Faculty Bibliography

Utilizing saliva instead of blood for diagnosis of both local and systemic health is a rapidly emerging field. Recognition of oral-systemic interrelationships for many diseases has fostered collaborations between medicine and dentistry, and many of these collaborations rely on salivary diagnostics. The oral cavity is easily accessed and contains most of the analytes present in blood. Saliva and mucosal transudate are generally utilized for oral diagnostics, but gingival crevicular fluid, buccal swabs, dental plaque and volatiles may also be useful depending on the analyte being studied. Examples of point-of-care devices capable of detecting HIV, TB, and Malaria targets are being developed and discussed in this overview.

A prototype dual-path microfluidic device (Rheonix CARD) capable of performing simultaneously screening (antigen or antibody) and confirmatory (nucleic acid) detection of pathogens is described. The device fully integrates sample processing, antigen or antibody detection, and nucleic acid amplification and detection, demonstrating rapid and inexpensive "sample-to-result" diagnosis with performance comparable to benchtop analysis. For the chip design, a modular approach was followed allowing the optimization of individual steps in the sample processing process. This modular design provides great versatility accommodating different disease targets independently of the production method. In the detection module, a lateral flow (LF) protocol utilizing upconverting phosphor (UCP) reporters was employed. The nucleic acid (NA) module incorporates a generic microtube containing dry reagents. Lateral flow strips and PCR primers determine the target or disease that is diagnosed. Diagnosis of HIV infection was used as a model to investigate the simultaneous detection of both human antibodies against the virus and viral RNA. The serological result is available in less than 30 min, and the confirmation by RNA amplification takes another 60 min. This approach combines a core serological portable diagnostic with a nucleic acid-based confirmatory test.

BACKGROUND: Diagnostics that involve the use of oral fluids have become increasingly available commercially in recent years and are of particular interest because of their relative ease of use, low cost and noninvasive collection of oral fluid for testing. TYPES OF STUDIES REVIEWED: The authors discuss the use of salivary diagnostics for virus detection with an emphasis on rapid detection of infection by using point-of-care devices. In particular, they review salivary diagnostics for human immunodeficiency virus, hepatitis C virus and human papillomavirus. Oral mucosal transudate contains secretory immunoglobulin (Ig) A, as well as IgM and IgG, which makes it a good source for immunodiagnostic-based devices. CLINICAL IMPLICATIONS: Because patients often visit a dentist more regularly than they do a physician, there is increased discussion in the dental community regarding the need for practitioners to be aware of salivary diagnostics and to be willing and able to administer these tests to their patients.

We report a clinical study that examines whether HIV infection affects Streptococcus mutans colonization in the oral cavity. Whole stimulated saliva samples were collected from 46 HIV-seropositive individuals and 69 HIV-seronegative control individuals. The level of S. mutans colonization was determined by conventional culture methods. The genotype of S. mutans was compared between 10 HIV-positive individuals before and after highly active antiretroviral therapy (HAART) and 10 non-HIV-infected control individuals. The results were analyzed against viral load, CD4+ and CD8+ T-cell counts, salivary flow rate, and caries status. We observed that S. mutans levels were higher in HIV-infected individuals than in the non-HIV-infected control individuals (p = 0.013). No significant differences in S. mutans genotypes were found between the two groups over the six-month study period, even after HAART. There was a bivariate linear relationship between S. mutans levels and CD8+ counts (r = 0.412; p = 0.007), but not between S. mutans levels and either CD4+ counts or viral load. Furthermore, compared with non-HIV-infected control individuals, HIV-infected individuals experienced lower salivary secretion (p = 0.009) and a positive trend toward more decayed tooth surfaces (p = 0.027). These findings suggest that HIV infection can have a significant effect on the level of S. mutans, but not genotypes.

In 2006, the Centers for Disease Control and Prevention (CDC) recommended routine HIV screening in health care settings regardless of the patient's level of risk. This pilot study was developed in response to the suggestion by some health care professionals that dental settings would be appropriate for expansion of HIV testing. This project consisted of two parts: oral fluid HIV testing of patients in the clinic of a dental school and a survey of the clinical dental faculty members' attitudes about acceptability of routine HIV testing in the dental clinic. When patients' agreement to participate in oral fluid HIV testing was examined, 8.2 percent of the patients contacted by the clinic administration staff completed testing. When approached by a faculty member or student during the dental visit admission and tested during the dental visit, however, 88.2 percent completed testing. Of the faculty members who took the survey, 27.4 percent were neutral, 26.4 percent were somewhat in agreement, and 32.1 percent were willing to incorporate HIV testing into routine dental care. In this pilot study, HIV testing of dental patients was most successful when a dental care provider approached patients about testing. If consent was given, the testing was performed during the visit. For the faculty members, the major barrier to testing was a lack of protocol familiarity.

BACKGROUND: More than 1 million individuals in the U.S. are infected with HIV; approximately 20% of whom do not know they are infected. Early diagnosis of HIV infection results in earlier access to treatment and reductions in HIV transmission. In 2006, the CDC recommended that health care providers offer routine HIV screening to all adolescent and adult patients, regardless of community seroprevalence or patient lifestyle. Dental providers are uniquely positioned to implement these recommendations using rapid oral fluid HIV screening technology. However, thus far, uptake into dental practice has been very limited. METHODS: The study utilized a qualitative descriptive approach with convenience samples of dental faculty and students. Six in-depth one-on-one interviews were conducted with dental faculty and three focus groups were conducted with fifteen dental students. RESULTS: Results were fairly consistent and indicated relatively high levels of acceptability. Barriers and facilitators of oral fluid HIV screening were identified in four primary areas: scope of practice/practice enhancement, skills/knowledge/training, patient service/patient reactions and logistical issues. CONCLUSIONS: Oral fluid HIV screening was described as having benefits for patients, dental practitioners and the public good. Many of the barriers to implementation that were identified in the study could be addressed through training and interdisciplinary collaborations.

This article reports and discusses how quantitative (physiological and behavioral) and qualitative methods are being combined in an open-label pilot feasibility study. The study evaluates safety, tolerability, and acceptability of a protocol to treat depression in HIV-infected individuals, using a 2-week block of transcranial direct current stimulation (tDCS) over the dorsolateral prefrontal cortex. Major depressive disorder (MDD) is the second most prevalent psychiatric disorder after substance abuse among HIV-positive adults, and novel antidepressant treatments are needed for this vulnerable population. The authors describe the challenges and contributions derived from different research perspectives and methodological approaches and provide a philosophical framework for combining quantitative and qualitative measurements for a fuller examination of the disorder. Four methodological points are presented: (1) the value of combining quantitative and qualitative approaches; (2) the need for context-specific measures when studying patients with medical and psychiatric comorbidities; (3) the importance of research designs that integrate physiological, behavioral, and qualitative approaches when evaluating novel treatments; and (4) the need to explore the relationships between biomarkers, clinical symptom assessments, patient self-evaluations, and patient experiences when developing new, patient-centered protocols. The authors conclude that the complexity of studying novel treatments in complex and new patient populations requires complex research designs to capture the richness of data that inform translational research.

Understanding of the human microbiome continues to grow rapidly; however, reports on changes in the microbiome after HIV infection are still limited. This review surveys the progress made in methodology associated with microbiome studies and highlights the remaining challenges to this field. Studies have shown that commensal oral, gut, vaginal, and penile bacteria are vital to the health of the human immune system. Our studies on crosstalk among oral and gastrointestinal soluble innate factors, HIV, and microbes indicated that the oral and gut microbiome was altered in the HIV-positive samples compared to the negative controls. The importance of understanding the bacterial component of HIV/AIDS, and likelihood of "crosstalk" between viral and bacterial pathogens, will help in understanding the role of the microbiome in HIV-infected individuals and facilitate identification of novel antiretroviral factors for use as novel diagnostics, microbicides, or therapeutics against HIV infection.

An estimated 1.1 million people in the USA are living with HIV/AIDS. Nearly 200,000 of these individuals do not know that they are infected. In 2006, the CDC recommended that all healthcare providers routinely offer HIV screening to adolescent and adult patients. Nurse-dentist collaborations present unique opportunities to provide rapid oral HIV screening to patients in dental clinic settings and reach the many adults who lack primary medical providers. However, little is known about the feasibility and acceptability of this type of innovative practice. Thus, elicitation research was undertaken with dental providers, students, and patients. This paper reports the results of qualitative interviews with 19 adults attending a university-based dental clinic in New York City. Overall, patients held very positive attitudes and beliefs toward HIV screening in dental sites and identified important factors that should be incorporated into the design of nurse-dentist collaborative HIV screening programs.