Routine HIV testing in acute care hospitals: Changing practice to curb a local HIV epidemic in Vancouver, BC

Early treatment of HIV infection increases life expectancy and reduces infectivity; however, delayed HIV diagnosis remains common. Implementation and sustainability of hospital-based routine HIV testing in Vancouver, British Columbia, was evaluated to address a local HIV epidemic by facilitating earlier diagnosis and treatment. Public health issued a recommendation in 2011 to offer HIV testing to all patients presenting to three Vancouver hospitals as part of routine care, including all patients admitted to medical/surgical units with expansion to emergency departments (ED). We evaluated acceptability, feasibility, and effectiveness from 2011 to 2014 and continued monitoring through 2016 for sustainability. Between October 2011-December 2016, 114,803 HIV tests were administered at the three hospitals; an 11-fold increase following implementation of routine testing. The rate of testing was sustained and remained high through 2018. Of those tested, 151 patients were diagnosed with HIV for a testing yield of 0.13%. Review of 12,996 charts demonstrated 4935/5876 (96·9%) of admitted patients agreed to have an HIV test when offered. People diagnosed in hospital were significantly more likely to be diagnosed with acute stage (aOR 1·96, 95% CI 1·19, 3·23) infection, particularly those diagnosed in the ED. This study provides practice-based evidence of the feasibility, acceptability, and effectiveness of implementing a recommendation for routine HIV testing among inpatient and emergency department admissions, as well as the ability to normalize and sustain this change. Routine hospital-based HIV testing can increase diagnoses of acute HIV infection and facilitate earlier initiation of antiretroviral treatment.

Stability of hepatitis B viral load during pregnancy and implications for antepartum prophylaxis: A prospective cohort study

BACKGROUND: We examined changes in hepatitis B virus (HBV) viral loads (VLs) in pregnancy, their association with hepatitis B e antigen (HBeAg), and the associated infant outcomes. METHODS: We prospectively followed 132 mothers positive for hepatitis B surface antigen (HBsAg) and their 135 infants from 2011 to 2015 in Vancouver, British Columbia. Outcome measures included association between maternal HBeAg and high (>200,000 IU/mL) or low (≤200,000 IU/mL) HBV VL, changes in HBV VL through pregnancy, infant HBsAg status, and infant completion of the HBV vaccination series. RESULTS: Of the 91 participants with an available HBV VL, 13 (14.3%) had an HBV VL of more than 200,000 IU/mL. Of 59 participants with paired HBeAg and HBV VL in pregnancy, 6 had an HBV VL of more than 200,000 IU/mL; of interest, 2 of the 6 (33.3%) were HBeAg-negative. Thirty-eight participants had HBV VL results at both mid-trimester and delivery. For these 38 participants, Wilcoxon signed-ranks test for paired data found that an HBV VL remained stable ( p = .58). We observed no perinatal transmissions. However, 20.7% of infants did not have a documented complete HBV vaccination series, 20.0% did not have post-vaccination HBsAg testing completed, and 18% did not have anti-HBs titres measured by age 12 months. CONCLUSIONS: Our study demonstrates that HBeAg and HBV VL are not reliably predictive of each other. This supports the improved predictive value of VL measurement in pregnancy to risk stratify pregnant patients to offer antiviral treatment when indicated and further minimize the risk of perinatal transmission.

Poor seroprotection but allosensitization after adjuvanted pandemic influenza H1N1 vaccine in kidney transplant recipients

BACKGROUND

Seasonal and pandemic influenza virus infections in renal transplant patients are associated with poor outcomes. During the pandemic of 2009-2010, the AS03-adjuvanted monovalent H1N1 influenza vaccine was recommended for transplant recipients, although its immunogenicity in this population was unknown. We sought to determine the safety and immunogenicity of an adjuvant-containing vaccine against pandemic influenza A H1N1 2009 (pH1N1) administered to kidney transplant recipients.

METHODS

We prospectively enrolled 124 adult kidney transplant recipients in the fall of 2009 at two transplant centers. Cohort 1 (n = 42) was assessed before and after pH1N1 immunization, while Cohort 2 (n = 82) was only assessed post immunization. Humoral response was measured by the hemagglutination inhibition assay. Vaccine safety was assessed by adverse event reporting, graft function, and human leukocyte antigen (HLA) alloantibody measurements.

RESULTS

Cohort 1 had a low rate of baseline seroprotection to pH1N1 (7%) and a low rate of seroprotection after immunization (31%). No patient <6 months post transplant (n = 5) achieved seroprotection. Seroprotection rate was greater in patients receiving double as compared with triple immunosuppression (80% vs. 24%, P = 0.01). In Cohort 2, post-immunization seroprotection was 35%. In both cohorts, no confirmed cases of pH1N1 infection occurred. No difference was seen in estimated glomerular filtration rate before (54.3 mL/min/1.73 m(2) ) and after (53.8 mL/min/1.73 m(2) ) immunization, and no acute rejections had occurred after immunization at last follow-up. In Cohort 1, 11.9% of patients developed new anti-HLA antibodies.

CONCLUSION

An adjuvant-containing vaccine to pH1N1 provided poor seroprotection in renal transplant recipients. Receiving triple immunosuppression was associated with a poor seroresponse. Vaccination appeared safe, but some patients developed new anti-HLA antibodies post vaccination. Alternative strategies to improve vaccine responses are necessary.

Fatal postlymphoma chemotherapy hepatitis B reactivation secondary to the emergence of a YMDD mutant strain with lamivudine resistance in a noncirrhotic patient

Hepatitis B reactivation is a well-known complication during or after chemotherapy in chronic hepatitis B (HBV) carriers. The current practice guidelines in Canada and the United States recommends patients receive antiviral prophylaxis prior to the onset of chemotherapy in chronic HBV carriers with lamivudine. We report a case of a 57-year-old man with follicular lymphoma on lamivudine prophylaxis and no clinical evidence of cirrhosis, and developed fatal HBV reactivation after the emergence of a YMDD mutant strain of HBV that confers lamivudine resistance. Fatal reactivation secondary to the development of lamivudine resistance has not, to date, been well- reported. Our experience indicates the need to carefully monitor patients for suspected drug- resistant HBV mutants with the addition of anti-viral agents effective against the YMDD mutational strain, when lamivudine resistance emerges.

Use of Sno Strip filter-paper wicks for collection of genital-tract samples allows reproducible determination of human immunodeficiency virus type 1 (HIV-1) RNA viral load with a commercial HIV-1 viral load assay

To assess the reproducibility of measurements of cervical and vaginal human immunodeficiency virus (HIV) viral load, 92 duplicate cervical and 88 duplicate vaginal samples were collected from 13 HIV-infected women using Sno Strip filter-paper wicks. RNA was eluted from the strips, extracted, and assayed using a modified protocol for the Roche Cobas Amplicor HIV-1 Monitor assay. Pearson's correlation coefficient (R), coefficient of determination (D), and Bland-Altman plots (BA) were used to compare paired log10-transformed viral loads. Analysis of duplicate same-site samples showed good reproducibility (cervix: R = 0.72, D = 52%, BA = 89% within range; vagina: R = 0.72, D = 51%, BA = 87% within range); paired cervix/vagina measurements showed moderate correlation only (R = 0.56; D = 31.3%). Standardized sample collection and simple modification of the Roche Cobas Amplicor HIV-1 Monitor assay allows reproducible measurement of genital viral load.

Utilization of a Liver Allograft from a Hepatitis B Surface Antigen Positive Donor

With today's donor organ shortage, enhanced efforts must be made to utilize organs that previously would have been declined. We report a 26-year-old man with chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) coinfection who received a liver transplant from an HBsAg-positive donor. HBV viremia (6,281,185 copies/ml) was seen early posttransplant despite lamivudine prophylaxis, but became negative with addition of adefovir. Virologic analysis revealed predominantly donor HBV strain immediately posttransplant. At 5 months there was an elevation of liver enzymes accompanied by histologic evidence of hepatitis. At this time, HCV-RNA was positive but HBV DNA was undetectable. Treatment with pegylated interferon and ribavirin resulted in sustained clearance of HCV RNA. Two years posttransplant, the patient has normal liver biochemistry and HCV and HBV viral load are undetectable with persistence of HBsAg. Our experience suggests that with effective antiviral therapy, the use of HBsAg seropositive donors is feasible in selected circumstances.

Seroepidemiology of hepatitis C virus in Beijing, China

To investigate the seroprevalence of hepatitis C virus (HCV) in China we tested sera from healthy individuals without hepatitis and no history of parenteral blood exposure and from patients admitted to a hepatitis hospital in Beijing. Sera were tested for anti-HCV by first-generation enzyme immunoassay; selected positives were tested with two second-generation EIAs, one utilizing recombinant antigens and the other synthetic peptides. We found anti-HCV with the following frequencies: 10 of 164 (6%) individuals with no disease; 2 of 36 (5.5%) patients with acute non-A non-B hepatitis (NANBH); 26 of 39 (67%) patients with post-transfusion NANBH; 10 of 34 (29%) patients with chronic hepatitis negative for hepatitis B surface antigen (HBsAg); 3 of 30 (10%) patients with chronic HBsAg-positive hepatitis; 0 of 19 patients with acute HBsAg-positive hepatitis. Of 24 repeat-positive sera, 19 were positive by both and 4 by one second-generation tests. We conclude that hepatitis C infection is common in China, that it contributes substantially to the incidence of post-transfusion hepatitis, and that HCV plays a significant role in both acute and chronic hepatitis. Further studies are needed to extend these observations and to define the predominant routes of transmission of HCV in China.

Multicenter evaluation of the VERSANT hepatitis B virus DNA 3.0 assay

The VERSANT hepatitis B virus (HBV) 3.0 Assay (branched DNA [bDNA]) (referred to herein as VERSANT 3.0) was evaluated at four external sites for analytical sensitivity, specificity, reproducibility, linearity of quantification, and limits of detection. In addition, each of the test evaluation sites provided HBV DNA-positive clinical samples that were previously analyzed by one of three commercially available HBV DNA quantitative tests: Digene Hybrid Capture II HBV DNA Test (Digene); VERSANT HBV DNA 1.0 Assay (bDNA) (VERSANT 1.0); and COBAS AMPLICOR HBV Monitor Test (COBAS AMPLICOR). These samples were reexamined using VERSANT 3.0. The results from these studies showed that VERSANT 3.0 has high specificity (99.3%), excellent reproducibility (between-run coefficient of variation [CV] = 1.6 to 9.4%; within-run CV = 6.5 to 20.7%), and a broad linear range of quantification (2.0 x 10(3) to 1.0 x 10(8) HBV DNA copies/ml) that facilitate the monitoring of HBV DNA levels at diagnosis and throughout the course of treatment. In general, correlation was very good between results obtained from clinical samples analyzed by VERSANT 3.0 and the comparative HBV DNA quantitative assays (VERSANT 1.0, R(2) = 0.900; Digene, R(2) = 0.985; COBAS AMPLICOR, R(2) = 0.771). The greatest differences in comparative quantitation occurred at HBV DNA levels approaching the limits of the dynamic ranges for the comparative assays. The performance characteristics of the new VERSANT 3.0 assay demonstrated that it provides a reliable and robust method for routinely monitoring serum HBV DNA levels in assessing disease activity and determining response to antiviral treatment.

The prevalence of herpes simplex virus shedding and infection in the oral cavity of seropositive patients undergoing head and neck radiation therapy

OBJECTIVE

Herpes viruses are characterized by their ability to establish and maintain a latent infection that can reactivate. Only 2 preliminary studies have examined herpes simplex virus (HSV) reactivation in patients receiving head and neck radiotherapy. The role of radiation therapy in the reactivation of a latent virus has not been established. The purpose of the present study was to evaluate the incidence of HSV reactivation in patients receiving radiation treatment for head and neck malignancies.

METHODS

Twenty patients, 19 of whom were HSV seropositive, undergoing head and neck radiation therapy were assessed weekly before and during radiation therapy, and HSV cultures were completed during cancer treatment.

RESULTS

Only 3.6% of the cultures were positive for HSV during radiation therapy. HSV was cultured in 4 men receiving a mean of 6,000 cGy to the head and neck area. Recovery from HSV was seen in patients nearing completion of radiation therapy.

CONCLUSIONS

The results of this study suggest that HSV reactivation is not common during radiation therapy. Therefore, this study does not support prophylaxis of HSV in patients undergoing head and neck irradiation.

"Discordant" increases in CD4 cell count relative to plasma viral load in a closely followed cohort of patients initiating antiretroviral therapy

BACKGROUND

In HIV-positive persons receiving antiretroviral therapy, CD4 cell responses are associated with optimal suppression of viral replication. However, increases in CD4 cell counts in the absence of viral suppression have been reported. We characterized plasma viral load (pVL) and CD4 cell count increases in closely followed patients to evaluate determinants and the prevalence of CD4 cell responses at a populational level.

METHODS

All HIV-positive patients in the province of British Columbia, Canada, who were antiretroviral naive and initiated therapy between August 1996 and May 1998 were eligible for the study. The selection criteria were that patients had to have CD4 cell counts and pVLs measured at baseline and at least once during eight 16-week periods after the initiation of therapy. We characterized CD4 cell responses and sought patients who had a "discordant" increase at 1 year, which was defined as an increase in CD4 cell count of >or=50/mm3 with a <1 log10 decrease in pVL. We also evaluated adherence and antiretroviral use.

RESULTS

Overall, when baseline and 1-year pVLs and CD4 cell counts were compared, 6.2% of patients had CD4 cell count increases without pVL decreases of >or=1 log10. However, when all pVLs before 1 year were considered, 92% of the discordant increases could be attributed to prior transient or partial viral suppression. Furthermore, although substantial increases in CD4 cell counts were observed in transient virologic responders, the cumulative number of antiretroviral agents used by this group was significantly higher than that used by full virologic responders (p <.001).

CONCLUSIONS

Our results demonstrate that virtually all CD4 cell count increases can be attributed to transient or partial pVL suppression. Unmeasured pVL suppression likely explains discordant responses that have been previously reported. Similarities between transient and full virologic responders also appear to be time limited and are often associated with greater cumulative use of antiretroviral therapy by transient virologic responders.

Incidence of hepatitis C virus infection among injection drug users during an outbreak of HIV infection

BACKGROUND

Beginning in 1994, Vancouver experienced an explosive outbreak of HIV infection among injection drug users (IDUs). The objectives of this study were to measure the prevalence and incidence of hepatitis C virus (HCV) infection in this context and to examine factors associated with HCV seroconversion among IDUs.

METHODS

IDUs recruited through a study site and street outreach completed interviewer-administered questionnaires covering subjects' characteristics, behaviour, health status and service utilization and underwent serologic testing for HIV and HCV at baseline and semiannually thereafter. A Cox proportional hazards model was used to identify independent correlates of HCV seroconversion.

RESULTS

As of Nov. 30, 1999, 1345 subjects had been recruited into the study cohort. The prevalence of anti-HCV antibodies was 81.6% (95% confidence interval [CI] 79.6% to 83.6%) at enrollment. Sixty-two HCV seroconversions occurred among 155 IDUs who were initially HCV negative and who returned for follow-up, for an overall incidence density rate of 29.1 per 100 person-years (95% CI 22.3 to 37.3). The HCV incidence remained above 16 per 100 person-years over 3 years of observation (December 1996 to November 1999), whereas HIV incidence declined from more than 19 to less than 5 per 100 person-years. Independent correlates of HCV seroconversion included female sex, cocaine use, injecting at least daily and frequent attendance at a needle exchange program.

INTERPRETATION

Because of high transmissibility of HCV among those injecting frequently and using cocaine, the harm reduction initiatives deployed in Vancouver during the study period proved insufficient to eliminate hepatitis C transmission in this population.

Can pooling be used for seroprevalence studies of hepatitis C?

Two hepatitis C antibody assays were used to test diluted positive sera. Dilutions of 1 in 5, 1 in 10, and 1 in 20 all resulted in loss of reactivity, with the greatest losses occurring in samples with low and moderate reactivities. These results disqualify pooling as a strategy for seroprevalence studies and screening programs.

De novo acute hepatitis B infection in a previously vaccinated liver transplant recipient due to a strain of HBV with a Met 133 Thr mutation in the "a" determinant

De novo HBV infection post-liver transplantation (LT) from an anti-HBc seropositive donor rarely presents as acute failure. We report a 42-year-old Caucasian female, HBsAg and anti-HBc seronegative, with primary biliary cirrhosis who received an allograft from a HBsAg negative, anti-HBc seropositive donor. The patient, previously vaccinated years pre-LT, was re-vaccinated against HBV and 1 year post-LT had an anti-HBs titre of 256 IU/l. Two years post-LT, elevated serum aminotransferases and worsening liver function with an INR of 2.0 developed. The HBsAg became positive, anti-HBs undetectable and serum HBV-DNA >2000 pg/ml by hybridisation assay. Liver biopsy revealed significant ballooning degeneration, piecemeal necrosis and positive immunostaining for HBsAg. Progressive liver failure developed followed by sepsis and terminal multi-organ failure. Subsequent analysis of the predominant HBV strain revealed mutations in the "a" determinant: Met 133 Thr (codon change ATG to ACG) and Asn 131 Thr.

CONCLUSION

' Acute de novo HBV infection from an anti-HBc sero-positive donor may occur long after LT despite protective anti-HBs titres post-vaccination secondary to the emergence of "a" determinant mutated strains of HBV.

Full suppression of viral load is needed to achieve an optimal CD4 cell count response among patients on triple drug antiretroviral therapy

OBJECTIVE

To characterize the relationship between plasma viral load (pVL) suppression and triple drug antiretroviral therapy, and the accompanying changes in CD4 cell counts.

METHOD

Retrospective study of 465 participants in a HIV/AIDS Treatment Program who initiated triple drug therapy between August 1996 and May 1998. Participants were divided into three groups according to their pVL response: (i) non-responders (NR; n = 112) exhibited pVL persistently > 500 copies/ml over the study period; (ii) partial responders (PR; n = 100) achieved a pVL < 100 copies/ml at least once and subsequently rebounded to > 500 copies/ml; and (iii) full responders (FR; n = 253) achieved a pVL < 500 copies/ml and sustained this level for the remainder of the study period. For each group, the accompanying changes in absolute and fractional CD4 cell counts were evaluated.

RESULTS

The median net change in pVL per person from baseline to the end of the observation period was -0.37, -2.27, and -2.56 log10 copies/ml for NR, PR and FR, respectively. During weeks 68-83, the median CD4 cell count (x 10(6) cells/l) was 150 [interquartile range (IQR) 90-370], 380 (IQR 300-480) and 525 (IQR 305-705) for NR, PR and FR, respectively. Median changes in CD4 cells (x 10(6) cells/l) were -20 (IQR -90 to 40), 150 (IQR 30-250) and 240 (IQR 110-365) for NR, PR, and FR, respectively. The net percentage change in CD4 cells per person was 0% (IQR -34-31), 54% (IQR 6-160), and 83% (IQR 39-173) for NR, PR, and FR, respectively. By weeks 68-83, the median fractional CD4 cells was 0.16 (IQR 0.07-0.22), 0.22 (IQR 0.15-0.28), and 0.26 (IQR 0.17-0.34) for NR, PR and FR respectively.

CONCLUSIONS

An optimal CD4 cell count response appears to be coupled with continued pVL suppression. Our data indicate that maximal suppression of viral replication should remain the primary goal of therapy.

Suppression of plasma virus load below the detection limit of a human immunodeficiency virus kit is associated with longer virologic response than suppression below the limit of quantitation

Suppression of human immunodeficiency virus type 1 plasma virus load (PVL) to <20 copies/mL is associated with a longer virologic response after initiation of antiretroviral therapy. The relationship between duration of virologic response and PVL nadir according to a less sensitive assay was explored. When compared with subjects with a PVL nadir >500 copies/mL, the relative risks of PVL rising above 1000 copies/mL for participants in the INCAS trial and the British Columbia Drug Treatment Program with a PVL nadir below the limit of detection (LOD) were 0.04 (95% confidence interval [CI], 0.02-0.09) and 0.06 (95% CI, 0.03-0.12), respectively. The corresponding relative risks for persons with a detectable but not quantifiable PVL nadir were 0.25 (95% CI, 0.13-0.50) and 0.54 (95% CI, 0.25-1.19). The relative risks of virologic failure associated with a PVL nadir detectable but not quantifiable and a PVL nadir below the LOD were statistically different (P<.0001) in both data sets.

Effects of anticoagulant, processing delay, and assay method (branched DNA versus reverse transcriptase PCR) on measurement of human immunodeficiency virus type 1 RNA levels in plasma

We conducted two studies to determine the potential influence of delays in blood processing, type of anticoagulant, and assay method on human immunodeficiency virus type 1 (HIV-1) RNA levels in plasma. The first was an experimental study in which heparin- and EDTA-anticoagulated blood samples were collected from 101 HIV-positive individuals and processed to plasma after delays of 2, 6, and 18 h. HIV-1 RNA levels in each sample were then measured by both branched-DNA (bDNA) and reverse transcriptase PCR (RT-PCR) assays. Compared to samples processed within 2 h, the loss (decay) of HIV-1 RNA in heparinized blood was significant (P < 0.05) but small after 6 h (bDNA assay, -0.12 log(10) copies/ml; RT-PCR, -0.05 log(10) copies/ml) and after 18 h (bDNA assay, -0.27 log(10) copies/ml; RT-PCR, -0.15 log(10) copies/ml). Decay in EDTA-anticoagulated blood was not significant after 6 h (bDNA assay, -0.002 log(10) copies/ml; RT-PCR, -0.02 log(10) copies/ml), but it was after 18 h (bDNA assay, -0.09 log(10) copies/ml; RT-PCR, -0.09 log(10) copies/ml). Only 4% of samples processed after 6 h lost more than 50% (>/=0.3 log(10) copies/ml) of the HIV-1 RNA, regardless of the anticoagulant or the assay that was used. The second study compared HIV-1 RNA levels in samples from the Multicenter AIDS Cohort Study (MACS; samples were collected in heparin-containing tubes in 1985, had a 6-h average processing delay, and were assayed by bDNA assay) and the British Columbia Drug Treatment Program (BCDTP) (collected in EDTA- or acid citrate dextrose-containing tubes in 1996 and 1997, had a 2-h maximum processing delay, and were assayed by RT-PCR). HIV-1 RNA levels in samples from the two cohorts were not significantly different after adjusting for CD4(+)-cell count and converting bDNA assay values to those corresponding to the RT-PCR results. In summary, the decay of HIV-1 RNA measured in heparinized blood after 6 h was small (-0.05 to -0.12 log(10) copies/ml), and the minor impact of this decay on HIV-1 RNA concentrations in archived plasma samples of the MACS was confirmed by the similarity of CD4(+)-cell counts and assay-adjusted HIV-1 RNA concentrations in the MACS and BCDTP.

Reactivation of oral herpes simplex virus: implications for clinical management of herpes simplex virus recurrence during radiotherapy

Herpes viruses are characterized by their ability to establish and maintain latent infections that can be reactivated. Several stimuli can trigger the reactivation of herpes viruses, which are perhaps best recognized in the recurrent blisters and ulcers associated with herpes simplex virus. We present two clinical cases of reactivation of herpes simplex virus during radiation therapy for management of cancers of the head and neck. Although the role of ionizing radiation in the reactivation of herpes simplex virus has not been established, we review the viral and host events associated with the establishment of orofacial herpes simplex virus infection, latency, and reactivation of the virus. We discuss current models of viral reactivation and suggest directions for further clinical research into the reactivation of orolabial herpes simplex virus during radiotherapy.

Microscopic polyangiitis after influenza vaccination

We describe a case of microscopic polyangiitis involving skin and joints after influenza vaccination. Titers of antiinfluenza A antibody were markedly elevated in synovial fluid (SF) relative to those in serum. Antiinfluenza B antibodies were not present in SF but were present in serum, suggesting a reaction specifically involving antiinfluenza A antibodies localized to the affected joint. A review identified 16 other cases of vasculitis after influenza vaccination. The cases reclassified according to the Chapel Hill diagnostic criteria identified multiple forms of vasculitis including 7 other cases of microscopic polyangiitis. Three patients had similar illnesses after previous influenza vaccination or influenza-like illness. As in our case 11 cases resolved without recurrence. While this does not provide conclusive evidence that the vaccination caused the vasculitis, together with the serologic data we present it supports this hypothesis.

Continuing investigation and controversy regarding risk of transmission of infection via dental handpieces

Current epidemiologic evidence indicates that infectious diseases, specifically blood-borne pathogens such as hepatitis B, hepatitis C and HIV, are not transmitted from patient to patient via dental instruments. However, ongoing laboratory investigations suggest that potential pathogens may be retained within dental handpieces, creating a theoretical risk of cross infection. Controversy regarding certain laboratory study results and the clinical implications of these studies continues. Guidelines and regulations for infection control should be rational, and based on a realistic response to a documented risk. Dental professionals should be aware of continuing research focusing on these issues.

Acyclovir prophylaxis of oral herpes virus during bone marrow transplantation

Oropharyngeal shedding of herpes viruses (herpes simplex, cytomegalovirus) was assessed in patients on standard acyclovir prophylaxis during bone marrow transplantation (BMT) to determine the frequency of viral shedding and to assess possible oropharyngeal complications that may be associated with viral reactivation in these patients. We conducted a prospective assessment of 83 patients receiving BMT. Patients were evaluated weekly and oral surveillance cultures were completed. Shedding of herpes simplex virus (HSV) was detected in the oropharynx of 2.9% of seropositive patients on prophylactic acyclovir, and only one case of clinical oral herpetic infection was seen. Cytomegalovirus (CMV) was cultured from the oropharynx in 13.3% of CMV seropositive patients provided with prophylactic acyclovir, but no oropharyngeal lesions were attributed to CMV reactivation. No correlation was seen between HSV and CMV pretransplant serology and severity of oral mucositis and acute graft versus host disease. No effect on time to engraftment was detected. This study supports the continuing use of acyclovir prophylaxis in HSV seropositive patients receiving BMT. Acyclovir prophylaxis was effective in preventing viral shedding in all but 2.9% of patients, and only one case of clinical infection was diagnosed. The frequency of CMV shedding was approximately four times that of HSV; however, no oral lesions were attributed to CMV.

Use of pooling and outpatient laboratory specimens in an anonymous seroprevalence survey of HIV infection in British Columbia, Canada

OBJECTIVE

To conduct an anonymous HIV seroprevalence survey to establish a baseline estimate of HIV seroprevalence in a general population; to evaluate serum pooling and alternative testing strategies as cost-saving measures.

DESIGN

Prospective anonymous HIV seroprevalence study using outpatient laboratory specimens.

SETTING

Two large non-hospital-associated outpatient chemistry testing laboratories in the major population centers in British Columbia, Canada. PATIENTS AND SERA: Leftover sera received for chemistry screen testing in outpatient laboratories were provided to the study after chemistry testing was completed. Those from patients aged < 15 and > or = 55 years were excluded.

METHODS

Patient identifiers were erased from samples. Sera were pooled 10:1 and tested by viral lysate enzyme-linked immunosorbent assay (ELISA). Sera from HIV-positive pools were tested individually. All individual HIV-positive specimens were retested for verification of positivity using a recombinant protein ELISA.

MAIN OUTCOME MEASURES

HIV seroprevalence rates were stratified by sex, age group, and geographic area; and costs of pooling and alternative algorithm strategy were compared with those of conventional methods.

RESULTS

A total of 80,238 sera were collected from 66,658 individuals (53% women, 47% men). Of these, 276 men (88.3 per 10,000) and 24 women (6.8 per 10,000) were HIV-seropositive. The highest rates were in those aged 30-34 years, for both men and women. Using pooling and non-Western blot verification saved US$2.07 per specimen, or 80% of the cost for conventional testing.

CONCLUSIONS

The anonymous outpatient laboratory setting is practicable to obtain a reasonable estimate of HIV seroprevalence rates in a general population. Such studies can be made cost-effective by pooling sera and using alternative confirmatory strategies.

Assessing viral retention and elimination in rotary dental instruments

The authors of this article used a laboratory model of herpes simplex virus infection to assess the potential for contamination of dental handpieces by a human viral pathogen. They found that although all the handpieces in the study were fitted with anti-retraction valves, it was not until the units were flushed internally and disinfected externally that the pathogens were eliminated.

Hepatitis C: rapid progress in medicine and implications for dentistry

Recent developments in the recognition and diagnosis of the major infectious cause of posttransfusion hepatitis, hepatitis C virus (HCV), have led to an explosion in research. These developments are of relevance to dental providers. Patients may now present to the dentist with a diagnosis of hepatitis C infection and may be undergoing medical treatment for this disease. The risk for transmission of HCV in the dental setting is minimal. The dentist must understand the implications for the diagnosis of HCV for the patient and for the provision of dental care.

Rotary dental instruments and the potential risk of transmission of infection: herpes simplex virus

A laboratory model of herpes simplex virus infection was used to assess the potential contamination of dental handpieces. When contaminated instruments were treated with surface disinfection and internal chemical disinfection, viable virus was eliminated in all instruments.

Hairy leukoplakia after bone marrow transplantation

Hairy leukoplakia in 10 patients after bone marrow transplantation was identified clinically and assessed histologically. In situ hybridization for Epstein-Barr virus and human papilloma virus confirmed Epstein-Barr virus in hairy leukoplakia in two cases, and human papillomavirus in three cases. All cases with clinical follow-up resolved without treatment. These findings suggest that severe immunosuppression after a bone marrow transplantation may result in the development of hairy leukoplakia, and that as the immunosuppression resolves after the transplant the lesions also resolve.

Oral manifestations of cytomegalovirus infection

Disease caused by cytomegalovirus is reported with increasing frequency. Cytomegalovirus is an important pathogen in immunocompromised and immunosuppressed patients. The most common manifestation of cytomegalovirus infection of the gastrointestinal tract including the oral mucosa is ulceration. The role of cytomegalovirus in xerostomia, Sjögren's syndrome, and Kaposi's sarcoma is continuing to be investigated. This article reviews the oral manifestations of cytomegalovirus, including recently reported oral manifestations.

Human papillomavirus infection of the uterine cervix. Tissue sampling and laboratory methods affect correlations between infection rates and dysplasia

Two common tissue sampling techniques--colposcopic biopsy and cervical scrape--and two common human papillomavirus (HPV) detection techniques--Southern blot and dot blot (SB and ViraPap [VP])--were compared to determine whether differences in these techniques alter correlations between "oncogenic" HPVs and cervical neoplasia. In 87 women with persistently abnormal Papanicolaou (Pap) smears, concurrent biopsy and scrape specimens contained HPV in 21 (24%) and contained no HPV in 26 (30%); 30 scrape specimens (34.5%) tested positive when the biopsy tested negative and 10 (11.5%) scrape specimens tested negative when the biopsy tested positive (overall concordance, 54%). Concordance for the most prevalent HPVs (16/18) was 59%. In carcinoma in situ, HPV was found in biopsy samples significantly more frequently than in scrape specimens: 17 of 23 (75%) biopsy samples versus 9 of 23 (39%) scrape specimens (P = 0.018). Conversely, in mild or no dysplasia, 0 of 42 biopsy samples tested positive for HPV 16/18 compared with 12 of 42 scrape specimens (29%; P = 0.0001). Of 229 specimens analyzed by SB and VP, 43 (19%) tested positive and 148 (65%) tested negative for HPV by both methods (concordance, 84%). Corroborative results indicated that 29 of 35 (83%) VP-positive SB-negative results were truly positive compared with none of three SB-positive VP-negative results. Both the cervical sampling technique and the method for HPV detection can significantly affect statistical correlations between cervical dysplasia and HPV type.

Serological responses to cytomegalovirus during renal transplant rejection

We studied the role played by CMV in kidney transplant rejection by recording serological responses to CMV replication in cadaver graft recipients and recording clinical graft rejection by monitoring acute changes in renal function and the appearance of antidonor lymphocyte antibody (anti-Dab). If CMV plays a significant role in rejection, clinical rejection should correlate with CMV activity; if CMV does not play a role, clinical rejection would be likely to correlate with anti-Dab but not necessarily with CMV activity. We selected retrospectively 18 rejectors and 18 nonrejectors by clinical criteria and assayed for anti-Dab (by fluorescence-activated flow cytometry) and CMV antibody (by complement fixation and Western blot for IgG and IgM) over a 3-6-month period after transplantation. Primary CMV infection occurred in 8 of 12 (67%) CMV seronegative graft recipients and reactivation or reinfection occurred in 16 of 24 (67%); 12 of 14 (86%) rejectors developed anti-Dab compared with 2 of 18 (11%) nonrejectors (P less than 0.00001). Active CMV infection occurred in 11 of 18 (61.1%) rejectors and 13 of 18 (72.2%) nonrejectors (P = 0.36), and in 8 of 15 (53.3%) of those who developed anti-Dab and 12 of 17 (70.6%) of those who did not (P = 0.26). The results show no evidence to link CMV activity with kidney graft rejection.

Viral serology after bone marrow transplantation

Bone marrow transplantation (BMT) may change the recipient's pretransplant serostatus for herpes group viruses. We reviewed 68 patient records (1 year's transplants) to determine how frequently this occurs. Only 7 had data on serostatus before as well as at days 20 to 35 and greater than 100 after BMT. Serostatus was assessed by complement fixation and ELISA. All patients received a variety of blood-product support after BMT. One patient converted from anti-varicella zoster virus (VZV) positive to negative after BMT and developed clinical chickenpox; an additional patient converted from anti-VZV negative to positive after BMT but reverted to seronegative by day 102. One patient converted from anti-cytomegalovirus (CMV) positive pre-BMT to persistently anti-CMV negative post-BMT (donor: anti-CMV negative). Two patients had a greater than 4-fold fall in anti-herpes simplex (HSV) antibody post-BMT, and both shed HSV after BMT. Most seronegative recipients of marrow from seropositive donors developed herpesvirus antibodies. We conclude that the herpesvirus serostatus of BMT recipients should be determined again after BMT to aid in decisions about antiviral prophylaxis and diagnosis of clinical disease.

Hairy leukoplakia-like lesions following bone-marrow transplantation

Hairy leukoplakia (HL) also occurs in immunosuppressed post-bone-marrow transplantation patients, and in the presence or absence of Epstein-Barr virus. It may not always be diagnostic of HIV positivity. However, HIV status should still be determined in patients with HL.

Commercial latex agglutination test for detection of Clostridium difficile-associated diarrhea

A commercially available latex agglutination test for Clostridium difficile was compared with a cell culture cytotoxin assay and bacteriological culture for the laboratory diagnosis of C. difficile-associated diarrhea and colitis (CAD). Stool specimens from 626 patients were tested by the three methods, and specimens from 118 patients (19%) were positive by at least one of the methods. The results of the three tests agreed in 88% of the specimens tested, overall, but they agreed in only 34% of the 118 positive specimens. Ninety-three patients were evaluated to assess the significance of positive and negative results for each assay. Of 40 patients found to have CAD, 70% were positive by the cytotoxin assay, 78% were positive by the latex agglutination test, and 90% were culture positive. Of 53 patients who did not have CAD, 2% were positive by the cytotoxin assay, 8% were positive by the latex test, and 4% were culture positive. The detection of CAD was improved by using the tests in combination, and 97% of specimens positive by two or three methods were from patients who had CAD. Testing of multiple specimens from individual patients also increased the sensitivity of detection of CAD. The results suggest that the latex agglutination test may be useful for rapid diagnosis of CAD, especially in laboratories that lack cell culture facilities. However, the accuracy of CAD detection is improved when the latex test is used in combination with culture or the cytotoxin assay.

Does Aeromonas hydrophila preferentially colonize the bowels of patients with hematologic malignancies?

Weekly cultures of stools from neutropenic patients and bone marrow transplant recipients yielded Aeromonas hydrophila from 8% of 88 patients over a 2-yr period. During this time stools in the routine enteric laboratory yielded A. hydrophila in 0.24% of 1632 patients. Although the patient groups and culture methods were not directly comparable, this significant difference in isolation rate (p less than 0.001) may reflect a higher colonization rate in the immunocompromised patient.

Type specificity of complement-fixing antibody against herpes simplex virus type 2 AG-4 early antigen in patients with asymptomatic infection

We evaluated the type specificity of complement-fixing (CF) antibody against the AG-4 early antigen of herpes simplex virus (HSV) type 2 (HSV-2) by comparing a commercial AG-4 CF kit (Simplex-2; Gene Link Australia, Inc., Princeton, N.J.) with quantal microneutralization (MN) and absorption-Western blotting in testing sera from patients with and without a history of genital herpes. Sera characterized as HSV type 1 (HSV-1) or HSV-2 positive or negative by MN were selected and tested by CF, and those with discordant results were further analyzed for specific antibodies by absorption with HSV-1 or HSV-2 antigen and Western blotting with heterologous HSV proteins. A total of 34 of 42 (81%) sera HSV-2 positive by MN, 19 of 43 (44%) sera HSV-1 positive by MN, and 0 of 19 sera negative by MN were positive by CF. Absorption-Western blotting showed that 12 of 18 (67%) sera HSV-1 positive by MN but positive by CF had no HSV-2-specific antibody and that all 7 sera HSV-2 positive by MN but negative by CF had HSV-2-specific antibody. When MN and absorption-Western blotting data were combined to analyze patients with no history of genital herpes, 7 of 19 (37%) with no HSV-2-specific antibody were positive by CF, and 7 of 27 (26%) with HSV-2-specific antibody were negative by CF. The positive and negative predictive values for the CF test were 78 and 75%, respectively, in this group. The presence of antibody to the HSV AG-4 antigen does not discriminate sufficiently between HSV-1- and HSV-2-infected patients to be of value in predicting HSV-2 infection in the absence of symptomatic disease.

Feasible method for routine surveillance culturing of stools from neutropenic patients

This study was undertaken to develop an accurate, yet inexpensive, method for determining whether the bowel of a neutropenic patient is colonized with bacteria resistant to the antimicrobial agents used in empiric therapy. Selective agar media were prepared in which Mueller-Hinton agar or MacConkey agar were supplemented with one of the following antimicrobial agents: carbenicillin (16 micrograms/ml), gentamicin (4 micrograms/ml), or tobramycin (4 micrograms/ml). Moxalactam was incorporated initially at 16 micrograms/ml and subsequently at 8 micrograms/ml. Stools from neutropenic patients and bone marrow transplant recipients were inoculated on these media and on unsupplemented MacConkey agar. All bacteria that grew on the antibiotic-containing media were categorized as resistant to the supplementing drug; failure to detect an organism that did grow on the antibiotic-free MacConkey agar indicated susceptibility. These results were compared with those obtained for all isolates on all media by agar disk diffusion. There were 512 gram-negative enteric isolates from 320 stools obtained from 98 patients. The antibiotic-containing media suppressed the growth of 95% of bacteria that were identified as susceptible by agar disk diffusion. In detecting resistant organisms, the correlation between agar disk diffusion and direct stool screening with Mueller-Hinton agar ranged from 73 to 83%, and on MacConkey agar it ranged from 87 to 97%. The predictive value of a resistant result was 80 to 97% for the four antimicrobial agents when MacConkey agar was used. MacConkey agar performed better than Mueller-Hinton agar because of the greater ease of detecting different bacterial morphotypes. The cost of direct stool screening with antibiotic-supplemented MacConkey agar is approximately half the cost of routine methods of surveillance. Its cost and accuracy make the method a useful adjunct to the routine management of neutropenic patients.