scholarly journals External introductions helped drive and sustain the high incidence of HIV-1 in rural KwaZulu-Natal, South Africa

2017 ◽  
Author(s):  
David A. Rasmussen ◽  
Eduan Wilkinson ◽  
Alain Vandormael ◽  
Frank Tanser ◽  
Deenan Pillay ◽  
...  
Keyword(s):  
Antiretroviral Therapy ◽  
Local Community ◽  
Human Mobility ◽  
Population Based ◽  
Subtype C ◽  
Epidemic Dynamics ◽  
Relative Contribution ◽  
Kwazulu Natal ◽  
High Incidence ◽  
Hiv 1

AbstractDespite increasing access to antiretroviral therapy, HIV incidence in rural KwaZulu-Natal communities remains among the highest ever reported in Africa. While many epidemiological factors have been invoked to explain this high incidence, widespread human mobility and movement of viral lineages between geographic locations have implicated high rates of transmission across communities. High rates of crosscommunity transmission call into question how effective increasing local coverage of antiretroviral therapy will be at preventing new infections, especially if many new cases arise from external introductions. To help address this question, we use a new phylodynamic modeling approach to estimate both changes in epidemic dynamics through time and the relative contribution of local transmission versus external introductions to overall incidence from HIV-1 subtype C phylogenies. Our phylodynamic estimates of HIV prevalence and incidence are remarkably consistent with population-based surveillance data. Our analysis also reveals that early epidemic dynamics in this population were largely driven by a wave of external introductions. More recently, we estimate that anywhere between 20-60% of all new infections arise from external introductions from outside the local community. These results highlight the power of using phylodynamic methods to study generalized HIV epidemics and the growing need to consider larger-scale regional transmission dynamics above the level of local communities when designing and testing prevention strategies.

scholarly journals Factors Associated with Recent Increase of Multiple Births in Spain

2008 ◽  
Vol 11 (1) ◽  
pp. 70-76 ◽  
Author(s):  
Vicente Fuster ◽  
Pilar Zuluaga ◽  
Sonia Colantonio ◽  
Clemente de Blas
Keyword(s):  
Older Women ◽  
Maternal Age ◽  
Reference Group ◽  
Population Based ◽  
Factors Associated ◽  
Relative Contribution ◽  
High Incidence ◽  
Spanish Women ◽  
Opposite Sex ◽  
Mother’S Age

AbstractThe increased incidence of multiple deliveries in Spain, in addition to changes in age at maternity and parity, is attributed to assisted reproductive treatments, but the relative contribution of the latter to this rise remains uncertain, due to the scarce information provided by clinics practicing those treatments. Population based data (1984–2004), including information on mother's age, nationality, marital status, date of delivery, and the characteristics of each (parity, single or multiple), and sex of newborns were provided by the Spanish Institute of Statistics. Twinning and triplet deliveries relate to maternal age, parity, and nationality. For younger ages (≤ 19, 20–24, 25–29) rates remained constant over time, but for older women (30–34, 35–39, ≥ 40) rates increased after 1994. From 1984 to 2004 the percentage of twins of opposite sex increased from 24.31 to 36.58 per cent. Since 1997, Spanish and non-Spanish mothers differentiate with respect to multiple maternity at ages over 30. In addition to unmarried Spanish women, immigrants constitute a reliable reference group that determines the convenience of segregating information on multiple deliveries respecting origin. The proportion of twins and triplets of opposite sex, maternal age, and parity patterns observed are concordant with a differential access to reproductive treatments depending on the woman's age. The present norm regulating the maximum number of fertilizations per cycle and the demand for these treatments explain the high incidence of multiple deliveries in Spain. A modified logistic curve predicts a stabilization of multiple deliveries, which will probably continue to be high in Spain.

scholarly journals Frequency and Env determinants of HIV-1 subtype C strains from antiretroviral therapy-naive subjects that display incomplete inhibition by maraviroc

Retrovirology ◽  
2016 ◽  
Vol 13 (1) ◽  
Author(s):  
Katharina Borm ◽  
Martin R. Jakobsen ◽  
Kieran Cashin ◽  
Jacqueline K. Flynn ◽  
Paula Ellenberg ◽  
...  
Keyword(s):  
Antiretroviral Therapy ◽  
Subtype C ◽  
Hiv 1

scholarly journals Detection of minority drug resistant mutations in Malawian HIV-1 subtype C-positive patients initiating and on first-line antiretroviral therapy

2018 ◽  
Vol 7 (1) ◽  
Author(s):  
Zhiyong Zhou ◽  
Kevin Tang ◽  
Guoqing Zhang ◽  
Nellie Wadonda-Kabondo ◽  
Kundai Moyo ◽  
...  
Keyword(s):  
Antiretroviral Therapy ◽  
Drug Resistant ◽  
Subtype C ◽  
First Line ◽  
Hiv 1

scholarly journals Virological failure in patients with HIV-1 subtype C receiving antiretroviral therapy: an analysis of a prospective national cohort in Sweden

2016 ◽  
Vol 3 (4) ◽  
pp. e166-e174 ◽  
Author(s):  
Amanda Häggblom ◽  
Veronica Svedhem ◽  
Kamalendra Singh ◽  
Anders Sönnerborg ◽  
Ujjwal Neogi
Keyword(s):  
Antiretroviral Therapy ◽  
Virological Failure ◽  
Subtype C ◽  
National Cohort ◽  
Hiv 1

scholarly journals High level of HIV-2 false positivity in KwaZulu-Natal province: A region of South Africa with a very high HIV-1 subtype C prevalence

2013 ◽  
Vol 85 (12) ◽  
pp. 2065-2071 ◽  
Author(s):  
Lavanya Singh ◽  
Raveen Parboosing ◽  
Justen Manasa ◽  
Pravi Moodley ◽  
Tulio de Oliveira
Keyword(s):  
South Africa ◽  
Subtype C ◽  
False Positivity ◽  
Kwazulu Natal ◽  
High Level ◽  
Very High ◽  
Hiv 1

scholarly journals Heightened resistance to host type 1 interferons characterizes HIV-1 at transmission and after antiretroviral therapy interruption

2021 ◽  
Vol 13 (576) ◽  
pp. eabd8179
Author(s):  
Marcos V. P. Gondim ◽  
Scott Sherrill-Mix ◽  
Frederic Bibollet-Ruche ◽  
Ronnie M. Russell ◽  
Stephanie Trimboli ◽  
...  
Keyword(s):  
Antiretroviral Therapy ◽  
Acute Infection ◽  
Cell Loss ◽  
Treatment Interruption ◽  
Analytical Treatment ◽  
Relative Contribution ◽  
Hiv 1 ◽  
Type 1 Interferons

Type 1 interferons (IFN-I) are potent innate antiviral effectors that constrain HIV-1 transmission. However, harnessing these cytokines for HIV-1 cure strategies has been hampered by an incomplete understanding of their antiviral activities at later stages of infection. Here, we characterized the IFN-I sensitivity of 500 clonally derived HIV-1 isolates from the plasma and CD4+ T cells of 26 individuals sampled longitudinally after transmission or after antiretroviral therapy (ART) and analytical treatment interruption. We determined the concentration of IFNα2 and IFNβ that reduced viral replication in vitro by 50% (IC50) and found consistent changes in the sensitivity of HIV-1 to IFN-I inhibition both across individuals and over time. Resistance of HIV-1 isolates to IFN-I was uniformly high during acute infection, decreased in all individuals in the first year after infection, was reacquired concomitant with CD4+ T cell loss, and remained elevated in individuals with accelerated disease. HIV-1 isolates obtained by viral outgrowth during suppressive ART were relatively IFN-I sensitive, resembling viruses circulating just before ART initiation. However, viruses that rebounded after treatment interruption displayed the highest degree of IFNα2 and IFNβ resistance observed at any time during the infection course. These findings indicate a dynamic interplay between host innate responses and the evolving HIV-1 quasispecies, with the relative contribution of IFN-I to HIV-1 control affected by both ART and analytical treatment interruption. Although elevated at transmission, host innate pressures are the highest during viral rebound, limiting the viruses that successfully become reactivated from latency to those that are IFN-I resistant.

scholarly journals Increasing HIV-1 Drug Resistance Between 2010 and 2012 in Adults Participating in Population-Based HIV Surveillance in Rural KwaZulu-Natal, South Africa

2016 ◽  
Vol 32 (8) ◽  
pp. 763-769 ◽  
Author(s):  
Justen Manasa ◽  
Siva Danaviah ◽  
Richard Lessells ◽  
Muna Elshareef ◽  
Frank Tanser ◽  
...  
Keyword(s):  
South Africa ◽  
Drug Resistance ◽  
Population Based ◽  
Hiv Surveillance ◽  
Kwazulu Natal ◽  
Hiv 1
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