Recommendations on prevention and screening for breast cancer in Hong Kong

In Hong Kong, breast cancer is the most common cancer among women and poses a significant health care burden. The Cancer Expert Working Group on Cancer Prevention and Screening (CEWG) was set up in 2002 by the Cancer Coordinating Committee to review and assess local and international scientific evidence, and to formulate recommendations for cancer prevention and screening. After considering the local epidemiology, emerging scientific evidence, and local and overseas screening practices, the CEWG concluded that it was unclear whether population-based breast cancer screening did more harm than good in local asymptomatic women at average risk. The CEWG considers that there is insufficient evidence to recommend for or against population-based mammography screening for such individuals. Women who consider breast cancer screening should be adequately informed about the benefits and harms. The CEWG recommends that all women adopt primary preventive measures, be breast aware, and seek timely medical attention for suspicious symptoms. For women at high risk of breast cancer, such as carriers of confirmed BRCA1/2 deleterious mutations and those with a family history of breast cancer, the CEWG recommends that they seek doctor's advice for annual mammography screening and the age at which the process should commence. Additional annual screening by magnetic resonance imaging is recommended for confirmed BRCA1/2 mutation carriers or women who have undergone radiation therapy to the chest between the age of 10 and 30 years. Women at moderate risk of breast cancer should discuss with doctors the pros and cons of breast cancer screening before making an informed decision about mammography screening every 2 to 3 years.

Normal Tissue Complication Probability (NTCP) Modelling of Severe Acute Mucositis using a Novel Oral Mucosal Surface Organ at Risk

AIMS

A normal tissue complication probability (NTCP) model of severe acute mucositis would be highly useful to guide clinical decision making and inform radiotherapy planning. We aimed to improve upon our previous model by using a novel oral mucosal surface organ at risk (OAR) in place of an oral cavity OAR.

MATERIALS AND METHODS

Predictive models of severe acute mucositis were generated using radiotherapy dose to the oral cavity OAR or mucosal surface OAR and clinical data. Penalised logistic regression and random forest classification (RFC) models were generated for both OARs and compared. Internal validation was carried out with 100-iteration stratified shuffle split cross-validation, using multiple metrics to assess different aspects of model performance. Associations between treatment covariates and severe mucositis were explored using RFC feature importance.

RESULTS

Penalised logistic regression and RFC models using the oral cavity OAR performed at least as well as the models using mucosal surface OAR. Associations between dose metrics and severe mucositis were similar between the mucosal surface and oral cavity models. The volumes of oral cavity or mucosal surface receiving intermediate and high doses were most strongly associated with severe mucositis.

CONCLUSIONS

The simpler oral cavity OAR should be preferred over the mucosal surface OAR for NTCP modelling of severe mucositis. We recommend minimising the volume of mucosa receiving intermediate and high doses, where possible.

The phenomenon of missing doses in a cohort of HIV patients with good adherence to highly active antiretroviral therapy

A self-administered questionnaire survey was conducted in a specialist HIV clinical service in Hong Kong. A total of 76 male Chinese patients who had been on highly active antiretroviral therapy for over one year were enrolled. All except one had undetectable viral load at the time of the assessment. Though a majority (76%) scored 100% in self-reporting adherence rating, one-third of these had in fact missed at least one dose in the preceding four-week period. Men having sex with men had a lower tendency of missing dose than heterosexuals (13.6% versus 42%, P = 0.019). There was no association between missing doses and clinical staging or the regimens. The study revealed that missing doses may occur despite report of almost complete adherence, which, in the long run, could be a cause for concern.

Management of health care workers following occupational exposure to hepatitis B, hepatitis C, and human immunodeficiency virus

INTRODUCTION

Needlestick injury or mucosal contact with blood or body fluids is well recognised in the health care setting. This study aimed to describe the post-exposure management and outcome in health care workers following exposure to hepatitis B, hepatitis C, or human immunodeficiency virus (HIV) during needlestick injury or mucosal contact.

METHODS

This case series study was conducted in a public clinic in Hong Kong. All health care workers with a needlestick injury or mucosal contact with blood or body fluids who were referred to the Therapeutic Prevention Clinic of Department of Health from 1999 to 2013 were included.

RESULTS

A total of 1525 health care workers were referred to the Therapeutic Prevention Clinic following occupational exposure. Most sustained a percutaneous injury (89%), in particular during post-procedure cleaning or tidying up. Gloves were worn in 62.7% of instances. The source patient could be identified in 83.7% of cases, but the infection status was usually unknown, with baseline positivity rates of hepatitis B, hepatitis C, and HIV of all identified sources, as reported by the injured, being 7.4%, 1.6%, and 3.3%, respectively. Post-exposure prophylaxis of HIV was prescribed to 48 health care workers, of whom 14 (38.9%) had been exposed to known HIV-infected blood or body fluids. The majority (89.6%) received HIV post-exposure prophylaxis within 24 hours of exposure. Drug-related adverse events were encountered by 88.6%. The completion rate of post-exposure prophylaxis was 73.1%. After a follow-up period of 6 months (or 1 year for those who had taken HIV post-exposure prophylaxis), no hepatitis B, hepatitis C, or HIV seroconversions were detected.

CONCLUSIONS

Percutaneous injury in the health care setting is not uncommon but post-exposure prophylaxis of HIV is infrequently indicated. There was no hepatitis B, hepatitis C, and HIV transmission via sharps or mucosal injury in this cohort of health care workers.

Treatment outcomes after early initiation of antiretroviral therapy for human immunodeficiency virus-associated tuberculosis

OBJECTIVE

To evaluate the optimal timing for initiating antiretroviral therapy in patients with human immunodeficiency virus (HIV)-associated tuberculosis in Hong Kong.

DESIGN

Historical cohort. SETTING. Tuberculosis and Chest Service and Special Preventive Programme, Public Health Service Branch, Centre for Health Protection, Department of Health, Hong Kong.

PATIENTS

Consecutive patients with HIV-associated tuberculosis in a territory-wide TB-HIV registry encountered from 1996 to 2009.

RESULTS

Of the 260 antiretroviral therapy-naïve patients with HIV-associated tuberculosis, 32 (12%) had antiretroviral therapy initiated within 2 months after starting anti-tuberculosis treatment (early antiretroviral therapy). Early antiretroviral therapy was associated with a more favourable outcome (cure or treatment completion without relapse) at 24 months (91% vs 67%; P=0.007) than those with antiretroviral therapy started later or not initiated, and remained an independent predictor of a favourable outcome after adjustment for potential confounders. Adverse effects from anti-tuberculosis drugs tended to occur more frequently in patients with early antiretroviral therapy (13/32 or 41%) compared with the remainder (59/228 or 26%; P=0.08). A significantly higher proportion of patients in the former group experienced immune reconstitution inflammatory syndrome than in the latter group (7/32 or 22% vs 9/228 or 4%; P<0.001). There was no death attributable to immune reconstitution inflammatory syndrome.

CONCLUSIONS

Early initiation of antiretroviral therapy is associated with more favourable tuberculosis treatment outcomes in patients with HIV-associated tuberculosis with a low CD4 count (<200/µL). Drug co-toxicity and immune reconstitution inflammatory syndrome that may be increased by earlier initiation of antiretroviral therapy does not undermine tuberculosis treatment outcomes to a significant extent.

Tuberculin sensitivity testing and treatment of latent tuberculosis remains effective for tuberculosis control in human immunodeficiency virus-infected patients in Hong Kong

OBJECTIVE

To evaluate whether a policy to treat latent tuberculosis identified by annual tuberculin sensitivity testing is effective for tuberculosis control in human immunodeficiency virus-infected patients in Hong Kong.

DESIGN

Historical cohort study.

SETTING

Integrated Treatment Centre, Department of Health, Hong Kong.

PATIENTS

Patients infected with human immunodeficiency virus without a history of tuberculosis were offered annual tuberculin sensitivity testing, coupled with treatment of latent tuberculosis if they tested positive. All such patients were followed for new tuberculosis.

RESULTS

In all, 1154 patients on antiretroviral therapy, contributing to 5587 patient-years of observation, were analysed; 1032 patients (89%) received annual tuberculin sensitivity testing. Their baseline characteristics, including CD4 counts and other risk factors for tuberculosis, did not differ significantly from those who declined testing. The overall incidence rate of tuberculosis was 0.59 case per 100 patient-years. It was lower in those who received annual tuberculin sensitivity testing than those who did not (0.41 vs 3.85 per 100 patient-years; P<0.0001). Only a low baseline CD4 count and a history of tuberculin sensitivity testing were shown to be significant indicators of incident tuberculosis using multivariate analysis. The hazard ratio was 0.36 (95% confidence interval, 0.16-0.85; P=0.02) for those with a baseline CD4 count of 100/mm3 or above, and 0.26 (95% confidence interval, 0.08-0.77; P=0.016) for those who received annual tuberculin sensitivity testing. The incidence of tuberculosis was highest within 90 days of antiretroviral therapy initiation.

CONCLUSION

The established policy continues to be effective. The high risk of tuberculosis during the early period of antiretroviral therapy supports early use of tuberculin sensitivity testing. Alternatively, the strategy of universal isoniazid preventive therapy at antiretroviral therapy initiation could be studied for those with very low baseline CD4 counts.

Accelerating prevention of mother-to-child transmission of HIV: ten-year experience of universal antenatal HIV testing programme in a low HIV prevalence setting in Hong Kong

Hong Kong has a low prevalence of HIV infection at less than 0.01%. Universal Antenatal HIV Testing Programme (UATP) was launched in all public antenatal units in September 2001. In 2008, voluntary rapid HIV testing was introduced in all public labour units to fill up the gap for pregnant women without HIV testing during the antenatal period. This study evaluated the performance of UATP and rapid HIV testing with indicators. From September 2001 to December 2011, process and outcome indicators for monitoring and evaluation were collected from the service providers in the form of monthly return of workload statistics and case-based statistics of each identified HIV-positive pregnancy via reporting forms. A total of 479,160 antenatal HIV tests and 2,675 rapid tests were performed in the study period. The acceptance rate for UATP and rapid HIV testing was 98% and 80.4% respectively. With the implementation of rapid HIV testing in January 2008, the proportion of pregnant women with HIV status discerned before delivery increased from 84.9% in 2006 to over 99.5% since 2008. The HIV prevalence in UATP and rapid HIV testing was 0.02% and 0.1% respectively. Fifty-three (68%) out of 78 HIV-infected pregnant women identified from the programme have delivered locally. Forty-three (81%) of them delivered by caesarean section and 50 (94%) of them were given antiretrovirals for intervention. Only three children born before the implementation of rapid HIV testing were HIV-infected. In conclusion, UATP and its rapid HIV testing component have been highly accepted and effective in the prevention of perinatal HIV transmission in Hong Kong.

Use of methylphenidate for the management of fatigue in Chinese patients with cancer

REASON FOR THE STUDY: Studies on methylphenidate for cancer-related fatigue showed conflicting results. This prospective study aims to determine whether methylphenidate is useful for relieving fatigue in Chinese patients with cancer. Chinese Version of Brief Fatigue Inventory (BFI-C) was administered on days 1, 8, and 29. Methylphenidate dose on day 1 was 5 mg daily then adjusted after day 8 according to response and side effects tolerance.

MAIN FINDINGS

Only 48% of the 25 recruited patients were on methylphenidate by day 29. Overall, no significant improvement in fatigue level was observed after methylphenidate, though benefits were shown in subgroups with age ≤ 65 and higher baseline BFI-C values.

PRINCIPAL CONCLUSIONS

Methylphenidate may be useful for management of cancer-related fatigue in selected Chinese patients.

The pentacyclic triterpenoids in herbal medicines and their pharmacological activities in diabetes and diabetic complications

Pentacyclic triterpenoids including the oleanane, ursane and lupane groups are widely distributed in many medicinal plants, such as Glycyrrhiza species, Gymnema species, Centella asiatica, Camellia sinensis, Crataegus species and Olea europaea, which are commonly used in traditional medicine for the treatment of diabetes and diabetic complications. A large number of bioactive pentacyclic triterpenoids, such as oleanolic acid, glycyrrhizin, glycyrrhetinic acid, ursolic acid, betulin, betulinic acid and lupeol have shown multiple biological activities with apparent effects on glucose absorption, glucose uptake, insulin secretion, diabetic vascular dysfunction, retinopathy and nephropathy. The versatility of the pentacyclic triterpenes provides a promising approach for diabetes management.

Incidence, mortality, and survival trends of ovarian cancer in Hong Kong, 1997 to 2006: a population-based study

OBJECTIVES

To assess the incidence and mortality of ovarian cancer, and the survival patterns of the invasive epithelial ovarian carcinoma in Hong Kong based on population-based cancer registry data.

DESIGN

Historical cohort study.

SETTING

Hong Kong.

PATIENTS

All patients with ovarian cancer diagnosed between 1997 and 2006 were included. Patients eligible for survival analysis were followed up until 31 December 2007.

MAIN OUTCOME MEASURES

Age-standardised incidence and mortality rates with their estimated annual percent changes were determined. Cumulative observed and relative survival rates were estimated using a period approach.

RESULTS

During the study period, in Hong Kong there was a steadily increasing ovarian cancer incidence rate (1.4% annually) but a steadily decreasing mortality rate (1.9% annually). The improvement in mortality was mainly in the age-group of 50-69 years (4.7% annually). Invasive epithelial ovarian carcinoma accounted for 79.6% of the study cohort. The 2-year and 5-year relative survival rates were 75.8% and 63.1%, respectively. Those diagnosed in the period 2002 to 2006 had significantly better survival than those diagnosed in the period 1997 to 2001 (65.3% vs 60.7%; P=0.008); a significant improvement was evident for patients with stage II disease and in the age-group of 50-69 years. Multivariate analyses confirmed that age, histological subtype, FIGO stage, and the period of diagnosis were independent prognostic indicators of invasive epithelial ovarian carcinoma.

CONCLUSION

In Hong Kong, invasive epithelial ovarian carcinoma showed an increasing incidence and an improving survival trend over the period 1997 to 2006. The survival data derived from this study provides a baseline from which to monitor the effectiveness of ovarian cancer treatment in Hong Kong.

In-house human immunodeficiency virus-1 genotype resistance testing to determine highly active antiretroviral therapy resistance mutations in Hong Kong

OBJECTIVE

To determine the frequency of highly active antiretroviral therapy resistance mutations in the viral pol gene of human immunodeficiency virus-1 (HIV-1) genotypes that circulate in Hong Kong, by means of an in-house HIV-1 genotyping system.

DESIGN

Retrospective study.

SETTING

Two HIV clinics in Hong Kong.

PATIENTS

A modified in-house genotyping resistance test was used to sequence the partial pol gene in 1165 plasma samples from 965 patients. The performance of our test was cross-compared with the US Food and Drug Administration-approved ViroSeq HIV-1 genotyping system. The results of genotyping were submitted to the Stanford HIV-1 drug resistance database for analysis.

RESULTS

The cost-effective in-house genotypic resistance test (US$40) demonstrated comparable performance to the US Food and Drug Administration-approved ViroSeq system. The detection limit of this in-house genotypic resistance test could reach 400 copies/mL for both HIV-1 subtype B and CRF01_AE, which were the predominant genotypes in Hong Kong. Drug resistance mutations were detected only in post-treatment samples from treatment-failure patients. However, there was no significant difference in the frequency of drug resistance mutations between subtype B and CRF01_AE.

CONCLUSION

Our cost-effective in-house genotypic resistance test detected no significant difference in drug resistance-related mutations frequencies between HIV-1 subtype B and CRF01_AE in Hong Kong. A drug resistance-related mutations database for different HIV-1 genotypes should be established in Hong Kong to augment guidance for HIV treatment.

The use of self-expanding metallic stents (SEMS) is effective in symptom palliation from recurrent tumor after esophagogastrectomy for cancer

The efficacy of using self-expanding metallic stent (SEMS) for palliation of symptoms because of tumor recurrence after prior esophagogastrectomy has not been properly assessed despite the well recognized use of SEMS in patients without prior surgery. The aim of this study is to evaluate the efficacy and safety of using SEMS in patients who had prior esophagogastrectomy. The study group included 35 patients with carcinoma of esophagus or cardia documented to have loco-regional recurrence after esophagogastrectomy and in whom SEMS were placed for palliation. The median age was 67 (ranged 41-85). The indications for stenting were dysphagia caused by recurrence at the esophageal anastomosis (n= 4) and in the esophageal remnant (n= 5), or extrinsic compression from mediastinal nodal disease (n= 7); gastric outlet obstruction produced by extrinsic tumor compression (n= 13); and tracheo-esophageal fistulae (n= 6). Forty-three stenting procedures were performed, and the technical success rate was 97.6%. The dysphagia score improved from 4.66 to 2.54 (P < 0.001). All patients with tracheo-esophageal fistula had their symptoms successfully palliated. The immediate complication rate was 14% (n= 5); two patients had stent malpositioning, two had inadequate opening of their stents, and one had a failed stenting procedure. On follow-up, 15 (42.8%) patients required a total of 22 re-intervention procedures for various reasons: endoscopic dilatation (five dilatations in three patients), removal of foreign bodies (nine procedures in four patients), and insertion of a second SEMS related to tumor growth (eight stents in eight patients). There was no procedure-related mortality. The median survival was short at 42 days (range 5-290 days), mostly related to advanced disease stage. SEMS in patients with recurrent tumor after esophagogastrectomy is safe and effective.

Antigens of mycobacterial cell walls

Three antigenic fractions from the cell walls of eight strains of mycobacteria were studied. Isolation and purification of these antigens were effected by enzymatic digestions, differential and sucrose gradient centrifugations, dialyses, and column chromatography. Two of the fractions were termed cell wall tuberculins (CWT-1, solubilized with lipase; CWT-2, solubilized with lysozyme); the third was termed "C" (cross-reacting) antigen. All appeared to be lipopolysaccharides. The CWT antigens, as compared with purified protein derivatives (human), were relatively species (group)-specific in both double immunodiffusion and guinea pig skin tests; in the latter, the reactions resembled those of delayed hypersensitivity. The C antigens reacted heterologously in double immunodiffusion and skin tests; the latter were the "immediate" type of reaction.

The epidemiology and clinical manifestations of human immunodeficiency virus-associated tuberculosis in Hong Kong

OBJECTIVE

To evaluate the epidemiology and clinical manifestations of human immunodeficiency virus-associated tuberculosis in Hong Kong.

DESIGN

Retrospective study.

SETTING

Tuberculosis and Chest Service and Special Preventive Programme, Public Health Services Branch, Centre for Health Protection, Department of Health, Hong Kong Special Administrative Region.

PATIENTS

Cases reported to the TB/HIV Registry jointly kept by the Tuberculosis and Chest Service and Special Preventive Programme from 1996 to 2006 were reviewed. The Registry includes cases of human immunodeficiency virus-associated tuberculosis diagnosed in the two services, and cases referred from regional hospitals under the Hong Kong Hospital Authority and the private sector.

RESULTS

Tuberculosis has become an increasingly important acquired immunodeficiency syndrome-defining illness in Hong Kong, and overtook Pneumocystis jiroveci pneumonia for the first time as the most common primary acquired immunodeficiency syndrome-defining illness in 2005 (accounting for 39% and 31% of all such illnesses, respectively in that year). The presentation of human immunodeficiency virus-associated tuberculosis is often atypical. In these patients moreover, there was a slightly higher rate of multidrug-resistant tuberculosis (2%) than in the general population (range, 0.7-1.5%).

CONCLUSIONS

Programmes for the provider-initiated human immunodeficiency virus testing policy to reduce diagnostic delays should continue and be enhanced. Continual surveillance of both conditions is imperative, especially in view of a possible link between human immunodeficiency virus and multidrug-resistant tuberculosis.

Profiling advanced disease in an Asian clinical human immunodeficiency virus cohort: comparison of two definitions for acquired immunodeficiency syndrome

OBJECTIVE

To compare advanced human immunodeficiency virus disease defined immunologically and clinically by evaluating the characteristics of human immunodeficiency virus patients in Hong Kong.

DESIGN

Retrospective observational study.

SETTING

A human immunodeficiency virus cohort database established at a university and the major human immunodeficiency virus specialist services in Hong Kong.

PATIENTS

Patients diagnosed with acquired immunodeficiency syndrome at the study centres between 1985 and 2006 were included.

MAIN OUTCOME MEASURES

Comparison of advanced human immunodeficiency virus disease defined (a) clinically as World Health Organization stage IV, and (b) immunologically as a CD4 count lower than 350/microL.

RESULTS

Between 1985 and 2006, a total of 1317 patients, a majority of whom Chinese, were evaluated. Of these, 914 (69%) and 335 (25%) fulfilled the criteria for immunologically and clinically defined advanced disease, respectively. The mean age of the study population was 38 years and male-to-female ratio 4:1. There were two peaks in the frequency distribution of CD4 counts, one at a low count of less than 100/microL and the other between 200 and 400/microL. All except four with clinically defined advanced disease had CD4 counts lower than 350/microL on presentation. Of those with immunologically defined advanced disease, men having sex with men accounted for a lower proportion in the clinically advanced category, and Pneumocystis pneumonia was the commonest advanced disease at presentation.

CONCLUSIONS

Both clinical and immunological definitions provide a consistent means for assessing advanced disease, the implications of which are different. Such profiling has been made possible through the operation of a standardised cohort database, which is useful in (1) enhancing human immunodeficiency virus epidemiology studies, and (2) evaluating the performance of public health services.

Photocatalytic oxidation of polycyclic aromatic hydrocarbons: intermediates identification and toxicity testing

Polycyclic aromatic hydrocarbons (PAHs) are hydrophobic pollutants and their low water solubility limits their degradation in aqueous solution. The presence of water-miscible solvent such as acetone can increase the water solubility of PAHs, however acetone will also affect the degradation of PAH. In this study the effects of acetone on the photocatalytic degradation efficiency and pathways of 5 selected PAHs, namely naphthalene (2 rings), acenaphthylene (3 rings), phenanthrene (3 rings), anthracene (3 rings) and benzo[a]anthracene (4 rings) were investigated. The Microtox toxicity test was used to determine whether the PCO system can completely detoxify the parental PAHs and its intermediates. The addition of 16% acetone can greatly alter the degradation pathway of naphthalene and anthracene. Based on intermediates identified from degradation of the 5 PAHs, the location of parental PAHs attacked by reactive free radicals can be correlated with the localization energies of different positions of the compound. For toxicity analysis, irradiation by UV light was found to induce acute toxicity by generating intermediates/degradation products from PAHs and possibly acetone. Lastly, all PAHs (10 mg l(-1)) can be completely detoxified by titanium dioxide (100 mg l(-1)) within 24h under UVA irradiation (3.9 mW cm(-2)).

Degradation of Acid Orange 7 using magnetic AgBr under visible light: the roles of oxidizing species

AgBr was creatively immobilized on a magnetic substrate (SiO(2)-coated Fe(3)O(4) nanoparticle, SFN) to achieve magnetic separation after visible light-driven photocatalytic oxidation (PCO). The resulted Ag/AgBr/SFN was characterized by TEM, vibrating sample magnetometer and other techniques. It is found that the average diameter of the Ag/AgBr/SFN particle is less than 20 nm. The typical superparamagnetic behavior of Ag/AgBr/SFN implies that the catalyst can be magnetically separated. The physicochemical features of the used Ag/AgBr/SFN after visible light irradiation were not dramatically changed by X-ray diffraction, UV-Vis diffuse reflectance spectra and Fourier transform-infrared analysis. SiO(2) interlayer was proven to slightly increase the degradation efficiency for an azo dye Acid Orange 7. UV-Vis spectra and HPLC analysis indicated that the dye was oxidized and decomposed. The photoactivity of Ag/AgBr/SFN was partly maintained after successive PCO under visible light. In order to evaluate the roles of e(-)-h(+) pairs and reactive oxygen species, the quenching effect was examined by employing Ag/AgBr/SFN and commercial TiO(2) (P-25) under visible light (lambda>400 nm) and UV-A irradiation, respectively. Active h(+) and the resulting (*)OH played the major roles for degradation. The effect of active h(+) and (*)OH were proven to be highly dependent on the concentration of photocatalysts. The effect of (*)OH was more obvious for P-25, while that of active h(+) was more predominant for Ag/AgBr/SFN.

Comparison of assessment tools to score recovery of function after repair of traumatic lesions of the median nerve

In this paper the recovery after repair of the median nerve has been used to compare different assessment tools for evaluation of peripheral nerve function: touch (moving 2-point discrimination (2PD); Semmes-Weinstein (SW) monofilament, motor (Medical Research Council (MRC) scale), combined motor and sensory (Dellon modification of the Moberg pick up test; Moberg Recognition test), and pain (visual analogue scale; pinprick-test). The mean (SD) age of our 28 patients was 28 (12) years. The mean (SD) follow-up period was 5 years, 2 months (2 years, 8 months). On the operated side three patients (11%) had a moving 2PD of less than 4 mm. The results of the moving 2PD were compared with those of the SW monofilaments, but with a poor correlation. The MRC score correlated well with opposition movement of the thumb and muscle wasting (p<0.01). We recommend a number of tests to evaluate (the chronological return of) peripheral nerve function.

Blue-shift and intensity enhancement of photoluminescence in lead-zirconate-titanate-doped silica nanocomposites

Transparent PbZr(0.52)Ti(0.48)O(3) (PZT)-doped silica nanocomposites were fabricated via a modified sol-gel process. The nanocomposites were annealed at different temperatures between 740 and 800 °C in order to produce PZT crystallites with different particle sizes. X-ray diffraction analysis indicated that the embedded PZT nanoparticles were crystallized with a perovskite structure while the SiO(2) matrix was still in an amorphous state. Transmission electron microscopy confirmed that the PZT particles were of nanosize with perovskite structure and dispersed within the SiO(2) matrix. Photoluminescence spectra of the samples were measured between 10 and 290 K. The pure silica matrix showed an emission band at 3.20 eV and a weak emission band at 2.65 eV. They were noticeably suppressed in the PZT/SiO(2) nanocomposites. An additional emission band at ∼2.30 eV, due to transition within the PZT crystallites, was identified. This emission band showed a large blue-shift with decreasing PZT crystallite size and a substantially enhanced intensity as compared with that of bulk PZT ceramics. Our studies demonstrate the typical quantum size effect of ferroelectric-doped nanocomposites and the large influence of the silica matrix on the PL intensity of the embedded PZT particles.

Universal antenatal human immunodeficiency virus (HIV) testing programme is cost-effective despite a low HIV prevalence in Hong Kong

OBJECTIVE

To evaluate the cost-effectiveness of universal antenatal human immunodeficiency virus (HIV) testing in Hong Kong.

DESIGN

Cost-effectiveness analysis from the health care provider's perspective.

SETTING

Public antenatal clinics in Hong Kong.

PARTICIPANTS

All pregnant women who gave birth in Hong Kong during the inclusive period 1 September 2001 and 31 December 2004.

MAIN OUTCOME MEASURES

The primary endpoints were (i) the cost per HIV infection avoided and (ii) the cost per life-year gained.

RESULTS

From 2001 to 2004, a total of 160,878 deliveries were recorded in Hong Kong; and 75% of the corresponding women had HIV testing before delivery. In all, 28 women tested HIV-positive and gave birth to 15 babies, one of which was HIV-positive. The mother of the infected baby presented late in labour, without her HIV status being diagnosed and thus missed the opportunity for prompt intervention. Assuming a natural transmission rate of 25%, it was estimated that six out of seven anticipated HIV infections among the newborns had been avoided. The cost for implementation of the programme for the first 3 years was HKD12 227 988. Hence, the average costs per HIV infection averted and per discounted life-year gained were HKD2 037 998 and HKD79 099, respectively. Sensitivity analysis showed that both the coverage and the loss-to-follow-up rate were the major determinants of the cost-effectiveness of the universal antenatal testing programme in Hong Kong.

CONCLUSION

The universal antenatal testing programme in Hong Kong is largely efficient. In view of the low prevalence of HIV infection, high rates of HIV testing and uptake of antiretroviral prophylaxis are crucial to the success of the programme.

Evaluation of an in-house genotyping resistance test for HIV-1 drug resistance interpretation and genotyping

INTRODUCTION

The human immunodeficiency virus type 1 (HIV-1) genotyping resistance test (GRT) has been considered essential for HIV-1 drug resistance monitoring. However, it is not commonly used in some developing countries in Asia and Africa due to its high running cost.

OBJECTIVE

This study aims to evaluate a new low-cost in-house GRT for both subtype B and non-B HIV-1.

STUDY DESIGN

The in-house GRT sequenced the entire protease and 410 codons of reverse transcriptase (RT) in the pol gene. Its performance on drug resistance interpretation was evaluated against the FDA-approved ViroSeq HIV-1 Genotyping System. Particularly, a panel of 235 plasma samples from 205 HIV-1-infected patients in Hong Kong was investigated. The HIV-1 drug resistance-related mutations detected by the two systems were compared. The HIV-1 subtypes were analyzed through the REGA HIV-1 Genotyping Tool and env phylogenetic analysis.

RESULTS

Among the 235 samples, 229 (97.4%) were successfully amplified by both in-house and ViroSeq systems. All PCR-negative samples harbored viral RNA at <400 copies/mL. The in-house and ViroSeq system showed identical drug resistance-related mutation patterns in 216 out of 229 samples (94.3%). The REGA pol genotyping results showed 93.9% (215/229) concordance with the env phylogenetic results including HIV-1 subtype A1, B, C, D, G, CRF01_AE, CRF02_AG, CRF06_cpx, CRF07_BC, CRF08_BC, CRF15_01B and other recombinant strains. The cost of running the in-house GRT is only 25% of that for the commercial system, thus making it suitable for the developing countries in Asia and Africa.

CONCLUSIONS

Overall, our in-house GRT provided comparable results to those of the commercial ViroSeq genotyping system on diversified HIV-1 subtypes at a more affordable price which make it suitable for HIV-1 monitoring in developing countries.