244 research outputs found
Hepatitis B and C in Malawi: Epidemiology, Disease Burden and Opportunities for a Public Health Treatment Programme
Abstract In sub-Saharan Africa, hepatitis B virus (HBV) infection is the principal cause of liver cirrhosis and hepatocellular carcinoma (HCC). Mortality from cirrhosis and HCC is projected to rise beyond 2030 unless adult HBV treatment programmes are implemented. Infant HBV vaccination was introduced across sub-Saharan Africa between 1994-2014, and in Malawi in 2002 where it is given at 6, 10 and 14 weeks of life. Hepatitis C virus (HCV) is an important contributor to liver disease globally, with an estimated population prevalence of 1% in sub-Saharan Africa. In Southern Africa there is a paucity of HCV prevalence data, with no previous random probability-sampling community studies. A hospital-based study of cirrhosis and HCC in a tertiary hospital, and seroprevalence studies in an urban township, were conducted in Blantyre, Malawi, to determine HBV and HCV prevalence and HBV vaccine impact. Of 97,386 censused individuals, single stage non-replacement age-stratified probability sampling was used to select 6,073 individuals who were tested for hepatitis B surface antigen (HBsAg) in a community serosurvey. HBsAg-positive individuals aged ≥16 were recruited to assess treatment eligibility. Among individuals aged ≥16 in the serosurvey, 1661 (51%) were randomly selected for HCV antigen/antibody (Ag/Ab) testing with confirmatory HCV RNA PCR. Prevalence estimates were standardised to census age and sex distribution using post-stratification proportional fitting. In the hospital study, the population attributable fraction (PAF) of HBV to cirrhosis and HCC was 23.1% (95% CI 15.7- 29.8) and 71.5% (59.3- 80.1) respectively among 250 consecutively recruited patients. For HCV the PAF was 1.6% (95% CI -0.4 – 3.6) for cirrhosis and 4.8% (-0.1, 9.5) for HCC. Patients with HCC were diagnosed at an advanced stage with a median tumour size of 12.6cm and a median survival of 1.3 months. Six-month survival was 67% (59.0- 73.8) among patients with cirrhosis. Standardised HBsAg prevalence in serosurvey participants born prior to, and after HBV vaccine introduction, was 5.1% (95% CI 4.3- 6.1) and 0.3% (95% CI 0.1- 0.6) respectively. Three-dose vaccination coverage was 97.4% (1141/1171) among 1171/2085 children aged ≤10 years with known vaccine status. By comparison of participants born 5 years before and after vaccine introduction, vaccine impact was 95.9% (95% CI 70.6- 99.4). Treatment eligibility was assessed in 94/150 HBsAg positive people aged ≥16 years from the serosurvey, of whom 24/93 (26%) were HIV positive, and 16/24 (67%) were receiving antiretroviral therapy containing tenofovir, with HBV DNA suppression. Among 69 HIV-negative HBsAg positive individuals, 3,6 and 9% were eligible for HBV treatment by WHO, EASL and AASLD criteria respectively. Standardised HCV Ag/Ab prevalence was 0.78% (95% CI 0.46- 1.33) and HCV RNA prevalence was 0.18% (95% CI 0.06- 0.53). HCV Ag/Ab positive individuals were older than the general population but no differences in sex, educational, employment or marital status were observed. In an urban township in Malawi, HBV prevalence was intermediate at 5.1% among unvaccinated adults. Infant HBV vaccination was associated with a vaccine impact of 96%. Among HBsAg-positive adults, one quarter were HIV-positive and 3-9% of HIV-negative adults were eligible for antiviral therapy. Estimated population HCV RNA prevalence was 0.2%. Future prevalence studies should sample rural communities and specific risk groups. HCC is diagnosed at an advanced stage with a poor prognosis in Malawi, and HBV is an important cause. The burden of HBV and HCV associated liver disease represents both a challenge, and an opportunity to implement public health treatment programmes to reverse rising liver-related mortality in Southern Africa
Drug resistance outcomes of long-term ART with tenofovir disoproxil fumarate in the absence of virological monitoring
Objectives: The resistance profiles of patients receiving long-term ART in sub-Saharan Africa have been poorly described. This study obtained a sensitive assessment of the resistance patterns associated with long-term tenofovir-based ART in a programmatic setting where virological monitoring is yet to become part of routine care.
Methods: We studied subjects who, after a median of 4.2 years of ART, replaced zidovudine or stavudine with tenofovir disoproxil fumarate while continuing lamivudine and an NNRTI. Using deep sequencing, resistance-associated mutations (RAMs) were detected in stored samples collected at tenofovir introduction (T0) and after a median of 4.0 years (T1).
Results: At T0, 19/87 (21.8%) subjects showed a detectable viral load and 8/87 (9.2%) had one or more major NNRTI RAMs, whereas 82/87 (94.3%) retained full tenofovir susceptibility. At T1, 79/87 (90.8%) subjects remained on NNRTI-based ART, 5/87 (5.7%) had introduced lopinavir/ritonavir due to immunological failure, and 3/87 (3.4%) had interrupted ART. Whilst 68/87 (78.2%) subjects maintained or achieved virological suppression between T0 and T1, a detectable viral load with NNRTI RAMs at T0 predicted lack of virological suppression at T1. Each treatment interruption, usually reflecting unavailability of the dispensary, doubled the risk of T1 viraemia. Tenofovir, lamivudine and efavirenz selected for K65R, K70E/T, L74I/V and Y115F, alongside M184V and multiple NNRTI RAMs; this resistance profile was accompanied by high viral loads and low CD4 cell counts.
Conclusions: Viraemia on tenofovir, lamivudine and efavirenz led to complex resistance patterns with implications for continued drug activity and risk of onward transmission
Randomized phase II study investigating pazopanib versus weekly paclitaxel in relapsed or progressive urothelial cancer
Purpose:
Two previous single-arm trials have drawn conflicting conclusions regarding the activity of pazopanib in urothelial cancers after failure of platinum-based chemotherapy.
Patients and Methods:
This randomized (1:1) open-label phase II trial compared the efficacy of pazopanib 800 mg orally with paclitaxel (80 mg/m2 days 1, 8, and 15 every 28 days) in the second-line setting. The primary end point was overall survival (OS).
Results:
Between August 2012 and October 2014, 131 patients, out of 140 planned, were randomly assigned. The study was terminated early on the recommendation of the independent data monitoring committee because of futility. Final analysis after the preplanned number of deaths (n = 110) occurred after a median follow-up of 18 months. One hundred fifteen deaths had occurred at the final data extract presented here. Median OS was 8.0 months for paclitaxel (80% CI, 6.9 to 9.7 months) and 4.7 months for pazopanib (80% CI, 4.2 to 6.4 months). The hazard ratio (HR) adjusted for baseline stratification factors was 1.28 (80% CI, 0.99 to 1.67; one-sided P = .89). Median progression-free survival was 4.1 months for paclitaxel (80% CI, 3.0 to 5.6 months) and 3.1 months for pazopanib (80% CI, 2.7 to 4.6 months; HR, 1.09; 80% CI, 0.85 to 1.40; one-sided P = .67). Discontinuations for toxicity occurred in 7.8% and 23.1% for paclitaxel and pazopanib, respectively.
Conclusion:
Pazopanib did not have greater efficacy than paclitaxel in the second-line treatment of urothelial cancers. There was a trend toward superior OS for paclitaxel
The global prevalence of hepatitis D virus infection : systematic review and metaanalysis
Background and Aims There are uncertainties about the epidemic patterns of hepatitis delta virus (HDV) infection and its contribution to the burden of liver disease. We estimated the global prevalence of HDV infection and explored its contribution to the development of cirrhosis and hepatocellular carcinoma (HCC) among hepatitis B surface antigen (HBsAg)-positive people. Methods We searched Pubmed, EMBASE and Scopus for studies reporting on total or IgG anti-HDV among HBsAg-positive people. Anti-HDV prevalence was estimated using a binomial mixed model, weighting for study quality and population size. The population attributable fraction (PAF) of HDV to cirrhosis and HCC among HBsAg-positive people was estimated using random-effects models. Results We included 282 studies, comprising 376 population samples from 95 countries, which together tested 120,293 HBsAg-positive people for anti-HDV. The estimated anti-HDV prevalence was 4.5% (95% CI 3.6, 5.7) among all HBsAg-positive people and 16.4% (14.6, 18.6) among those attending hepatology clinics. Worldwide, 0.16% (0.11, 0.25) of the general population, totalling 12.0 (8.7, 18.7) million people, were estimated to be anti-HDV positive. Prevalence among HBsAg-positive people was highest in Mongolia, the Republic of Moldova and countries in Western and Middle Africa, and was higher in injecting drug users, haemodialysis recipients, men who have sex with men, commercial sex workers, and those with hepatitis C virus or HIV. Among HBsAg-positive people, preliminary PAF estimates of HDV were 18% (10, 26) for cirrhosis and 20% (8, 33) for HCC. Conclusions An estimated 12 million people worldwide have experienced HDV infection, with higher prevalence in certain geographic areas and populations. HDV is a significant contributor to HBV-associated liver disease. More quality data are needed to improve the precisions of burden estimates
Outcomes of COVID-19 related hospitalization among people with HIV in the ISARIC WHO Clinical Characterization Protocol (UK):a prospective observational study
BACKGROUND:Evidence is conflicting about how HIV modulates COVID-19. We compared the presentation characteristics and outcomes of adults with and without HIV who were hospitalized with COVID-19 at 207 centers across the United Kingdom and whose data were prospectively captured by the ISARIC WHO CCP study. METHODS:We used Kaplan-Meier methods and Cox regression to describe the association between HIV status and day-28 mortality, after separate adjustment for sex, ethnicity, age, hospital acquisition of COVID-19 (definite hospital acquisition excluded), presentation date, ten individual comorbidities, and disease severity at presentation (as defined by hypoxia or oxygen therapy). RESULTS:Among 47,592 patients, 122 (0.26%) had confirmed HIV infection and 112/122 (91.8%) had a record of antiretroviral therapy. At presentation, HIV-positive people were younger (median 56 versus 74 years; p<0.001) and had fewer comorbidities, more systemic symptoms and higher lymphocyte counts and C-reactive protein levels. The cumulative day-28 mortality was similar in the HIV-positive vs. HIV-negative groups (26.7% vs. 32.1%; p=0.16), but in those under 60 years of age HIV-positive status was associated with increased mortality (21.3% vs. 9.6%; p<0.001 [log-rank test]). Mortality was higher among people with HIV after adjusting for age (adjusted hazard ratio [aHR] 1.47, 95% confidence interval [CI] 1.01-2.14; p=0.05), and the association persisted after adjusting for the other variables (aHR 1.69; 95% CI 1.15-2.48; p=0.008) and when restricting the analysis to people aged <60 years (aHR 2.87; 95% CI 1.70-4.84; p<0.001). CONCLUSIONS:HIV-positive status was associated with an increased risk of day-28 mortality among patients hospitalized for COVID-19
Stability of the human gut virome and effect of gluten-free diet
The human gut microbiome consists of bacteria, archaea, eukaryotes, and viruses. The gut viruses are relatively underexplored. Here, we longitudinally analyzed the gut virome composition in 11 healthy adults: its stability, variation, and the effect of a gluten-free diet. Using viral enrichment and a de novo assembly-based approach, we demonstrate the quantitative dynamics of the gut virome, including dsDNA, ssDNA, dsRNA, and ssRNA viruses. We observe highly divergent individual viral communities, carrying on an average 2,143 viral genomes, 13.1% of which were present at all 3 time points. In contrast to previous reports, the Siphoviridae family dominates over Microviridae in studied individual viromes. We also show individual viromes to be stable at the family level but to vary substantially at the genera and species levels. Finally, we demonstrate that lower initial diversity of the human gut virome leads to a more pronounced effect of the dietary intervention on its composition
Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae
We systematically surveyed period variations of superhumps in SU UMa-type
dwarf novae based on newly obtained data and past publications. In many
systems, the evolution of superhump period are found to be composed of three
distinct stages: early evolutionary stage with a longer superhump period,
middle stage with systematically varying periods, final stage with a shorter,
stable superhump period. During the middle stage, many systems with superhump
periods less than 0.08 d show positive period derivatives. Contrary to the
earlier claim, we found no clear evidence for variation of period derivatives
between superoutburst of the same object. We present an interpretation that the
lengthening of the superhump period is a result of outward propagation of the
eccentricity wave and is limited by the radius near the tidal truncation. We
interpret that late stage superhumps are rejuvenized excitation of 3:1
resonance when the superhumps in the outer disk is effectively quenched. Many
of WZ Sge-type dwarf novae showed long-enduring superhumps during the
post-superoutburst stage having periods longer than those during the main
superoutburst. The period derivatives in WZ Sge-type dwarf novae are found to
be strongly correlated with the fractional superhump excess, or consequently,
mass ratio. WZ Sge-type dwarf novae with a long-lasting rebrightening or with
multiple rebrightenings tend to have smaller period derivatives and are
excellent candidate for the systems around or after the period minimum of
evolution of cataclysmic variables (abridged).Comment: 239 pages, 225 figures, PASJ accepte
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