Low occupational risk of human immunodeficiency virus infection among dental professionals

Clinical Outcomes of Post-exposure Prophylaxis following Occupational Exposure to Human Immunodeficiency Virus at Dental Departments of Hiroshima University Hospital

Background

Dental professionals have so many opportunities to use injection needles and sharp instruments during dental treatment that they face an increased risk of needlestick injuries. This retrospective study reports the utilization and clinical outcomes of occupational post-exposure prophylaxis (PEP) with anti-retroviral agents after being potentially exposed to HIV at the dental departments of Hiroshima University Hospital.

Objective

This study reports the utilization and clinical outcomes of occupational post-exposure prophylaxis (PEP) with antiretroviral agents after being potentially exposed to HIV at dental departments of Hiroshima University Hospital.

Methods

Data on the clinical status of HIV-infected source patients and information on HIV-exposed dental professionals from 2007 to 2018 were collected.

Results

Five dentists with an average experience of 5.6 years (1-15 years) were exposed. The averaged CD4-positive cell number and HIV-RNA load were 1176 (768-1898) /μl and less than 20 copies/ml, respectively, in all the patients. Two of the five HIV exposed dentists received PEP. Three months after the exposures, all of their results were negative in HIV antibody/antigen tests.

Conclusion

These data might support the concept of “undetectable equals untransmittable”, although HIV exposure in this study was not through sexual transmission.

Human Immunodeficiency Virus (HIV) Transmission in Dentistry

HIV transmission in the health-care setting is of concern. To assess the current position in dentistry, we have reviewed the evidence to November 1, 2005. Transmission is evidently rare in the industrialized nations and can be significantly reduced or prevented by the use of standard infection control measures, appropriate clinical and instrument-handling procedures, and the use of safety equipment and safety needles. We hope that breaches in standard infection control will become vanishingly small. When occupational exposure to HIV is suspected, the application of post-exposure protocols for investigating the incident and protecting those involved from possible HIV infection further reduces the likelihood of HIV disease, and also stress and anxiety.

Influence of disinfectant solutions on test materials used for the determination of masticatory performance

Masticatory function can be evaluated objectively as the capacity of an individual to fragment solid food after a fixed number of chewing cycles, the so-called masticatory performance (MP). The objective of this study was to evaluate the reliability of four different test materials (Optosil, Optocal, Zetapuls, and Perfil) and five disinfection protocols by aspersion and immersion (no disinfection, 2% glutaraldehyde, 2% chlorhexidine, 5.25% sodium hypochlorite, and 70% alcohol) on the MP, determined at three moments (24 hours, 15 and 60 days) after storing the fragmented blocks. MP was evaluated by calculating X50 through the sieving technique and the Rosim-Ramler equation. The weight and microbiologic count (colony forming units, CFUs) of chewed blocks were measured to identify any variations that would make MP determination unfeasible. Differences in MP were observed among the materials (p < 0.01). Perfil presented the highest X50 value (worst MP determination), followed by Zetaplus (both p < 0.05), Optosil, and Optocal (both p > 0.05). The time and disinfection type had no influence on MP (p > 0.05). The number of CFUs differed between the nondisinfected group and all other disinfection groups at all time points (p < 0.01). No other significant difference in CFU count between disinfection groups was observed. In conclusion, disinfection did not alter the reliability of the test materials for the MP calculation for up to 60 days.

Occupational exposure to blood and body fluids in a department of oral sciences: results of a thirteen-year surveillance study

Objectives. Aim of this analysis was to identify trends that will aid in the prevention of injury. Methods. Our data were collected from 1999 to 2011 during a surveillance program of occupational exposures to blood or other potentially infectious materials in a Dental School by using a standard coded protocol. Results. 63 exposures were reported. 56/63 (89%) percutaneous and 7/63 (11%) mucosal, involving a splash to the eye of the dental care workers (DCW). 25/63 (40%) involved students, 23/63 (36%) DCW attending masters and doctorate, 13/63 (21%) DCW attending as tutors and 2/63 (3%) staff. 45/63 (71%) and 18/63 (29%) occurred respectively during and after the use of the device; of last ones, 1/18 (0.05%) were related to instrument clean-up and 1/18 (0.05%) to laboratory activity, 12/18 (67%) occurred when a DCW collided with a sharp object during the setting, and 4/18 (22%) during other activities. The instrument and the body part most likely involved were needle and finger respectively. The overall exposure rate was 4.78 per 10,000 patient visits. Conclusions Our results may serve as benchmark that Dental Schools can employ to assess their frequency of injury.

COVER STORY Guidelines for infection control in dental health care settings—2003

BACKGROUND

The Centers for Disease Control and Prevention, or CDC, is the lead federal agency for disease prevention in the United States. It has been 10 years since CDC infection control guidelines for dental health care settings were last published. During those 10 years, new technologies and issues have emerged, and other CDC infection control guidelines for health care settings have been updated.

RESULTS

In light of these developments, CDC collaborated with experts in infection control to revise its infection control recommendations for dental health care settings. Existing guidelines and published research pertinent to dental infection control principles and practices were reviewed. This article provides background information, describes the process used to create these guidelines, and lists the new recommendations.

CLINICAL IMPLICATIONS

CDC believes that dental offices that follow these new recommendations will strengthen an already admirable record of safe dental practice. Patients and providers alike can be assured that oral health care can be delivered and received in a safe manner.

Infection control of lung function equipment: a practical approach

The degree of risk of cross-infection of patients via lung function testing equipment has yet to be quantified. Based on current evidence, elaborate precautions are not justified for the majority of patients attending the laboratory, but attention to appropriate routine cleaning and disinfection protocols is important. Disinfection and sterilization can be achieved by a variety of methods, although chemical methods should be used with caution. Identification of factors increasing the susceptibility or infectivity of particular patients is important in determining appropriate precautions. Where patients are known to be infectious or are immunocompromized, additional precautions such as using a barrier filter may be appropriate. However, because of cost constraints, the routine use of barrier filters is difficult to justify based on current evidence of minimal cross-infection associated with lung function equipment. Until further studies have been conducted to quantify the degree of risk of cross-infection that lung function test equipment poses, the recommendations given in this review provide a practical approach to dealing with this problem.

Occupational exposures to human immunodeficiency virus, hepatitis B virus, and hepatitis C virus: risk, prevention, and management

Current data indicate that the risk for transmitting bloodborne pathogens in dental health care settings is low. Pre-exposure hepatitis B vaccination and the use of standard precautions to prevent exposure to blood are the most effective strategies for preventing DHCP from occupational infection with HIV, HBV or HCV. Each dental health care facility should develop a comprehensive written program for preventing and managing occupational exposures to blood that: (1) describes the types of blood exposures that may place DHCP at risk for infection; (2) outlines procedures for promptly reporting and evaluating such exposures; and (3) identifies a health care professional who is qualified to provide counseling and perform all medical evaluations and procedures in accordance with the most current USPHS recommendations. Finally, resources should be available that permit rapid access to clinical care, testing, counseling, and PEP for exposed DHCP and the testing and counseling of source patients.

Prevalence of transfusion-transmissible viral infections in first-time US blood donors by donation site

BACKGROUND

Understanding the donor base, infectious disease prevalence, and donation loss at various blood donation sites will help maximize blood collection efforts and blood availability.

STUDY DESIGN AND METHODS

Using donation data collected at five US blood centers, the prevalence of HIV, HTLV, HBsAg, and HCV in first-time whole-blood donations at 10 donation sites was evaluated: military, education, religious, professional, industry, services, community, health care, government, and fixed sites. Donation loss from screening test reactivity at each donation site was also evaluated.

RESULTS

During the study, 1.2 million first-time whole-blood donations were collected. Military and education sites had a low prevalence of all viral markers, except for HBsAg, which was highest at education sites. Variations in viral marker prevalence among donation sites were partially explained by donor demographic differences. Donation loss varied by donation site, ranging from 3.3 percent at education sites to 6.4 percent at industry sites, indicating differential efficiency of blood collection efforts.

CONCLUSION

Different rates of positive viral test results and donation loss in first-time whole-blood donors were observed at various types of donation sites. This information may be useful in estimating the yield of usable units from specific blood drives and in allocating resources to meet blood center collection goals.

Comparative assessment of two methods used for interdental immobilization

AIM

This investigation was carried out to compare Dimac wires with arch bars for interdental immobilization.

MATERIAL AND METHODS

The assessment was conducted on 50 patients who had mandibular fractures and in whom intermaxillary fixation was required as a part of the treatment. The time required for applying each method of fixation, the needle-stick injuries that occurred during their application, and the periodontal damage that followed interdental immobilization was investigated.

RESULTS

The mean time required for the application of Dimac wires was significantly less than that required for arch bars. The needle-stick injuries were significantly less with Dimac wires. Patients reported difficulty with oral hygiene with arch bars in place. This was associated with periodontal damage following removal of fixation.

CONCLUSION

Dimac wires is safer to use and less traumatic to the periodontium

Occupationally acquired human immunodeficiency virus (HIV) infection: national case surveillance data during 20 years of the HIV epidemic in the United States

OBJECTIVE

To characterize occupationally acquired human immunodeficiency virus (HIV) infection detected through case surveillance efforts in the United States.

DESIGN

National surveillance systems, based on voluntary case reporting.

SETTING

Healthcare or laboratory (clinical or research) settings.

PATIENTS

Healthcare workers, defined as individuals employed in healthcare or laboratory settings (including students and trainees), who are infected with HIV.

METHODS

Review of data reported through December 2001 in the HIV/AIDS Reporting System and the National Surveillance for Occupationally Acquired HIV Infection.

RESULTS

Of 57 healthcare workers with documented occupationally acquired HIV infection, most (86%) were exposed to blood, and most (88%) had percutaneous injuries. The circumstances varied among 51 percutaneous injuries, with the largest proportion (41%) occurring after a procedure, 35% occurring during a procedure, and 20% occurring during disposal of sharp objects. Unexpected circumstances difficult to anticipate during or after procedures accounted for 20% of all injuries. Of 55 known source patients, most (69%) had acquired immunodeficiency syndrome (AIDS) at the time of occupational exposure, but some (11%) had asymptomatic HIV infection. Eight (14%) of the healthcare workers were infected despite receiving postexposure prophylaxis (PEP).

CONCLUSIONS

Prevention strategies for occupationally acquired HIV infection should continue to emphasize avoiding blood exposures. Healthcare workers should be educated about both the benefits and the limitations of PEP, which does not always prevent HIV infection following an exposure. Technologic advances (eg, safety-engineered devices) may further enhance safety in the healthcare workplace.

Use of HIV postexposure prophylaxis by dental health care personnel: an overview and updated recommendations

BACKGROUND

The authors conducted a study on the use of postexposure prophylaxis, or PEP, for exposure to human immunodeficiency virus, or HIV, among dental health care personnel, or DHCP, enrolled in a surveillance system established by the Centers for Disease Control and Prevention, or CDC. They also discuss updated U.S. Public Health Service, or USPHS, recommendations for managing occupational exposures to HIV, as well as considerations for dentistry.

METHODS

The authors analyzed occupational exposures reported by DHCP to the CDC to describe characteristics of the exposure (for example, type and severity), the source patient's HIV status and use of PEP.

RESULTS

From June 1995 through August 2001, DHCP reported 208 exposures--199 percutaneous injuries, six mucous membrane exposures and three skin exposures--to the CDC. One-third of these percutaneous injuries were caused by small-bore hollow syringe needles, and most (66 percent) were moderate in depth. Nearly half the devices involved (46 percent) were visibly bloody at the time of injury. Per the criteria described in USPHS guidelines, one-half of the injuries were categorized as "less severe." Twenty-four (13 percent) known source patients were HIV-positive; 14 had symptomatic HIV infection or a high viral load. In this study, three in four DHCP exposed to an HIV-positive source warranted a three-drug PEP regimen. Twenty-nine (24 percent) DHCP exposed to a source patient who subsequently was found to be HIV-negative took PEP; six took PEP for five to 29 days. No exposures resulted in HIV infection.

CONCLUSIONS

Findings of this study are consistent with earlier reports indicating that the risk of HIV transmission in dental settings is low. Strategies such as rapid HIV testing of source patients and follow-up counseling may reduce unnecessary use of PEP.

CLINICAL IMPLICATIONS

Dental practices should develop comprehensive, written programs for preventing and managing occupational exposures to blood.

Transmission of HIV in the dental clinic and elsewhere

This review focuses on the risk of transmission of HIV in dental practice in developed and developing countries; and as a result of oral sex, perinatal transmission and breast feeding. Postexposure prophylaxis (PEP) and practical measures to control cross-infection with TB are also discussed. There are few data from resource-poor countries where prevalence of HIV and risk of infection are higher--issues that deserve priority. Available information indicates that the risk of HIV transmission in the dental office is very low. Transmission of HIV from three healthcare workers to patients has been confirmed, including a dentist who infected six patients. There are >300 reports (102 confirmed) of occupational transmission to healthcare workers, including nine dental workers (unconfirmed). Exposure to HIV has been reported by 0.5% dentists/year. The risk of HIV infection after percutaneous exposure (0.3%) can be reduced by 81% with zidovudine PEP. However, risk assessment is required to assess the need and appropriate regimen. The risk of HIV transmission associated with orogenital sex exists, but is considered extremely low: barrier protection is recommended. Conversely, the proportion of babies who acquire HIV from untreated HIV-seropositive mothers is 15-25% in developed countries and 25-45% in developing countries. The frequency of HIV transmission attributable to breastfeeding is 16%. Airborne transmission of TB can be avoided by the prompt referral of known/suspected cases of active TB for chemotherapy, deferral of elective procedures until patients are not infectious, and the use of appropriate standard/isolation precautions including adequate ventilation of treatment areas.

Infection control in the private dental sector in Riyadh

BACKGROUND

With the global rise in the number of people infected with hepatitis B and C and HIV viruses, cross infection has become of paramount concern to dental health care workers and their patients. The objective of this study was to assess the infection control practice in the private dental sector in Riyadh, Saudi Arabia.

SUBJECTS AND METHODS

The study was conducted through a cross-sectional survey of private dental practices in the city of Riyadh. A total sample size of 132 dental units was chosen using the proportional allocation method. Three hospitals, 45 clinics and 39 centers were selected randomly. A self-administered questionnaire was completed by dentists working in the selected settings.

RESULTS

Of the 206 questionnaires sent, 203 (98.5%) were completed. The mean age of the responding dentists was 36.8+/-6.7 years. A total of 139 dentists (68.5%) were general practitioners and 64 (31.5%) were specialists. A total of 129 (63.5%) stated that they had been vaccinated against hepatitis B virus and 189 (93.1%) stated that they always took a medical history of each patient before treatment. All the studied dentists reported that they always used gloves for every patient during dental treatment, and 90.6% stated that they always wore a face mask during dental treatment. The primary source of infection control information for the studied dentists was from the colleges (78.3%). Only 37.9% of the dentists sterilized their handpieces by autoclaving, while the other 53.7% used disinfectant. About 56% disposed of used needles and sharp instruments in special safety containers. Multivariate logistic regression analysis revealed that working in clinics, age >40 years and knowledge of correct sterilization steps were independent promoting factors for adherence to infection control practice (OR=3.8, CI=1.2-12.1; OR=10.2, CI=1.61-64.8; OR=5.6, CI=1.04-29.9, respectively).

CONCLUSION

The development of infection control manual for dental practices, in addition to a campaign of health education for dentists in the private sector, is recommended.

Amplification of extracellular matrix and oncogenes in tat-transfected human salivary gland cell lines with expression of laminin, fibronectin, collagens I, III, IV, c-myc and p53

Considerable progress has been made in the transfer of foreign genes into salivary glands in vivo using adenovirus vectors in rats. In an attempt to avoid the transient expression inherent, when using these vectors, retroviral vectors and human cell lines where used here in attempt to develop an in vitro model of HIV-associated salivary gland disease. The HIV-1-tat protein is increasingly implicated in the pathogenesis of the AIDS through altering the expression of strategic cellular genes. The purpose of this study was to transfect human salivary gland (HSG) cell lines in vitro, with the pHIV-1/LTR-tat plasmid, and examine the effect of tat on expression of matrix and basement membrane genes known to be important in the pathogenesis of salivary gland disease. HSG cells were transfected with HIV-1-tat plasmid by the lipofection method. Transfection was confirmed by polymerase chain reaction (PCR) and Southern blot, which verified that tat-specific DNA was present. Tat-mRNA was analysed by Northern blotting and quantified by reverse transcriptase polymerase chain reaction (RT-PCR) to demonstrate its expression. Numerous clones were found to contain integrated tat DNA sequences and analysis of mRNA showed stable expression of tat-specific RNA. Further analysis of mRNA expression for various marker proteins important in HIV pathogenesis showed that the HSG cell line transfected with HIV-1-tat, was associated with significant induction of mRNA expression for extracellular matrix protein. Tat-amplified transcription of the major basement membrane protein laminin, as well as of fibronectin, collagen I and III, and c-myc oncogene was demonstrated. Conversely, expression of p53 suppressor gene mRNA was reduced. Post-transfection expression of collagen IV was erratic and inconclusive. It was concluded that the presence of HIV-tat in this in vitro model of salivary ductal epithelial cell model alters the mRNA expression of several matrix, basement membrane and oncoproteins known to be involved in HIV pathogenesis. These cell lines provide a useful system for studying the role of tat in the immunopathogenesis of HIV-associated salivary gland disease.

Sex and sexual orientation: the effect of group membership on individuals' judgments about self and others' HIV risk

No previous study has directly compared homosexual and heterosexual men and women's perceptions of HIV risk. In fact, empirical research focusing on homosexual women's perception of HIV risk is scarce. This paper, therefore, examines whether homosexual and heterosexual women and men (N = 60) make varied self and other (peer and non-peer) HIV risk judgments. The paper also examines the roles of motivational (health anxiety) and cognitive (HIV knowledge) factors in relation to HIV risk judgments. The results show that each group held different perceptions of risk for various "other" groups. Only homosexual men showed evidence for an optimistic bias, whereas homosexual women showed evidence of realistic perceptions. Both cognitive and motivational factors were shown to be associated with risk judgments for homosexual women and heterosexual men. Methodologically the use of Multidimensional scaling as an analytic strategy is recommended.

Positive and negative aspects of the human immunodeficiency virus protease: development of inhibitors versus its role in AIDS pathogenesis

In this review we summarize multiple aspects of the human immunodeficiency virus (HIV) protease from both structural and functional viewpoints. After an introductory overview, we provide an up-to-date status report on protease inhibitors (PI). This proceeds from a discussion of PI structural design, to how PI are optimally utilized in highly active antiretroviral triple therapy (one PI along with two reverse transcriptase inhibitors), the emergence of PI resistance, and the natural role of secretory leukocyte PI. Then we switch to another focus: the interaction of HIV protease with other genes in acute and persistent infection, which in turn may have an effect on AIDS pathogenesis. We conclude with a discussion on future directions in HIV treatment, involving multiple-target anti-HIV therapy, vaccine development, and novel reactivation-inhibitory reagents.

Risk and management of blood-borne infections in health care workers

Exposure to blood-borne pathogens poses a serious risk to health care workers (HCWs). We review the risk and management of human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) infections in HCWs and also discuss current methods for preventing exposures and recommendations for postexposure prophylaxis. In the health care setting, blood-borne pathogen transmission occurs predominantly by percutaneous or mucosal exposure of workers to the blood or body fluids of infected patients. Prospective studies of HCWs have estimated that the average risk for HIV transmission after a percutaneous exposure is approximately 0.3%, the risk of HBV transmission is 6 to 30%, and the risk of HCV transmission is approximately 1.8%. To minimize the risk of blood-borne pathogen transmission from HCWs to patients, all HCWs should adhere to standard precautions, including the appropriate use of hand washing, protective barriers, and care in the use and disposal of needles and other sharp instruments. Employers should have in place a system that includes written protocols for prompt reporting, evaluation, counseling, treatment, and follow-up of occupational exposures that may place a worker at risk of blood-borne pathogen infection. A sustained commitment to the occupational health of all HCWs will ensure maximum protection for HCWs and patients and the availability of optimal medical care for all who need it.

Proviral HIV-1 DNA in gingival crevicular fluid of HIV-1-infected patients in various stages of HIV disease

The oral cavity is rarely reported to be a site of human immunodeficiency virus (HIV) transmission, despite detectable virus in saliva and relatively frequent prevalence of periodontal disease in HIV-infected persons yielding increased excretion of mononuclear-cell-enriched gingival fluid. To search for possible sources of HIV in saliva, and using the polymerase chain-reaction technique, we sought the presence and shedding patterns of proviral HIV-1 DNA in gingival crevicular fluid in a group of patients previously determined as HIV-1-seropositive. Periodontal status at the collection sites was monitored by several clinical parameters, including Plaque Index, Gingival Index, probing depth, and clinical attachment loss. Gingival crevicular fluid samples were collected by means of paper points. Proviral HIV-1 DNA was detected in the gingival fluid of 17 out of 35 HIV-1-infected patients. Its detection correlated significantly with higher plasma HIV-1 RNA viral load (p = 0.03) and not with peripheral blood CD4+ cell count, the presence of blood in gingival fluid, or oral lesions. There was a significant correlation between clinical attachment loss at the sites of fluid collection and plasma HIV-1 RNA viral load (p = 0.002), and borderline correlation between the latter and probing depth (p = 0.54) in the group of patients harboring proviral HIV-1 DNA in gingival crevicular fluid. The results of our study suggest that mononuclear cells present in gingival crevicular fluid and harboring proviral HIV-1 DNA could represent a potential source of HIV-1 in the presence or absence of local bleeding, especially in persons with advanced HIV infection and increased loss of clinical attachment.

Risk and management of blood-borne infections in health care workers

Exposure to blood-borne pathogens poses a serious risk to health care workers (HCWs). We review the risk and management of human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) infections in HCWs and also discuss current methods for preventing exposures and recommendations for postexposure prophylaxis. In the health care setting, blood-borne pathogen transmission occurs predominantly by percutaneous or mucosal exposure of workers to the blood or body fluids of infected patients. Prospective studies of HCWs have estimated that the average risk for HIV transmission after a percutaneous exposure is approximately 0.3%, the risk of HBV transmission is 6 to 30%, and the risk of HCV transmission is approximately 1.8%. To minimize the risk of blood-borne pathogen transmission from HCWs to patients, all HCWs should adhere to standard precautions, including the appropriate use of hand washing, protective barriers, and care in the use and disposal of needles and other sharp instruments. Employers should have in place a system that includes written protocols for prompt reporting, evaluation, counseling, treatment, and follow-up of occupational exposures that may place a worker at risk of blood-borne pathogen infection. A sustained commitment to the occupational health of all HCWs will ensure maximum protection for HCWs and patients and the availability of optimal medical care for all who need it.

HIV topic update: oro-genital transmission of HIV

Several viruses, including the human immunodeficiency virus (HIV), can be found in blood and many body fluids including saliva, and are transmissible sexually across genital and particularly anal mucosae. A persisting concern has been the question of transmission of HIV by oral sexual practices. This review discusses the evidence for oro-genital transmission of HIV, detailing the presence and infectivity of HIV in genital fluids and saliva, the case reports and epidemiology of oro-genital HIV transmission, and the evidence from animal studies. Oral intercourse is not risk-free. The evidence suggests that the risk of HIV transmission from oro-genital sexual practices is substantially lower than that from penile-vaginal or penile-anal intercourse, that exposure to saliva presents a considerably lower risk than exposure to semen, and that oral trauma and ulcerative conditions might increase the risk of HIV transmission.

Tooth extraction in HIV sero-positive patients

Tooth extraction is the dental treatment most commonly carried out among HIV positive patients. In this paper we propose a simple protocol for dental extractions in patients of this type, based on a review of the literature and on our own experience in this field. The factors to be considered when planning a dental extraction for HIV positive patients are: diagnosis of the lesion justifying the need for tooth extraction and medical assessment of the patient including the infection pathway, the stage of the disease, laboratory tests and drug therapy. The most frequent post extraction complications are a delay in the wound healing process, alveolitis and surgical wound infection. Fortunately, these complications tend to be rather uncommon and not too severe; they can be managed on an out-patient basis and their prevalence will probably tend to decrease with the introduction of the new anti-retroviral drugs for HIV-1.

Enhanced secretory leukocyte protease inhibitor in human immunodeficiency virus type 1-infected patients

Secretory leukocyte protease inhibitor (SLPI) has been found to possess activity against the human immunodeficiency virus type 1 (HIV-1) in vitro at physiological concentrations. A study was undertaken to evaluate SLPI levels in human saliva and plasma among HIV-positive (HIV(+)) patients with various HIV-1 viral loads in comparison to uninfected controls. Whole blood in EDTA and unstimulated saliva samples were collected from 37 HIV(+) patients, of whom 20 had a history of intravenous drug abuse (IVDA). Control samples were collected from 20 appropriate age- and sex-matched HIV-1-negative individuals. SLPI was estimated from both saliva and serum samples by an enzyme-linked immunosorbent assay. HIV viral load was determined using a quantitative reverse transcription-PCR. SLPI levels were increased 16.7% in plasma and 10.3% in saliva among HIV(+) patients in comparison to uninfected controls. SLPI levels were increased 5.9% in saliva and 3.9% in plasma among HIV(+) patients with a high viral load (>10,000 copies/ml) as compared to patients with a low viral load (<400 copies/ml). Only 23% of patients with a high viral load used combination therapy with protease inhibitor drugs, whereas 92.9% of HIV(+) patients with a low viral load used protease inhibitors. SLPI levels did not differ significantly among the IVDA patients, patients with different viral loads, or patients using protease inhibitor drugs. There was a statistically significant increase in SLPI levels in saliva among HIV patients in comparison to non-HIV-infected controls. An increase in SLPI levels among HIV(+) patients may be a natural consequence of HIV pathogenesis and an important factor in preventing oral transmission of HIV, but this increase may not be evident during plasma viremia in patients with a high viral load.

Factors associated with occupational exposure and compliance with universal precautions in an urban school district

Factors associated with occupational exposure and universal precautions (UP) compliance were assessed among employees in one urban school district. Half of the employees surveyed reported responding to bleeding injuries and cleaning blood or other body fluids (e.g., vomit, urine) during the previous school year. Also, 1 in 4 custodians and 1 in 10 teachers/teacher's aides had direct contact with blood or body fluids without protection. In multivariate logistic regression analyses, direct contact was most likely among secondary school employees in unpredictable situations who did not have protective equipment or comply with UP. UP compliance was greater among those who had protective equipment available and felt self-confident. Self-confidence was associated with having received training or protective equipment. Routine communications between administrators and employees, staff training, provision of protective equipment, and exposure incident monitoring are essential to effective implementation of UP policies in schools and work settings where occupational exposure could occur.

Risk and prevention of hepatitis C virus infection. Implications for dentistry

BACKGROUND

The occupational risk of hepatitis C virus, or HCV, infection in dentistry is very low. Nonetheless, the lack of an effective vaccine, the high rates of chronic infection and the limited effectiveness of treatment may cause concern for dental workers who come into contact with blood in their daily practices.

DESCRIPTION OF THE DISORDER

The authors discuss the natural history, diagnosis and treatment, and patterns of transmission of HCV infection, including the Centers for Disease Control and Prevention's recommendations for management and follow-up of health care workers after occupational exposure to HCV.

CLINICAL IMPLICATIONS

In the absence of an effective vaccine or postexposure prophylaxis, prevention of occupational transmission of HCV in dental settings continues to rely on the use of universal precautions, including barrier precautions and the safe handling of sharp instruments.

Using a biological indicator to detect potential sources of cross-contamination in the dental operatory

The authors conducted a study using surveillance monitoring methodology to identify operatory contamination and to evaluate the effectiveness of infection control procedures. Viridans streptococci were evaluated as biological indicators of oral contamination. Viridans streptococci, abundant in human saliva, were detected on operatory surfaces after dental treatments were finished and surfaces were disinfected. The findings validate current concepts of infection control as demonstrated in barrier methods.

Occupational blood exposure and HIV infection among oral and maxillofacial surgeons

OBJECTIVE

The purpose of this study was to examine occupational blood exposure and the seroprevalence of HIV infection among oral and maxillofacial surgeons.

STUDY DESIGN

Three hundred twenty-one oral and maxillofacial surgeons attending an annual meeting voluntarily and anonymously participated in an HIV serosurvey and completed a questionnaire assessing practice and demographic factors. Statistical tests included the Wilcoxon rank-sum test and the chi-squared test.

RESULTS

Eighty percent of those who completed the survey reported one or more blood-skin contacts within the previous month. The mean number of percutaneous injuries within the previous year was 2.36 +/- 0.2. Wire was most commonly associated with percutaneous injuries. Oral maxillofacial surgeons who reported three or more percutaneous injuries performed more fracture reductions than oral and maxillofacial surgeons reporting no percutaneous injuries (p < 0.01). No participant was HIV-positive; the upper limit of the 95% confidence interval was 1.15%.

CONCLUSION

The findings suggest that the occupational risk for HIV infection in oral surgery is very low even though most oral and maxillofacial surgeons experienced blood contact. Associations of percutaneous injuries with fracture reductions and wire may assist in the development of new techniques and equipment to minimize blood exposures.

Identification of a CD36-related thrombospondin 1-binding domain in HIV-1 envelope glycoprotein gp120: relationship to HIV-1-specific inhibitory factors in human saliva

Human and non-human primate salivas retard the infectivity of HIV-1 in vitro and in vivo. Because thrombospondin 1 (TSP1), a high molecular weight trimeric glycoprotein, is concentrated in saliva and can inhibit the infectivity of diverse pathogens in vitro, we sought to determine the role of TSP1 in suppression of HIV infectivity. Sequence analysis revealed a TSP1 recognition motif, previously defined for the CD36 gene family of cell adhesion receptors, in conserved regions flanking the disulfide-linked cysteine residues of the V3 loop of HIV envelope glycoprotein gp120, important for HIV binding to its high affinity cellular receptor CD4. Using solid-phase in vitro binding assays, we demonstrate direct binding of radiolabeled TSP1 to immobilized recombinant gp120. Based on peptide blocking experiments, the TSP1-gp120 interaction involves CSVTCG sequences in the type 1 properdin-like repeats of TSP1, the known binding site for CD36. TSP1 and fusion proteins derived from CD36-related TSP1-binding domains were able to compete with radiolabeled soluble CD4 binding to immobilized gp120. In parallel, purified TSP1 inhibited HIV-1 infection of peripheral blood mononuclear cells and transformed T and promonocytic cell lines. Levels of TSP1 required for both viral aggregation and direct blockade of HIV-1 infection were physiologic, and affinity depletion of salivary TSP1 abrogated >70% of the inhibitory effect of whole saliva on HIV infectivity. Characterization of TSP1-gp120 binding specificity suggests a mechanism for direct blockade of HIV infectivity that might be exploited to retard HIV transmission that occurs via mucosal routes.

Accidental exposures to blood and body fluids among health care workers in dental teaching clinics: a prospective study

The authors evaluated accidental exposures to blood and body fluids reported to a hotline or to health officials at four dental teaching clinics. The authors used a standard questionnaire to solicit and record data regarding each exposure. During a 63-month period, 428 parenteral exposures to blood or body fluids were documented. Dental students and dental assistants had the highest rates of exposure. Syringe needle injuries were the most common type of exposure, while giving injections, cleaning instruments after procedures and drilling were the activities most frequently associated with exposures.

Inhibition of Human Immunodeficiency Virus Type 1 Infectivity by Secretory Leukocyte Protease Inhibitor Occurs Prior to Viral Reverse Transcription

Infection of monocytes with human immunodeficiency virus type 1Ba-L (HIV-1Ba-L ) is significantly inhibited by treatment with the serine protease inhibitor, secretory leukocyte protease inhibitor (SLPI). SLPI does not appear to act on virus directly, but rather the inhibitory activity is most likely due to interaction with the host cell. The current study was initiated to investigate how SLPI interacts with monocytes to inhibit infection. SLPI was found to bind to monocytes with high affinity to a single class of receptor sites (∼7,000 receptors per monocyte, KD = 3.6 nmol/L). The putative SLPI receptor was identified as a surface protein with a molecular weight of 55 ± 5 kD. A well-characterized function of SLPI is inhibition of neutrophil elastase and cathepsin G. However, two SLPI mutants (or muteins) that contain single amino acid substitutions and exhibit greatly reduced protease inhibitory activity still bound to monocytes and retained anti–HIV-1 activity. SLPI consists of two domains, of which the C-terminal domain contains the protease inhibiting region. However, when tested independently, neither domain had potent anti–HIV-1 activity. SLPI binding neither prevented virus binding to monocytes nor attenuated the infectivity of any virus progeny that escaped inhibition by SLPI. A polymerase chain reaction (PCR)-based assay for newly generated viral DNA demonstrated that SLPI blocks at or before viral DNA synthesis. Therefore, it most likely inhibits a step of viral infection that occurs after virus binding but before reverse transcription. Taken together, the unique antiviral activity of SLPI, which may be independent of its previously characterized antiprotease activity, appears to reside in disruption of the viral infection process soon after virus binding.

Postexposure chemoprophylaxis for occupational exposure to HIV in the dental office

Occupational exposure to HIV continues to be a concern for health care workers. Preventing exposure through the use of universal precautions is the primary means of protection. New Public Health Service interagency work group recommendations for postexposure chemoprophylaxis provide information to help manage occupational exposure to HIV.

Inhibition of Human Immunodeficiency Virus Type 1 Infectivity by Secretory Leukocyte Protease Inhibitor Occurs Prior to Viral Reverse Transcription

Infection of monocytes with human immunodeficiency virus type 1Ba-L (HIV-1Ba-L ) is significantly inhibited by treatment with the serine protease inhibitor, secretory leukocyte protease inhibitor (SLPI). SLPI does not appear to act on virus directly, but rather the inhibitory activity is most likely due to interaction with the host cell. The current study was initiated to investigate how SLPI interacts with monocytes to inhibit infection. SLPI was found to bind to monocytes with high affinity to a single class of receptor sites (∼7,000 receptors per monocyte, KD = 3.6 nmol/L). The putative SLPI receptor was identified as a surface protein with a molecular weight of 55 ± 5 kD. A well-characterized function of SLPI is inhibition of neutrophil elastase and cathepsin G. However, two SLPI mutants (or muteins) that contain single amino acid substitutions and exhibit greatly reduced protease inhibitory activity still bound to monocytes and retained anti–HIV-1 activity. SLPI consists of two domains, of which the C-terminal domain contains the protease inhibiting region. However, when tested independently, neither domain had potent anti–HIV-1 activity. SLPI binding neither prevented virus binding to monocytes nor attenuated the infectivity of any virus progeny that escaped inhibition by SLPI. A polymerase chain reaction (PCR)-based assay for newly generated viral DNA demonstrated that SLPI blocks at or before viral DNA synthesis. Therefore, it most likely inhibits a step of viral infection that occurs after virus binding but before reverse transcription. Taken together, the unique antiviral activity of SLPI, which may be independent of its previously characterized antiprotease activity, appears to reside in disruption of the viral infection process soon after virus binding.

Surgical risk assessment and management in patients with HIV disease

Determining the perioperative risks associated with surgical procedures performed in patients with HIV disease is a difficult and complex task. Because HIV is a contagious, blood-borne pathogen, it threatens the health and well-being of both patient and health care provider. Despite poor early results, there is now convincing evidence that HIV infection is not a significant, independent risk factor for major surgical procedures. In practice, the authors evaluate the risk of surgery in patients with HIV infection using the same basic tools and guidelines applied to the uninfected, with the best predictors of surgical morbidity and mortality stemming from a careful and accurate assessment of the patient's cardiopulmonary, renal, endocrine, and nutritional reserve. Although HIV disease provides a unique constellation of diagnoses and challenges to the health care provider, the risk of major surgery in this population is not unlike that for other immunocompromised or malnourished patients. The authors believe that members of the surgical team have a professional, moral, and ethical responsibility to provide the highest possible quality of care for their patients, regardless of their HIV status. If after weighing the risks and benefits to the patient the surgeon believes the procedure will have a positive effect on the patient's life, the surgeon must offer surgical treatment. To do less does a disservice to the patient, the provider, and the profession as a whole.

Occupational risk of human immunodeficiency virus infection in healthcare workers: an overview

Healthcare workers (HCWs) are at risk for occupational acquisition of human immunodeficiency virus (HIV) infection, primarily due to percutaneous exposure to infected blood. As of June 1996, 51 documented cases and 108 possible cases of occupationally acquired HIV infection in HCWs in the United States had been reported to the Centers for Disease Control and Prevention. The frequency of blood exposure among HCWs varies according to occupation, procedures performed, and use of preventive measures. Based on limited data, it has been estimated that approximately 500,000 percutaneous blood exposures may occur annually among hospital-based HCWs in the United States. Of these, approximately 5,000 may involve exposures to blood that is known to be HIV infected. The average risk of HIV transmission after percutaneous exposure to HIV-infected blood is approximately 0.3%; however, the risk is believed to be higher for exposures involving an increased volume of blood and/or high viral load.

Dental lesions: diagnosis and treatment

Oral health care has been an integral part of the care of patients with HIV infection and AIDS since the disease was first identified in the early eighties. The spectrum of HIV-associated opportunistic diseases occurring in the oral cavity propelled dental health care providers to the forefront of patient care. Infection control issues soon became important in oral health care for patients infected with HIV, and for the first decade these two issues overshadowed the concerns about appropriate management of the dental needs of HIV-infected patients. Several concerns need to be considered in the management of dental care for patients infected with HIV. These include decreased salivary flow and increased sugar intake, prevention and management of routine inflammatory gingival and periodontal disease as well as the atypical forms of gingival and periodontal disease associated with HIV infection (linear gingival erythema [LGE], necrotizing ulcerative gingivitis [NUG] and necrotizing ulcerative periodontitis [NUP]). Finally, although reports of complications secondary to dental treatment of HIV-infected individuals are rare, it is important to consider those factors related to the medical status of HIV-infected patients which may interfere with oral health care. These include potential bleeding problems related to thrombocytopenia and disease or medication related liver abnormalities, increased risk of local infection particularly in patients with severe neutropenia and adverse effects of multiple medications taken by HIV patients. Prevention and management of dental and periodontal disease in HIV-infected individuals is important to self esteem, quality of life and maintenance of adequate nutritional intake. Oral health care continues to be an important component of overall health care for HIV-infected patients.

Secretory leukocyte protease inhibitor (SLPI) in mucosal fluids inhibits HIV-I

Despite the presence of HIV-1 in the oral cavity, transmission of the virus through saliva has not been proven. Consistent with these observations, we recently identified an endogenous 12 kD protein, secretory leukocyte protease inhibitor (SLPI), in saliva which blocks HIV-1 infection in vitro. Whereas other salivary proteins tested were inactive, purified native or recombinant SLPI inhibited HIV-1 infection of human monocytes at 100 ng ml-1. Levels of SLPI quantitated by ELISA in saliva from control and HIV-1 infected individuals exceeded this level, consistent with in vivo antiviral activity. As in saliva, levels of SLPI mRNA determined by Northern hybridization, and protein as assessed by immunohistochemistry in the salivary glands of control and infected populations were comparable. In contrast to adults, oral transmission occurs in infants, possibly due to their lack of fully developed salivary glands. To determine whether the inadequate antiviral protection might be compensated for by maternal sources, we evaluated breast milk samples obtained 6 months postpartum. Levels of SLPI were significantly lower than in saliva and not sufficient to provide antiviral protection in contrast to colostrum samples in which SLPI levels were equivalent to those in saliva and able to inhibit HIV-1 infection when tested in vitro. These data suggest that breast milk may provide transient antiviral activity in the newborn, but that this maternal source of SLPI is of insufficient duration to maintain protection against mucosal transmission of the virus over time. The high functional levels of SLPI in saliva and the low levels in mature breast milk correlate with negligible rates of HIV-1 transmission by saliva and higher rates by breast feeding.

Detection of HIV in oral mucosal cells

OBJECTIVE

To determine the prevalence of HIV DNA and RNA and the morphologic localization of HIV in the oral cavity of HIV-seropositive subjects.

DESIGN

A cross-sectional analysis of saliva, buccal scrapings and buccal biopsies from HIV-seropositive injecting drug users (IDUs).

SUBJECTS AND METHODS

Whole saliva, buccal mucosal scrapings and buccal biopsies were obtained from HIV-seropositive and seronegative IDUs. Presence of HIV DNA and RNA was assessed by polymerase chain reaction (PCR) and reverse transcriptase PCR (RT-PCR). RT in situ PCR was used to detect HIV tat/rev RNA in buccal mucosal scrapings. Host-cell integrated HIV-proviral DNA in buccal biopsies was detected by in situ PCR. Presence of intact HIV viral particles in buccal scrapings was assessed by electron microscopy.

RESULTS

HIV DNA was detected in 40% (18/45) and HIV RNA in 69.2% (25/36) of saliva samples from HIV-seropositive IDUs. Viral particles consistent with HIV were localized in inter-epithelial spaces by electron microscopy. RT in situ PCR revealed the presence of HIV tat/rev RNA in 36% (8/22) of the seropositive samples tested.

CONCLUSIONS

Our results suggest that epithelial cells can be productively infected by HIV. Epithelial cells in buccal mucosa may acquire HIV in the basal layers through contact with submucosal HIV-positive lymphocytes and/or Langerhans' cells. HIV infection may also spread by inter-epithelial cell contact. As HIV infected cells mature they travel to more superficial layers and are shed into the oral cavity.

Psychological aspects of infection control and the care of the patient with HIV in dentistry

HIV presents a number of challenges to the dentist. There is a need to control infection risks and, in spite of all the information available, a minority of dentists still have incomplete infection control procedures. The reasons for this and the implications for dental education are explored. There is also a need to ensure that the patient is optimally managed by the dentist and the importance of linkages to other services and the likely demands of patients on the dentist are reviewed. Finally the impact of treating the patient with HIV disease on the dentist and ways of minimising stress associated with the work are considered.

Virucidal activity of an oral fluid human immunodeficiency virus-1 antibody preservative

Diagnosis of human immunodeficiency virus-1 (HIV-1) infection requires the collection of either serum or oral fluid that is subsequently tested for the presence of antibodies to HIV-1. The effective use of oral fluid for the detection of HIV antibodies is contingent on stabilization of immunoglobulins in the sample through the use of preservatives. Oral fluid preservatives also contain agents that can disrupt and inactivate viruses. This study demonstrates the virucidal activity of a commercially available oral fluid preservative against HIV-1 using a sensitive 28-day cell culture assay designed to detect infectious virus. The results demonstrate that a 5-log reduction in viral titer is obtained when equal volumes of HIV-1 viral stocks and the preservative are mixed. The data provide strong evidence that preserved oral fluid samples from infected individuals are noninfectious for HIV-1.

Human submandibular saliva specifically inhibits HIV type 1

Studies from a number of laboratories have shown the presence of factor(s) in whole, parotid, and submandibular human saliva capable of inhibiting HIV-1 infectivity in vitro. Data from our laboratory suggested that the level of anti-HIV-1 activity is higher in submandibular than parotid or whole saliva. Previous results obtained with pooled submandibular saliva from seronegative individuals included a filtration step following saliva-virus interaction. In this article, we present data on the HIV-1 inhibitory activity of individual submandibular saliva samples collected from 15 donors. We show that although anti-HIV activity is quantitatively similar in most individuals (9 of 15), some (4 of 15) are much less active than others and some (2 of 15) lack inhibitory activity. We also show that for most individuals the level of anti-HIV inhibitor is similar with or without a filtration step. However, 2 of the 15 samples demonstrated activity only after filtration. The quantitative and qualitative anti-HIV activity of individual saliva samples appeared to reflect differences in the individual donors. We further show that the anti-HIV activity of submandibular saliva is demonstrated not only against laboratory strains of HIV-1 but is similarly active against three clinical HIV-1 isolates. In contrast, submandibular saliva had little effect on the infectivity of HIV-2 or SIV.

Risks and issues for the health care worker in the human immunodeficiency virus era

The perception of degree of risk can vary markedly from actual risk. About 5% of the cases of AIDS and HIV infection in the United States have occurred in health care workers, a percentage that has remained stable over time. Nearly all of these infections are related to lifestyle factors, not occupational risk. The rise of occupational transmission is greatest with parenteral injuries. If there is an HIV risk to patients, it appears to be very much smaller than the risk to workers although it has received even more publicity. Apprehension exists concerning the future framework of the medical care delivery system and who will care for whom. The sensitive handling of legitimate fears and the balancing of conflicting risks will continue to be a challenging task in the decades ahead.

The anti-HIV-1 activity associated with saliva

This review summarizes the data on the anti-human immunodeficiency virus (HIV) activity associated with saliva and the possible routes of oral transmission of HIV. Saliva can be passed from an HIV-infected individual to an uninfected person via sexual or non-sexual activities. The relative risk of HIV transmission through saliva is a subject of continuing concern for dental practitioners. HIV-infected individuals frequently have oral lesions that can cause bleeding and release of the virus into the oral cavity. In addition, viral p24 and HIV-1 RNA were detected in tonsils and adenoids even in asymptomatic seropositive individuals. Nevertheless, the potential HIV-infectivity of saliva is low, although both infectious HIV-1 and HIV DNA have been detected in saliva. This observation has led to the suggestion that saliva may contain factors that inhibit HIV-1 infectivity. At least two anti-HIV activities have been partially characterized: (i) physical entrapment of HIV by high-molecular-weight molecules (e.g., mucins), and (ii) inhibition of viral infection by soluble proteins. Several studies have indicated that, of the salivary proteins evaluated, recombinant secretory leukocyte protease inhibitor (rSLPI) could inhibit HIV-1 infection in macrophages at physiological concentrations. The anti-HIV activity of the serine protease inhibitor rSLPI is most likely due to its interaction with a cell-surface molecule(s) other than the primary HIV-1 receptor, CD4, and may involve (i) inhibition of cell-surface serine protease(s), and/or (ii) interaction with other human-specific co-factors essential for viral entry.

Reducing the risk of needlesticks: methods used to reload syringes

To achieve local anesthesia, dentists may need to administer a second injection. One widely used textbook advocates removing the needle before replacing the used cartridge. To determine the extent to which practicing dentists follow this recommendation, the author surveyed 144 practicing dentists in an upstate New York community and found that only 3 percent use this method. The rest leave the needle on to minimize their risk of a needlestick.