Adeno-associated virus 2 infection in children with non-A-E hepatitis.

An outbreak of acute hepatitis of unknown aetiology in children was reported in Scotland in April 2022 and has now been identified in 35 countries. Several recent studies have suggested an association with human adenovirus with this outbreak, a virus not commonly associated with hepatitis. Here we report a detailed case-control investigation and find an association between adeno-associated virus 2 (AAV2) infection and host genetics in disease susceptibility.

The experience of point-of-care testing for influenza in Scotland in 2017/18 and 2018/19 - no gain without pain.

BackgroundDuring the 2017/18 and 2018/19 influenza seasons, molecular amplification-based point-of-care tests (mPOCT) were introduced in Scotland to aid triaging respiratory patients for hospital admission, yet communication of results to national surveillance was unaccounted for.AimThis retrospective study aims to describe steps taken to capture mPOCT data and assess impact on influenza surveillance.MethodsQuestionnaires determined mPOCT usage in 2017/18 and 2018/19.

Value of repeat testing using Cepheid GeneXpert CT/NG for indeterminate PCR results when diagnosing Chlamydia trachomatis and Neisseria gonorrhoeae.

Nucleic acid amplification tests (NAATs) are the most sensitive method for diagnosing chlamydia and gonorrhoea. We use the COBAS 4800 CT/NG combined assay (Roche Molecular Diagnostics, CA, USA), and whilst the majority of samples yield definitive results, a small proportion are reported as indeterminate. In these instances, it is usual practice to request repeat samples which delays diagnosis.

Lopinavir/ritonavir monotherapy after 24 weeks of second-line antiretroviral therapy in Africa: a randomized controlled trial (SARA).

Background: Boosted protease inhibitor (bPI) monotherapy (bPImono) potentially has substantial cost, safety and operational benefits. It has never been evaluated as second-line antiretroviral therapy (ART) in Africa.

Methods: After 24 weeks of lopinavir/ritonavir-containing second-line therapy, DART participants were randomized to remain on combination therapy (CT), or change to bPImono maintenance (SARA trial; ISRCTN53817258).

Evolution of drug resistance during 48 weeks of zidovudine/lamivudine/tenofovir in the absence of real-time viral load monitoring.

Objectives: To describe the resistance mutations selected by a first-line regimen of zidovudine/lamivudine/tenofovir in the absence of real-time viral load monitoring.

Design: A substudy of 300 participants from the Development of Antiretroviral Therapy in Africa trial in Uganda and Zimbabwe, which compared managing antiretroviral therapy with and without laboratory monitoring.

Methods: Stored plasma samples from selected time points were assayed retrospectively for HIV-1 RNA.

Novel subtype C human immunodeficiency virus type 1 envelopes cloned directly from plasma: coreceptor usage and neutralization phenotypes.

Human immunodeficiency virus type 1 (HIV-1) is classified into different phylogenetic subtypes, with subtype C representing more than half of the novel infections globally. However, there are relatively few subtype C envelopes available for study. We amplified 18 unique env genes from 13 patients who were infected with subtype C HIV-1 in six African countries and in Scotland to create replication-competent viruses.

Viral rebound and emergence of drug resistance in the absence of viral load testing: a randomized comparison between zidovudine-lamivudine plus Nevirapine and zidovudine-lamivudine plus Abacavir.

Background: We investigated virological response and the emergence of resistance in the Nevirapine or Abacavir (NORA) substudy of the Development of Antiretroviral Treatment in Africa (DART) trial.

Methods: Six hundred symptomatic antiretroviral-naive human immunodeficiency virus (HIV)-infected adults (CD4 cell count, <200 cells/mm(3)) from 2 Ugandan centers were randomized to receive zidovudine-lamivudine plus abacavir or nevirapine. Virology was performed retrospectively on stored plasma samples at selected time points.

Host HLA B*allele-associated multi-clade Gag T-cell recognition correlates with slow HIV-1 disease progression in antiretroviral therapy-naïve Ugandans.

Background: Some HIV infected individuals remain asymptomatic for protracted periods of time in the absence of antiretroviral therapy (ART). Virological control, CD4 T cell loss and HIV-specific responses are some of the key interrelated determinants of HIV-1 disease progression. In this study, possible interactions between viral load, CD4 T cell slopes, host genetics and HIV-specific IFN-gamma responses were evaluated in chronically HIV-1-infected adults.

Molecular evidence for polyphyletic origin of human immunodeficiency virus type 1 subtype C in Bangladesh.

HIV-1 positive blood samples were collected between 1999 and 2005 from population groups most at risk of HIV infection in Bangladesh through the national surveillance, from clients of the Voluntary Counseling and Testing (VCT) Unit for HIV at ICDDR,B and a survey of HIV in patients with tuberculosis. Partial sequences of the gag gene were used for subtyping the HIV strains by nested PCR using selective primers. Of the 198 HIV strains tested, subtype C (41.

Tat mutations in an African cohort that do not prevent transactivation but change its immunogenic properties.

Humoral responses against extra-cellular HIV-1 Tat may be beneficial as Tat has been implicated in the viral pathogenesis associated with HIV-1 disease progression. We determined the levels of anti-Tat IgG in sera of HIV-1 seropositive individuals from the Rural Clinical Cohort in Uganda using nine different Tat proteins representative of the major subtypes presently accounting for 97% of infections worldwide. We observed the presence of anti-Tat IgG able to react against the various subtypes tested, although none cross-reacted against all nine variants.

Relation between chemokine receptor use, disease stage, and HIV-1 subtypes A and D: results from a rural Ugandan cohort.

Objectives: To determine whether there are differences in coreceptor use in subjects infected with HIV-1 envelope subtypes A and D that could explain the differences in progression rates between these subtypes in a rural Ugandan cohort.

Methods: HIV-1 was subtyped in env by V3 sequencing or heteroduplex mobility assay. Coreceptor use was determined by the ability of the isolates to replicate in U87 CD4 cells expressing different coreceptors.

Genotypic variation in the pol gene of HIV type 1 in an antiretroviral treatment-naive population in rural southwestern Uganda.

The majority of studies of HIV-1 drug resistance have involved subtype B viruses. Here we have characterized subtype distribution and determined the levels of polymorphism at protease (PR) and reverse transcriptase (RT) drug resistance positions, in antiretroviral treatment-naive HIV-positive Ugandan patients. We have also investigated codon usage variability at these positions and assessed intersubtype recombination within the pol gene.

The relationship between HIV type 1 disease progression and V3 serotype in a rural Ugandan cohort.

Antigenic properties of the V3 region are reflected by HIV-1 serotypes. These may represent biological properties of the virus. We serotyped HIV-1 in 142 serum samples from participants in a rural Uganda cohort who seroconverted between August 1991 and December 2001.

The glutamine-rich region of the HIV-1 Tat protein is involved in T-cell apoptosis.

Human immunodeficiency virus (HIV) infection and the progression to AIDS are characterized by the depletion of CD4(+) T-cells. HIV-1 infection leads to apoptosis of uninfected bystander cells and the direct killing of HIV-infected cells. This is mediated, in part, by the HIV-1 Tat protein, which is secreted by virally infected cells and taken up by uninfected cells.

HIV type 1-specific inter- and intrasubtype cellular immune responses in HIV type 1-infected Ugandans.

Investigations concerning the extent and nature of subtype-specific and intersubtype immune responses in HIV-1-infected persons are necessary for the development of appropriate candidate vaccines. In the cross-sectional study described here, 26 HIV-1-positive Ugandan patients were tested for their ability to mount HIV antigen-specific cellular immune responses. Subjects were infected with either HIV-1 subtypes A, C, or D.

Full-length HIV-1 Tat protein necessary for a vaccine.

AIDS vaccines now use a truncated version of 86 residues of the Tat protein related to the HIV-1 HXB2 strain predominant in Europe and North America. We compared antibodies raised in rabbits using a B subtype short Tat HXB2(86) and a full-length Tat HXB2(100). Serum against HXB2(86) recognizes only B and D subtypes while serum against HXB2(100) recognizes B, D, and C subtype variants.

HIV-1 subtype dynamics over 10 years in a rural Ugandan cohort.

Our objective was to monitor changes in the subtypes of HIV-1 infecting a rural Ugandan cohort where the spread of HIV-1 is by unprotected heterosexual contact and subtypes A and D predominate. Should one subtype be better able to spread we would anticipate a rise in incidence of one subtype at the expense of the other over a decade of study. We employed a natural history cohort, which had been established by the Medical Research Council in 1990 and subtyped virus from 90% (139) incident cases by DNA sequencing in two separate genes.

HIV type 1 antigen-responsive CD4+ T-lymphocytes in exposed yet HIV Type 1 seronegative Ugandans.

CD4(+) T cell help is important for the functionality of CD8(+) cytotoxic T-lymphocytes (CTLs) in limiting viral replication and may contribute to mediation of apparent resistance to HIV-1 infection in exposed seronegative (ESN) individuals. Using five HIV-1 antigens in an intracellular cytokine assay, the presence of specific antigen-responsive interferon- gamma-positive (IFN-gamma(+)) CD69(+) CD4(+) T-lymphocytes was evaluated in ESNs, their seropositive partners, and unexposed seronegative controls. Ten ESNs (five females, five uncircumcised males) were identified from 10 HIV-1 serodiscordant couples with a history of frequent unprotected sexual intercourse.

Tat HIV-1 primary and tertiary structures critical to immune response against non-homologous variants.

Clinical studies show that in the absence of anti-retroviral therapy an immune response against the human immunodeficiency virus type 1 (HIV-1), transacting transcriptional activator (Tat) protein correlates with long term non-progression. The purpose of this study is to try to understand what can trigger an effective immune response against Tat. We used five Tat variants from HIV strains identified in different parts of the world and showed that mutations of as much as 38% exist without any change in activity.

Effect of human immunodeficiency virus (HIV) type 1 envelope subtypes A and D on disease progression in a large cohort of HIV-1-positive persons in Uganda.

The effect of human immunodeficiency virus (HIV) type 1 envelope subtypes A and D on disease progression was investigated in 1045 adults in Uganda. At enrollment and every 6 months, a clinical history, examination, and laboratory investigations that included CD4 cell counts were done. HIV-1 envelope subtype was assessed mainly by peptide serology supplemented by heteroduplex mobility assay and DNA sequencing.

Inter- and intra-genic intersubtype HIV-1 recombination in rural and semi-urban Uganda.

Objective: To investigate the number and variety of viruses with discrepant subtypes between env and gag and within gag in two cohorts in Uganda.

Methods: Sequences were generated from PCR products amplified directly (without cloning) from patient blood and compared in the v3/v4 region of env and the p17 and p24 regions of gag to reference subtype strains by phylogenetic analysis. Gag sequences with a discrepant subtype between p17 and p24 were analysed further to indicate approximate sites of recombination.