Transmission dynamics and vaccination strategies for Crimean-Congo haemorrhagic fever virus in Afghanistan: A modelling study.

BACKGROUND: Crimean-Congo haemorrhagic fever virus (CCHFV) is a highly pathogenic virus for which a safe and effective vaccine is not yet available, despite being considered a priority emerging pathogen. Understanding transmission patterns and the use of potential effective vaccines are central elements of the future plan against this infection. METHODS: We developed a series of models of transmission amongst livestock, and spillover infection into humans. We use real-world human and animal data from a CCHFV endemic area in Afghanistan (Herat) to calibrate our models. We assess the value of environmental drivers as proxy indicators of vector activity, and select the best model using deviance information criteria. Finally we assess the impact of vaccination by simulating campaigns targeted to humans or livestock, and to high-risk subpopulations (i.e, farmers). FINDINGS: Saturation deficit is the indicator that better explains tick activity trends in Herat. Recent increments in reported CCHFV cases in this area are more likely explained by increased surveillance capacity instead of changes in the background transmission dynamics. Modelling suggests that clinical cases only represent 31% (95% CrI 28%-33%) of total infections in this area. Vaccination campaigns targeting humans would result in a much larger impact than livestock vaccination (266 vs 31 clinical cases averted respectively) and a more efficient option when assessed in courses per case averted (35 vs 431 respectively). Targeted vaccination of farmers is impactful and more efficient, resulting in 19 courses per case averted (95% CrI 7-62) compared to targeting the general population (35 courses 95% CrI 16-107). CONCLUSIONS: CCHFV is endemic in Herat, and transmission cycles are well predicted by environmental drivers like saturation deficit. Vaccinating humans is likely to be more efficient and impactful than animals, and importantly targeted interventions to high risk groups like farmers can offer a more efficient approach to vaccine roll-out

P1917 Antiretrovirals adverse reactions from a prospective HIV AIDS cohort study in Bogotá, Colombia

Comunicación breves550Background: Adverse Drug Reactions (ADR), lead not just to a high percentage of therapy abandonment, but also to a poor adherence to treatment instructions resulting in failure of therapy. The purpose of this study was to show the relation between the use of drugs and ADRs, their impact on treatment and the severity of reaction as defined by the DAIDS scale

Vaccine efficacy trials for Crimean-Congo haemorrhagic fever: Insights from modelling different epidemiological settings

Background Crimean-Congo haemorrhagic fever (CCHF) is a priority emerging pathogen for which a licensed vaccine is not yet available. We aim to assess the feasibility of conducting phase III vaccine efficacy trials and the role of varying transmission dynamics. Methods We calibrate models of CCHF virus (CCHFV) transmission among livestock and spillover to humans in endemic areas in Afghanistan, Turkey and South Africa. We propose an individual randomised controlled trial targeted to high-risk population, and use the calibrated models to simulate trial cohorts to estimate the minimum necessary number of cases (trial endpoints) to analyse a vaccine with a minimum efficacy of 60%, under different conditions of sample size and follow-up time in the three selected settings. Results A mean follow-up of 160,000 person-month (75,000–550,000) would be necessary to accrue the required 150 trial endpoints for a target vaccine efficacy of 60 % and clinically defined endpoint, in a setting like Herat, Afghanistan. For Turkey, the same would be achieved with a mean follow-up of 175,000 person-month (50,000–350,000). The results suggest that for South Africa the low endemic transmission levels will not permit achieving the necessary conditions for conducting this trial within a realistic follow-up time. In the scenario of CCHFV vaccine trial designed to capture infection as opposed to clinical case as a trial endpoint, the required person-months is reduced by 70 % to 80 % in Afghanistan and Turkey, and in South Africa, a trial becomes feasible for a large number of person-months of follow-up (>600,000). Increased expected vaccine efficacy > 60 % will reduce the required number of trial endpoints and thus the sample size and follow-time in phase III trials. Conclusions Underlying endemic transmission levels will play a central role in defining the feasibility of phase III vaccine efficacy trials. Endemic settings in Afghanistan and Turkey offer conditions under which such studies could feasibly be conducted

The HIV Modes of Transmission model: a systematic review of its findings and adherence to guidelines

Introduction: The HIV Modes of Transmission (MOT) model estimates the annual fraction of new HIV infections (FNI) acquired by different risk groups. It was designed to guide country-specific HIV prevention policies. To determine if the MOT produced context-specific recommendations, we analyzed MOT results by region and epidemic type, and explored the factors (e.g. data used to estimate parameter inputs, adherence to guidelines) influencing the differences. Methods: We systematically searched MEDLINE, EMBASE and UNAIDS reports, and contacted UNAIDS country directors for published MOT results from MOT inception (2003) to 25 September 2012. Results: We retrieved four journal articles and 20 UNAIDS reports covering 29 countries. In 13 countries, the largest FNI (range 26 to 63%) was acquired by the low-risk group and increased with low-risk population size. The FNI among female sex workers (FSWs) remained low (median 1.3%, range 0.04 to 14.4%), with little variability by region and epidemic type despite variability in sexual behaviour. In India and Thailand, where FSWs play an important role in transmission, the FNI among FSWs was 2 and 4%, respectively. In contrast, the FNI among men who have sex with men (MSM) varied across regions (range 0.1 to 89%) and increased with MSM population size. The FNI among people who inject drugs (PWID, range 0 to 82%) was largest in early-phase epidemics with low overall HIV prevalence. Most MOT studies were conducted and reported as per guidelines but data quality remains an issue. Conclusions: Although countries are generally performing the MOT as per guidelines, there is little variation in the FNI (except among MSM and PWID) by region and epidemic type. Homogeneity in MOT FNI for FSWs, clients and low-risk groups may limit the utility of MOT for guiding country-specific interventions in heterosexual HIV epidemics

Building a tuberculosis-free world: The Lancet Commission on tuberculosis

___Key messages___ The Commission recommends five priority investments to achieve a tuberculosis-free world within a generation. These investments are designed to fulfil the mandate of the UN High Level Meeting on tuberculosis. In addition, they answer

Desarrollo, impacto y eficacia de la vacuna conjugada contra Streptococcus pneumoniae en Am\ue9rica Latina

Streptococcus pneumoniae es un microorganismo de frecuente aparici\uf3n como colonizador normal de la nasofaringe y como causante de enfermedad invasora especialmente dentro del grupo de edad de ni\uf1os menores de 5 a\uf1os, generando a nivel mundial una mortalidad de hasta 700 000 casos por a\uf1o en ni\uf1os menores de 2 a\uf1os. El estudio de la antigenicidad capsular del S. pneumoniae ha llevado a la producci\uf3n de vacunas, desde la compuesta por polisac\ue1ridos, inefectiva en el grupo de edad de ni\uf1os menores, a la conjugada que mostr\uf3 alta eficacia (97,4%) en prevenir la forma invasora de la enfermedad neumoc\uf3ccica en quienes completaron las 4 dosis propuestas. En una proyecci\uf3n del cubrimiento en Latinoam\ue9rica con las tres formas conjugadas de la vacuna disponibles, 7 valente, 9 valente y 11 valente, se muestra que la 11 valente cubrir\ueda un alto porcentaje de serotipos causantes de enfermedad invasora neumoc\uf3ccica y respalda la necesidad de implementar las vacunas conjugadas como medida masiva de salud p\ufablica. El objetivo del presente art\uedculo es revisar el comportamiento del neumococo, de la vacuna conjugada disponible en America Latina y su potencial importancia en la regi\uf3

Blood Cyst of the Mitral Valve Diagnosed in an Adult after Systemic Thrombolysis

Blood cysts in valves are very rare entities in adults, which can be distinguished through their echocardiographic features. A 57-year-old woman developed sudden dyspnea while hospitalized in the context of urinary sepsis; high-risk pulmonary embolism was diagnosed and she was prescribed systemic thrombolysis. She persisted with fever raising the suspicion of bacterial endocarditis. Transthoracic echocardiography did not report any masses, but later transesophageal imaging revealed a vegetation that was finally characterized as a blood cyst of the mitral valve based on ultrasound features. The patient evolved satisfactorily and did not require surgery