Spatial variability in HIV prevalence declines in several countries in sub-Saharan Africa

AbstractEvidence suggests substantial declines in HIV prevalence in parts of sub-Saharan Africa. However, the observed aggregate declines at the national level may obscure local variations in the temporal dynamics of the infection. Using spatial scan statistics, we identified marked spatial variability in the within-country declines in HIV prevalence in Tanzania, Malawi, Kenya, and Zimbabwe. Our study suggests that the declines in the national HIV prevalence in some of the SSA countries may not be representative of downward trends in prevalence in areas of high HIV prevalence, as much as the result of sharp declines in prevalence in areas of already low HIV prevalence. Our findings provide insights for resource allocation and HIV prevention interventions in these countries

О перспективах рынка станкостроения с позиций анализа мировых тенденций, концепции жизненного цикла оборудования и CALS-технологий

В статье рассматриваются существующие методики выбора и проектирования нового оборудования с позиций анализа наиболее эффективных видах обработки, проводится анализ недостатков "классического" подхода к выбору оборудования. На основании CALS-технологий, принципа агрегатирования и паспортизации оборудования предлагается новая модель проектирования оборудования, позволяющая продлить жизненный цикл станков, уменьшить стоимость и сроки проектирования и изготовления оборудования.This article reviews the existing methods of choice and design of new equipment from the standpoint of analyzing the most effective forms of treatment, an analysis of the shortcomings of "classical" approach to the choice of equipment. Based on CALS-technologies, the principle of aggregation and certification of equipment, a new model for the design of equipment are proposed. This model allows to extend the life cycle of machines, reduce the cost and terms of designing and manufacturing equipment

The emerging face of the HIV epidemic in the Middle East and North Africa.

PURPOSE OF REVIEW: A volume of quality HIV data has materialized recently in the Middle East and North Africa (MENA). This review provides a thematic narrative of the patterns of HIV infection transmission in this region in light of these data. RECENT FINDINGS: Tens of integrated bio-behavioral surveillance surveys among hard-to-reach key populations at higher risk have been conducted in MENA in the recent years. Many of the studies reported appreciable and growing HIV prevalence. A few studies found alarming prevalence of as much as 87.2% HIV prevalence among people who inject drugs in Tripoli, Libya. The discovery of these hitherto hidden epidemics was unsettling to some authorities after years in which the importance of a focus on HIV prevention among key populations was not recognized. SUMMARY: The new data from MENA indicate growing HIV epidemics among key populations across the region. There is heterogeneity, however, as to which key populations are affected and in what proportions in different countries. In a few countries, HIV appears to affect only one key population and often there is substantial geographical heterogeneity in HIV transmission. Data are indicative of a growing HIV disease burden in this part of the globe, in contrast with the declining epidemics in most other regions

External infections contribute minimally to HIV incidence among HIV sero-discordant couples in sub-Saharan Africa.

OBJECTIVE: Recent randomised clinical trials among stable HIV sero-discordant couples (SDCs) in sub-Saharan Africa (SSA) have reported that about 20-30% of new HIV infections are acquired from external sexual partners, rather than transmitted from the infected to the uninfected partner within the couple. The aim of this study is to examine whether, and to what extent, these findings are generalisable to SDCs in the wider population in SSA. METHODS: A mathematical model was constructed to calculate the fraction of new HIV-1 infections among SDCs that are due to sources external to the couple. The model was parameterised using empirical and population-based data for 20 countries in SSA. Uncertainty and sensitivity analyses were also conducted. RESULTS: The contribution of external infections among SDCs was generally modest, but it varied widely across SSA. In low HIV prevalence countries (≤ 3.0%), it ranged from 0.6-2.9%. In intermediate prevalence countries (3.0-18.0%), it ranged from 4.9-11.7%. In Swaziland and Lesotho, the world's most-intense epidemics, sizable levels of 27.9% and 27.3% were found, respectively. CONCLUSIONS: In most countries in SSA, nearly all HIV acquisitions by the uninfected partners in SDCs appear to be due to transmissions from the HIV infected partners in the SDCs. The contribution of externally acquired infections varies with HIV population prevalence, but rarely exceeds 10% in the majority of countries. Only in hyperendemic HIV epidemics the contribution of external infections is substantial and may reach the levels reported in recent randomised clinical trials involving SDCs

الانتشار المصلى لفيروس الهربس البسيط (الدمط 1 والنمط 2) فى أوساط المجموعات السكانية ال هندية والفلبينية المهاجرة في قطر: مسح مقطعي

Background: The epidemiology of herpes simplex virus infections is of growing interest but information on its seroprevalence in many countries is scarce. Aims: This study aimed to measure the seroprevalence of herpes simplex virus type 1 and type 2 in Filipino and Indian men living in Qatar. Methods: Blood serum specimens were collected from male blood donors aged ≥ 18 years in Qatar from 2013 to 2016. HerpeSelect® 1/2 and Euroline‐WB assays were used to measure antibodies to herpes simplex virus types 1 and 2 in 120 Filipino and 325 Indian men. Results: The seroprevalence of herpes simplex virus‐1 was 84.9% (95% confidence interval (CI): 78.4–90.0%) in Filipino men and 48.3% (95% CI: 43.6–53.0%) in Indian men. The seroprevalence of herpes simplex virus‐2 was 8.3% (95% CI: 4.6–13.7%) in Filipinos and 3.7% (95% CI: 2.2–5.9%) in Indians. The seroprevalence of herpes simplex virus types 1 and 2 increased with age, but this trend was only statistically significant in Indian men (P = 0.013 and P = 0.011 respectively). Conclusions: The seroprevalence rates of herpes simplex virus‐2 in Filipino and Indian men living in Qatar were similar to those found in the Philippines and India. However, the seroprevalence of herpes simplex virus‐1 in Indians, while similar to that found in India, was substantially lower than that of other countries in Asia and developing countries worldwide, which needs further investigation.Contexte : L'épidémiologie des infections par le virus de l'herpès suscite un intérêt croissant, mais les informationsrelatives à sa séroprévalence dans de nombreux pays sont rares.Objectifs : La présente étude visait à mesurer la séroprévalence du virus de l'herpès de types 1 et 2 parmi les hommesphilippins et indiens vivant au Qatar.Méthodes : Des échantillons de sérum sanguin ont été prélevés sur des donneurs de sang masculins âgés d'au moinsdix-huit ans au Qatar entre 2013 et 2016. Les tests HerpeSelect® 1/2 et Euroline-WB ont été utilisés pour mesurer lesanticorps dirigés contre le virus de l'herpès de types 1 et 2 chez 120 hommes philippins et 325 hommes indiens.Résultats : La séroprévalence du virus de l'herpès de type 1 était de 84,9 % (intervalle de confiance (IC) à 95 % : 78,4-90,0 %)chez les hommes philippins et de 48,3 % (IC à 95 % : 43,6-53,0 %) chez les hommes indiens. La séroprévalence du virus del'herpès de type 2 était de 8,3 % (IC à 95 % : 4,6-13,7 %) chez les hommes philippins et de 3,7 % (IC à 95 % : 2,2- 5,9 %) chezles hommes indiens. La séroprévalence du virus de l'herpès de types 1 et 2 augmentait avec l'âge, mais cette tendancen'était statistiquement importante que chez les homme indiens (p = 0,013 et p = 0,011 respectivement).Conclusions : Les taux de séroprévalence du virus de l'herpès de type 2 parmi les hommes philippins et indiens vivantau Qatar étaient similaires à ceux constatés aux Philippines et en Inde. Toutefois, le taux de séroprévalence du virus del'herpès de type 1 chez les Indiens, bien que comparable à celui relevé en Inde, était beaucoup moins élevé que celui desautres pays d'Asie et des pays en développement, ce qui mérite d'être étudié plus attentivement.الخلفية: يتزايد الاهتمام بدراسة السمات الوبائية لحالات العدوى بفيروس الهريس البسيط. غير أن المعلومات حول انتشاره مصليا في العديد من البُلدان شحيحة للغاية. الأهداف: هدفت هذه الدراسة إلى قياس الانتشار المصلي لفيروس الحربس البسيط (النمط 1 والنمط 2) بين الرجال الذين يعيشون في قطر وينتمون إلى الجنسيتين الهندية والفلبينية. طرق البحث: أخذت عينات من مصل الدم من متبرعين بالدم من الذكور يبلغون من العمر 18 عاما أو أكثر في قطر في الفترة من 2013 وحتى 2016. واستّخدمت مقايستئ Euroline–WB و ® HerpeSelect 1/2 لقياس الأجسام المضادة لفيروس المريس البسيط (النمط 1 والنمط 2) لدى 120 رجلا فليبينيا و 325 رجلا هنديا. النتائج: كانت نسبة الانتشار المصلي لفيروس الهربس البسيط (النمط -1)(84.9%; 95% CI=78.4-90%) في صفوف الرجال من الجنسية الفليبينية و (48.3%; 95% CI=43.6-53.0%) في صفوف الرجال من الجنسية الهندية. كانت نسبة الانتشار المصلي لفيروس الهريس البسيط النمط 2 (8.3%; 95% CI=4.6-13.7%) في صفوف الرجال من الجنسية الفليبينية و (3.7%; 95% CI=2.2-5.9%) في صفوف الرجال من الجنسية الهندية. وارتفع معدل الانتشار المصلي لفيروس الهربس البسيط (النمط 1 والنمط 2) مع تقدم العمرء غير أن هذا الاتجاه لم يُظهر أهمية إحصائية يُعتد بها إلا بين الرجال من الجنسية الهندية (P=0.013; P=0.011) على التوالي. الاستنتاجات: كانت معدلات الانتشار المصلي لفيروس الهربس البسيط النمط 2 في صفوف الرجال من الجنسيتين الفليبينية والهندية الذين يعيشون في قطر ممائلة لنفس المعدلات الموجودة في الفلبين والهند. ولكن بالنسبة لمعدل الانتشار المصلي لفيروس الهربس البسيط النمط 1 في صفوف الرجال من الجنسية الهندية، وبالرغم من مماثلته للمعدل الموجود في الهند. فقد كان أقل بصورة ملحوظة من بُلدان أخرى في قارة آسيا وفي بلدان نامية أخرى حول العالم، وهو الأمر الذي يتطلب مزيدا من الدراس

Epidemiological impact of public health interventions against diabetes in Qatar: mathematical modeling analyses

AimsTo predict the epidemiological impact of specific, and primarily structural public health interventions that address lifestyle, dietary, and commuting behaviors of Qataris as well as subsidies and legislation to reduce type 2 diabetes mellitus (T2DM) burden among Qataris.MethodsA deterministic population-based mathematical model was used to investigate the impact of public health interventions on the epidemiology of T2DM among Qataris aged 20–79 years, which is the age range typically used by the International Diabetes Federation for adults. The study evaluated the impact of interventions up to 2050, a three-decade time horizon, to allow for the long-term effects of different types of interventions to materialize. The impact of each intervention was evaluated by comparing the predicted T2DM incidence and prevalence with the intervention to a counterfactual scenario without intervention. The model was parameterized using representative data and stratified by sex, age, T2DM risk factors, T2DM status, and intervention status.ResultsAll intervention scenarios had an appreciable impact on reducing T2DM incidence and prevalence. A lifestyle management intervention approach, specifically applied to those who are categorized as obese and ≥35 years old, averted 9.5% of new T2DM cases by 2050. An active commuting intervention approach, specifically increasing cycling and walking, averted 8.5% of new T2DM cases by 2050. Enhancing consumption of healthy diets including fruits and vegetables, specifically a workplace intervention involving dietary modifications and an educational intervention, averted 23.2% of new T2DM cases by 2050. A subsidy and legislative intervention approach, implementing subsidies on fruits and vegetables and taxation on sugar-sweetened beverages, averted 7.4% of new T2DM cases by 2050. A least to most optimistic combination of interventions averted 22.8–46.9% of new T2DM cases by 2050, respectively.ConclusionsImplementing a combination of individual-level and structural public health interventions is critical to prevent T2DM onset and to slow the growing T2DM epidemic in Qatar

Negative epidemiological association between HSV-1 and HSV-2 infections

Objectives: Existing evidence on an epidemiological association between herpes simplex virus (HSV) type 1 and type 2 infections remains conflicting and inconclusive. Using a multi-national database of HSV-1/2 serological testing, we aimed to assess the existence of an association between both infections. Design, Setting, and Participants: An HSV-1/2 cross-sectional serological testing database was assembled by merging databases of seroprevalence studies on men blood donors residing currently in Qatar, but from different countries. Specimens were tested for anti-HSV-1 IgG antibodies using HerpeSelect® 1 ELISA, and for anti-HSV-2 IgG antibodies following a two-test algorithm: HerpeSelect® 2 ELISA to test the sera, and Euroline-WB to confirm positive and equivocal specimens. Logistic regressions were conducted to estimate unadjusted and adjusted infection odds ratios. Results: Serological testing for HSV-1/2 was performed on 2522 specimens. Sero-positivity for HSV-1 and HSV-2 was identified in 2053 (81.5%) and 87 (3.5%) specimens, respectively. Univariable analyses estimated higher odds of HSV-2 infection with increasing age and increasing country income level, and an unadjusted odds ratio with HSV-1 sero-positivity of 0.71 (95% CI 0.43–1.17; p-value 0.172). Adjusting for age and country income level, the adjusted odds ratio of HSV-2 infection with HSV-1 sero-positivity was 0.51 (95% CI 0.30–0.87; p-value 0.013). Sensitivity analyses confirmed this association. Conclusions: There is a negative association between HSV-1 and HSV-2 infections, suggestive of a protective effect for HSV-1 sero-positivity against HSV-2 acquisition. This finding supports earlier pooled but inconclusive evidence from prospective studies, yet contrasts with pooled findings of earlier cross-sectional studies

Vertical transmission of hepatitis C virus: systematic review and meta-analysis.

BACKGROUND: We conducted a systematic review of estimates of hepatitis C virus (HCV) vertical transmission risk to update current estimates published more than a decade ago. METHODS: PubMed and Embase were searched and 109 articles were included. Pooled estimates of risk were generated for children born to HCV antibody-positive and viremic women, aged ≥18 months, separately by maternal human immunodeficiency virus (HIV) coinfection. RESULTS: Meta-analysis of the risk of vertical HCV infection to children of HCV antibody-positive and RNA-positive women was 5.8% (95% confidence interval [CI], 4.2%-7.8%) for children of HIV-negative women and 10.8% (95% CI, 7.6%-15.2%) for children of HIV-positive women. The adjusted meta-regression model explained 51% of the between-study variation in the 25 included risk estimates. Maternal HIV coinfection was the most important determinant of vertical transmission risk (adjusted odds ratio, 2.56 [95% CI, 1.50-4.43]). Additional methodological (follow-up rate and definition of infection in children) and risk factors independently predicted HCV infection and need to be captured and reported by future studies of vertical transmission. Studies assessing the contribution of nonvertical exposures in early childhood to HCV prevalence among children at risk of vertical transmission are needed. CONCLUSIONS: More than 1 in every 20 children delivered by HCV chronically infected women are infected, highlighting that vertical transmission likely constitutes the primary transmission route among children. These updated estimates are a basis for decision making in prioritization of research into risk-reducing measures, and inform case management in clinical settings, especially for HIV-positive women in reproductive age

Dynamics of non-cohabiting sex partnering in sub-Saharan Africa: a modelling study with implications for HIV transmission.

OBJECTIVE: To develop an analytical understanding of non-cohabiting sex partnering in sub-Saharan Africa (SSA) using nationally representative sexual behaviour data. METHOD: A non-homogenous Poisson stochastic process model was used to describe the dynamics of non-cohabiting sex. The model was applied to 25 countries in SSA and was fitted to Demographic and Health Survey data. The country-specific mean values and variances of the distributions of number of non-cohabiting partners were estimated. RESULTS: The model yielded overall robust fits to the empirical distributions stratified by marital status and sex. The median across all country-specific mean values was highest for unmarried men at 0.574 non-cohabiting partners over the last 12 months, followed by that of unmarried women at 0.337, married men at 0.192 and married women at 0.038. The median of variances was highest for unmarried men at 0.127, followed by married men at 0.057, unmarried women at 0.003 and married women at 0.000. The largest variability in mean values across countries was for unmarried men (0.103-1.206), and the largest variability in variances was among unmarried women (0.000-1.994). CONCLUSIONS: Non-cohabiting sex appears to be a random 'opportunistic' phenomenon linked to situations that may facilitate it. The mean values and variances of number of partners in SSA show wide variation by country, marital status and sex. Unmarried individuals have larger mean values than their married counterparts, and men have larger mean values than women. Unmarried individuals appear to play a disproportionate role in driving heterogeneity in sexual networks and possibly epidemiology of sexually transmitted infections