Regional disparity of HIV incidence and prevalence among men who have sex with men.

BACKGROUND: HIV incidence can be estimated with cross-sectional studies using clinical, serological, and molecular data. Worldwide, HIV incidence data in only men who have sex with men (MSM) are scarce and principally focus on those with healthcare or under treatment. However, better estimates can be obtained through studies with national representativeness. The objective was to estimate the prevalence, incidence, and factors associated with acquiring HIV in a national sample of MSM who attend meeting places, considering geographical regions. METHODS: A nationally representative survey of MSM attending meeting places was performed in Mexico. Participants answered a questionnaire, and a dried blood spot (DBS) was collected. Samples were classified as recent infections using an algorithm with HIV status, antiretroviral therapy, and the result of BED-EIA assay. Parameters were analysed considering regions and demographic and sexual behaviour characteristics. RESULTS: The national HIV prevalence was 17.4% with regional differences; the highest prevalence (20.7%) was found in Mexico City, and the lowest prevalence was found in the West region (11.5%). The incidence was 9.4 per 100 p/y, with regional values from 6.2 to 13.2 for the Northeast and the Centre regions, respectively. Age, age at sexual debut, low wealth index, and rewarded sex were associated with HIV prevalence. Centre region, use of private clinics as health services, and having sex exclusively with men were associated with recent HIV infections. CONCLUSIONS: The incidence and prevalence showed regional differences, suggesting a difference in the dynamics of HIV transmission; some regions have a greater case accumulation, and others have a greater rate of new infections. Understanding this dynamic will allow developing health programs focused on HIV prevention or treating people already living with HIV.

The World Organisation for Animal Health and the World Health Organization: intergovernmental disease information and reporting systems and their role in early warning.

Only two international organisations have a global legal framework that allows them to request, collect, and release global animal or human health information: the World Organisation for Animal Health (OIE), which is responsible for transparently assessing the global animal health situation, and the World Health Organization (WHO), which is responsible for transparently assessing the global human health situation. Legal instruments bind OIE Member Countries and WHO States Parties (OIE's Standards and WHO's International Health Regulations [IHR]) to report certain disease outbreaks and public health events to their respective organisations. OIE Member Countries must report exceptional epidemiological events involving any OIE-listed diseases, including zoonoses. Moreover, they must notify the OIE of any emerging animal diseases. The IHR require WHO Member States to provide notification of events that may constitute a public health emergency of international concern. These include, but are not restricted to, outbreaks of communicable diseases of international concern. In both organisations, in addition to reporting outbreaks and exceptional events, Members also monitor diseases on an ongoing basis and provide regular reports. To complement these passive surveillance mechanisms, the OIE, WHO and the Food and Agriculture Organization of the United Nations track signals from informal sources of outbreaks of animal and zoonotic infectious diseases, thereby increasing the sensitivity of worldwide disease reporting. The formal information collected is disseminated to Members and the general public through various communication channels, so that countries can apply science-based measures to prevent further disease spread. Both the OIE and WHO reporting systems are supported by a range of coordinating activities to ensure the proper flow of information between national and international levels.

Deux organisations internationales seulement disposent d'un cadre juridique mondial permettant de demander, collecter et diffuser des informations sur la santé animale ou humaine dans le monde : il s'agit de l'Organisation mondiale de la santé animale (OIE), qui est chargée d'évaluer de manière transparente la situation zoosanitaire mondiale, et de l'Organisation mondiale de la santé (OMS), qui est chargée d'évaluer de manière transparente la situation de la santé humaine dans le monde. Ces deux organisations ont mis en place des instruments juridiques (les normes sanitaires de l'OIE et le Règlement sanitaire international [RSI] de l'OMS) qui imposent aux Pays membres de l'OIE et aux États parties au RSI de notifier tout événement sanitaire important à leurs organisations respectives. Les Pays Membres de l'OIE doivent notifier tout événement épidémiologique exceptionnel concernant les maladies de la liste de l'OIE, y compris les zoonoses. En outre, ils doivent notifier à l'OIE toute maladie animale émergente. Le RSI impose aux États membres de l'OMS de notifier tout événement pouvant constituer une urgence de santé publique de portée internationale. Cela couvre notamment les foyers de maladies transmissibles importantes au plan international. Outre le signalement des foyers et des événements exceptionnels, les Membres des deux organisations exercent également une surveillance de routine des maladies et communiquent des rapports réguliers. En complément de ces mécanismes de surveillance passive, l'OIE, l'OMS et l'Organisation des Nations Unies pour l'alimentation et l'agriculture (FAO) assurent le suivi de tout signalement provenant de sources non officielles concernant d'éventuels foyers de maladies animales infectieuses et zoonotiques, ce qui accroît la sensibilité du système de notification des maladies à l'échelle mondiale. Les informations recueillies par la voie officielle sont diffusées aux Pays membres et au grand public par divers canaux de communication afin que les pays puissent appliquer des mesures fondées sur la science et empêcher ainsi toute nouvelle propagation. Les systèmes de notification de l'OIE et de l'OMS s'appuient tous deux sur une série d'activités de coordination afin d'assurer la bonne circulation de l'information entre les niveaux national et international.

Solo dos organizaciones internacionales disponen de un mecanismo jurídico de alcance planetario que les permita solicitar, reunir y hacer pública información sanitaria o zoosanitaria de dimensión mundial: la Organización Mundial de Sanidad Animal (OIE), responsable de evaluar con transparencia la situación zoosanitaria del mundo; y la Organización Mundial de la Salud (OMS), que se encarga de evaluar con transparencia la situación mundial en materia de salud humana. Hay instrumentos jurídicos que obligan a los Países Miembros de la OIE y los Estados Miembros de la OMS a notificar a la organización correspondiente todo caso importante de enfermedad (las normas de la OIE, por un lado, y el Reglamento Sanitario Internacional de la OMS [RSI]), por el otro). Los Países Miembros de la OIE deben comunicar episodios epidemiológicos excepcionales en los que intervenga cualquiera de las enfermedades que figuran en la lista de la OIE, zoonosis inclusive. Además, deben notificar a la OIE la aparición de toda enfermedad animal emergente. El RSI obliga a los Estados Miembros de la OMS a notificar todo episodio que pueda constituir una emergencia de salud pública de importancia internacional, como pueden ser, por ejemplo, los brotes de enfermedades transmisibles de importancia internacional. Los Miembros de ambas organizaciones, además de comunicar brotes y episodios excepcionales, deben vigilar continuamente la presencia de enfermedades y presentar informes periódicos. Para complementar estos mecanismos de vigilancia pasiva, la OIE, la OMS y la Organización de las Naciones Unidas para la Alimentación y la Agricultura (FAO) siguen de cerca las señales procedentes de fuentes oficiosas que puedan indicar la presencia de brotes infecciosos de enfermedades animales o zoonóticas, con lo que acrecientan la sensibilidad del dispositivo mundial de notificación. La información oficial así obtenida transita por diversos canales de comunicación para llegar a los Países Miembros y el gran público, de forma que los países puedan adoptar medidas científicamente fundamentadas para evitar la ulterior propagación de los brotes. Los sistemas de notificación de la OIE y la OMS están respaldados por una serie de actividades de coordinación que aseguran la adecuada circulación de información entre los niveles nacional e internacional.

Binational outbreak of Guillain-Barré syndrome associated with Campylobacter jejuni infection, Mexico and USA, 2011.

In June 2011, a cluster of suspected cases of Guillain-Barré syndrome (GBS), which can follow Campylobacter jejuni infection, was identified in San Luis Río Colorado (SLRC), Sonora, Mexico and Yuma County, Arizona, USA. An outbreak investigation identified 26 patients (18 from Sonora, eight from Arizona) with onset of GBS 4 May-21 July 2011, exceeding the expected number of cases (n = 1-2). Twenty-one (81%) patients reported antecedent diarrhoea, and 61% of 18 patients tested were seropositive for C. jejuni IgM antibodies. In a case-control study matched on age group, sex, ethnicity, and neighbourhood of residence, all Arizona GBS patients travelled to SLRC during the exposure period vs. 45% of matched controls (matched odds ratio 8·1, 95% confidence interval 1·5-∞). Exposure information and an environmental assessment suggested that GBS cases resulted from a large outbreak of C. jejuni infection from inadequately disinfected tap water in SLRC. Binational collaboration was essential in investigating this cross-border GBS outbreak, the first in mainland North America since 1976.

Drug resistance in Mexico: results from the National Survey on Drug-Resistant Tuberculosis.

OBJECTIVE: To present estimations obtained from a population-level survey conducted in Mexico of prevalence rates of mono-, poly- and multidrug-resistant strains among newly diagnosed cases of pulmonary tuberculosis (TB), as well as the main factors associated with multidrug resistance (combined resistance to isoniazid and rifampicin). DESIGN: Study data came from the National Survey on TB Drug Resistance (ENTB-2008), a nationally representative survey conducted during 2008-2009 in nine states with a stratified cluster sampling design. Samples were obtained for all newly diagnosed cases of pulmonary TB in selected sites. Drug susceptibility testing (DST) was performed for anti-tuberculosis drugs. RESULTS: DST results were obtained for 75% of the cases. Of these, 82.2% (95%CI 79.5-84.7) were susceptible to all drugs. The prevalence of multidrug-resistant TB (MDR-TB) was estimated at 2.8% (95%CI 1.9-4.0). MDR-TB was associated with previous treatment (OR 3.3, 95%CI 1.1-9.4). CONCLUSIONS: The prevalence of drug resistance is relatively low in Mexico. ENTB-2008 can be used as a baseline for future follow-up of drug resistance.

The epidemiology of rubella in Mexico: seasonality, stochasticity and regional variation.

The factors underlying the temporal dynamics of rubella outside of Europe and North America are not well known. Here we used 20 years of incidence reports from Mexico to identify variation in seasonal forcing and magnitude of transmission across the country and to explore determinants of inter-annual variability in epidemic magnitude in rubella. We found considerable regional variation in both magnitude of transmission and amplitude of seasonal variation in transmission. Several lines of evidence pointed to stochastic dynamics as an important driver of multi-annual cycles. Since average age of infection increased with the relative importance of stochastic dynamics, this conclusion has implications for the burden of congenital rubella syndrome. We discuss factors underlying regional variation, and implications of the importance of stochasticity for vaccination implementation.

Effect of tuberculosis on the survival of women infected with human immunodeficiency virus.

Evidence regarding the effect of tuberculosis (TB) disease on progression of human immunodeficiency virus (HIV) disease is inconclusive. The authors estimated the effect of time-varying incident TB on time to acquired immunodeficiency syndrome (AIDS)-related mortality using a joint marginal structural Cox model. Between 1995 and 2002, 1,412 HIV type 1 (HIV-1)-infected women enrolled in the Women's Interagency HIV Study were followed for a median of 6 years. Twenty-nine women incurred incident TB, and 222 died of AIDS-related causes. Accounting for age, CD4 cell count, HIV-1 RNA level, serum albumin level, and non-TB AIDS at study entry, as well as for time-varying CD4 cell count, CD4 cell count nadir, HIV-1 RNA level, peak HIV-1 RNA level, serum albumin level, HIV-related symptoms, non-TB AIDS, anti-Pneumocystis jiroveci prophylaxis, antiretroviral therapy, and household income, the hazard ratio for AIDS-related death comparing time after incident TB with time before incident TB was 4.0 (95% confidence interval (CI): 1.2, 14). The effect of incident TB on mortality was similar among highly active antiretroviral therapy (HAART)-exposed women (hazard ratio = 4.3, 95% CI: 0.9, 22) and non-HAART-exposed women (hazard ratio = 3.9, 95% CI: 0.9, 17; interaction p = 0.91). Although results were imprecise because few women incurred TB, irrespective of HAART exposure, incident TB increases the hazard of AIDS-related death among HIV-infected women.