Screening for Epstein-Barr virus (EBV) infection status in university freshmen: acceptability of a gingival swab method.

Prophylactic vaccines against Epstein-Barr virus (EBV) are under development. EBV-naïve college freshmen are ideal candidates for an efficacy trial, because their incidence of infectious mononucleosis (mono) during freshman year is as high as 20%. To assess perceptions about mono and a mono vaccine, and to learn if EBV immune status could be determined using a gingival swab rather than phlebotomy, we performed a cross-sectional study of 235 healthy students at the beginning of their freshman year. Subjects completed questionnaires and donated oral washes, gingival swabs and venous blood. Overall, 90% of students found the swab easy to use and 80% preferred the swab over venepuncture. Of the 193 students with sufficient samples, 108 (56%) had EBV antibodies in blood vs. 87 (45.1%) in the gingival swab. The sensitivity and specificity of the swab compared with blood for detecting EBV antibodies was 75.9% and 94.1%, respectively, with an accuracy of 89.3%. EBV DNA was detected in the oral wash and swab of 39.2% and 30.4% of blood-antibody-positive individuals, respectively. In conclusion, 44% of our freshmen were EBV-naïve and thus vaccine candidates, the gingival swab was an acceptable alternative to phlebotomy for detecting EBV antibody but needs improved sensitivity, and the perceived value of EBV vaccine was high (72% believed they would benefit).

Revisiting assumptions about age-based mixing representations in mathematical models of sexually transmitted infections.

BACKGROUND: Sexual mixing between heterogeneous population subgroups is an integral component of mathematical models of sexually transmitted infections (STIs). This study compares the fit of different mixing representations to survey data and the impact of different mixing assumptions on the predicted benefits of hypothetical human papillomavirus (HPV) vaccine strategies. METHODS: We compared novel empirical (data-driven) age mixing structures with the more commonly-used assortative-proportionate (A-P) mixing structure. The A-P mixing structure assumes that a proportion of sexual contacts - known as the assortativity constant, typically estimated from survey data or calibrated - occur exclusively within one's own age group and the remainder mixes proportionately among all age groups. The empirical age mixing structure was estimated from the National Survey on Sexual Attitudes and Lifestyles 3 (Natsal-3) using regression methods, and the assortativity constant was estimated from Natsal-3 as well. Using a simplified HPV transmission model under each mixing assumption, we calibrated the model to British HPV16 prevalence data, then estimated the reduction in steady-state prevalence and the number of infections averted due to expanding HPV vaccination from 12- through 26-year-old females alone to 12-year-old males or 27- to 39-year-old females. RESULTS: Empirical mixing provided a better fit to the Natsal-3 data than the best-fitting A-P structure. Using the model with empirical mixing as a reference, the model using the A-P structure often under- or over-estimated the benefits of vaccination, in one case overestimating by 2-fold the number of infections prevented due to extended female catch-up in a high vaccine uptake setting. CONCLUSIONS: An empirical mixing structure more accurately represents sexual mixing survey data, and using the less accurate, yet commonly-used A-P structure has a notable effect on estimates of HPV vaccination benefits. This underscores the need for mixing structures that are less dependent on unverified assumptions and are directly informed by sexual behavior data.

An ecological analysis of pertussis disease in Minnesota, 2009-2013.

The increase in pertussis cases in Minnesota in the last decade has been mainly attributed to the switch from whole cell to acellular pertussis [as part of the diphtheria, tetanus and acellular pertussis vaccine (DTaP)]. It is unclear, however, to what degree community-level risk factors also contribute. Understanding these factors can help inform public health policy-makers about where else to target resources. We performed an ecological analysis within Minnesota to identify risk factors at the county level using a Bayesian Poisson generalized linear areal model to account for spatial dependence. Univariate analyses suggested an association between increased pertussis rates at the county level and white maternal ethnicity, being US born, urban counties and average household size. In the multivariable analysis, the rate of pertussis was 1·79 times greater for urban vs. rural counties and 4·75 times greater for counties with a one-person larger average household size. Pertussis rates in counties with higher (i.e. 4+DTaP) receipt in children were 0·97 times lower. Examining county-level factors associated with varying levels of pertussis may help identify those counties that would most benefit from targeted interventions and increased resource allocation.

Preferences for surveillance strategies for women treated for high-grade precancerous cervical lesions.

OBJECTIVES: Data are lacking on how women view alternative approaches to surveillance for cervical cancer after treatment of high-grade cervical intraepithelial neoplasia. We measured and compared patient preferences (utilities) for scenarios with varying surveillance strategies and outcomes to inform guidelines and cost-effectiveness analyses of post-treatment surveillance options. METHODS: English- or Spanish-speaking women who had received an abnormal Pap test result within the past 2 years were recruited from general gynecology and colposcopy clinics and newspaper and online advertisements in 2007 and 2008. Participation consisted of one face-to-face interview, during which utilities for 11 different surveillance scenarios and their associated outcomes were elicited using the time tradeoff metric. A sociodemographic questionnaire also was administered. RESULTS: 65 women agreed to participate and successfully completed the preference elicitation exercises. Mean utilities ranged from 0.989 (undergoing only a Pap test, receiving normal results) to 0.666 (invasive cervical cancer treated with radical hysterectomy or radiation and chemotherapy). Undergoing both Pap and HPV tests and receiving normal/negative results had a lower mean utility (0.953) then undergoing only a Pap test and receiving normal results (0.989). Having both tests and receiving normal Pap but positive HPV results was assigned an even lower mean utility (0.909). 15.9% of the respondents gave higher utility scores to the Pap plus HPV testing scenario (with normal/negative results) than to the "Pap test alone" scenario (with normal results), while 17.5% gave the Pap test alone scenario a higher utility score. CONCLUSIONS: Preferences for outcomes ending with normal results but involving alternative surveillance processes differ substantially. The observed differences in utilities have important implications for clinical guidelines and cost-effectiveness analyses.

Meta-analysis: the detection of pancreatic malignancy with positron emission tomography.

BACKGROUND: Several factors contribute to the high mortality of pancreatic cancer, including limitations of diagnostic imaging. AIM: To perform a meta-analysis to assess the diagnostic accuracy of Fluro-deoxy-glucose positron emission tomography with computed tomography compared with computed tomography alone. METHODS: Articles were identified through a MEDLINE search and bibliography review. Summary estimates and receiver operating curves were calculated using Meta-Test 0.6. Publication bias and heterogeneity were assessed with a funnel plot and chi-squared test. RESULTS: The summary estimate and 95% confidence interval for sensitivity and specificity were as follows: computed tomography 81% (72-88%) and 66% (53-77%), PET after a positive computed tomography 92% (87-95%) and 68% (51-81%), PET after a negative computed tomography 73% (50-88%) and 86% (75-93%) and PET after an indeterminate computed tomography 100 and 68%. The area under the summary receiver operating curve was 0.82 for computed tomography and 0.94 for PET. There was no heterogeneity or publication bias. CONCLUSIONS: Our results suggest that although adding Fluro-deoxy-glucose positron emission tomography to the diagnostic work-up may enhance the diagnosis of pancreatic malignancy, its usefulness will vary depending upon the pretest probability of the patient, the results of computed tomography and the provider's testing thresholds. Further evaluation using a well-designed prospective study with a cost-effectiveness analysis is needed to clarify the appropriate role of Fluro-deoxy-glucose positron emission tomography.

Detection of Kaposi's sarcoma-associated herpesvirus in oral and genital secretions of Zimbabwean women.

Kaposi's sarcoma-associated herpesvirus (KSHV) in oral and genital secretions of women may be involved in horizontal and vertical transmission in endemic regions. Nested polymerase chain reaction assays were used to detect KSHV DNA sequences in one-third of oral, vaginal, and cervical specimens and in 42% of peripheral blood mononuclear cell (PBMC) specimens collected from 41 women infected with human immunodeficiency virus type 1 who had Kaposi's sarcoma (KS). KSHV DNA was not detected in specimens from 100 women without KS, 9 of whom were seropositive for KSHV. A positive association was observed between KSHV DNA detection in oral and genital mucosa, neither of which was associated with KSHV DNA detection in PBMC. These data suggest that KSHV replicates in preferred anatomic sites at levels independent of PBMC viremia. Detection of genital-tract KSHV only among relatively immunosuppressed women may provide an explanation for infrequent perinatal transmission of KSHV.

Forgetting as a cause of incomplete reporting of sexual and drug injection partners.

BACKGROUND AND OBJECTIVES: Partner notification and social network studies of infectious disease often involve interviewing people to elicit their sexual and/or drug injection partners. Incomplete reporting of partners in these contexts would significantly hamper efforts to understand and control the spread of sexually transmitted diseases, HIV, and other infections. There are many reasons why individuals might not name their partners in interviews. This study provides a comprehensive assessment of forgetting as a cause of incomplete reporting of sexual and injection partners. STUDY DESIGN: One hundred fifty-six persons in Seattle, Washington, at presumed high risk for HIV recalled their sexual and/or injection partners in two interviews separated by 1 week or 3 months. RESULTS: Repeated, nonspecific prompting elicited, on average, 10% of all partners recalled in an interview. Subjects displayed substantial forgetting of partners across partner types, recall periods, and four independent measurement approaches, with up to 72% of partners forgotten. The number of partners recalled and subjective assessment of forgetting are moderate to good predictors of the number of partners forgotten. Recalled and forgotten partners do not differ dramatically on any of several partner variables. CONCLUSIONS: Forgetting is a primary factor in the incomplete reporting of sexual and injection partners. Interviewers should prompt repeatedly to maximize recall of partners. Reinterviewing is currently the best method available for identifying partners as completely as possible and should be focused on individuals who report many partners and/or sense they have other partners they cannot recall.