48 research outputs found
Global disparities in SARS-CoV-2 genomic surveillance
Genomic sequencing is essential to track the evolution and spread of SARS-CoV-2, optimize molecular tests, treatments, vaccines, and guide public health responses. To investigate the global SARS-CoV-2 genomic surveillance, we used sequences shared via GISAID to estimate the impact of sequencing intensity and turnaround times on variant detection in 189 countries. In the first two years of the pandemic, 78% of high-income countries sequenced >0.5% of their COVID-19 cases, while 42% of low- and middle-income countries reached that mark. Around 25% of the genomes from high income countries were submitted within 21 days, a pattern observed in 5% of the genomes from low- and middle-income countries. We found that sequencing around 0.5% of the cases, with a turnaround time <21 days, could provide a benchmark for SARS-CoV-2 genomic surveillance. Socioeconomic inequalities undermine the global pandemic preparedness, and efforts must be made to support low- and middle-income countries improve their local sequencing capacity
Longevity and Composition of Cellular Immune Responses Following Experimental Plasmodium falciparum Malaria Infection in Humans
Cellular responses to Plasmodium falciparum parasites, in particular interferon-gamma (IFNγ) production, play an important role in anti-malarial immunity. However, clinical immunity to malaria develops slowly amongst naturally exposed populations, the dynamics of cellular responses in relation to exposure are difficult to study and data about the persistence of such responses are controversial. Here we assess the longevity and composition of cellular immune responses following experimental malaria infection in human volunteers. We conducted a longitudinal study of cellular immunological responses to sporozoites (PfSpz) and asexual blood-stage (PfRBC) malaria parasites in naïve human volunteers undergoing single (n = 5) or multiple (n = 10) experimental P. falciparum infections under highly controlled conditions. IFNγ and interleukin-2 (IL-2) responses following in vitro re-stimulation were measured by flow-cytometry prior to, during and more than one year post infection. We show that cellular responses to both PfSpz and PfRBC are induced and remain almost undiminished up to 14 months after even a single malaria episode. Remarkably, not only ‘adaptive’ but also ‘innate’ lymphocyte subsets contribute to the increased IFNγ response, including αβT cells, γδT cells and NK cells. Furthermore, results from depletion and autologous recombination experiments of lymphocyte subsets suggest that immunological memory for PfRBC is carried within both the αβT cells and γδT compartments. Indeed, the majority of cytokine producing T lymphocytes express an CD45RO+ CD62L- effector memory (EM) phenotype both early and late post infection. Finally, we demonstrate that malaria infection induces and maintains polyfunctional (IFNγ+IL-2+) EM responses against both PfRBC and PfSpz, previously found to be associated with protection. These data demonstrate that cellular responses can be readily induced and are long-lived following infection with P. falciparum, with a persisting contribution by not only adaptive but also (semi-)innate lymphocyte subsets. The implications hereof are positive for malaria vaccine development, but focus attention on those factors potentially inhibiting such responses in the field
Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy
Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe
Bottom trawl fishing footprints on the world’s continental shelves
Publication history: Accepted - 23 August 2018; Published online - 8 October 2018.Bottom trawlers land around 19 million tons of fish and invertebrates
annually, almost one-quarter of wild marine landings. The extent of
bottom trawling footprint (seabed area trawled at least once in a
specified region and time period) is often contested but poorly
described. We quantify footprints using high-resolution satellite vessel
monitoring system (VMS) and logbook data on 24 continental shelves
and slopes to 1,000-m depth over at least 2 years. Trawling footprint
varied markedly among regions: from <10% of seabed area in Australian
and New Zealand waters, the Aleutian Islands, East Bering Sea,
South Chile, and Gulf of Alaska to >50% in some European seas.
Overall, 14% of the 7.8 million-km2 study area was trawled, and
86% was not trawled. Trawling activity was aggregated; the most
intensively trawled areas accounting for 90% of activity comprised
77% of footprint on average. Regional swept area ratio (SAR; ratio
of total swept area trawled annually to total area of region, a metric
of trawling intensity) and footprint area were related, providing an
approach to estimate regional trawling footprints when highresolution
spatial data are unavailable. If SAR was ≤0.1, as in 8 of
24 regions, therewas >95% probability that >90%of seabed was not
trawled. If SAR was 7.9, equal to the highest SAR recorded, there
was >95% probability that >70% of seabed was trawled. Footprints
were smaller and SAR was ≤0.25 in regions where fishing rates consistently
met international sustainability benchmarks for fish stocks,
implying collateral environmental benefits from sustainable fishing.Funding for meetings of the study group and salary
support for R.O.A. were provided by the following: David and Lucile Packard
Foundation; the Walton Family Foundation; the Alaska Seafood Cooperative;
American Seafoods Group US; Blumar Seafoods Denmark; Clearwater Seafoods
Inc.; Espersen Group; Glacier Fish Company LLC US; Gortons Seafood; Independent
Fisheries Limited N.Z.; Nippon Suisan (USA), Inc.; Pesca Chile S.A.;
Pacific Andes International Holdings, Ltd.; San Arawa, S.A.; Sanford Ltd. N.Z.;
Sealord Group Ltd. N.Z.; South African Trawling Association; Trident Seafoods;
and the Food and Agriculture Organisation of the United Nations. Additional
funding to individual authors was provided by European Union Project
BENTHIS EU-FP7 312088 (to A.D.R., O.R.E., F.B., N.T.H., L.B.-M., R.C., H.O.F.,
H.G., J.G.H., P.J., S.K., M.L., G.G.-M., N.P., P.E.P., T.R., A.S., B.V., and M.J.K.); the
Instituto Português do Mar e da Atmosfera, Portugal (C.S.); the International
Council for the Exploration of the Sea Science Fund (R.O.A. and K.M.H.); the
Commonwealth Scientific and Industrial Research Organisation (C.R.P. and
T.M.); the National Oceanic and Atmospheric Administration (R.A.M.); New
Zealand Ministry for Primary Industries Projects BEN2012/01 and DAE2010/
04D (to S.J.B. and R.F.); the Institute for Marine and Antarctic Studies, University
of Tasmania and the Department of Primary Industries, Parks, Water and
Environment, Tasmania, Australia (J.M.S.); and UK Department of Environment,
Food and Rural Affairs Project MF1225 (to S.J.)
31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two
Background
The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd.
Methods
We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background.
Results
First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001).
Conclusions
In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival
Global variation in anastomosis and end colostomy formation following left-sided colorectal resection
Background
End colostomy rates following colorectal resection vary across institutions in high-income settings, being influenced by patient, disease, surgeon and system factors. This study aimed to assess global variation in end colostomy rates after left-sided colorectal resection.
Methods
This study comprised an analysis of GlobalSurg-1 and -2 international, prospective, observational cohort studies (2014, 2016), including consecutive adult patients undergoing elective or emergency left-sided colorectal resection within discrete 2-week windows. Countries were grouped into high-, middle- and low-income tertiles according to the United Nations Human Development Index (HDI). Factors associated with colostomy formation versus primary anastomosis were explored using a multilevel, multivariable logistic regression model.
Results
In total, 1635 patients from 242 hospitals in 57 countries undergoing left-sided colorectal resection were included: 113 (6·9 per cent) from low-HDI, 254 (15·5 per cent) from middle-HDI and 1268 (77·6 per cent) from high-HDI countries. There was a higher proportion of patients with perforated disease (57·5, 40·9 and 35·4 per cent; P < 0·001) and subsequent use of end colostomy (52·2, 24·8 and 18·9 per cent; P < 0·001) in low- compared with middle- and high-HDI settings. The association with colostomy use in low-HDI settings persisted (odds ratio (OR) 3·20, 95 per cent c.i. 1·35 to 7·57; P = 0·008) after risk adjustment for malignant disease (OR 2·34, 1·65 to 3·32; P < 0·001), emergency surgery (OR 4·08, 2·73 to 6·10; P < 0·001), time to operation at least 48 h (OR 1·99, 1·28 to 3·09; P = 0·002) and disease perforation (OR 4·00, 2·81 to 5·69; P < 0·001).
Conclusion
Global differences existed in the proportion of patients receiving end stomas after left-sided colorectal resection based on income, which went beyond case mix alone
Hepatitis B virus and human T-cell lymphotropic virus type 1 co-infection in the Northern Territory, Australia.
To establish the relationship between hepatitis B virus (HBV) and human T-cell lymphotropic virus type 1 (HTLV-1) serological markers in the Northern Territory, Australia. A retrospective serological study of patients presenting to public healthcare facilities in the Northern Territory between 2008 and 2015 was performed in order to determine the presence and relationships of serological markers of HBV and HTLV-1. Seven hundred and forty individual patients were found to be serologically positive for HTLV-1 in the Northern Territory over the 8-year period. Hepatitis B results were available for 521 of these patients. Hepatitis B surface antigen (HBsAg) positivity was demonstrated in 15.9% (83/521) of this cohort, which was significantly different to the HTLV-1-negative group (3.7%, 125/3354) (p<0.001). Excluding individuals with isolated hepatitis B surface antibody (anti-HBs), those in the HTLV-1-positive group had a higher HBV exposure history (67.5%, 352/521) when compared to HTLV-1-negative individuals (37.8%, 1259/3354) (p<0.001). HTLV-1-positive individuals had a lower prevalence of HBV combined anti-HBs and hepatitis B core antibody (anti-HBc) positive markers compared to those who were HTLV-1-negative (56.3% (198/352) versus 73.8% (937/1269), respectively; p<0.001). A significantly higher prevalence rate of HBV was found in HTLV-1-positive individuals from the Northern Territory. When considering the higher exposure to HBV in HTLV-1-positive individuals, the clearance of HBV appears lower than in those individuals testing HTLV-1-negative. A lower prevalence of clearance in HTVL-1-positive individuals than in HTLV-1-negative individuals, as signified by formation of HBVcAb and HBVsAb in HTVL-1 positive individual's may equate to higher prevalence of ongoing coinfection
HIV testing rate increased following recommendation of routine screening of acute medical admissions at Royal Darwin Hospital.
Background To improve HIV detection, Royal Darwin Hospital implemented a guideline in 2012 recommending routine HIV testing for all adult acute medical admissions. This study aimed to determine the uptake, point prevalence and impact on late diagnosis of HIV screening following guideline implementation. Data on the number of HIV tests and number of acute medical admissions over the 8 months prior and post guideline implementation were extracted from hospital databases. A qualitative survey was conducted to ascertain clinician response to routine screening. Fourteen per cent of admissions were tested post-implementation compared with 5.3% during the implementation period (P<0.001). HIV prevalence pre-implementation was 1.4% compared with 0.3% following implementation (P<0.05). The average CD4 count at diagnosis was <200 cells/mm(3). There was a significant increase in HIV testing following guideline implementation; however, the overall testing rate remained low. Routine screening did not increase detection of HIV, and HIV continues to be diagnosed late at Royal Darwin Hospital. Methods for improving understanding of the rationale for routine screening and increased promotion of the guidelines are required to increase testing
Neurosyphilis: Still prevalent and overlooked in an at risk population.
BackgroundNeurosyphilis (NS) presents with a variety of clinical syndromes that can be attributed to other aetiologies due to difficulties in its diagnosis. We reviewed all cases of NS from the "Top End" of the Australian Northern Territory over a ten-year period to assess incidence, clinical and laboratory manifestations.MethodsPatient data (2007-2016) were extracted from hospital records, centralised laboratory data and Northern Territory Centre for Disease Control records. Clinical records of patients with clinically suspected NS were reviewed. A diagnosis of NS was made based on the 2014 US CDC criteria. Results were also recategorized based on the 2018 US CDC criteria.ResultsThe population of the "Top End" is 185,570, of whom 26.2% are Indigenous. A positive TPPA was recorded in 3126 individuals. A total of 75 (2.4%) of TPPA positive patients had a lumbar puncture (LP), of whom 25 (35%) were diagnosed with NS (9 definite, 16 probable). Dementia was the most common manifestation (58.3%), followed by epilepsy (16.7%), psychosis (12.5%), tabes dorsalis (12.5%) and meningovascular syphilis (8.3%). 63% of probable NS cases were not treated appropriately due to a negative CSF VDRL. Despite increased specificity of the 2018 US CDC criteria, 70% of patient in the probable NS group were not treated appropriately. The overall annual incidence [95%CI] of NS was 2.47[1.28-4.31] per 100 000py in the Indigenous population and 0.95[0.50-1.62] in the non-Indigenous population (rate ratio = 2.60 [1.19-5.70];p = 0.017).ConclusionNeurosyphilis is frequently reported in the NT, particularly in Indigenous populations. Disturbingly, 60% of probable neurosyphilis patients based on the 2014 criteria, and 70% based on the 2018 criteria with were not treated appropriately. It is critical that clinicians should be aware of the diagnosis of NS and treat patients appropriately