golan, Yoav; Hecht, David W; Goldstein, Ellie JC; Harrell, Lizzie; Jenkins, Stephen; Newton, Duane; Pierson, Carl; Rihs, John D; Yu, Victor L; Venezia, Richard; Finegold, Sydney M; Rosenblatt, Jon E; Gorbach, Sherwood LBackground. The rationale and lessons learned through the evolution of the National Survey for the Susceptibility of Bacteroides fragilis Group from its initiation in 1981 through 2007 are reviewed here. The survey was conceived in 1980 to track emerging antimicrobial resistance in Bacteroides species. Methods. Data from the last 11 years of the survey (1997-2007), including 6574 isolates from 13 medical centers, were analyzed for in vitro antimicrobial resistance to both frequently used and newly developed anti-anaerobic agents. The minimum inhibitory concentrations of the antibiotics were determined using agar dilution in accordance with Clinical and Laboratory Standards Institute recommendations. Results. The analyses revealed that the carbapenems (imipenem, meropenem, ertapenem, and doripenem) and piperacillin-tazobactam were the most active agents against these pathogens, with resistance rates of 0.9%-2.3%. In the most recent 3 years of the survey (2005-2007), resistance to some agents was shown to depend on the species, such as ampicillin-sulbactam against Bacteroides distasonis (20.6%) and tigecycline against Bacteroides uniformis and Bacteroides eggerthii (similar to 7%). Very high resistance rates (>50%) were noted for moxifloxacin and trovafloxacin, particularly against Bacteroides vulgatus. During that period of study, non-B. fragilis Bacteroides species had >40% resistance to clindamycin. Metronidazole-resistant Bacteroides strains were also first reported during that period. Conclusions. In summary, resistance to antibiotics was greater among non-B. fragilis Bacteroides species than among B. fragilis and was especially greater among species with a low frequency of isolation, such as Bacteroides caccae and B. uniformis. The emergence of resistance among the non-B. fragilis Bacteroides species underscores the need for speciation of B. fragilis group isolates and for clinicians to be aware of associations between species and drug resistance.Item Open Access Perforin and IL-2 Upregulation Define Qualitative Differences among Highly Functional Virus-Specific Human CD8(+) T Cells(2010) Ferrari, GuidoThe prevailing paradigm of T lymphocyte control of viral replication is that the protective capacity of virus-specific CD8(+) T cells is directly proportional to the number of functions they can perform, with IL-2 production capacity considered critical. Having recently defined rapid perforin upregulation as a novel effector function of antigen-specific CD8(+) T cells, here we sought to determine whether new perforin production is a component of polyfunctional CD8(+) T cell responses that contributes to the control of several human viral infections: cytomegalovirus (CMV), Epstein-Barr virus (EBV), influenza (flu), and adenovirus (Ad). We stimulated normal human donor PBMC with synthetic peptides whose amino acid sequences correspond to defined CTL epitopes in the aforementioned viruses, and then used polychromatic flow cytometry to measure the functional capacity and the phenotype of the responding CD8(+) T cells. While EBV and flu-specific CD8(+) T cells rarely upregulate perforin, CMV-specific cells often do and Ad stimulates an exceptionally strong perforin response. The differential propensity of CD8(+) T cells to produce either IL-2 or perforin is in part related to levels of CD28 and the transcription factor T-bet, as CD8(+) T cells that rapidly upregulate perforin harbor high levels of T-bet and those producing IL-2 express high amounts of CD28. Thus, "polyfunctional'' profiling of antigen-specific CD8(+) T cells must not be limited to simply the number of functions the cell can perform, or one particular memory phenotype, but should actually define which combinations of memory markers and functions are relevant in each pathogenic context.Item Open Access Reconciling phylodynamics with epidemiology: the case of dengue virus in southern Vietnam.(Mol Biol Evol, 2014-02) Rasmussen, David A; Boni, Maciej F; Koelle, KatiaCoalescent methods are widely used to infer the demographic history of populations from gene genealogies. These approaches-often referred to as phylodynamic methods-have proven especially useful for reconstructing the dynamics of rapidly evolving viral pathogens. Yet, population dynamics inferred from viral genealogies often differ widely from those observed from other sources of epidemiological data, such as hospitalization records. We demonstrate how a modeling framework that allows for the direct fitting of mechanistic epidemiological models to genealogies can be used to test different hypotheses about what ecological factors cause phylodynamic inferences to differ from observed dynamics. We use this framework to test different hypotheses about why dengue serotype 1 (DENV-1) population dynamics in southern Vietnam inferred using existing phylodynamic methods differ from hospitalization data. Specifically, we consider how factors such as seasonality, vector dynamics, and spatial structure can affect inferences drawn from genealogies. The coalescent models we derive to take into account vector dynamics and spatial structure reveal that these ecological complexities can substantially affect coalescent rates among lineages. We show that incorporating these additional ecological complexities into coalescent models can also greatly improve estimates of historical population dynamics and lead to new insights into the factors shaping viral genealogies.Item Open Access Synergistic Pandemics: Confronting the Global HIV and Tuberculosis Epidemics(2010) Mayer, Kenneth H; Dukes Hamilton, Carol