Mixed methods study on elimination of tuberculosis in Hong Kong.

INTRODUCTION: Tuberculosis (TB) commonly affects developing countries. Several developed regions in Asian still have a stagnant intermediate TB burden. Information to adequately inform TB strategies is lacking. We conducted a mixed methods study to fill this information gap in Hong Kong. METHODS: Data from the Hong Kong government were used to analyse trends of TB notification rates compared with World Health Organization (WHO) targets. A review of policy documents and literature was conducted to evaluate TB control and elimination in Hong Kong. RESULTS: Extrapolated trends showed that Hong Kong will be unable to meet the WHO target of a 90% drop in incidence rate by 2030. The policy review showed that the Hong Kong government has not set a clear strategy and timeline for specific goals in TB control and elimination. The literature review found that older adults are largely responsible for the stagnant TB prevalence because of reactivation of latent TB infection (LTBI), while mortality of hospitalised patients with TB is still high because of delayed diagnosis and treatment. CONCLUSION: Tuberculosis incidence is currently under control in Hong Kong, but further actions are needed if the elimination targets are to be achieved. Improved diagnostic tools are required, and policies targeting LTBI in older adults should be implemented to achieve the WHO target by 2030.

A systematic surveillance programme for infectious salmon anaemia virus supports its absence in the Pacific Northwest of the United States.

In response to reported findings of infectious salmon anaemia virus (ISAV) in British Columbia (BC), Canada, in 2011, U.S. national, state and tribal fisheries managers and fish health specialists developed and implemented a collaborative ISAV surveillance plan for the Pacific Northwest region of the United States. Accordingly, over a 3-1/2-year period, 4,962 salmonids were sampled and successfully tested by real-time reverse-transcription PCR. The sample set included multiple tissues from free-ranging Pacific salmonids from coastal regions of Alaska and Washington and farmed Atlantic salmon (Salmo salar L.) from Washington, all representing fish exposed to marine environments. The survey design targeted physiologically compromised or moribund animals more vulnerable to infection as well as species considered susceptible to ISAV. Samples were handled with a documented chain of custody and testing protocols, and criteria for interpretation of test results were defined in advance. All 4,962 completed tests were negative for ISAV RNA. Results of this surveillance effort provide sound evidence to support the absence of ISAV in represented populations of free-ranging and marine-farmed salmonids on the northwest coast of the United States.

Molecular testing of adult Pacific salmon and trout (Oncorhynchus spp.) for several RNA viruses demonstrates widespread distribution of piscine orthoreovirus in Alaska and Washington.

This research was initiated in conjunction with a systematic, multiagency surveillance effort in the United States (U.S.) in response to reported findings of infectious salmon anaemia virus (ISAV) RNA in British Columbia, Canada. In the systematic surveillance study reported in a companion paper, tissues from various salmonids taken from Washington and Alaska were surveyed for ISAV RNA using the U.S.-approved diagnostic method, and samples were released for use in this present study only after testing negative. Here, we tested a subset of these samples for ISAV RNA with three additional published molecular assays, as well as for RNA from salmonid alphavirus (SAV), piscine myocarditis virus (PMCV) and piscine orthoreovirus (PRV). All samples (n = 2,252; 121 stock cohorts) tested negative for RNA from ISAV, PMCV, and SAV. In contrast, there were 25 stock cohorts from Washington and Alaska that had one or more individuals test positive for PRV RNA; prevalence within stocks varied and ranged from 2% to 73%. The overall prevalence of PRV RNA-positive individuals across the study was 3.4% (77 of 2,252 fish tested). Findings of PRV RNA were most common in coho (Oncorhynchus kisutch Walbaum) and Chinook (O. tshawytscha Walbaum) salmon.

The parasite Ichthyophonus sp. in Pacific herring from the coastal NE Pacific.

The protistan parasite Ichthyophonus occurred in populations of Pacific herring Clupea pallasii Valenciennes throughout coastal areas of the NE Pacific, ranging from Puget Sound, WA north to the Gulf of Alaska, AK. Infection prevalence in local Pacific herring stocks varied seasonally and annually, and a general pattern of increasing prevalence with host size and/or age persisted throughout the NE Pacific. An exception to this zoographic pattern occurred among a group of juvenile, age 1+ year Pacific herring from Cordova Harbor, AK in June 2010, which demonstrated an unusually high infection prevalence of 35%. Reasons for this anomaly were hypothesized to involve anthropogenic influences that resulted in locally elevated infection pressures. Interannual declines in infection prevalence from some populations (e.g. Lower Cook Inlet, AK; from 20-32% in 2007 to 0-3% during 2009-13) or from the largest size cohorts of other populations (e.g. Sitka Sound, AK; from 62.5% in 2007 to 19.6% in 2013) were likely a reflection of selective mortality among the infected cohorts. All available information for Ichthyophonus in the NE Pacific, including broad geographic range, low host specificity and presence in archived Pacific herring tissue samples dating to the 1980s, indicate a long-standing host-pathogen relationship.

Case Report: Primary Spinal Lymphoma.

This is the report on the case of a 74 year old male patient who was admitted to hospital emergency because of a distended bladder, which was detected on an MRI. This MRI was performed because of an acute paralysis of the patient's left leg. After various examinations we could conclude that the patient's neurological symptoms were not due to metastases of a solid tumour as we expected, but to a primary spinal diffuse B-cell lymphoma. The central nervous system, and especially the spinal cord, are an extremely rare location for primary B-Cell lymphoma.

Microbiological investigation for tuberculosis among HIV-infected children in Soweto, South Africa.

SETTING: A paediatric human immunodeficiency virus (HIV) clinic in an academic hospital in Soweto, South Africa. OBJECTIVES: 1) To describe and compare the clinical, immunological and virological characteristics of HIV-infected children co-treated for tuberculosis (TB), and 2) to compare those investigated microbiologically with those who were not, with a description of the results of the microbiological TB investigation. DESIGN: Retrospective analysis of TB-HIV-infected children aged <15 years treated for TB between 1 October 2007 and 15 March 2009. RESULTS: Anti-tuberculosis treatment was initiated in 616/3358 (18%) children during the study period. Microbiological TB investigation results were available for 399/616 (65%), among whom culture-confirmed TB was diagnosed in 49 (12%). Drug susceptibility testing was performed in 29/49 (59%) children: 5/29 (17%) were isoniazid-resistant, and 3 had multidrug-resistant TB. Children aged >8 years and those between 3 and 8 years were more likely to have culture-confirmed TB than those aged <3 years (aOR 9.4, 95%CI 2.26-39.08 vs. aOR 6.7, 95%CI 1.60-27.69), as were those with CD4 count <200 cells/mm(3) compared to those with >500 cells/mm(3) (aOR 3.95, 95%CI 1.23-12.72). CONCLUSION: Our study in HIV-infected children showed a high TB case rate, a low rate of definite TB and a high rate of drug-resistant TB based on World Health Organization case definitions. Increased uptake of available TB tests and availability of new diagnostic tests remains a priority in high TB-HIV burden settings.

Viral tropism and pathology associated with viral hemorrhagic septicemia in larval and juvenile Pacific herring.

Viral hemorrhagic septicemia virus (VHSV) genotype IVa causes mass mortality in wild Pacific herring, a species of economic value, in the Northeast Pacific Ocean. Young of the year herring are particularly susceptible and can be carriers of the virus. To understand its pathogenesis, tissue and cellular tropisms of VHSV in larval and juvenile Pacific herring were investigated with immunohistochemistry, transmission electron microscopy, and viral tissue titer. In larval herring, early viral tropism for epithelial tissues (6d post-exposure) was indicated by foci of epidermal thickening that contained heavy concentrations of virus. This was followed by a cellular tropism for fibroblasts within the fin bases and the dermis, but expanded to cells of the kidney, liver, pancreas, gastrointestinal tract and meninges in the brain. Among wild juvenile herring that underwent a VHS epizootic in the laboratory, the disease was characterized by acute and chronic phases of death. Fish that died during the acute phase had systemic infections in tissues including the submucosa of the gastrointestinal tract, spleen, kidney, liver, and meninges. The disease then transitioned into a chronic phase that was characterized by the appearance of neurological signs including erratic and corkscrew swimming and darkening of the dorsal skin. During the chronic phase viral persistence occurred in nervous tissues including meninges and brain parenchymal cells and in one case in peripheral nerves, while virus was mostly cleared from the other tissues. The results demonstrate the varying VHSV tropisms dependent on the timing of infection and the importance of neural tissues for the persistence and perpetuation of chronic infections in Pacific herring.

Influence of CYP2B6 516G>T polymorphism and interoccasion variability (IOV) on the population pharmacokinetics of efavirenz in HIV-infected South African children.

OBJECTIVE: To investigate the influence of CYP2B6 516G>T polymorphism, as a covariate, and of interoccasion variability (IOV) on the oral clearance (CL/F) of efavirenz (EFV) in treatment-naïve black South African children over a period of 24 months post-antiretroviral therapy (ART) initiation. METHODS: HIV-infected black children (n = 60, aged 3-16 years), with no prior exposure to ART, eligible to commence ART and attending an outpatient clinic were enrolled into this study. Blood samples were taken at mid-dose interval at 1, 3, 6, 12, 18 and 24 months post-ART initiation. EFV plasma samples were determined with an adapted and validated LC/MS/MS method. Genotyping of the CYP2B6 G516T single nucleotide polymorphism (SNP) was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). NONMEM was used for the population pharmacokinetic modelling. RESULTS: EFV concentrations below 1 µg/mL accounted for 18% (116/649), EFV concentrations >4 µg/mL accounted for 29.5% (192/649) and concentrations within the therapeutic range (1-4 µg/mL) represented 52.5% (341/649) of all the samples determined. The covariates age, weight and CYP2B6 G516Tgenotype were included in the final model with population estimates for CL/F determined as 2.46, 4.60 and 7.33 L/h for the T/T, G/T and G/G genotype groups respectively. CONCLUSIONS: The inclusion of both age and weight to predict accurate EFV CL values for the respective genotype groups within this paediatric population was required, whereas the addition of gender and body surface area did not improve the predictions. The importance of introducing IOV in a PK model for a longitudinal study with sparsely collected data was again highlighted by this investigation.

Prevalence of viral erythrocytic necrosis in Pacific herring and epizootics in Skagit Bay, Puget Sound, Washington.

Epizootics of viral erythrocytic necrosis (VEN) occurred among juvenile Pacific herring Clupea pallasii in Skagit Bay, Puget Sound, Washington, during 2005-2007 and were characterized by high prevalences and intensities of cytoplasmic inclusion bodies within circulating erythrocytes. The prevalence of VEN peaked at 67% during the first epizootic in October 2005 and waned to 0% by August 2006. A second VEN epizootic occurred throughout the summer of 2007; this was characterized by disease initiation and perpetuation in the age-1, 2006 year-class, followed by involvement of the age-0, 2007 year-class shortly after the latter's metamorphosis to the juvenile stage. The disease was detected in other populations of juvenile Pacific herring throughout Puget Sound and Prince William Sound, Alaska, where the prevalences and intensities typically did not correspond to those observed in Skagit Bay. The persistence and recurrence of VEN epizootics indicate that the disease is probably common among juvenile Pacific herring throughout the eastern North Pacific Ocean, and although population-level impacts probably occur they are typically covert and not easily detected.

HAART and risk of tuberculosis in HIV-infected South African children: a multi-site retrospective cohort.

SETTING: Four human immunodeficiency virus (HIV) clinics located at South African tertiary hospitals. OBJECTIVE: To assess the effectiveness of highly active antiretroviral therapy (HAART) in reducing incident tuberculosis (TB) in HIV-infected children. DESIGN: Retrospective cohort. RESULTS: A total of 1132 children's records were included in the study. At entry to the cohort, the median (interquartile range [IQR]) age, CD4%, CD4 count and viral load of all children was respectively 6.3 years (4.1-8.8), 15% (9.0-22.2), 576 cells/mm(3) (287-960) and 160 000 copies/ml (54 941.5-449 683); 75.9% were started on HAART. The male:female ratio was 1:1, and median follow-up time was 1.7 years. In children whose follow-up included both pre-HAART and on-HAART periods, the incidence of clinically diagnosed TB was respectively 21.1 per 100 person-years (py; 95%CI 18.2-24.4) and 6.4/100 py (95%CI 4.8-8.1), and when restricted to confirmed cases, respectively 3.1/100 py (95%CI 2.2-4.2) and 0.8/100 py (95%CI 0.5-1.4). Only 23% of all cases of TB were microbiologically confirmed. Multivariate analyses showed that HAART reduced incident TB by approximately 70%, both for confirmed and all TB cases. CONCLUSIONS: In this high TB burden country, the incidence of diagnosis of TB in HIV-infected children is at least as high as that of adults. HAART reduces incident TB, but further prospective TB preventive and diagnostic studies are urgently needed in children.

The utility of fine needle aspiration in HIV positive children.

OBJECTIVE: To determine the spectrum of disease, diagnostic accuracy and adequacy of fine needle aspirates (FNA) in human immunodeficiency virus (HIV) positive children who present with mass lesions. METHODS: Between January 1997 and December 2002, 95 FNAs were performed in 91 children aged 15 years and younger who were known to be infected with the human immunodeficiency virus (HIV). RESULTS: Head and neck masses including salivary gland swellings were the most common presentation (58.9%) followed by axillary masses (25.3%). Groin masses were aspirated in six children, flank and abdominal masses in four children, buttock masses in three children, a chest wall mass in one child and a sonar guided FNA of a lung mass in one child. Eight FNAs (8.4%) proved inadequate. Reactive lymphadenopathy was diagnosed in 42 cases, mycobacterial infection in 22, four children were diagnosed with abscess, one child had a fungal infection and five were found to have non-Hodgkin's lymphoma. There were four cases each of lymphoepithelial lesion and Kaposi sarcoma. There was one case each of nephroblastoma, rhabdomyosarcoma, myeloma, melanotic progonoma and spindle cells, not otherwise specified. CONCLUSION: Fine needle aspiration in HIV positive children is a worthwhile procedure and in most instances allows a rapid diagnosis obviating the need for surgery and enabling swift treatment to be undertaken where necessary. Ancillary studies form an important diagnostic component. Universal safety precautions must be strictly adhered to.

Expanded geographical distribution of Myxobolus cerebralis: first detections from Alaska.

The parasite responsible for salmonid whirling disease, Myxobolus cerebralis, was introduced to the USA in 1958. It has since spread across the country causing severe declines in wild trout populations, but has never been documented from Alaska. However, while assessing the risk of introduction of M. cerebralis into the state, we detected the parasite using a species-specific polymerase chain reaction (PCR) assay. Testing of 180 hatchery rainbow trout, Oncorhynchus mykiss (Walbaum), by pepsin trypsin digest (PTD) and quantitative PCR (QPCR) revealed 14 positive samples. Infection was confirmed by sequencing the parasite 18S rRNA gene and by a nested PCR assay based on the same gene. Sequence comparison of M. cerebralis from several locations demonstrated the Alaska isolates were genetically distinct and therefore not false-positives arising from contamination during processing. We were unable to visually identify myxospores, indicating that either infection was light or mature spores had not formed. A reference set of fish samples spiked with known numbers of myxospores verified the QPCR and PTD results. This paper presents DNA sequence data from the Alaska M. cerebralis isolates, provides a brief history of the fish and facility of origin, and discusses implications of different testing methods on asymptomatic fish populations.

Novel use of accelerator mass spectrometry for the quantification of low levels of systemic therapeutic recombinant protein.

Although 14C-labelling has been routinely used for small molecules, this technique is not routinely applied to therapeutic proteins due to difficulties of incorporating the label into the protein to a sufficiently high specific activity. An analytical method known as accelerator mass spectrometry (AMS) offers an extremely sensitive method of 14C quantification, thereby enabling (14)C-labeling methods to be applied to therapeutic protein detection. The therapeutic protein CAT-192 (metelimumab), a human anti-TGFss1 monocloncal antibody was manufactured in the presence of 14C-precursors resulting in a low specific activity product (1.4% 14C incorporation). [14C]-CAT-192 was administered to rats (1mg/kg and 222, 22 and 2.2 dpm/kg) and serum samples were collected. 14C in serum samples from the 2.2 dpm dosing was not detectable but samples from the 22 and 2220 dpm doses were measured by AMS and by ELISA for comparison. By both ELISA and AMS bioassay, the half-lives approximated 140 h (S.E.M. 15 h). The estimates of clearance were also comparable, 7.3 and 4.6 x 10(-4)ml/h/g (S.E.M. 6.6 and 5.1 x 10(-5)) for ELISA and AMS, respectively. The estimated limit of quantification (LOQ) was approximately 1 ng/ml, about 15 times lower than the ELISA LOQ of 15.6 ng/ml.

Clinical benefits of continuous leukocyte filtration during cardiopulmonary bypass in patients undergoing valvular repair or replacement.

Valve operations in the form of repair or replacement make up a significant population of patients undergoing surgical procedures in the USA annually with the use of cardiopulmonary bypass. These patients experience a wide range of complications that are considered to be mediated by activation of complement and leukocytes. The extracorporeal perfusion circuit consists of multiple synthetic artificial surfaces. The biocompatibility of the blood contact surfaces is a variable that predisposes patients to an increased risk of complement mediation and activation. This can result in an inflammatory process, causing leukocytes to proliferate and sequester in the major organ systems. The purpose of this study was to determine whether filtration of activated leukocytes improved clinical outcomes following surgical intervention for valve repair or replacement. In this paper, we report a retrospective matched cohort study of 700 patients who underwent valve procedures from June 1999 to December 2002. The control group (CG) consisted of patients who had a conventional arterial line filter. In the study group (SG), patients had a conventional arterial line filter and a leukocyte arterial line filter (Pall Medical, NY). In the SG, blood diverted to the cardioplegia system was also leukocyte depleted to enhance myocardial preservation by adapting this device to the outflow port on the filter. Patient characteristics were similar for the SG and the CG, including 228 males and 122 females, mean age (62.4 versus 64.2 years), cardiopulmonary bypass time (127+/-64 versus 116+/-53 min), and aortic crossclamp time (84+/-23 versus 81+/-23 min). Our results demonstrate that the SG achieved statistically significant reduction in the time to extubation (p =0.03) and the number of patients with prolonged intubation in excess of 24 hours (p <0.04), in addition to improved postoperative oxygenation (p=0.01), and decreased length of hospital stay (p =0.03). We believe that leukocyte filters are clinically beneficial, as demonstrated by the results presented in this study.

Full-length genome characterization of HIV type 1 subtype C isolates from two slow-progressing perinatally infected siblings in South Africa.

Isolation and characterization of HIV-1 from asymptomatic, slow-progressing individuals are important in studying viral pathogenesis and facilitate the development of vaccines and antivirals. In this study we identified two slow-progressing HIV-1-infected siblings, isolated viruses, and sequenced the full-length genome, to identify virus attenuations that may contribute to their altered rate of disease progression. Proviral DNA from strains 99ZATM10 and 01ZATM45 was isolated from peripheral blood mononuclear cells (PBMC) coculture.Virtually full-length genomes and long terminal repeat (LTR) regions were polymerase chain reaction (PCR) amplified, sequenced, and assembled to generate the complete genomes. Phylogenetic analysis confirmed that both isolates were subtype C throughout their genome. Predicted amino acid sequence analysis for all the HIV-1 proteins showed that both viruses had open reading frames for all genes, and encoded proteins of the expected length, except for the rev gene. The 3' end of rev exon 2 did not have the 16-amino acid (aa) truncation characteristic of subtype C viruses, and in addition, had a three-aa extension (GlyCysCys). Rev is a necessary regulatory factor for HIV expression, and changes in the protein may affect viral replication. These results suggest that slower HIV disease progression in these children may be attributed, at least in part, to an altered Rev protein.

Clinical features and T-cell subsets in HIV-infected children with and without lymphocytic interstitial pneumonitis.

Lymphocytic interstitial pneumonitis (LIP) is a non-infective lung condition common in untreated older children with vertically acquired HIV infection. Little is known about the prognosis in children with LIP, and diagnosis remains a problem where lung biopsy is not feasible. Our aim was to determine which clinical features aid the diagnosis of LIP in conjunction with the typical reticulonodular radiological picture, and whether the prognosis in children with LIP is different from that in HIV-infected children of the same age without LIP. We retrospectively compared the clinical features and T-cell subsets of 49 children with LIP with those of 56 children of similar age without LIP. Diagnosis of LIP was made radiologically. All children were apyrexial at the time of X-ray and acute intercurrent infections and tuberculosis had been excluded as far as possible. Ages ranged from 24 to 112 months in the non-LIP group and from 24 to 120 months in the LIP group. Digital clubbing and reticulo-endothelial hyperplasia were significantly more common in children with LIP than in those without. Children with LIP tended to have lower CD4+ counts and CD4% and higher CD8+ counts and CD8%, which resulted in significantly lower CD4/CD8 ratios in children under 5 years with LIP. It is possible in most cases to diagnose LIP using a combination of clinical and X-ray findings, as long as every effort is made to exclude tuberculosis. Lower CD4+ counts and CD4% as well as more frequent hospital admissions suggest that LIP adversely affects prognosis in children with HIV.

Human immunodeficiency virus type 1 envelope-stimulated interleukin-2 production and survival of infected children with severe and mild clinical disease.

Interleukin (IL)-2 production after stimulation with human immunodeficiency virus type 1 (HIV-1) envelope (Env) peptides, tetanus toxoid, and phytohemagglutinin was measured in peripheral blood mononuclear cells (PBMC) from 25 HIV-1-infected children with mild and 24 with severe clinical disease and from 15 uninfected children. Env-specific IL-2 production was detected in PBMC of 26.5% of HIV-1-infected children but in none of the uninfected. The absence of Env-specific responses at enrollment among infected children was associated with a 6-fold increased risk of mortality within a year, adjusting for clinical severity (P=.04). Among those with severe clinical disease, Env-stimulated IL-2 reactivity in PBMC was negatively correlated with HIV-1 RNA copy numbers in plasma at enrollment and was positively correlated with CD4 T cell percentages 1 year later. HIV-specific cellular immune responses may play a role in containing progression of HIV-1 infection in children, despite early deficits in cell-mediated immunity.

Altered expression of L-selectin (CD62L) on polymorphonuclear neutrophils of children vertically infected with human immunodeficiency virus type 1.

The expression of the leukocyte adhesion molecule L-selectin (CD62L) on polymorphonuclear neutrophils (PMN) and circulating levels of the soluble form of the receptor (sCD62L) were determined for a group of HIV-1-infected children, categorized as having mild or severe disease, and a group of uninfected control children. The fluorescence intensity of CD62L on PMN was significantly reduced in the HIV-1-infected children with mild disease compared to the uninfected controls. The proportion of lymphocytes expressing CD62L, as well as their corresponding fluorescence intensities, was significantly reduced in both the mild and the severe disease groups compared to the uninfected children, while peripheral levels of sCD62L were significantly elevated in the HIV-1-infected children with mild and severe disease compared to the controls. Altered cell migration resulting from reduced expression of CD62L may be an important contributor to the increased susceptibility to secondary microbial infections seen in HIV-1-infected children.