1,721,255 research outputs found
Chronic hepatitis B infection in sub-Saharan Africa: A grave challenge and a great hope
No full textIn sub-Saharan Africa, chronic infection with the hepatitis B virus (HBV) is a profoundly important public health issue characterised by high prevalence, frequent co-infection with HIV, and sub-optimally applied ascertainment and management strategies. Prevalence of hepatitis B surface antigen (HBsAg) in the general population varies geographically, with the highest rates (>8%) measured in West Africa.1 Among people living with HIV, between 6% and 25% are co-infected with HBV, and co-infection accelerates fibrosis and increases the risk of liver-related mortality and development of hepatocellular carcinoma (HCC) compared to HIV-negative controls.2
In part, as a consequence of reduced HIV-related mortality, both HCC and cirrhosis are increasing in sub-Saharan Africa.3 The proportion of deaths due to cirrhosis increased by 31% between 1990 and 2010.3 Lemoine et al. argue that if HCC and cirrhosis were grouped together, chronic viral hepatitis would rank within the top 10 causes of global mortality, above malaria and TB.4 However, accurate epidemiological data on liver-related mortality in sub-Saharan Africa are lacking, and verbal autopsy remains the predominant method of ascertaining the cause of death, which is highly likely to underestimate the true burden of disease.
Herpes simplex virus type 2: epidemiology and management options in developing countries
Full text linkGenital herpes simplex virus type 2 (HSV2) is highly prevalent worldwide and an increasingly important cause of genital ulcer disease (GUD). Continued HSV2 transmission is facilitated by the large number of undiagnosed cases, the frequency of atypical disease and the occurrence of asymptomatic shedding. The lack of easy, affordable diagnostic methods and specific antiviral treatment in countries with low and middle income is of great concern, given the ability of GUD to enhance HIV transmission and acquisition. With rising HSV2 prevalence contributing to an increase in the proportion of GUD attributed to genital herpes in high-HIV prevalence settings, a safe and effective HSV vaccine is urgently needed. Meanwhile, multifaceted interventions are required to improve recognition of genital herpes, to prevent its spread and also to prevent its potential to promote HIV transmission in developing countries
Virus replication and evolution drive the kinetics and specificity of SIV-specific cytotoxic T lymphocyte.
Full text linkSIV (simian immunodeficiency virus) infection of cynomolgus macaques provides an excellent model for investigating the basis of protective immunity against HIV (human immunodeficiency virus). We explored the protective role of cytotoxic T lymphocytes (CTL) against the pathogenic molecular clone SIVmac-J5. Vaccine-induced CTL precursors (CTLp) against Env, Gag or Nef did not protect macaques against intravenous challenge. However, detection of Rev-specific CTLp in infected macaques was associated with effective virus containment. Furthermore, CTL against an immunodominant Gag/p26 epitope (amino acids 242-250) resulted in the emergence of a mutant virus that uniformly replaced wild-type virus in the spleen and partially escaped recognition. During primary infection, CTLp detection in blood coincided with decreasing viremia. After 12 months, two outcomes emerged. In one group of macaques, persistent viremia was associated with high viral load in lymphoid organs and declining CD4+ T-cell counts. CTLp were maintained in asymptomatic macaques, but declined in the symptomatic phase of infection. In a second group, loss of detectable viremia was associated with low-level virus reservoirs in lymphoid organs, asymptomatic status and maintained CD4+ T-cell counts. CTLp peaked in the first 4 months of infection and subsequently declined in this group. These studies provide insights into the complex interplay between virus replication and host immunity
Cytotoxic T lymphocytes in AIDS pathogenesis: lessons to be learned from the macaque model of simian immunodeficiency virus infection
Full text link
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Hepatitis B virus (HBV) infection and re-activation during nucleos(t)ide reverse transcriptase inhibitor-sparing antiretroviral therapy in a high-HBV endemicity setting
Full text linkBackground: We monitored the evolution of markers of hepatitis B virus (HBV) infection in virologically suppressed HIVpositive patients switching to nucleoside reverse transcriptase inhibitor (NRTI)-sparing antiretroviral therapy within a randomized trial in Cameroon. Methods: HBV surface antigen (HBsAg), HBV DNA, and antibodies against surface (anti-HBs), core (total anti-HBc), and e-antigen (anti-HBe) were measured retrospectively in samples collected at study entry and over 48 weeks after NRTI discontinuation. Results: Participants (n = 80, 75% females) had a plasma HIV-1 RNA 3, and undetectable HBsAg and HBV DNA at study entry. After NRTI discontinuation, 3/20 (15.0%) anti-HBc-negative patients showed evidence indicative or suggestive of incident HBV infection (163 cases/1000 person-years); 6/60 (10.0%) anti-HBc-positive patients showed evidence indicative or suggestive of HBV reactivation (109 cases/1000 person-years). In one case of reactivation, anti-HBs increased from 14 to >1000 IU/L; sequencing showed HBV genotype A3 and 3 escape mutations in surface (Y100C, K122R, Y161FY). Alongside new-onset detection of HBsAg or HBV DNA, 1 patient experienced acute hepatitis and 6 patients experienced mild or marginal increases in serum transaminase levels. Conclusions: Evolving treatment strategies for sub-Saharan Africa must be accompanied by the formulation and implementation of policy to guide appropriate assessment and management of HBV status
- …
