RESUMEN
In 2011 the Incidence Assay Critical Path Working Group reviewed the current state of HIV incidence assays and helped to determine a critical path to the introduction of an HIV incidence assay. At that time the Consortium for Evaluation and Performance of HIV Incidence Assays (CEPHIA) was formed to spur progress and raise standards among assay developers, scientists and laboratories involved in HIV incidence measurement and to structure and conduct a direct independent comparative evaluation of the performance of 10 existing HIV incidence assays, to be considered singly and in combinations as recent infection test algorithms. In this paper we report on a new framework for HIV incidence assay evaluation that has emerged from this effort over the past 5 years, which includes a preliminary target product profile for an incidence assay, a consensus around key performance metrics along with analytical tools and deployment of a standardized approach for incidence assay evaluation. The specimen panels for this evaluation have been collected in large volumes, characterized using a novel approach for infection dating rules and assembled into panels designed to assess the impact of important sources of measurement error with incidence assays such as viral subtype, elite host control of viraemia and antiretroviral treatment. We present the specific rationale for several of these innovations, and discuss important resources for assay developers and researchers that have recently become available. Finally, we summarize the key remaining steps on the path to development and implementation of reliable assays for monitoring HIV incidence at a population level.
Asunto(s)
Métodos Epidemiológicos , Infecciones por VIH/epidemiología , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , Recursos en Salud , Humanos , IncidenciaRESUMEN
OBJECTIVE: To examine the quality of HIV sero-surveillance systems in 127 low-income and middle-income countries by 2007, as well as gaps in data needed for reliable estimates of HIV prevalence and size of populations at risk for infection. METHODS: The quality of countries' surveillance systems was scored using information from 2001 through 2007. Sero-surveillance data were compiled from the US Census Bureau's HIV/AIDS Surveillance Database, from countries' national HIV surveillance reports available to UNAIDS, from demographic and health survey (DHS) data, from the scientific literature and from countries' Estimation and Projection Programme (EPP) data files. The quality of systems was scored according to the classification of the epidemic in each country (generalised, concentrated or low-level). RESULT: The number of countries categorised as fully functioning in 2007 was 40. 43 countries were identified as partially functioning while 44 were categorised as poorly functioning. Low scores were most often attributed to a lack of recent data or data from appropriate risk groups. CONCLUSION: Many countries still have poorly functioning surveillance systems. The inclusion of HIV testing in national population-based surveys in recent years has resulted in some countries with generalised epidemics receiving higher coverage scores, but many countries with concentrated or low-level epidemics continue to lack data on high-risk populations.
Asunto(s)
Brotes de Enfermedades/estadística & datos numéricos , Infecciones por VIH/epidemiología , Seroprevalencia de VIH/tendencias , Adolescente , Adulto , Recolección de Datos/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Vigilancia de Guardia , Factores SocioeconómicosRESUMEN
OBJECTIVE: This paper describes improvements and updates to an established approach to making epidemiological estimates of HIV prevalence in countries with low level and concentrated epidemics. METHODS: The structure of the software used to make estimates is briefly described, with particular attention to changes and improvements. DISCUSSION: The approach focuses on identifying populations which, through their behaviour, are at high risk of infection with HIV or who are exposed through the risk behaviour of their sexual partners. Estimates of size and HIV prevalence of these populations allow the total number of HIV infected people in a country or region to be estimated. Major changes in the software focus on the move away from short term projections and towards developing an epidemiological curve that more accurately represents the change in prevalence of HIV over time. The software continues to provide an output file for use in the Spectrum software so as to estimate the demographic impact of HIV infection at country level.
Asunto(s)
Brotes de Enfermedades/estadística & datos numéricos , Infecciones por VIH/epidemiología , Programas Informáticos/normas , Adulto , Recolección de Datos/métodos , Recolección de Datos/normas , Homosexualidad Masculina/estadística & datos numéricos , Humanos , Modelos Logísticos , Masculino , Prevalencia , Medición de Riesgo/métodos , Parejas SexualesRESUMEN
BACKGROUND: Sentinel surveillance among pregnant women attending antenatal clinics (ANCs) has been the main source of information on HIV trends in sub-Saharan Africa. These data have also been used to generate national HIV and AIDS estimates. New technologies and resources have allowed many countries to conduct national population based surveys that include HIV prevalence measurement, as an additional source of information on the AIDS epidemic. METHODS: The authors reviewed the reports of 20 national population based surveys from 19 countries carried out in sub-Saharan Africa since 2001. They examined the sampling methodology, HIV testing and response rates, and female:male and urban:rural prevalence ratios. They also constructed adjusted prevalence scenarios assuming different relative risks for survey non-responders. RESULTS: The national population based surveys vary considerably in quality, as reflected in the household response rate (ranging from 75.4% to 99.7%), women's testing rate (ranging from 68.2% to 97.3%), and men's testing rate (ranging from 62.2% to 95.4%), while for some surveys detailed response information is lacking. While 95% confidence intervals around the female:male and urban:rural prevalence ratios in individual countries are large, the median female:male ratio of the combined set of surveys results is 1.5 and the median urban:rural ratio 1.7. A scenario assuming that non-responders have twice the HIV prevalence of those who fully participated in the survey suggests that individual non-response could result in an adjusted HIV prevalence 1.03 to 1.34 times higher than the observed prevalence. CONCLUSIONS: Population based surveys can provide useful information on HIV prevalence levels and distribution. This information is being used to improve national HIV and AIDS estimates. Further refinements in data collection, analysis, and reporting, combined with high participation rates, can further improve HIV and AIDS estimates at national and regional level.
Asunto(s)
Infecciones por VIH/epidemiología , Adolescente , Adulto , África del Sur del Sahara , Anciano , Femenino , Encuestas Epidemiológicas , Humanos , Masculino , Persona de Mediana Edad , Vigilancia de la Población , Prevalencia , Salud Rural , Distribución por Sexo , Salud UrbanaRESUMEN
OBJECTIVE: To determine whether observed changes in HIV prevalence in countries with generalised HIV epidemics are associated with changes in sexual risk behaviour. METHODS: A mathematical model was developed to explore the relation between prevalence recorded at antenatal clinics (ANCs) and the pattern of incidence of infection throughout the population. To create a null model a range of assumptions about sexual behaviour, natural history of infection, and sampling biases in ANC populations were explored to determine which factors maximised declines in prevalence in the absence of behaviour change. Modelled prevalence, where possible based on locally collected behavioural data, was compared with the observed prevalence data in urban Haiti, urban Kenya, urban Cote d'Ivoire, Malawi, Zimbabwe, Rwanda, Uganda, and urban Ethiopia. RESULTS: Recent downturns in prevalence observed in urban Kenya, Zimbabwe, and urban Haiti, like Uganda before them, could only be replicated in the model through reductions in risk associated with changes in behaviour. In contrast, prevalence trends in urban Cote d'Ivoire, Malawi, urban Ethiopia, and Rwanda show no signs of changed sexual behaviour. CONCLUSIONS: Changes in patterns of HIV prevalence in urban Kenya, Zimbabwe, and urban Haiti are quite recent and caution is required because of doubts over the accuracy and representativeness of these estimates. Nonetheless, the observed changes are consistent with behaviour change and not the natural course of the HIV epidemic.
Asunto(s)
Brotes de Enfermedades/estadística & datos numéricos , Infecciones por VIH/epidemiología , Conducta Sexual/psicología , Adolescente , Adulto , Femenino , Infecciones por VIH/psicología , Haití/epidemiología , Heterosexualidad , Humanos , Kenia/epidemiología , Masculino , Prevalencia , Conducta de Reducción del Riesgo , Distribución por Sexo , Conducta Sexual/estadística & datos numéricos , Uganda/epidemiología , Salud Urbana , Zimbabwe/epidemiologíaRESUMEN
BACKGROUND: Second generation surveillance for HIV aims to improve the validity and utility of routine serial HIV prevalence data. It includes the collection of data on sexual behaviour and sexually transmitted disease prevalence. METHODS: This paper reviews the function of sexual behaviour data in HIV surveillance and the methods used to determine which behaviours are monitored and how changes in behaviour can be assessed. RESULTS: Sexual behaviour data provide a poor predictor of the future spread of HIV, but these data can provide corroboration of changes in HIV incidence and assist in attributing changes to particular aspects of risk. Significance tests should be used to assess changes in behaviour, but this requires transparent reporting of methods and sample sizes. CONCLUSIONS: Collection of behavioural data will provide important retrospective information about the HIV epidemic progress and should not be neglected because of the focus on improving HIV sero-surveillance.
Asunto(s)
Infecciones por VIH/epidemiología , Conducta Sexual/estadística & datos numéricos , Adolescente , Adulto , Métodos Epidemiológicos , Femenino , Infecciones por VIH/psicología , Humanos , Incidencia , Masculino , Prevalencia , Medición de Riesgo , Factores de Riesgo , Enfermedades de Transmisión Sexual/epidemiologíaRESUMEN
This paper describes an approach to making estimates and short term projections of future scenarios of HIV/AIDS in countries with low level and concentrated epidemics. This approach focuses on identifying populations which through their behaviour are at higher risk of infection with HIV or who are exposed through the risk behaviour of their sexual partners. Estimates of the size and HIV prevalence of these populations allow the total number of HIV infected people in a country or region to be estimated. Subsequently, assumptions about the possible level and timing of saturation of HIV prevalence among each population can be used to explore future scenarios of HIV prevalence. The basic structure of the software used to make estimates and projections is described. This software includes a set of consistency and audit checks to help exclude unrealistic projections. The paper also discusses the strengths and weakness to this approach to making estimates and projections of HIV/AIDS in countries with low level and concentrated epidemics.
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Brotes de Enfermedades , Infecciones por VIH/epidemiología , Síndrome de Inmunodeficiencia Adquirida/epidemiología , Adulto , Femenino , Humanos , Masculino , Prevalencia , Factores de Riesgo , Asunción de Riesgos , Parejas Sexuales/psicología , Programas InformáticosRESUMEN
OBJECTIVE: To examine the quality of HIV sero-surveillance systems in countries by 2002, as well as trends between 1995 and 2002. METHODS: The quality of countries' surveillance systems was scored for five years: 1995, 1997, 1999, 2001, and 2002. Sero-surveillance data were compiled from the US Census Bureau's HIV/AIDS Surveillance Database, the EuroHIV database, and from countries' national HIV surveillance reports that were available to WHO/UNAIDS. The quality of systems was scored according to the level of the countries' epidemic. RESULTS: There has been a large variation in the quality of HIV surveillance systems across the 132 countries by type of the epidemic and over time from 1995 to 2002. Over the 1995-2002 period the number of countries with a fully implemented system decreased from 57 (43%) in 1995 to 48 (36%) in 2002. The proportion of countries with a fully implemented system was 58%, 34%, and 10% in countries with a generalised, concentrated, and low level epidemic, respectively. In the 53 countries with generalised epidemics the number of countries with a fully implemented system increased from 24 (45%) in 2001 to 31 (58%) in 2002. CONCLUSION: Many countries still have poor functioning HIV surveillance systems and require urgent strengthening. Countries should monitor and evaluate their own HIV surveillance systems and examine whether the systems are appropriate and adequate.
Asunto(s)
Brotes de Enfermedades , Infecciones por VIH/epidemiología , Seroprevalencia de VIH/tendencias , Países en Desarrollo , Humanos , Calidad de la Atención de Salud/normas , Calidad de la Atención de Salud/tendencias , Vigilancia de GuardiaRESUMEN
OBJECTIVE: The objective of this paper was to analyse the quality of HIV/AIDS sentinel surveillance systems in countries and the resulting quality of the data used to make estimates of HIV/AIDS prevalence and mortality. METHODS: Available data on sero-surveillance of HIV/AIDS in countries were compiled in the process of making the end of 1999 estimates of HIV/AIDS. These data came primarily from the HIV/AIDS Surveillance Database developed by the United States Census Bureau, from a database maintained by the European Centre for the Epidemiological Monitoring of AIDS and all country reports on sentinel surveillance that had been provided to World Health Organization or UNAIDS. Procedures were developed to score quality of surveillance systems based on four dimensions of quality: timeliness and frequency; appropriateness of groups; consistency of sites over time; and coverage provided by the system. In total, the surveillance systems from 167 countries were analysed. RESULTS: Forty-seven of the 167 countries whose surveillance systems were rated were judged to have fully implemented sentinel surveillance systems; 51 were judged to have systems that had some or most aspects of a good HIV surveillance system in place and 69 were rated as having poorly functioning or non-existent surveillance systems. CONCLUSION: This analysis suggests that the quality of HIV surveillance varies considerably. The majority of countries most affected by HIV/AIDS have systems that are providing sufficient sero-prevalence data for tracking the epidemic and making reasonable estimates of HIV prevalence. However, many countries have poor systems and strengthening these is an urgent priority.
Asunto(s)
Brotes de Enfermedades , Salud Global , Infecciones por VIH/epidemiología , Seroprevalencia de VIH , Vigilancia de Guardia , Adolescente , Adulto , Recolección de Datos/métodos , Humanos , Persona de Mediana Edad , Evaluación de Programas y Proyectos de SaludRESUMEN
Among 332 female sex workers in Douala, Cameroon, 113 were HIV-1 seropositive, 3 were HTLV-I seropositive, and only 1 had specific anti-HTLV-II antibodies. By cocultivation with BJAB cells, an HTLV-II was isolated from the peripheral blood mononuclear cells of this 32-year-old woman coinfected by HIV-1. This new African HTLV-II isolate (PH230PCAM) belongs to the molecular subtype A, exhibiting, however, a nucleotide variability of 2.4% and 0.8%, vis-à-vis the MO prototype, in the LTR and in the gp21 env gene, respectively. These data, as well as the previous findings of another HTLV-II subtype A in a Ghanean prostitute, suggest that this viral subtype had been imported into Africa, while the HTLV-II subtype B, described in remote areas of Zaire, Gabon, and Cameroon, could be a genuine African HTLV-II, present in this continent for a long period of time.
Asunto(s)
Infecciones por VIH/complicaciones , VIH-1/aislamiento & purificación , Infecciones por HTLV-II/virología , Virus Linfotrópico T Tipo 2 Humano/aislamiento & purificación , Adulto , Secuencia de Bases , Camerún , Femenino , Infecciones por HTLV-II/complicaciones , Virus Linfotrópico T Tipo 2 Humano/genética , Humanos , Datos de Secuencia Molecular , Trabajo SexualAsunto(s)
Infecciones por HTLV-II/epidemiología , Trabajo Sexual , Adulto , Camerún/epidemiología , Femenino , HumanosRESUMEN
As of December 1991, Cameroon has reported 827 cases of AIDS. The results from the Sentinel Surveillance System show a seroprevalence of 1.3% HIV1 among pregnant women, 2.5% in people attending STD clinic and 3.5% in tuberculosis patients. The World Health Organization projection model was used to make a short term projection of HIV infection and AIDS cases. Results show that the number estimated of HIV infected populations varies between 24 to 45,000 people by the year 1995. Results show also an estimated 8,500 cumulative AIDS cases. Even in a low prevalence country as Cameroon the impact of the HIV epidemic is important and will result in a burden for the health care system.
Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/epidemiología , Infecciones por VIH/epidemiología , Seroprevalencia de VIH , Modelos Estadísticos , Vigilancia de la Población , Complicaciones Infecciosas del Embarazo/epidemiología , Síndrome de Inmunodeficiencia Adquirida/etiología , Síndrome de Inmunodeficiencia Adquirida/prevención & control , Síndrome de Inmunodeficiencia Adquirida/transmisión , Adolescente , Adulto , Camerún/epidemiología , Niño , Control de Enfermedades Transmisibles , Comorbilidad , Femenino , Predicción , Infecciones por VIH/etiología , Infecciones por VIH/prevención & control , Infecciones por VIH/transmisión , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Embarazo , Complicaciones Infecciosas del Embarazo/etiología , Complicaciones Infecciosas del Embarazo/prevención & control , Enfermedades de Transmisión Sexual/complicaciones , Tuberculosis/complicaciones , Organización Mundial de la SaludAsunto(s)
Seroprevalencia de VIH , Adulto , Camerún/epidemiología , Femenino , Humanos , Masculino , EmbarazoRESUMEN
By September 1991 Cameroon had reported 650 cases of the acquired immune deficiency syndrome (AIDS). The results from the sentinnel surveillance system showed a seroprevalence of human immunodeficiency virus (HIV)1 of 1.3% among pregnant women, 2.5% in people attending sexually transmitted disease clinics and 3.5% in tuberculosis patients in 1990. The estimated number of persons infected with HIV varies between 10,000 and 30,000. The World Health Organization projection model was used to make a short-term projection of HIV infection and AIDS cases; it indicated that the number of persons infected with HIV will double by the year 1995, with an estimated 8500 AIDS cases. Even in a low prevalence country such as Cameroon, the impact of the HIV epidemic is important and will result in a burden for the health care system.
Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/epidemiología , Infecciones por VIH/epidemiología , Camerún/epidemiología , Femenino , Predicción , Seroprevalencia de VIH , Humanos , Incidencia , MasculinoRESUMEN
We present the case of a patient with old frontal headache, who was admitted with frontal acute sinusitis symptoms at the emergency service. The radiology study shows a compatible image with frontal osteoma, which was extirpated as being asymptomatic, by frontal osteoplastic technique. The case is described and it is made a frontal osteoma review and the surgical technique used to do it.
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Hueso Frontal/cirugía , Osteoma/cirugía , Neoplasias Craneales/cirugía , Adolescente , Hueso Frontal/diagnóstico por imagen , Humanos , Masculino , Osteoma/diagnóstico por imagen , Radiografía , Neoplasias Craneales/diagnóstico por imagenRESUMEN
We describe the case of a patient with odynophagia without treatment response. The pharynx exploration shows a stony tumor in vertex of left palatine amygdala which was extirpated. The laboratory analysis signs calcium and oxalic calculus. The anatomopathological study of the amygdala bed biopsy informs like absent of malignancy images.