No increased risk of tuberculosis-related immune reconstitution inflammatory syndrome with integrase inhibitor-based antiretroviral therapy in people with HIV with profound immunosuppression.

INTRODUCTION: The issue of whether integrase inhibitors (INSTIs) may confer a higher risk of paradoxical tuberculosis-related immune reconstitution inflammatory syndrome (TB-IRIS) compared with other classes of antiretroviral in people with HIV with a profound level of immunosuppression remains insufficiently explored. We aimed to assess whether such a higher risk exists by examining a cohort of patients with TB-HIV initiating antiretroviral therapy (ART) in Hong Kong. METHODS: This was a retrospective review of 133 patients registered in the TB-HIV Registry of the Department of Health during the period 2014-2021. RESULTS: Sixteen of 70 patients (22.9%; 95% confidence interval [CI] 13.0-32.7) and 14 of 63 patients (22.2%; 95% CI 12.0-32.5) from the INSTI and non-INSTI groups experienced TB-IRIS (p = 0.920). The median intervals between ART initiation and IRIS among patients from the two groups were similar (3 weeks [interquartile range IQR 2.0-7.8] vs. 4 weeks [IQR 2.0-5.1], p = 0.620). The proportion of patients requiring steroid therapy were similar, as were the hospitalization rates. There was no IRIS-related death in either group. The risk of TB-IRIS with INSTI versus non-INSTI was also similar in a stratified analysis in a subgroup of patients with a baseline CD4 count of <50 µL (10/33 [30.3%; 95% CI 14.6-46.0] vs. 10/22 [45.5%; 95% CI 24.7-66.3], p = 0.252) and another subgroup of patients with ART initiated within 4 weeks of anti-TB treatment (10/26 [38.5%; 95% CI 19.8-57.2] vs. 10/23 [43.5%; 95% CI 23.2-63.7], p = 0.721). CONCLUSION: Our cohort study did not offer support for an increased risk of TB-IRIS with INSTIs compared with non-INSTIs, even in severely immunocompromised people with HIV.

Development of an ICR mouse bioassay for toxicity evaluation in neurotoxic poisoning toxins-contaminated shellfish.

OBJECTIVE: To develop an ICR (female) mouse bioassay (MBA) for toxicity confirmation and evaluation of neurotoxins (brevetoxins)-contaminated shellfish. METHODS: Brevetoxins (BTX-B) as a causative agent of neurotoxic shellfish poisoning (NSP) under different shellfish matrices were intraperitoneally injected at different doses into mice to study their toxic effects and to differentiate the range of lethal and sublethal dosages. Their sensitivity and specificity were analyzed with 2 competitive ELISA kits for quantitative determination of standard BTX-B and dihydroBTX-B under different shellfish matrix-diluent combinations. Detection rates of MBA and two antibody-based assays for BTX-B from field NSP-positive shellfish samples were compared. RESULTS: BTX-B could be detected in shellfish tissues at concentration of 50-400 µg/100 g under shellfish matrix-Tween-saline media, which were appropriate to identify toxic shellfish at or above the regulatory limit (80 µg/100 g shellfish tissues). The LD50 identified was 455 mg/kg for BTX-B under general shellfish matrices (excluding oyster matrices) dissolved in Tween-saline. The presence of shellfish matrices, of oyster matrices in particular, retarded the occurrence of death and toxicity presentation in mice. Two antibody-based assays, even in the presence of different shellfish matrix-diluent combinations, showed acceptable results in quantifying BTX-B and dihydroBTX-B well below the regulatory limit. CONCLUSION: The two ELISA analyses agree favorably (correlation coefficient, r³â‹0.96; Student's t-tests, P>0.05) with the developed bioassay.

Information needs, expectations, and treatment preference of patients considering spinal surgery: A case-control survey.

STUDY DESIGN: Case-control survey. OBJECTIVES: To explore intrapersonal factors associated with decision of patients with degenerative back pain for surgery. METHODS: From September 2018 to May 2019 patients were invited to complete a questionnaire. Patients who decided on (case) and declined surgery (control) were later confirmed from medical records. RESULTS: Seventy-five patients were recruited. Male patients (75.0%, p = 0.019), those who were married (78.7%, p = 0.0045), and had spousal care-givers (89.2%, p < 0.0001) were more likely to decide for surgery. All patients who decided on surgery expressed need for information on "the severity of their spine conditions" (p = 0.039). Those who decided on surgery did not have as the high expectation on "to sleep more comfortably" as those who declined (4.71 vs. 4.91, p = 0.022). The predictive factors for surgery decision by logistic regression analysis were: male gender (OR = 3.23, 95% CI: 1.19-8.77, p = 0.021); married (OR = 5.231, 95% CI: 1.87-14.61, p = 0.002); with available spousal care-giver (OR = 1.85, 95% CI: 0.198-3.89, p = 0.031); and those who preferred to treat/cure the spine disorder by pharmacological treatment (OR = 2.77, 95% CI: 1.02-7.50, p = 0.045). CONCLUSION: Patients who decided on surgery were likely to indicate need of medical information related to their condition. Patients were in hope of better relief of physical symptoms, especially related to sleep comfort. Patients would escalate their treatment from conservative to surgery when conservative treatments were no longer effective.

Cluster analysis of toxins profile pattern as a tool for tracing shellfish contaminated with PSP-toxins.

Paralytic shellfish poisoning (PSP) is one of the most lethal biotoxin-induced diseases worldwide, which may pose serious public health threat and potential devastating economic damage on fisheries industry in the affected region(s). To prevent the importation of PSP contaminated shellfish to a community, detailed documentation on the supply chain and routine surveillance systems are, in principle, crucial measures to protect people from this intoxication. However, difficulties have always been encountered on the traceability of the source/origin of contaminated shellfish. In the present study, we reported the potential application of PSP-toxins profiles with similarity analysis that can be used to identify epidemiological linkage between shellfish samples collected from markets and patients during a PSP outbreak. PSP-toxins were identified and quantified by ion-pair chromatographic separation followed by post-column oxidation to fluorescent imino purine derivatives. Samples from a PSP incident and other surveillance samples collected in our past 7-year record were also compared for their similarity in PSP-toxins profiles patterns. Molar distributions (nmol%) of 10 PSP-toxins were analyzed by Unweighted Pair Group Method with Arithmetric averages (UPGMA). Three prominent clusters emerged with similarity levels reaching over 80% for each, suggesting that each group of samples probably originated from a same source/batch. The PSP-toxins profiles and toxicities determined from surveillance samples could provide premonitory clues on the occurrences of PSP incident and outbreak with corresponding toxin profiles in the later time. Due to species-specific characteristics of PSP-toxins composition and profile in shellfish under varieties of environmental and physiological conditions, PSP-toxins profile can be a specific and useful biochemical indicator for tracing PSP contaminated shellfish provided that spatio-temporal occurrence patterns of toxins profiles are available in a databank for inter-laboratory comparison and standardized methodologies such as consentaneous toxins extraction and identification criteria are used for analysis and comparison.

Personal and physical factors affecting the decision of patients to opt for spinal surgery: A case-control study.

STUDY DESIGN: A retrospective case-control study. OBJECTIVES: To explore the personal and physical factors influencing the decision of patients to opt for spinal surgery. METHODS: The medical records of patients who attended the Spine Nurse Clinic of a hospital in Hong Kong in the year 2017 were retrieved and reviewed. Comparisons were made of the physical symptoms, myelopathy, sensory deficits, and level of disability of patients who decided to undergo spinal surgery (case) and those who did not (control). RESULTS: Among the 122 medical records that were reviewed, it was found that 102 (83.6%) patients decided to undergo spinal surgery (case) while 20 (16.4%) chose not to (control). The patients in the case group were more likely to be unemployed than those in the control group (67% vs. 35%, p = 0.01), to have higher scores in primary pain (4.75 vs. 2.6, p = 0.003), higher scores in radiated pain (4.4 vs. 2.55, p = 0.021), a higher level of disability as reflected in a higher Oswestry Disability Index (ODI) score (41.6 vs. 30.9, p = 0.021), and a lower Japanese Orthopedic Association (JOA) score (13.7 vs. 15.6, p = 0.008). Point biserial correlation showed that exercise tolerance was associated with the decision to undergo the surgery. A multiple regression analysis of the factors predictive of the decision to opt for spinal surgery showed that these factors were: unemployment (OR = 5.42, 95% CI: 1.689-17.44, p = 0.005); severe primary pain (OR = 3.83, 95% CI: 1.241-11.832, p = 0.02); and the presence of radicular symptoms (OR = 5.372, 95% CI: 1.704-16.93, p = 0.004). CONCLUSION: The results of this study showed that besides physical factors such as pain radiation and disability level, which influenced the decision of patients to take the surgical option, patients who were unemployed were also more likely to choose surgery. This indicates that patients were worried about the possible impact of surgery on their employment, or on their ability to continue to work. It is important that patients be given a clear picture of the expected outcomes of their surgery, and that the information needs of patients regarding the surgery be explored and addressed.

Infection Risks Faced by Public Health Laboratory Services Teams When Handling Specimens Associated With Coronavirus Disease 2019 (COVID-19).

Infection risks of handling specimens associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by public health laboratory services teams were assessed to scrutinize the potential hazards arising from the work procedures. Through risk assessments of all work sequences, laboratory equipment, and workplace environments, no aerosol-generating procedures could be identified except the procedures (mixing and transfer steps) inside biological safety cabinets. Appropriate personal protective equipment (PPE) such as surgical masks, protective gowns, face shields/safety goggles, and disposable gloves, together with pertinent safety training, was provided for laboratory work. Proper disinfection and good hand hygiene practices could minimize the probability of SARS-CoV-2 infection at work. All residual risk levels of the potential hazards identified were within the acceptable level. Contamination by gloved hands was considered as a major exposure route for SARS-CoV-2 when compared with eye protection equipment. Competence in proper donning and doffing of PPE accompanied by hand washing techniques was of utmost importance for infection control.

Features of ciguatera fish poisoning cases in Hong Kong 2004-2007.

OBJECTIVE: To review the clinical features and laboratory investigations of ciguatera patients in Hong Kong between 2004 and 2007 in order to show the timely sampling of implicated fish from ciguatera victims and application of validated mouse bioassay for confirming suspected clinical cases of ciguatera. METHODS: Diagnosis of the ciguatera victims was based on history of coral fish consumption and clinical presentations stated in official guidelines for clinical diagnosis of ciguatera fish poisoning in Hong Kong. Food remnants of coral fish samples were collected swiftly from ciguatera victims between 2004 and 2007 for ciguatoxins (CTXs) analysis. RESULTS: Major clinical symptoms in ciguatera patients included gastrointestinal and neurological effects including limb numbness and diarrhoea, which developed at 0.5 to 15 hours after consumption of fish. In most cases, neurological symptoms were more common than gastrointestinal symptoms. A broad range of attack rate (10%-100%) was observed in each ciguatera outbreak. Validated mouse bioassay on ether extracts of the food remnant samples confirmed that all were CTXs-positive (<0.5 - 4.3 MU/20 mg ether extract) and directly linked to the corresponding ciguatera cases. CONCLUSION: Consistency between clinical and laboratory analysis for ciguatera poisoning illustrates the application of laboratory mouse bioassay in a timely fashion for confirming ciguatera poisoning cases and implementing effective public health measures. With further improvement in laboratory techniques, features of ciguatera fish poisoning cases can be better defined. Further studies are needed to determine the risk of each class of CTXs (Pacific-, Indian- and Caribbean-CTXs) in Hong Kong.

History of Asbestos Ban in Hong Kong.

As millions of immigrants moved to Hong Kong (HK) from China in the recent decades, large amount of residential housings were built in the early years and a substantial proportion of those buildings used asbestos-containing materials (ACMs). Since the number of new cases of ARDs diagnosed has increased year by year since 1990's, the remarkable increase of incidences had drawn the attention of the public and most importantly the HK government. It became one of the trigger points leading to asbestos ban in HK history. Comparatively, non-governmental organizations (NGOs), labor unions and patients' self-help organizations demonstrated a more aggressive and proactive attitude than the HK government and have played a key role in the development of asbestos banning policy in HK. After numerous petitions and meetings with the government representatives by those parties in the past decade, the HK government eventually changed its attitude and started to consider terminating the endless threat from asbestos by amending the policy, and the new clause of legislation for banning of all forms of asbestos was enacted on 4 April 2014. Other than the restriction of asbestos use, the compensation system about ARDs has also made some great moves by the effort of those parties as well. Based on the experience we learnt through the years, efforts from different stakeholders including patients' self-help organizations, NGOs, legislative councilors, and media power are absolutely essential to the success of progression and development in today's asbestos banning in HK.

Study of an outbreak of ciguatera fish poisoning in Hong Kong.

Ciguatera fish poisoning (CFP) has been a significant and increasing public health problem in Hong Kong since 1980s. With growing demand for imported live coral fishes, the number of people who suffered from this disease has also been increasing. An outbreak of CFP in 2004 was the second most prominent in record as compared with the most significant one that occurred in 1998. In 2004, out of a total of 823 reported food poisoning outbreaks involving 3159 persons, 65 incidents (7.9%) affecting 247 people (7.8%) were attributed to CFP. Validated mouse bioassay analysis of surveillance samples revealed that seven samples (13%) were confirmed to be contaminated with ciguatoxins (CTXs). Typical symptoms of CTXs were found in mice injected with 20mg of fish extracts. The causative fishes included Cheilinus undulatus, Epinephelus coioides, Plectropomus areolatus, and Plectropomus leopardus. Most of these CTX-positive samples analyzed had only trace amounts of CTXs in their extract, except a C. undulatus sample which contained a mice lethal dose (2.5MU/20mg ether extract). This fish species was also the major origin of coral fish that caused clusters of CFP in the last quarter of 2004. Cigua-Check analysis of 20 flesh grains from seven CTX-positive fishes, previously confirmed as CTX-positive samples by mouse bioassay, showed that 50% of flesh grains were CTX contaminated.

Protective effects of N-acetylcysteine against carbon tetrachloride- and trichloroethylene-induced poisoning in rats.

This research investigates the protective effect of N-acetylcysteine (NAC) against carbon tetrachloride (CCl(4))- and trichloroethylene (TCE)-induced hepatotoxicity in rats. A single dose of 1.25 ml/kg of 20% CCl(4) in corn oil, administered orally, or 20% TCE, administered intraperitoneally, produced significantly elevated levels of serum glutamic pyruvic transaminase (SGPT) and serum glutamic oxaloacetic transaminase (SGOT) activities. Histopathological examinations showed massive centrilobular necrosis and fat accumulation in CCl(4)-treated animals. In the curative test, especially in animals treated with higher dosages of NAC, there was significant reduction in SGPT and SGOT levels. Although there was no sign of abnormality in the livers of rats treated with TCE, NAC demonstrated its action against TCE-induced elevation of transaminases in the enzyme assays. Compared to the curative tests, the overall performance of NAC against toxin-induced toxicity in the preventive tests was poor. Even at the highest dosage applied, the effect was not as prominent as that achieved in the curative test. It is therefore concluded that NAC is effective for lowering chemical-induced elevated levels of SGPT and SGOT in the curative mode.

Effects of dimethyl sulphoxide against liver injury caused by carbon tetrachloride in rats.

A single oral dose of 1.25 ml kg(-1) of carbon tetrachloride (CCl(4)) was sufficient to induce significantly elevated levels of serum glutamic pyruvic transaminase (SGPT) and serum glutamic oxaloacetic transaminase (SGOT) together with signs of acute centrilobular necrosis and fatty accumulation in liver tissue. Dimethyl sulfoxide (DMSO) in different dosages (2750 mg kg(-1), 5500 mg kg(-1) and 8250 mg kg(-1); dissolved in saline) were screened for their potential activity against CCl(4)-induced liver injury in Sprague-Dawley rats. The results showed that post-administration of high dosages (5500 mg kg(-1) and 8250 mg kg(-1)) of DMSO-saline solution significantly reduced CCl(4)-induced acute elevation in the levels of SGPT and SGOT. The same result was observed in histopathological study of liver tissue. DMSO, in high doses, probably prevented CCl(4)-induced liver injury through its antioxidant, anti-inflammatory or microsomal enzyme arresting properties.

Ciguatera fish poisoning in Hong Kong--a 10-year perspective on the class of ciguatoxins.

The present study used liquid chromatography-tandem mass spectrometry (LC-MS/MS) to investigate retrospectively ciguatoxin (CTX)-positive samples as determined by mouse bioassay (MBA) in the past 10 years in Hong Kong. The results showed that Pacific CTXs (P-CTX-1, -2 and -3) were the most commonly observed toxins found in the samples, indicating Pacific Ocean areas as the most important origin of ciguatera fish poisoning. Clinical diagnosis from ciguatera patients also revealed the predominance of neurological illnesses in most cases, supporting intoxication of Pacific origin. This study demonstrated the ability of laboratory analysis to identify and quantify Pacific CTXs in suspected fish samples, so as to support the clinical diagnosis of ciguatera. Comparative analysis (Student's t-test and Spearman's rank correlation analysis) on the two CTX detection methods showed approximate linearity for overall P-CTXs (P-CTX-1, -2 and -3)/P-CTX-1 alone as derived by LC-MS/MS and total toxicity levels (P-CTX-1 equivalent) as determined by MBA. The LC-MS/MS method coupled with the rapid extraction method could allow the detection of trace amount of CTXs at levels below the clinically relevant limit, 0.1 ppb P-CTX-1 in fish flesh. For practical application, the adoption of a two-tiered approach for testing, chemical analysis by LC-MS/MS for toxic fish screening, coupled with biological assay by MBA for final toxicity confirmation, was proposed for first-line screening of CTX in potentially contaminated fish samples in the market, with an aim to minimizing the use of laboratory mice and at the same time providing reasonably effective means for routine analysis.

Solid-phase extraction clean-up of ciguatoxin-contaminated coral fish extracts for use in the mouse bioassay.

Florisil solid-phase extraction (SPE) cartridges were used for purifying ciguatoxin (CTX)-contaminated coral fish extracts, with the aim of removing extracted lipid but retaining optimal level of CTXs in the purified fractions. The CTX-containing fraction (target fraction) in fish ether extract was isolated and purified by eluting through a commercially available Florisil cartridge with hexane-acetone-methanol solvent mixtures of increasing polarity (hexane-acetone (4:1, v/v) < acetone-methanol (7:3, v/v) < 100% methanol). Application of Florisil SPE using acetone-methanol (7:3, v/v) condition facilitated the separation of 4.2 +/- 0.4 mg (mean +/- standard error of the mean (SEM)) of purified target fraction from 20 mg ether extract with good retention of CTXs. The mouse bioassay was used to demonstrate that the average CTX recovery of the target fraction from CTX-spiked samples was 75.8% +/- 3.3%, which was significantly increased by 96.7% +/- 15% when compared with CTX recovery from ether extracts (44.8% +/- 5.2%) without performing SPE purification. Over 70% of non-target lipids were removed in which no CTX toxicity was found. Moreover, the target fractions of both CTX-spiked and naturally CTX-contaminated samples gave more prominent toxic responses of hypothermia and/or induced more rapid death of the mice. The use of acetone-methanol (7:3, v/v) condition in the elution could significantly improve overall recovery of CTXs, while minimizing the possible interferences of lipid matrix from co-extractants on mice.