The emergence and evolution of the research fronts in HIV/AIDS research

In this paper, we have identified and analyzed the emergence, structure and dynamics of the paradigmatic research fronts that established the fundamentals of the biomedical knowledge on HIV/AIDS. A search of papers with the identifiers "HIV/AIDS", "Human Immunodeficiency Virus", "HIV-1" and "Acquired Immunodeficiency Syndrome" in the Web of Science (Thomson Reuters), was carried out. A citation network of those papers was constructed. Then, a sub-network of the papers with the highest number of inter-citations (with a minimal in-degree of 28) was selected to perform a combination of network clustering and text mining to identify the paradigmatic research fronts and analyze their dynamics. Thirteen research fronts were identified in this sub-network. The biggest and oldest front is related to the clinical knowledge on the disease in the patient. Nine of the fronts are related to the study of specific molecular structures and mechanisms and two of these fronts are related to the development of drugs. The rest of the fronts are related to the study of the disease at the cellular level. Interestingly, the emergence of these fronts occurred in successive "waves" over the time which suggest a transition in the paradigmatic focus. The emergence and evolution of the biomedical fronts in HIV/AIDS research is explained not just by the partition of the problem in elements and interactions leading to increasingly specialized communities, but also by changes in the technological context of this health problem and the dramatic changes in the epidemiological reality of HIV/AIDS that occurred between 1993 and 1995

La influenza A/H1N1 2009. Una crónica de la primera pandemia del siglo XXI

Tema del mesLa historia de la primera pandemia del siglo XXI inició, oficialmente, el 21 de abril de 2009 con una publicación que dio a conocer dos casos de infección respiratoria aguda ocasionados por un nuevo tipo de influenza A, el cual posteriormente fue identificado como un virus de origen porcino con dos genes de linaje euroasiático. A partir de entonces, se desencadenó una ola de sucesos que llevaron a suponer que dicho virus se había originado en La Gloria, una comunidad localizada en el valle de Perote, en Veracruz, México. No obstante, con el análisis en retrospectiva, ha sido posible recabar datos que sugieren que el nuevo virus se encontraba en circulación a nivel mundial desde varios meses antes de ser identificado y que la letalidad de la enfermedad –tan temida en un inicio–resultó ser selectiva (en general, sólo afecta a personas con enfermedades subyacentes) y tan pequeña como la de la influenza estacional. Estudios de diferentes países sostienen la teoría de que una proporción elevada de sus poblaciones fue infectada por el nuevo virus, desarrollando inmunidad contra la enfermedad, lo que proporciona una posible explicación para la disminución de casos que se ha venido dando en los últimos mesesThis century’s fist pandemic officially began on April 21st of last year with a publication about two cases of respiratory disease due to a new type of Influenza A virus, which was identified as a recombination of swine virus with a few Euroasiatic gens. Since then, an important amount of facts lead the experts o think that the virus was originated in La Gloria, a community in the state of Veracruz, Mexico. However, the analysis of further data suggest that the new virus had been all over the world for a few months before it was identified and that it’s lethality was smaller and safer than it appeared in the beginning of the pandemic. Studies form different countries stated that the new Influenza A had already infected a high portion of their population, creating collective immunity against it. This theory could explain the decrease in the number of cases over the last few month

The contribution of the sub-modules to the evolution of the research front 1.

<p>The contribution of the sub-modules to the evolution of the research front 1.</p

Main interactions among the research fronts.

<p>Each node represents one of the seven research fronts. The edges represent the sum of the inter-citations between two clusters. Only the interactions formed by a minimal of 500 inter-citations or the largest interaction (If the front have none interaction ≥ 500 inter-citations) of each front are shown.</p

Number of papers per year for each of the research fronts.

<p>A: Research fronts whose number of papers peaked between 1990 and 1991, B: peaked between 1996 and 1999 and C: peaked between 2004 and 2007.</p

Estimating the Impact of Earlier ART Initiation and Increased Testing Coverage on HIV Transmission among Men Who Have Sex with Men in Mexico using a Mathematical Model

<div><p>Objective</p><p>To estimate the impact of late ART initiation on HIV transmission among men who have sex with men (MSM) in Mexico.</p><p>Methods</p><p>An HIV transmission model was built to estimate the number of infections transmitted by HIV-infected men who have sex with men (MSM-HIV+) MSM-HIV+ in the short and long term. Sexual risk behavior data were estimated from a nationwide study of MSM. CD4⁺ counts at ART initiation from a representative national cohort were used to estimate time since infection. Number of MSM-HIV+ on treatment and suppressed were estimated from surveillance and government reports. Status quo scenario (SQ), and scenarios of early ART initiation and increased HIV testing were modeled.</p><p>Results</p><p>We estimated 14239 new HIV infections per year from MSM-HIV+ in Mexico. In SQ, MSM take an average 7.4 years since infection to initiate treatment with a median CD4⁺ count of 148 cells/mm³(25^th-75^th percentiles 52–266). In SQ, 68% of MSM-HIV+ are not aware of their HIV status and transmit 78% of new infections. Increasing the CD4⁺ count at ART initiation to 350 cells/mm³ shortened the time since infection to 2.8 years. Increasing HIV testing to cover 80% of undiagnosed MSM resulted in a reduction of 70% in new infections in 20 years. Initiating ART at 500 cells/mm³ and increasing HIV testing the reduction would be of 75% in 20 years.</p><p>Conclusion</p><p>A substantial number of new HIV infections in Mexico are transmitted by undiagnosed and untreated MSM-HIV+. An aggressive increase in HIV testing coverage and initiating ART at a CD4 count of 500 cells/mm³ in this population would significantly benefit individuals and decrease the number of new HIV infections in Mexico.</p></div

Estimation of number of infections transmitted in the first year of simulation by HIV awareness and treatment status in different scenarios modeled.

<p>Estimation of number of infections transmitted in the first year of simulation by HIV awareness and treatment status in different scenarios modeled.</p

Number of infections estimated for the first year of the simulated Status Quo scenario due to changes in the selected parameters.

<p>Number of infections estimated for the first year of the simulated Status Quo scenario due to changes in the selected parameters.</p

Number of accumulated infections and relative reductions compared to the Status Quo in each scenario simulated along time.

<p>N = number of acummulated infections. Percentage of reduction relative to Status Quo scenario.</p><p>Number of accumulated infections and relative reductions compared to the Status Quo in each scenario simulated along time.</p