miércoles, 5 de enero de 2011

Molecular Epidemiology of HIV Type 1 in Ecuador, Peru, Bolivia, Uruguay, and Argentina.

AIDS Res Hum Retroviruses. 2002 Dec 10;18(18):1339-50.

 

U.S. Military HIV Research Program, Henry M. Jackson Foundation, Rockville, Maryland 20850, USA.

Abstract

Surveillance for HIV infection among people at increased risk was conducted in five countries in South America. Seroprevalence studies were conducted in more than 36,000 people in Ecuador, Peru, Boliva, Uruguay, and Argentina, along with genetic analysis of the HIV-1 strains. In all countries, the prevalence of HIV-1 among men who have sex with men (MSM) was high (3-30%), whereas the prevalence among female commercial sex workers (FCSMs) was low (0.3-6%). By envelope heteroduplex mobility assay, subtype B predominated in MSM communities and in FCSWs in Ecuador, Bolivia, and Peru. A new genetic screening assay, the multiregion hybridization assay for subtypes B and F (MHA-bf), was developed to improve large-scale genetic screening in South America. MHA-bf can screen four regions of the genome for subtype B or subtype F, and thus can detect most recombinants. The sensitivity of MHA-bf when applied to a panel of pure subtypes and CRF12_BF was 100%, and 88% of unique recombinants were also detected as recombinant. Using MHA-bf, more than 80% of samples from Ecuador, Peru, and Bolivia were classified as pure subtype B, whereas in Uruguay and Argentina this proportion was only 30 to 40%. BF recombinants were the most prevalent form of HIV-1 in Uruguay and Argentina. Subtype B is the most common subtype in countries lacking injecting drug use (IDU) epidemics, whereas BF recombinants are more common in countries where extensive IDU epidemics have been documented, suggesting the ontogeny of recombinant strains in particular risk groups in South America.
PMID: 12487805 [PubMed - indexed for MEDLINE]

http://www.ncbi.nlm.nih.gov/pubmed/12487805


Dr. Carlos Erazo


Seroprevalence of and risk factors for HIV-1 infection among South American men who have sex with men.

Sex Transm Infect. 2004 Dec;80(6):498-504.

US Military HIV Research Program and Henry M Jackson Foundation, 1 Taft Court, Suite 250, Rockville, MD 20850, USA. cbautista@hivresearch.org

Abstract

"OBJECTIVES: Sex among men constitutes an important route of transmission for HIV type 1 (HIV-1) in Latin America. Seeking better understanding of risk behaviours in this region, we determined the seroprevalence, potential risk factors, and geographic distribution of HIV-1 among groups of men who have sex with men (MSM).
METHODS: Seroepidemiological, cross sectional studies of 13,847 MSM were conducted in seven countries of South America during the years 1999-2002. Volunteers were recruited in city venues and streets where anonymous questionnaires and blood samples were obtained. HIV-1 infection was determined by enzyme linked immunosorbent assay (ELISA) screening and western blot (WB) confirmatory tests.
RESULTS: HIV-1 seroprevalence varied widely (overall 12.3%, range 11.0%-20.6%). The highest HIV-1 seroprevalence was noted in Bolivia (20.6%) and the lowest in Peru (11.0%). Predictors of HIV-1 infection varied among countries; however, a history of previous sexually transmitted disease (STD) was associated with a consistent increased risk (ORs=1.9-2.9, AORs=1.8-2.7). Multiple weekly sexual contacts was found to represent a secondary risk factor in Ecuador, Peru, and Argentina (ORs=1.6-2.9, AORs=1.6-3.1), whereas use of drugs such as cocaine was found to increase risk in Bolivia, Uruguay, and Paraguay (ORs=2.5-6.5, AORs=2.6-6.1).
CONCLUSION: The results of this study illustrate an elevated HIV-1 seroprevalence among MSM participants from Andean countries. A previous STD history and multiple partners predicted HIV-1 infection in the seven countries of South America. In Southern Cone countries, HIV-1 infection was also associated with use of illegal drugs such as cocaine".

Para más información sobre este asrtículo entrar en el siguiente link:  http://www.ncbi.nlm.nih.gov/pubmed/15572623



Dr. Carlos Erazo

Improving the safety of the blood supply in Ecuador through external performance evaluation of serological screening of blood donors.

Este artículo, esta copiado del Pubmed, y tiene acceso a el total del mismo de forma libre, pueden acceder por medio del link colocado al final de este y entrar por el PUBMED al artículo completo.

J Clin Virol. 2005 Dec;34 Suppl 2:S47-52.

Infectious Disease Research Laboratory, School of Biological Sciences, Catholic University, Quito, Ecuador. grijalva@ohio.edu

Abstract

BACKGROUND: The Ecuadorian National Blood System collects approximately 100 000 units of blood per year. Screening for infectious agents is conducted by 23 autonomous blood services using different methodologies and reagents.
OBJECTIVES: To evaluate the performance of serology testing by laboratories of the Ecuadorian National Blood Bank System.
STUDY DESIGN: Four proficiency panels were distributed between April 2003 and December 2004 containing samples that were characterized as either reactive or non-reactive for hepatitis B surface antigen (HBsAg), antibodies against hepatitis C virus (HCV), and antibodies against human immunodeficiency virus (HIV). Laboratories were classified according to the volume of blood units processed per year, as small (<5000), medium (5000-12000) and large (>12000).
RESULTS: Large and medium blood services consistently obtained better results than small ones. All of the 37 anti-HIV antibody false negative results and all of the 20 HBsAg false negative results were reported by small laboratories. False negative results were associated with the use of rapid tests. Laboratories using rapid tests and certain lots of an enzyme-linked immunosorbent assay (ELISA) failed to detect HCV reactive sera in December 2004.
CONCLUSION: The high number of incorrect results in most small blood services indicates serious weaknesses in blood screening that require urgent corrective action. The National Blood System has implemented on-site audits, training, technical assistance, and increased oversight. The long-term proposal is to centralize blood testing in two large blood centers. The results presented here underline the importance of strengthening the regulatory framework and oversight in Ecuador and highlight the role of external performance evaluation programs for blood safety improvement.
PMID: 16461240 [PubMed - indexed for MEDLINE]

http://www.ncbi.nlm.nih.gov/pubmed/16461240
Dr. Carlos Erazo

CCR5delta32, CCR2-64I, and SDF1-3'A polymorphisms related to resistance to HIV-1 infection and disease in the Ecuadorian population.

Este artículo no tiene acceso al texto libre, pero les coloco aquí para que ustedes sepan que existe esta investigación y para quienes quieran adquirirlo esta aquí la copia completa revisada en el PUBMED. 

Hum Biol. 2005 Aug;77(4):521-6.

Laboratorio de Genética Molecular y Citogenética Humana, Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Quito, Ecuador.

Abstract

The aim of this study was to determine the allele frequencies of genetic variants CCR5delta32, CCR2-64I, and SDF1-3'A (SDF1 801 A), which influence susceptibility to HIV-1 infection. We also investigated the effect of these variants on the general Ecuadoran population and on a group of HIV-infected individuals to determine the frequency of these genetics variants.
PMID: 16485782 [PubMed - indexed for MEDLINE]


Dr. Carlos Erazo

Inconsistent condom use among sexual workers in Ecuador: results from a behavior survey

"OBJECTIVE: Whilst existing data suggests that the HIV epidemic in Ecuador is concentrated amongst men who have sex with men (MSM), there is very little available information on the situation of key populations, i.e. those most at risk of HIV infection and/or transmitting the infection. In particular, there is very little known about sex workers (SWs), their rate of condom use and other behaviors and characteristics with respect to the risk of acquiring sexually transmitted infections (STIs). This study presents findings from a survey carried out with SWs in eight cities in Ecuador.
MATERIAL AND METHODS: Using a cross-sectional design, a questionnaire focusing on behaviours, attitudes and socio-economic and demographic characteristics was administered to SWs in eight cities in Ecuador. These eight cities together account for the majority of the population in the country, and they were also identified as the locations with high reported levels of HIV.
RESULTS: Information from a total of 2867 SWs was obtained, the majority were captured in their workplaces. Most of SWs interviewed carry out their activities in closed settings dedicated to sex work (i.e. not in the street). The average age of respondents was 28 (95%CI 27-29), and around half of them live with a male partner (married or not). The rate of condom use with the last client was 88% (82% consistently with the last three), whilst with regular partners it was 6%. A high index of life-skills, high socio-economic status and having an official document that allows them to work, were positively associated with condom use with clients (PR [CI95%] 1.40 [1.40-1.40], 1.37 [1.36-1.37], y 7.26 [6.87-7.46], respectively).
CONCLUSIONS: Whilst condom use with clients amongst Ecuadorian SWs is high, this diminishes if one analyzes consistent condom use and is notably low with respect to regular partners. Condom use appears to be related to variables that can be linked to interventions, e.g. life-skills and official permission to carry out sex work. It is, therefore, important to tailor interventions for this population so they maximize the likelihood to increase consistent condom use."

Salud Publica Mex. 2006 Mar-Apr;48(2):104-12.

http://www.ncbi.nlm.nih.gov/pubmed/16619867


Dr. Carlos Erazo

Correlates of condom use in a sample of MSM in Ecuador.

Gutiérrez JP, Molina-Yepez D, Morrison K, Samuels F, Bertozzi SM.


"BACKGROUND: In Ecuador, the prevalence of HIV in the general population is approximately 0.3%. However, up to 17% prevalence has been reported among specific groups of homosexual and bisexual men. The objective of this study is to explore correlates of condom use among men who have sex with men (MSM) across eight cities in Ecuador.
METHODS: A cross-sectional survey design was used. A questionnaire including variables on sexual behaviour, demographics, and socio-economic characteristics was distributed to a sample of MSM in eight Ecuadorian cities.
RESULTS: Information was obtained for 2,594 MSM across the eight cities. The largest subcategory of self-identification was active bisexuals (35%), followed by those who described themselves as "hombrados" (masculine gays, 22%). The mean age was 25 years, and the majority were unmarried (78%), with a median of 10 years of schooling (IQR 7 - 12). Regarding condom use, 55% of those interviewed had unprotected penetrative sex with each of their last three partners, and almost 25% had never used a condom. The most important correlates of condom use were single status, high life-skills rating, and high socio-economic status (RP 5.45, 95% CI 4.26 - 6.37; RP 1.84, 95% CI 1.79 - 1.86, and RP 1.20, 95% CI 1.01 - 1.31, respectively).
CONCLUSION: Our data illustrate the urgent need for targeted HIV-prevention programs for MSM populations in Ecuador. MSM have the highest HIV prevalence in the country, and condom use is extremely low. It is imperative that prevention strategies be re-evaluated and re-prioritized to more effectively respond to the Ecuadorian epidemic."

BMC Public Health. 2006 Jun 12;6:152.

http://www.ncbi.nlm.nih.gov/pubmed/16768794


Dr. Carlos Erazo

Low educational level: a risk factor for sexually transmitted infections among commercial sex workers in Quito, Ecuador.

"Few studies have assessed the effect of educational level on sexually transmitted infections (STIs) and risk-taking behaviours among commercial sex workers (CSWs). This study analysed this association among female CSWs in Quito, Ecuador. Eighty-five CSWs were given a Spanish-language questionnaire on behaviours, socioeconomics and demographics. The correlation between years of education and number of prior STIs was calculated. Three groups of varying education level were formed and risk factors were analysed by Chi-square tests and analysis of variances. Lower educational level was associated with more STIs (r= -0.36; F=4.2; P=0.04), poorer knowledge of HIV/AIDS (P=0.03), earlier first prostitution (P=0.05) and first sex (P=0.00), willingness to engage in group sex (P=0.05) and work on the street (P=0.02), and presence of non-paying sexual partners (P=0.05). CSWs with lower educational levels were disproportionately afflicted with STIs and participated in more high-risk behaviours. Low educational level may predispose CSWs to STIs and associated risk factors."

Int J STD AIDS. 2008 Apr;19(4):264-7.

http://www.ncbi.nlm.nih.gov/pubmed/18482947


Dr. Carlos Erazo

Preventing mother-to-child transmission in Guayaquil, Ecuador: HIV knowledge and risk perception.

"An important step in preventing mother-to-child transmission is testing pregnant women for HIV. Health literacy measures, such as HIV knowledge and risk perception, may determine which women are tested in prenatal clinics where routine opt-out testing is not available. A survey was conducted in Guayaquil, Ecuador in 2006 (n=485), where approximately 0.7% of HIV tests in prenatal clinics were positive. Pregnant women over the age of 18 were invited to complete the survey in the waiting rooms at four city hospitals. There were 67.2% of women reported being tested previously for HIV. The most notable finding was that women who perceived a risk were 1.74 times more likely to request testing (p=0.021), but a woman's risk perception was not related to established risk factors. In addition, a physician's recommendation would result in the testing of nearly all women (94.3%). This data suggest that interventions in prenatal care clinics should incorporate educational strategies to increase accurate perception of personal risk. These efforts must occur in conjunction with increasing the access to HIV tests to achieve the goal of universal prenatal testing.""


Glob Public Health. 2010 Nov;5(6):649-62.

http://www.ncbi.nlm.nih.gov/pubmed/19960396

Dr. Carlos Erazo

Conocimientos elementales sobre educación sexual en alumnos de una escuela secundaria básica urbana

 
 "La iniciación de las relaciones sexuales es cada vez más temprana en los jóvenes.Entre otras razones, esto se debe a cambios en la actitud social hacia la sexualidad y a una maduración sexual más temprana. La precocidad en las relaciones sexualesno ocurre paralelamente con una adecuada educación sexual que brinde al adolescente la información sobre las consecuencias de tal acto, para el cual no está preparado; los profesionales de la atención primaria de salud deben conocer la situación existente en su área para actuar convenientemente. Identificar el nivel de conocimientos elementales sobre educación sexual en adolescentes de la Escuela Secundaria Básica Urbana (ESBU). ubicada en nuestra área de salud. Se realizó una investigación descriptiva, transversal, en la ESBU "XI Festival de la Juventud y los Estudiantes" del Reparto Alamar, Municipio Habana del Este, ubicada en el área de salud atendida por nuestro policlínico 13 de marzo. El universo estuvo constituidopor 200 estudiantes. Se incluyeron todos los estudiantes de noveno grado, quienes voluntariamente desearon participar; no hubo criterios de exclusión. Se aplicó una encuesta para conocer: edad de comienzo de relaciones sexuales y conocimientos sobre riesgo del embarazo en la adolescencia, infecciones de transmisión sexual (ITS), métodos anticonceptivos, uso de anticonceptivos en la primera relación y vías de información sobre educación sexual. La información fue almacenada en una base de datos EPIINFO; los datos se organizaron en tablas y para su análisis se utilizó el método porcentual. Cerca de 60% de los encuestados habían tenido relaciones sexuales. Entre las ITS más conocidas se encontraron el VIH/SIDA, gonorrea y sífilis. A pesar de conocer de la existencia de métodos para la anticoncepción, 70% de los 114 jóvenes, quienes manifestaron haber tenido relaciones sexuales, acudieron a este primer evento sin ninguna protección. Las fuentes de mayor información sobre educación sexual fueron de manera general, TV, maestros y padres. Los varones recibieron información mayormente de TV (58.3%), padres (48.5%) y la radio (34.9%), mientras que las féminas la obtuvieron de maestros (54.6%), TV (44.3%) y médico y enfermera de la familia (39.2%). En estos jóvenes, los conocimientos elementales sobre educación sexual son aún insuficientes y la familia debe tener un mayor papel protagónico para ambos sexos,
pues mucha información proviene de otras fuentes."


Link para poder acceder al artículo:  http://scielo.sld.cu/pdf/rhcm/v9n4/rhcm18410.pdf

Dr. Carlos Erazo

Neurological Complications of HIV Disease

Buenos días, aquí les dejo otro artículo interesante.


"Mild neurological impairment remains common in HIV-infected patients.

Before the advent of potent combination antiretroviral therapy (ART), neurological disease, including HIV-associated dementia (HAD), was common in HIV-infected individuals. How prevalent is such disease in the current HIV treatment era? Baseline data from the NIH-supported CHARTER study provide some insight.
A total of 1555 HIV-infected patients at six U.S. academic centers underwent extensive neurocognitive testing and psychiatric evaluation; 71% were receiving combination ART. Patients were categorized according to whether they had comorbidities that could cause neurocognitive impairment: 15% had confounding comorbidities severe enough to preclude diagnosing HIV-associated neurological disease, 30% had potentially contributing comorbidities, and 54% had other or no comorbidities.
Overall, 814 patients (52%) had neurocognitive impairment — 83% of those with confounding comorbidities, 59% of those with contributing comorbidities, and 40% of those with other or no comorbidities. In the latter two groups, 33% of patients had neurocognitive impairment that did not influence their everyday functioning, 12% had mild neurocognitive impairment, and 2% had HAD.
HIV-associated factors were associated with neurocognitive impairment only in the group with the least comorbidity. In that group, neurocognitive impairment was associated with both an AIDS diagnosis and a lower nadir CD4-cell count. Patients on ART had a higher prevalence of neurocognitive disease than those not on ART. However, the lowest rate among patients on ART was in those with both a nadir CD4 count ≥200 cells/mm3 and an undetectable viral load.
Comment: This study documents a continued high prevalence of neurocognitive impairment in the HIV-infected population. Some of the impairment is likely attributable to the infection itself and some to common comorbidities. Longitudinal data from this study should help to define the effect of ART on neurological conditions."



Link para mayor informafción para el tema: http://infectious-diseases.jwatch.org/cgi/content/full/2010/1215/2?q=etoc_jwneuro

Dr. Carlos Erazo

Hormone Therapy and Dementia Risk: A Critical Window?

 Este artículo es interesante en cuanto al uso de Terapia Hormonal y la demencia. 





"A prospective cohort study reveals a decreased risk for dementia in women taking HT in midlife but an increased risk for those taking HT in later life. 


Several observational studies have demonstrated a reduced risk for dementia in women who use hormone therapy (HT). However, well-designed interventional trials of estrogen–progesterone combinations have revealed an increased risk for dementia, cancer, and vascular events associated with HT use. This prospective cohort study was designed to further investigate the critical window theory that estrogen is beneficial only immediately before and immediately after menopause and may have deleterious effects in later life. More than 5000 women without dementia at baseline had been screened between ages 40 and 55 and reported whether they used HT (i.e., midlife use). Thirty years later, the authors identified participants' HT use (i.e., later-life use) from pharmacy databases. Starting when the cohort reached a median age of 80, the authors identified dementia from ICD-9 coding of diagnoses by neurologists, neuropsychologists, and internists; dementia assessment lasted 7.5 years.
During dementia assessment, 27% of the cohort received a diagnosis of dementia. Women who reported taking HT at midlife but had no evidence of later-life HT use had a significantly decreased risk for dementia diagnosis (adjusted hazard ratio, 0.74). In contrast, those who did not report midlife HT use but had evidence of later-life use had a significant increase in risk (AHR, 1.48). Women who had used HT in both midlife and later life had similar risks to those of women who had no evidence of HT use.
Comment: This study is potentially confounded by self-report data in its early phase and by the limitations inherent in the accuracy of pharmacy records and diagnostic coding in its later phase. Nonetheless, the findings unify data from observational and interventional studies of women using hormone therapy. Moreover, the findings are consistent with animal modeling of a critical window of estrogen-related neuroprotection, which is reportedly associated with improved cerebral blood flow and glucose use and with reduced amyloid deposition in the brain. The bottom line clinically is that HT use around menopause may help protect against dementia, but later use may increase risk."

Link para leer más sobre este tema:  http://neurology.jwatch.org/cgi/content/full/2011/104/1?q=etoc_jwneuro

Saludos

Dr. Carlos Erazo